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2022-12-14: How Can Matter Be BOTH Liquid AND Gas?

  • 00:03: ... - like how at very high emperatures we get the plasma that the sun is made of, or at extreme densities we get the nuclear matter of neutron ...
  • 18:29: These neutrinos would now have energies 10 billion times smaller than regular neutrinos, say from the Sun.
  • 19:30: The limit for the Milky Way’s black hole is around 100-billion times brighter than the Sun.
  • 19:37: ... limit would be about 3 times brighter on our sky compared to the Sun. ...

2022-11-23: How To See Black Holes By Catching Neutrinos

  • 01:03: They report seeing neutrinos produced in the colossal magnetic fields surrounding a black hole with the mass of 10 million Suns.
  • 02:38: By far the brightest neutrino source on the sky is the Sun.
  • 06:02: The sun produces an enormous number, but those are easy to distinguish because they come from the direction of the Sun.
  • 08:30: In this case with a mass of around 10 million suns.
  • 11:00: The only other sure neutrino detections from space are the Sun and the remnant of supernova 1987A in the large magellanic cloud.

2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations?

  • 07:07: ... will only be habitable for another 1 billion years, after which the sun will be too hot for liquid water to exist on the surface of the ...
  • 07:49: ... known as red dwarfs, can live for thousands of times longer than our sun, meaning they could have planets that remain habitable for trillions of ...

2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics?

  • 15:49: There was the one about using the Sun’s gravitational field as a lens to take pictures of distant planets.
  • 17:03: Well there’s no real range limit in terms of  what planets will be brought to a focus in the sun’s gravitational focal range.
  • 17:37: The report talks about Earth-mass planets around Sun-like stars, of which there are plenty.

2022-10-12: The REAL Possibility of Mapping Alien Planets!

  • 00:03: ... chance of actually happening.  A train of spacecraft sailing the sun’s   light to a magical point out there in space  where the Sun’s own ...
  • 01:25: ... directly along the line connecting your favorite exoplanet and the Sun, but away from   them both, you’ll reach this spot where light ...
  • 04:36: ... like this   galaxy being lensed by an intervening galaxy. The sun also has a gravitational field that would   create an Einstein ...
  • 06:05: ... it with the very clean, well-understood gravitational field of our Sun.   All we need to do is get our telescope to  the right spot. ...
  • 07:45: ... are  proposing an advanced solar sail design called   the SunVane - multiple controllable sail panels mounted along the narrow ...
  • 09:31: ... sort of tack inwards. They speeds up rapidly plummeting towards the Sun,   ideally at around a quarter of Mercury’s  orbital radius, assuming ...
  • 10:07: ... While a regular lens creates a focal point,   the Sun’s gravitational field creates a focal line, starting at 550 ...
  • 14:06: ... the surfaces of distant worlds, brought into focus by our own Sun and its lens of curved ...

2022-09-14: Could the Higgs Boson Lead Us to Dark Matter?

  • 01:18: ... a hundred trillion neutrinos emitted by the sun pass through your body every second, but you don’t notice because they ...

2022-06-22: Is Interstellar Travel Impossible?

  • 06:08: ... the Milky Way disk is around 1 atom per cubic centimeter, however the Sun is in an under-dense region called the local ...

2022-05-25: The Evolution of the Modern Milky Way Galaxy

  • 02:19: ... Milky Way is a pretty typical barred  spiral galaxy. Our sun is in the disk,   on a minor outcropping of one of the ...
  • 06:32: ... 10 billion years ago. This merger was so  large - around 50 billion Suns worth of matter -   that it must have reshaped the galaxy and ...
  • 07:58: ... arms and the big, bright star forming clouds   and our sun. We did an episode on why galaxies  become flat disks - but the TLDW ...
  • 11:10: ... of these passes even happens to line up  with the formation of our sun and solar system   4.5 billion years ago. Now, we’re not ...

2022-05-18: What If the Galactic Habitable Zone LIMITS Intelligent Life?

  • 00:24: ... requirements   has nothing to do with the planet. Our Sun  also seems pretty ideal in a number of ways.   A bit more ...
  • 01:07: ... is the Sun unique enough to explain one of  the most perplexing mysteries of ...
  • 01:36: ... as well as being an expert in folklore.  Who better to compare the Sun’s uniqueness   from the perspectives of science versus  our ...
  • 02:06: ... a modern astronomer’s perspective,  our Sun is objectively mediocre,   average in terms of mass, age, ...
  • 02:20: ... our distant ancestors, the Sun  was a wondrous source of warmth,   light, food, and stability. ...
  • 02:52: ... of the seasons. To the Maori people   of New Zealand, the Sun was personified  by the God Tamanuitera. In one story,   ...
  • 03:29: This myth paints and others about the sun paint a nice picture of its importance.
  • 03:34: But pf course, modern science has  its own origin story for our nearest and dearest star, the sun.
  • 03:40: ... Sun formed around 5 billion years ago, collapsing from an overdense ...
  • 04:32: ... star has a pretty cool backstory, but  hardly a unique one. Our Sun is a pretty ordinary   G-type main sequence star. Around 5% of ...
  • 06:56: ... it seems that to really understand the  Sun’s uniqueness, we need to take our story   back even further - ...
  • 11:12: ... Way’s formation history, our  starting intuition seems right: the Sun and solar   system are NOT special as far as our galaxy ...
  • 12:04: ... what did they find? As we suspected, the Sun  is not unique, but it’s also not the most typical.   Fewer ...

2022-03-23: Where Is The Center of The Universe?

  • 03:04: General relativity can be used to calculate the spacetime curvature produced by the Earth or the Sun to determine their gravitational effects.

2022-03-08: Is the Proxima System Our Best Hope For Another Earth?

  • 01:28: ... alpha-cen sway relative to the background stars as Earth orbited the Sun. ...
  • 01:47: The two stars were so near and so familiar - both within 10% or so of our own Sun’s mass.
  • 03:05: This one was barely a star at all, really, at only 12% of the Sun’s mass and only a little larger than Jupiter.
  • 03:12: Hardly exciting compared to its vibrant, Sun-like siblings.
  • 06:29: That sounds perilous, until you realize that Proxima’s energy output is nearly 600 times lower than the Sun’s.
  • 08:36: ... much  more tentative detections   of planets around its Sun-like siblings - a Neptunish body may have been imaged around Rigel Kentaurus ...
  • 12:32: By the way, unlike the Sun which grows brighter over time, red dwarfs fade.
  • 14:28: After all, Proxima, with its many-trillion-year lifespan will far outlive our own Sun.

2022-01-27: How Does Gravity Escape A Black Hole?

  • 02:28: Imagine for a moment that the Sun just disappeared.
  • 02:46: It would take 8 minutes for the Sun’s deep indentation in the fabric of space to smooth itself - in the wake of some pretty crazy gravitational waves.
  • 03:42: ... example, when Earth feels the pull of the Sun’s gravity - it’s not directly interacting with the Sun itself, it’s ...

2022-01-19: How To Build The Universe in a Computer

  • 00:42: The event I just described will happen as surely as the Sun will rise tomorrow.

2022-01-12: How To Simulate The Universe With DFT

  • 15:37: Most likely the black hole was moving faster than 42 km/s - that would only be the case if it had exactly the same galactic orbit as the sun.
  • 15:57: ... multiple interactions on its way to the Earth - perhaps it punctured the Sun, swung around Jupiter, etc, and lost speed that ...
  • 16:21: And speaking of black holes hitting the Sun, Christian asks whether that would be detectable.
  • 16:32: ... for the sun and Jupiter it’s marginally possible that if you were looking at the ...
  • 18:10: ... Dyson sphere reprocessing a sun’s visible light into infrared, ultimately releasing exactly as much energy ...

2021-12-29: How to Find ALIEN Dyson Spheres

  • 01:00: ... of room to expand if we were to cover the entire sphere surrounding the Sun with the radius of Earth’s orbit, we’d collect all of the Sun’s light - ...
  • 01:16: The idea of wrapping the sun in solar collectors is not new.
  • 02:49: It doesn’t reflect nearly as much of the Sun’s light as you’d expect for a globe of water and rock - it's as though that energy is being sucked up.
  • 03:05: ... the Sun produces a thermal spectrum - light generated by its 6000K surface is ...
  • 03:36: ... incredibly sensitive telescope to pick the Earth’s faint glow from the Sun’s overwhelming ...

2021-12-20: What Happens If A Black Hole Hits Earth?

  • 07:40: ... Witnesses described a stripe of light in the sky as bright as the sun and a thunderous sound like cannons that leveled trees and broke windows ...

2021-12-10: 2021 End of Year AMA!

  • 00:02: ... they're giant stars so you know many many times larger than our sun and they pulsate they pulsate in brightness and they pulsate in size ...

2021-11-17: Are Black Holes Actually Fuzzballs?

  • 01:34: ... large number - 10^10^77 bits for a black hole the mass of our Sun. ...

2021-11-02: Is ACTION The Most Fundamental Property in Physics?

  • 06:47: ... equations of motion correctly describing the orbit of Mercury around the Sun. ...

2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light

  • 04:03: ... necessary for the nuclear fusion reactions that power the sun, in some biological processes, and it’s even a critical part of the ...

2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe

  • 01:42: ... fields are a billion  times stronger than those of the earth or sun. ...
  • 02:00: ... is very different from  the magnetized space around the earth or sun.   It’s filled with electrons and  positrons. These ...
  • 04:04: ... a white dwarf - the dead core of a lower   mass star like our Sun. The plasma is crushed so tight that electrons are on the verge ...

2021-09-07: First Detection of Light from Behind a Black Hole

  • 03:13: ... the universe - anything more than a million or so times the mass of the Sun. ...
  • 11:33: ... of good stuff like measuring the mass of the black hole - 30 million Suns - to verifying Einstein’s general theory of ...

2021-08-03: How An Extreme New Star Could Change All Cosmology

  • 01:45: ... the final fate of any star less than 8 or so times the mass of the Sun. ...
  • 03:19: ... fields. Fields around a billion times stronger than the earth or sun’s magnetic field. That’s at the top tier of the most magnetic white ...
  • 05:51: ... comparison, a white dwarf the mass of our sun would be around the size of the earth, this new guy is barely 25% bigger ...
  • 08:05: ... quantum mechanics, it was found that it must weigh in at 1.32 times the Sun’s mass. And that’s a lot, at least for a white dwarf. We’ve known for some ...
  • 14:14: ... of this show. Without your support and enthusiasm, we’d probably have sunk to space-themed reaction videos and quantum mechanics based pranks. As ...

2021-07-21: How Magnetism Shapes The Universe

  • 00:43: Threads tugged lightly towards the Earth, tightly towards the Sun, or into inescapable knots towards black holes.
  • 03:44: But while we’re here, it’s worth following one of Earth’s field lines that connects directly to the surface of the Sun.
  • 03:53: Here the field is generated by electrical currents flowing in the searing plasma near the Sun’s surface.
  • 04:05: But the Sun is entirely fluid, and its rate of rotation speeds up towards the equator.
  • 04:21: We can see those tangled field lines in ultraviolet light as charged particles spiral along them, up and down from the Sun’s surface.
  • 04:49: This is still the Sun’s magnetic field, which connects here and there to the piddling little fields of the planets.
  • 04:55: About 4x the distance to Pluto, the Sun’s magnetic field connects to the field of the galaxy itself.
  • 05:03: This is the heliopause, the boundary of the heliosphere, which defines the limit of the Sun’s influence in the galaxy.
  • 05:11: Although it’s less of a sphere and more of a teardrop - dragged into that shape by the Sun’s orbital motion through the galaxy.

2021-05-11: How To Know If It's Aliens

  • 06:27: ... the same way that comets do due to outgassing - ices vaporizing in the Sun’s radiation acting like jets. In the case of comets, this also results in ...

2021-04-21: The NEW Warp Drive Possibilities

  • 10:39: The energy required to carry a 100-meter diameter bubble is about the rest-mass energy of a tenth of our Sun.

2021-04-13: What If Dark Matter Is Just Black Holes?

  • 05:13: ... and could be anything from a grain of salt to tens of thousands of suns. ...
  • 05:43: The most massive black holes in the universe weigh in at millions to billions of times the mass of our Sun.
  • 08:52: ... MACHOs between roughly the moon’s mass to 10 or so times the mass of the Sun as a main contributor to dark ...
  • 09:30: So far we’ve mostly ruled out black holes around the Sun’s mass or lower as an explanation for dark matter.
  • 10:20: ... - if there were lots of black holes of several tens times the Sun’s mass then these binaries would long ago have been torn apart by close ...

2021-03-16: The NEW Crisis in Cosmology

  • 07:28: ... measure the distance to stars. As the earth orbits the   sun over the course of the year, nearby stars appear to move relative ...

2021-03-09: How Does Gravity Affect Light?

  • 11:43: ... measure the slight offset in the apparent positions of stars around the sun, due to their light rays being “refracted” in the Sun’s gravitational ...

2021-02-17: Gravitational Wave Background Discovered?

  • 00:00: ... a few different ways black holes with masses of millions to billions of suns live in the cores of most galaxies these super massive black holes can ...

2020-12-22: Navigating with Quantum Entanglement

  • 02:04: Across long distances, birds often rely on the sun or even the stars.
  • 15:10: ... Russell’s teapot is a hypothetical piece of chinaware that orbits the sun between the earth and mars, and which science has yet to prove doesn’t ...

2020-12-15: The Supernova At The End of Time

  • 02:20: But first, there are many questions to be answered - like how do stars including our Sun end up as one of these “iron stars” in the first place?
  • 04:43: It had become clear that this must be the Sun’s ultimate fate.
  • 06:24: ... behind by an ordinary star that should be 1.44 times the mass of the Sun. ...
  • 08:02: ... inside the crystalized black dwarf that our Sun will become, a single carbon or oxygen nucleus has been sitting neatly ...
  • 08:29: ... is called pycnonuclear fusion - and it will very VERY slowly convert the Sun’s core from carbon into the most stable form of matter - iron - over ...
  • 10:48: times the Sun’s mass.
  • 11:28: And the remnants of our solar system get to see all of this - our Sun stays a black dwarf - probably of crystalized iron - through all of this.

2020-10-05: Venus May Have Life!

  • 00:59: It’s the brightest thing in the sky besides the sun and moon, hanging just above sunrise and sunset.
  • 01:12: In many ways it’s Earth’s twin - it’s even inside that band around the Sun where liquid water is possible - the so-called habitable zone.
  • 02:22: ... other weird thing is that the clouds of Venus appear to absorb the Sun’s light in a weird way - more short wavelength visible and UV light is ...
  • 13:48: And, ultimately, to ally with them in war against the cosmic string entities in the heart of the Sun that we discussed recently.

2020-09-28: Solving Quantum Cryptography

  • 16:08: There’s david brin’s sundiver, and Frank Herbert's "Whipping Star", and several more.
  • 16:25: Some of you thought it was funny that we would do an episode on life in the sun right after the potential discovery of life on venus.
  • 16:42: ... don't you think it's important to understand possible life in the sun before we decide what diplomatic relations to develop with the ...
  • 16:52: Well, Celsius notes that these sun creatures would have had a very different experience in their scientific development.

2020-09-21: Could Life Evolve Inside Stars?

  • 08:35: For example, life uses the energy flowing from the high energy-density of the Sun to the lower energy density of the Earth.
  • 11:28: ... of cosmic strings and monopoles, visiting Earth from the core of the Sun to help spread cosmic ...

2020-09-08: The Truth About Beauty in Physics

  • 01:26: Nicholaus Copernicus found more beauty of simplicity by placing the Earth along with all planets in simple circular orbits around the Sun.
  • 14:42: That's the case when looking through the Sun's atmosphere at it's bright interior.

2020-09-01: How Do We Know What Stars Are Made Of?

  • 00:28: ... first thing you learn in astronomy is that the sun and the other stars are giant balls of fiery hydrogen and helium, ...
  • 03:06: ... is a modern spectrum of the Sun - it’s the amount of light we receive at different colors - or in other ...
  • 03:15: Most of this light comes the photosphere - a layer around 100 km deep at the surface of the Sun.
  • 03:26: The colour of a star depends on that temperature - blue for hot stars, red for cooler stars, and sort of greenish-yellow for stars like our Sun.
  • 03:51: A photon trying to escape from inside the Sun encounters a lot of obstacles.
  • 03:56: One of the most severe is that the Sun is full of free electrons - electrons that were stripped from their atoms due to the intense heat.
  • 04:12: ... photon coming from the core of the Sun will be or scattered so many times that what should be a 1-second ...
  • 05:07: So any photons trying to escape the Sun that happen to have one of these particular energies are going to get sucked up on its way out.
  • 05:26: Just seeing which absorption lines are present tells you which elements are present inside the Sun.
  • 05:32: ... the spectrum of the Sun was first studied, it was noticed that the most prominent lines ...
  • 05:41: The prevailing wisdom came to be that the sun was made of exactly the same stuff as the Earth - just a lot, lot hotter.
  • 05:48: ... to test this - to figure out the true composition of the sun from these absorption lines - was going to take some serious advances in ...
  • 06:38: In energetic environments like the Sun, electrons are regularly kicked free from their atoms.
  • 07:38: ... one thing, each absorption line is formed as light deeper within the sun traverses a large distance, over which temperature and pressure drop ...
  • 09:05: Her results suggested that hydrogen was by far the most common atom in the sun, followed closely by helium.
  • 09:13: Cecilia Payne had discovered what the sun and stars were made of.
  • 09:18: This was totally against the current scientific consensus - which was that the Sun was made of the same stuff as the Earth.
  • 09:39: ... the fact of the sun being made mostly of hydrogen and helium was confirmed only a few years ...

2020-08-24: Can Future Colliders Break the Standard Model?

  • 07:25: ... energies - for example using natural particle accelerators like the sun or supernovae or quasars or galactic magnetic fields, which continuously ...
  • 15:59: ... who don't know - the Chandrashekar limit is 1.4 times the mass of the sun - it’s the maximum mass of a white dwarf before crushing gravitational ...

2020-08-17: How Stars Destroy Each Other

  • 00:20: When our galaxy was a little younger there were two ordinary stars - perhaps not unlike our sun, and they danced together in binary orbit.
  • 06:42: The nearest such system is the famous Cynus X1 X-ray binary, where a black hole the mass of 15 Suns is busy gorging on a blue giant star.

2020-07-28: What is a Theory of Everything: Livestream

  • 00:00: ... symmetry particles um you know speaking of lisa you know randall some sundrum gravitons large extra dimensions any of these would be fantastic ...

2020-07-20: The Boundary Between Black Holes & Neutron Stars

  • 01:14: One was a hefty 23 times the mass of our Sun - making it definitely a black hole, and pretty similar to other LIGO mergers.
  • 05:11: So you end up with at least one and a half suns worth of matter locked in a ball that would fit inside a small city.
  • 08:00: Those models have predicted maximum masses in the range 2 to 3 times the mass of the sun.
  • 08:59: But, the most massive so far is around 2.1 Suns.
  • 09:33: So far we’ve never observed a black hole with masses lower than around 5 times that of the Sun.
  • 10:28: Based on our calculations and simulations of how stars die, that minimum black hole mass of 5 Suns seems about right.

2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing?

  • 05:43: ... anti-electrons - are created all the time in nature - for example in the Sun, or in radioactive decay, or when cosmic rays hit the atmosphere, which ...

2020-05-11: How Luminiferous Aether Led to Relativity

  • 02:33: ... flows carried the celestial bodies, for example in circles around the Sun. The Dutch physicist Christiaan Huygens developed a detailed mathematical ...
  • 08:02: ... lab when you already have a fast-moving planet? Earth hurtles around the Sun at 30 km/s - that’s only one one hundredth of one percent of the speed ...

2020-04-28: Space Time Livestream: Ask Matt Anything

  • 00:00: ... piece of art okay it's a it's a beautiful time to see it because the Sun shines off the gold leaf but what is it where did it come from well ...

2020-04-14: Was the Milky Way a Quasar?

  • 00:47: ... is it home to an enormous black hole four million times the mass of the Sun, but it also swarms with smaller black holes, searing hot clouds of gas, ...
  • 08:16: Now A full quasar might devour many millions of times the mass of the Sun over one active period, which could last for several million years.
  • 15:59: ... and was able to announce triumphantly that the Earth was created on Sunday the 21th of October, 4004 B.C., at exactly 9:00 A.M., because God liked ...

2020-04-07: How We Know The Earth Is Ancient

  • 11:55: ... solar system meteorites and also from our calculations of the age of the Sun. ...
  • 12:35: ... Canyon. Not that our ancient Earth cares - it’s revolved around the sun 4.5 billion times through deep space and out of deep time, and it’ll do ...

2020-02-11: Are Axions Dark Matter?

  • 08:58: ... then they should be produced in reasonable quantities in the core of the sun. There, X-rays are constantly bouncing off electrons and protons in the ...

2020-01-27: Hacking the Nature of Reality

  • 15:56: ... black holes a few tens of millions to 10 billion times the mass of the sun - and the small end of that range is indeed a "little" compared to the ...

2020-01-20: Solving the Three Body Problem

  • 04:12: ... solar system can be thought of as a separate two-body system with the Sun. That gives you a series of simple elliptical orbits, like those ...
  • 04:29: ... be used to approximate the orbits of the moon relative to the Earth and Sun, or the Earth relative to the Sun and ...
  • 05:01: ... mass, and the solar system as a whole has many massive constituents. The Sun, Jupiter and Saturn alone are automatically a three-body system with no ...
  • 06:43: ... it will stay there indefinitely, tracking the Earth’s orbit around the Sun. We now call these the Lagrange points, and they’re useful places to park ...
  • 12:00: ... so long after Poincare stern proclamation, Finnish mathematician Karl Sundman found a solution to the general three-body ...
  • 12:21: ... the equation could be written out on paper. However the convergence of Sundman’s series is so slow that it would 10^8 million terms to converge for a ...

2020-01-13: How To Capture Black Holes

  • 00:24: ... lit up the sky, When we learned to see in neutrinos the core of the Sun became visible to us. But now that our vision extends to gravitational ...
  • 02:50: ... supermassive black hole of millions to billions of times the mass of the Sun. Recently we’ve also learned that the galactic center likely also ...
  • 07:17: ... mass” black holes can form, with 1000s of times the mass of the Sun. ...

2020-01-06: How To Detect a Neutrino

  • 02:05: ... thick to have a 50/50 chance at stopping a single neutrino from the Sun. ...

2019-12-17: Do Black Holes Create New Universes?

  • 10:08: Lee Smolin calculates that optimized cutoff at around 2 times the mass of the Sun.

2019-11-18: Can You Observe a Typical Universe?

  • 00:34: ... the center of the universe into just one of several planets orbiting the Sun. ...
  • 00:45: ... our astronomy improved, we realized that our sun is a typical example out of 100s of billions of stars in the Milky Way, ...
  • 12:13: ... been made to have me in it!" This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets ...

2019-11-11: Does Life Need a Multiverse to Exist?

  • 06:21: ... of the key steps in the fusion process inside stars - so stars like our sun wouldn’t burn at ...

2019-11-04: Why We Might Be Alone in the Universe

  • 04:31: ... about the size of the Earth in orbit around stars very similar to the Sun at the right distance to sustain liquid water on their surface - in the ...
  • 08:32: ... emerging as a primordial soup sloshed in these pools, baking in the sun. ...

2019-10-07: Black Hole Harmonics

  • 08:09: ... GW150914 – a pair of black holes, each 30 or so times the mass of the sun, spiraling into each other one and a half billion light years ...

2019-09-30: How Many Universes Are There?

  • 16:01: Here the IAU definition again: "A planet is a sun-orbiting body massive enough to be round and to have cleared it's orbit of debris".
  • 16:42: If Earth formed at 100 times its current distance from the sun it wouldn't have cleared its orbit either, and so wouldn't be considered a planet.
  • 16:55: ... somewhat complicated relationship between mass and distance from the Sun that determines whether you get called a planet - and that relationship ...
  • 17:22: That brings us to the first part of the IAU definition - a planet has to be orbiting our Sun.

2019-09-23: Is Pluto a Planet?

  • 01:44: ... included Mercury, Venus, Mars, Jupiter, and Saturn, but also the sun and the moon - basically anything that moved relative to the background ...
  • 02:07: ... published “On the Revolutions of the Heavenly Spheres” which cast the Sun, not the Earth, as the center of the universe and the Earth in its proper ...
  • 02:34: The solar system finally made observational and theoretical sense: there were now 6 planets orbiting the sun in perfect mathematical harmony.
  • 09:02: A planet must: One - be in its own orbit around the Sun, not around another planet like a moon.
  • 16:27: ... that's a long time for any photosynthesizing life to survive without the sun, and 2) it has essentially no water, so we'd have to be bringing all of ...

2019-09-16: Could We Terraform Mars?

  • 01:47: Light from the Sun, which is already fainter due to Mars’ distance – is radiated directly back out into space.
  • 02:15: And of course Earth’s atmosphere protects us from harmful cosmic rays and the most dangerous ultraviolet radiation from the Sun.
  • 13:19: The easiest would be to do that in space – an orbiting field generator placed between Mars and the Sun, like a giant space umbrella.
  • 18:23: Electrical currents are induced and these produce a magnetic field that pushes back against the Sun's magnetic field.

2019-09-03: Is Earth's Magnetic Field Reversing?

  • 00:46: Now, that’s helpful, because Earth is constantly bombarded by very fast moving charged particles, especially coming from the Sun.
  • 07:27: ... a fluid conductor can produce such a field – the Earth, but also the Sun with its flowing hydrogen plasma, or the liquid metallic hydrogen in ...

2019-07-25: Deciphering The Vast Scale of the Universe

  • 06:23: ... Earth, the Sun, and our solar system behind, we’re zipping past the hundreds of billions ...

2019-07-01: Thorium and the Future of Nuclear Energy

  • 00:33: ... force holding nuclei together contains an enormous amount of energy The Sun is powered that way Releasing a mere 0.4 percent of the mass of hydrogen ...

2019-06-20: The Quasar from The Beginning of Time

  • 06:24: ... hole. That allows us to estimate the mass of the black hole: 800 million Suns. ...
  • 06:39: If it replaced our Sun, it would easily swallow Saturn's orbit.

2019-06-17: How Black Holes Kill Galaxies

  • 00:08: ... could have masses of Millions or even Billions of times that of the Sun It came as a bit of a shock they were discovered as the driving force ...
  • 04:05: ... less than a Billion years after the Big bang with masses of 10 Billion suns Easily as large as the largest in the modern Universe so if Black Holes ...

2019-05-16: The Cosmic Dark Ages

  • 07:19: ... first supermassive black holes with millions, even billions of times the Sun’s mass – inescapable spheres the size of solar systems. And in the final ...

2019-05-09: Why Quantum Computing Requires Quantum Cryptography

  • 05:48: ... photon through a horizontal polarization filter like a polarized sunglasses lens and the photon will either decide it’s vertically polarized and be ...
  • 06:19: Try it with two polarized sunglasses lenses at 90-degrees – all light gets blocked.
  • 15:41: Munrais asks whether putting radio telescopes around the sun would improve the resolution of an interferometer.

2019-05-01: The Real Science of the EHT Black Hole

  • 01:00: It has an estimated mass of several billion times that of the Sun, which gives it an event horizon larger than the solar system.

2019-04-24: No Dark Matter = Proof of Dark Matter?

  • 00:03: ... orbits they inferred a mass for Fritz of 130 million times that of our Sun although with an error bar of 18 million solar masses the comparison our ...

2019-01-24: The Crisis in Cosmology

  • 03:53: ...whose distances can be figured using stellar parallax Tracking their tiny motions on the sky, as Earth orbits the Sun.

2018-12-06: Did Life on Earth Come from Space?

  • 00:37: ... cells like cyanobacteria and lichens can also survive direct sunlight in low Earth orbit briefly mortality is still high in all of these like ...

2018-11-21: 'Oumuamua Is Not Aliens

  • 00:29: ... of our solar system drifting on their endless orbits around the sun, and faintly glimmering with its reflected ...
  • 00:48: It was not in orbit around the sun at all.
  • 02:56: It appears to be accelerating, or at least it's not slowing down as much as you'd expect due to the sun's gravitational pull.
  • 03:20: Comets show the same sort of acceleration on their way out from the sun.
  • 03:27: As the sun heats the rear surface of the comet, water, ice, and frozen gases, so-called volatiles, evaporate.
  • 03:38: In regular comets, the outgassing is typically visible as sunlight reflects off dust carried along with the jets.
  • 04:32: The sun's own light could be pushing on the object speeding it up.
  • 04:41: The acceleration is decreasing with the square of the distance from the sun.
  • 04:49: ... from outgassing, because outgassing also depends on the strength of the sun's ...
  • 06:48: ... I mentioned that in regular comets, the coma and tail are seen through sunlight reflected off dust, tiny mineral grains that are carried out with the ...

2018-10-10: Computing a Universe Simulation

  • 05:35: The mass of a 100 kilometer radius black hole would be 30 times that of our sun.
  • 06:05: You'd need a black hole a few million times the mass of the sun and 10 million kilometers in radius.

2018-10-03: How to Detect Extra Dimensions

  • 04:16: We do see slight deviations in very strong gravitational fields, like close to the sun.

2018-09-12: How Much Information is in the Universe?

  • 07:48: Sagittarius A star in the center of the Milky Way, which has a mass of four million suns.

2018-08-30: Is There Life on Mars?

  • 00:43: ... the Red Planet, fourth rock from the sun, it's currently just past its closest approach to Earth, making it an ...
  • 04:00: Mars was at its closest approach to the sun and the Earth at its closest to Mars.

2018-08-23: How Will the Universe End?

  • 02:13: ... will almost certainly befall the Earth, to the heating and death of the sun, to the merger with the Andromeda Galaxy, and, finally, to the death of ...
  • 07:30: Some have grown to masses of up to 100 trillion suns, having swallowed good-sized bites from entire galaxy clusters.
  • 07:51: The small black holes, say, around 10 times the mass of the sun, completely evaporate in around 10 to the power of 67 years.

2018-08-15: Quantum Theory's Most Incredible Prediction

  • 13:14: And now onto your comments about getting close to the sun with the very recently launched Parker Solar Probe.
  • 14:23: Andrea Smith asks whether the Suns million Kelvin corona temperature is caused by magnetic reconnection.
  • 14:36: ... the mystery here is why the sun's corona, the extremely diffuse layer of material surrounding the sun, can ...
  • 15:24: ... caused widespread auroral activity, and the big one that occurred on the sun on September 1, 1859, and reached the earth 17.6 hours ...
  • 15:51: ... usually take several days to cross the distance between Earth and the sun, and making its effect even more powerful than if it had happened ...

2018-08-01: How Close To The Sun Can Humanity Get?

  • 00:00: [MUSIC PLAYING] The sun-- an entity worshiped as a god throughout time and across cultures.
  • 00:15: ... will reach out its collective hand and come closer to touching the sun than we ever have before, with the launch of the Parker Solar ...
  • 00:49: The Parker Solar Probe will fly within a hair's breadth of the sun itself.
  • 00:57: The sun-- a vast ball of incandescent gas.
  • 01:41: We still don't understand exactly why it burns at millions of Kelvin in temperature-- far hotter than the sun's surface below it.
  • 03:09: So maybe it's a good idea to learn more about the sun's surface?
  • 03:12: We already monitor it constantly with ground-based telescopes and spacecraft orbiting the earth or orbiting the sun at a safe distance.
  • 03:51: It'll directly probe the sun's electromagnetic field and will connect the sun's magnetic activity with the sources of the solar wind.
  • 04:46: Next up is the integrated science investigation of the sun or ISIS.
  • 05:32: Together, these instruments work in tandem, creating a complete picture of the environment near the surface of the sun.
  • 05:39: Of course, as exciting as all of this is, the big question is, how do we make sure the sun doesn't melt them?
  • 06:12: ... challenges with this mission is getting the spacecraft that close to the sun, even ignoring its ability to survive ...
  • 06:23: The sun's the biggest object in the solar system and has the strongest source of gravity.
  • 06:41: ... move closer to the sun, you need to first, escape the Earth and then, lose speed, which can be ...
  • 07:06: ... a more stretched out elliptical orbit that will take it closer to the sun. ...
  • 07:26: By the end of 2024, if all goes according to plan, Parker will reach its closest approach to the sun of 6.2 million kilometers.
  • 07:38: ... of its eccentric orbit, Parker will get roughly 10 times closer to the sun than the closest ...
  • 08:06: ... seven years, Parker will have completed 26 close approaches to the sun, five of which will be a relative hair's breadth from the sun where it ...
  • 08:30: And the dream of flying to the sun is as old as the legend of Icarus.

2018-06-27: How Asteroid Mining Will Save Earth

  • 06:59: Fortunately for asteroid miners, though less fortunately for the dinosaurs, many asteroids do cross Earth's orbit in their passage around the Sun.

2018-06-20: The Black Hole Information Paradox

  • 14:58: HebaruSan noticed that, in our graphic, the Earth completed 1.75 orbits in the supposed 8 minutes it took the Sun's gravitational field to vanish.

2018-06-13: What Survives Inside A Black Hole?

  • 03:54: The Earth orbits the Sun, but more directly it orbits the Sun's gravitational field.
  • 04:00: You could change anything about the Sun other than its mass and the Earth would continue in the same orbit.
  • 04:06: If the Sun were to suddenly vanish, Earth would continue to orbit the existing gravitational field for 8 minutes.

2018-05-09: How Gaia Changed Astronomy Forever

  • 01:37: The spacecraft orbits the sun at Lagrange point two, tracking the Earth's orbit, but 1.5 million kilometers further from the sun.
  • 03:17: ... census of the stellar population far beyond the neighborhood of the sun, compared to the HR diagram of ...
  • 10:29: On the other hand, a star that weighs twice as much as the sun, burns about 25 times brighter and burns out 10 times faster.

2018-05-02: The Star at the End of Time

  • 00:25: We somehow persist through the gradual heating of our Sun and the evaporation of our oceans.
  • 00:40: We seek refuge in the outer solar system as the Sun finally expands into a red giant twice.
  • 00:47: And finally, our heirs or successors find new homes among the stars after the Sun's final death and transformation into a dim white dwarf.
  • 01:55: ... Sun burns through 600 billion kilograms of hydrogen every second, generating ...
  • 02:11: This rate will only increase as the core's temperature increases, and the Sun will burn through the hydrogen supply in its core in five billion years.
  • 02:36: Stars less massive than the Sun burn through their fuel much more slowly.
  • 02:41: ... also known as "M dwarfs." We observe that a red dwarf with 10% of the Sun's mass is about 1,000 times fainter than the ...
  • 03:04: Actually, wrong-- stars like our Sun can only burn the hydrogen in their cores.
  • 03:09: The layer above the Sun's core is what we call "radiative." All of the energy travels in the form of photons bouncing their way upwards.
  • 03:17: Closer to the surface, the Sun becomes convective.
  • 03:25: That radiation zone isolates the Sun's core, preventing new material from reaching those depths.
  • 03:31: As a result, the Sun will only have access to 10% of its mass for fusion fuel.
  • 03:58: A red dwarf with 10% the Sun's mass has just as much fuel to burn as the Sun does, yet it burns it 1,000 times slower.
  • 04:07: That means it should live 1,000 times longer-- so 10 trillion years instead of the Sun's 10 billion years.
  • 04:20: Just like the Sun, the cores of red dwarf stars shrink and heat up over time.
  • 05:46: First, they shine white as their black-body spectrum spans the visible range, just like our Sun.
  • 05:52: In the final few billion years of their lives, some red dwarfs may even become hotter than our Sun, developing a faint blue tinge.
  • 06:33: ... new Sun-like stars will be born in the Milky Way/Andromeda collision four billion ...
  • 06:58: As these brighten one by one, the most massive will shine brighter than the current Sun.
  • 07:57: ... wharfs in the middle range of mass, around 15% of the Sun's mass, are predicted to enter a period of relatively constant brightness ...
  • 08:06: This period could last for up to five billion years, during which the star will shine almost as bright as the Sun and quite a bit hotter.

2018-04-25: Black Hole Swarms

  • 00:30: A supermassive black hole-- four million times the mass of our sun-- lurks in the center.
  • 07:42: If the sun was near the galactic core, the nearest black hole would be inside the solar systems Oort cloud.

2018-04-18: Using Stars to See Gravitational Waves

  • 00:58: In three cases, both members of the black hole binary pair were well over 20 times the mass of the sun.
  • 04:17: The three components of this craft will trail behind the earth in an orbit around the sun.
  • 11:14: Without life, Earth would reflect a higher intensity spectrum closer to the 6,000 Kelvin thermal spectrum it receives from the sun.

2018-04-11: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!)

  • 03:54: Ultimately, that source of energy is the sun.
  • 04:08: On the other hand, the system of the Earth plus the sun is increasing in entropy.
  • 04:46: By free energy, I mean the special out-of-equilibrium energy sources like a cup of coffee or the sun.
  • 05:58: The water of tidal pools is both cooled by the earth and the ocean and warmed by the sun.
  • 08:10: A plant absorbs the concentrated ultraviolet light from the sun and reprocesses it into a much higher entropy infrared heat glow.

2018-03-28: The Andromeda-Milky Way Collision

  • 00:38: ... hides a giant black hole that contains the mass of well over 100 million suns. ...
  • 01:21: But what about the sun, the solar system, the Earth?
  • 04:40: Then they averaged the observed motion of all of those stars and removed the effects due to the rotation of Andromeda and the motion of the sun.
  • 06:50: But what about the sun and the earth?
  • 07:22: ... der Marel, et al's, simulation follows several candidate suns, simulation particles with similar orbits and masses to our sun, and they ...
  • 07:49: There's also a small chance that the sun will encounter one of the supermassive black holes as they descend to the core.
  • 08:21: At this point, the sun will already have expanded into a red giant.
  • 08:29: Earth will long ago have been roasted by our own brightening and then expanding sun, which we talked about in earlier episodes.

2018-03-07: Should Space be Privatized?

  • 07:45: Aerospace billionaires see themselves as the new Wright brothers and see risk and sunk investment as necessary for true innovation.
  • 10:31: In a recent episode, we talked about the death of the sun.
  • 10:45: As the hydrogen fuel in the sun's core gets diluted by helium, the fusion rate does decrease and the core shrink.
  • 11:19: By contrast, the sun is only convective in its outer layers.
  • 11:48: ... the dramatic cycle of shell burning and red giant phases that the sun will go ...
  • 12:04: ... stars consume their fuel thousands of times more slowly than the sun, which means they can live hundreds of times longer, even though they ...

2018-02-21: The Death of the Sun

  • 00:12: The sun has inflated to around 1 1/2 times its original size, and shines brighter than ever before.
  • 00:34: It's time to watch the death of the sun.
  • 01:17: That is not the fate of our sun.
  • 01:21: The sun is now 4.6 billion years old.
  • 01:43: ... the course of its life, the sun's core is heating, causing the sun to grow and brighten with disastrous ...
  • 02:01: But what are the prospects for our little planet after the sun runs out of fuel?
  • 03:09: That incredible outward flow energy does counteract gravity for the outer layers of the sun, and those layers expand.
  • 03:17: Over the next half billion years, the sun doubles in size as a sub giant.
  • 03:21: ... the following half billion years, the process accelerates, and the sun inflates to around the size of Venus' orbit, shining with a few thousand ...
  • 03:45: The sun is now a red giant, and it is vast on the Earth's daytime sky.
  • 04:20: It'll save the sun from collapsing into a black hole, and it's also currently stopping you from falling through the floor.
  • 05:25: The energy output is insane, and the sun swells to a red giant once more.
  • 05:41: See, the red giant sun is so large and luminous that it only has a tenuous hold on its outer layers.
  • 05:54: ... expands, perhaps eventually taking it out beyond Mars' orbit, if the sun doesn't overtake it ...
  • 06:08: By now, the red giant sun fills most of the sky and it's getting larger.
  • 06:16: On the one hand, these diminish the sun's hold on us, expanding our orbit.
  • 06:25: ... own gravitational pull creates a tidal bulge in the sun that may increase its gravitational hold on us, or the sun may just ...
  • 06:44: It may well end up in orbit inside the sun.
  • 07:18: The sun has become a white dwarf.
  • 07:28: ... the Earth-- perhaps it just managed to escape the expanding sun and is now a lonely desolate world orbiting out in the old location of ...
  • 07:46: It's also possible that the iron core survives and will continue to orbit the white dwarf sun until the end of everything.
  • 08:47: ... moons may be a final temperate vantage point to watch the sun's inevitable death, and to look to the greater galaxy for a new home ...

2018-02-14: What is Energy?

  • 13:30: Well, solar system formation models do indicate a scenario in which our sun may have swallowed some early terrestrial planets.
  • 13:45: That could have sent a new generation of planets spiraling into the sun.
  • 13:56: If only the sun had a binary partner, we could actually test this by comparing metallicities.

2018-01-31: Kronos: Devourer Of Worlds

  • 00:56: Our sun wanders alone.
  • 02:14: If we understand this chemical tagging, perhaps one day we'll be able to locate the sun's lost siblings.
  • 03:24: They're both G-type stars like our sun.
  • 05:54: The researchers tested the hypothesis by throwing a bunch of Earth-like planets into a sun-like star-- mathematically, I mean.
  • 06:18: Lithium gets depleted in the early years of stars like the sun.
  • 07:36: ... of "Space Time." We recently discussed the gradual brightening of the sun and the inevitable extinction of all life on Earth that will result. Or ...
  • 07:57: ... mentioned the idea of star lifting, of actually reducing the mass of the sun to reduce its luminosity and, as a side benefit, to potentially greatly ...
  • 08:28: Andrew Milo recommends we block out some of the sun's light with orbiting solar farms.

2018-01-24: The End of the Habitable Zone

  • 00:10: In several hundred million years, the brightening sun will turn the poles into tropical paradises.
  • 00:25: The sun is slowly burning through its fuel.
  • 00:27: Hydrogen is fused into helium in the sun's core, producing energy that keeps it shining and keeps the earth warm and hospitable to life.
  • 00:36: But that fuel will run out, after which the sun will swell into a red giant and flash fry the earth.
  • 00:48: See, the sun is getting brighter even now.
  • 01:09: ... the sun is able to remain as a giant ball of fiery hydrogen due to a delicate ...
  • 01:28: ... when the sun was born, it's initial gravitational collapse from a giant gas cloud was ...
  • 01:43: At that point, the sun had plenty of hydrogen fuel.
  • 01:49: As the sun's fuel gets diluted, you might expect fusion to slow down.
  • 02:30: So over time, the sun's core shrinks and heats up, brightening the entire star.
  • 02:45: It's been calculated that the sun should currently be increasing in energy output by close to 1% every 100 million years.
  • 03:01: ... the sun was around 30% dimmer and 10% smaller when it first formed, but it will ...
  • 03:27: But that's not the first disaster to result from the sun's brightening.
  • 05:02: This is the distance from the sun where sustained liquid water is possible.
  • 05:06: The brightening of the sun means the habitable zone has shifted outwards since the formation of the solar system.
  • 05:12: ... fact, in the beginning when the sun was at 70% of its current brightness, Earth would have been outside the ...
  • 05:36: ... prediction and the geological evidence is called the faint young sun paradox, and was pointed out by Carl Sagan and George Mullen in the ...
  • 05:56: ... then the increased heat retention may have compensated for the fainter sun. ...
  • 09:02: And so its ice reserves should thaw as the sun brightens.
  • 09:26: Now we're not going to stop the sun from brightening but we might try to block some of the extra light.
  • 09:47: ... perhaps we can hold out until the sun eventually exhausts its fuel and becomes a red giant expanding to ...

2018-01-10: What Do Stars Sound Like?

  • 02:03: When we try to understand other stars, we always start with our sun.
  • 02:07: While the distance stars are infinitesimal points of light to even our best telescopes, the surface of the sun can be resolved in incredible detail.
  • 03:24: However, it's the pressure waves-- the p-waves-- that really dominate in stars like the sun.
  • 04:21: The strongest oscillations in the sun are in the two to four millihertz range.
  • 04:26: These are the sun's 5-minute oscillations.
  • 04:31: Well, for the sun, we can map these oscillations in two ways-- changes in brightness and changes in velocity.
  • 04:38: Brightness of spectral lines in the sun's atmosphere can change by around one part per million over the course of an oscillation.
  • 05:52: Helioseismology has allowed us to verify and improve the models of the sun's internal structure.
  • 06:11: This differential rotation powers the sun's magnetic field and is also responsible for twisting that magnetic field to drive the sunspot cycle.
  • 06:21: ... to measure the composition of the core, which tells us how much of the sun's hydrogen fuel source has already been burned into ...
  • 06:31: ... this way, it's been revealed that our sun is currently around halfway through its 10-billion-year lifespan, which ...
  • 06:42: Observations of the sun's surface are relatively easy.
  • 07:58: But at least for the sun, it's possible to learn about current local events that are hidden from our view.
  • 08:12: ... the distribution of Doppler velocities across the visible surface of the sun-- is used to infer the current state of the standing waves throughout the ...
  • 08:26: That includes the far side of the sun.
  • 08:28: In fact, helioseismic holography is capable of detecting sunspots long before the sun rotates them into visibility.
  • 11:30: Now, it may eventually happen as the sun wanders the galaxy and encounters new neighbors, but it's still spectacularly unlikely.
  • 12:18: But so would hats and sunscreen.

2017-12-20: Extinction by Gamma-Ray Burst

  • 00:49: For example, the gradual heating and eventual death of the sun.
  • 02:41: Now, some won't die that way, but any star more than around eight times the Sun's mass will.
  • 04:22: And nitrogen dioxide absorbs visible light, reducing the energy received from the sun.
  • 05:05: ... by the global cooling triggered by a few years of NO2 absorption of sunlight. ...
  • 06:22: That event may have been the increase in sunlight absorbing NO2 after a GRB.
  • 07:27: The exposed inner star shines several times hotter and hundreds of thousands of times brighter than the Sun.
  • 08:58: However, the Sun isn't stationary.
  • 12:03: Recent studies suggest that there's a 3% chance that the Sun will jump galaxies on Andromeda's first fly by.

2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor

  • 00:29: On October 19th this year, astronomers spotted an unusual object moving rapidly away from the sun.
  • 02:32: Oumuamua doesn't have a tail like a comet, so its surface isn't vaporizing in the sun's radiation.
  • 03:22: Meaning the object is gravitationally bound to the sun.
  • 03:47: And they never actually orbit the sun.
  • 03:49: Rather, they're deflected by the sun's gravity as they pass by.
  • 04:07: Oumuamua had a maximum speed of 87.7 kilometers per second at its closest approach to the sun, which is well inside Mercury's orbit.
  • 04:24: That means Oumuamua has enough speed to climb out of the sun's gravitational well and escape back to interstellar space.
  • 05:25: PZ 17 performed more computer simulations to rewind the motion of both Oumuamua and the 3,700 stars within 100 light years of the sun.
  • 06:46: Our sun, as it moves around the galaxy, passes through this field of debris.

2017-11-22: Suicide Space Robots

  • 08:44: ... solar system in 2012, it passed the heliopause-- the boundary where the sun's magnetic field and solar wind give way to the ambient environment of the ...

2017-10-25: The Missing Mass Mystery

  • 00:41: When we extrapolate observations to the entire observable universe, we find a billion trillion suns worth of mass.
  • 08:14: The secret is the thermal Sunyaev-Zel'Dovich effect.
  • 09:00: ... just published the results of their attempts to look for the Sunyaev-Zel'Dovich ...
  • 09:44: Both teams report detection of the thermal Sunyaev-Zel'Dovich effect with around 5 sigma significance.

2017-10-04: When Quasars Collide STJC

  • 01:40: They start with masses of up to 10 or so Suns.
  • 01:44: The ones in the course of galaxies contain the mass of a million two billion Suns.
  • 02:55: Quasar is the term for the most powerful AGNs, and they contain SMBHs with up to billions of Suns in mass.

2017-09-28: Are the Fundamental Constants Changing?

  • 12:50: Mike Williams asks about the possibility of using our sun as a gravitational lensing telescope.
  • 13:17: It would then look back at light lensed in the sun's gravitational field.
  • 13:29: Among the many challenges presented by this idea is that you could really only have a look in one direction back towards the sun.

2017-09-20: The Future of Space Telescopes

  • 01:41: Our sun is about 10 billion times brighter than Earth.
  • 01:44: Train a distant telescope on us, and it would be overwhelmed by the sun's rays.
  • 02:24: ... where near the factor of 10 billion difference between the Earth and the sun. ...
  • 04:01: So one of these things would allow us to see Earth in orbit around the sun from 60-light years away.
  • 04:08: There are a couple of thousand stars within that range, and hundreds of sun-like stars, many of which certainly have Earth-like planets.

2017-09-13: Neutron Stars Collide in New LIGO Signal?

  • 02:06: A remnant core between 1.4 and around 3 times the mass of our sun instead ends up as a neutron star.
  • 04:00: See, black holes only form in the deaths of the most massive stars, those over approximately 20 times the Sun's mass.

2017-08-24: First Detection of Life

  • 07:22: We do it by enjoying lovely exoplanet sunsets.

2017-08-16: Extraterrestrial Superstorms

  • 01:45: In the case of earth storms, the energy powering that convection comes from the sun-warmed ocean.
  • 03:58: The most powerful storms tend to be low-pressure cyclonic systems powered by sun-warmed water.
  • 04:09: They are most often anti-cyclonic, high-pressure systems and are powered not by the sun, but by the collapse of the planet itself.
  • 04:23: They originally collapsed from the vast gas disk left over after the sun's birth.

2017-08-02: Dark Flow

  • 02:05: This motion is due to the sun's orbit around the Milky Way and the Milky Way falling to the Great Attractor-- more on that last one soon.
  • 03:27: To explain this, I'll need to tell you about the kinematic Sunyaev-Zeldovich, KSZ, effect.
  • 03:33: And actually, let's just start with the regular old thermal Sunyaev-Zeldovich effect.
  • 04:17: Now, kinematic Sunyaev-Zeldovich effect is much, much harder to see than the thermal SZ effect.

2017-07-07: Feynman's Infinite Quantum Paths

  • 12:49: And this is a really great way to simultaneously support the show and to not burn your eyes out staring at the sun.

2017-05-31: The Fate of the First Stars

  • 00:30: [MUSIC PLAYING] The sun is a late-comer to our universe.
  • 00:45: See, the sun and all stars are made of the raw material forged in the heat of the Big Bang itself-- hydrogen and helium, mostly.
  • 00:54: When the sun's light is broken into a spectrum, it reveals traces of many of the heavier elements of the periodic table.
  • 01:01: ... spread their element-enriched guts through the galaxy, long before the sun was even a twinkle in the eye of a giant molecular ...
  • 01:47: The sun is a population one star, meaning 2% to 3% of its mass is metals.
  • 03:17: Even stars a little smaller than our sun-- the orangish K-type stars-- live for longer than the current age of the universe.
  • 03:31: But stars of the sun's mass and higher that formed over 13 billion years ago, near the beginning of the universe, would now be long gone.
  • 04:34: So the cores of very massive stars are much hotter than our suns-- up to a couple hundred million Kelvin, versus the sun's 15 million K.
  • 04:58: A star 10 times the mass of the sun shines around 10,000 times brighter.
  • 05:04: Now, burning through 10 times the fuel at 10,000 times the rate, compared to the sun, means its life is 1,000 times shorter-- only 10 million years.
  • 05:15: ... three stars would have had masses of at least several times that of the sun, while the largest would have been as much as 1,000 or more times the ...
  • 09:15: ... black holes, with millions to billions of times the mass of the sun, that we find lurking in the centers of ...

2017-05-17: Martian Evolution

  • 06:49: ... the other hand, the less intense sunlight at Mars compared to Earth means it'll be harder to produce vitamin D. ...
  • 13:15: ... offset in the positions of stars around the limb, the edge, of the sun due to the powers of their light bending in the suns gravitational ...
  • 13:40: ... need to compare the positions of stars on either side of the sun during the eclipse and then several months later when the sun has moved ...
  • 14:29: And it's also the sun's angular diameter.
  • 14:31: So it takes one hour for the moon to fully eclipse the sun and another hour to move past it.

2017-05-10: The Great American Eclipse

  • 00:08: ... to raise your hands to the heavens and threaten to block out the sun. ...
  • 01:00: ... moon has to be on the opposite side of the Earth compared to the sun to catch the Earth's shadow and so lunar eclipses are always during full ...
  • 01:08: And the moon has to be between the sun and the Earth for its shadow to hit us.
  • 01:26: The moon's orbit about the Earth and the Earth's orbit about the sun, the ecliptic plane, are misaligned by about 5 degrees.
  • 01:58: It'll be partial because the Earth won't completely covered the sun from the moon's perspective.
  • 02:23: So that's the penumbra of the moon's shadow, where the sun isn't completely blocked.
  • 02:38: At first, you won't notice much change in the glorious sunny day, fingers crossed for the weather.
  • 03:01: In fact, the spaces between the leaves act like pinhole cameras, projecting the sun's image to the ground.
  • 03:20: But whatever you do, don't look directly at the sun, at least not yet.
  • 03:28: So no joke here-- you need these, and sunglasses won't cut it.
  • 03:32: You need aluminized mylar or number 14 welder's glass, something approved specifically for viewing the sun.
  • 03:42: Over the course of the next hour, the moon eats further and further into the sun.
  • 03:53: The moon is much smaller, but much closer than the sun.
  • 04:01: This August, the moon will span 0.538 degrees, just big enough to completely obscure our 0.527 degrees sun.
  • 04:12: The moon's orbit is elliptical, and so sometimes it eclipses the sun when it's a bit further away from the Earth.
  • 04:19: It appears smaller to us and so doesn't completely block the sun.
  • 04:23: Such eclipses are called annular eclipses, because they leave a ring of bright sunlight around the moon's disk.
  • 04:48: And so in the future, it won't be able to block out the entire sun anymore.
  • 05:16: With your glasses on, you see the sun is a mere sliver, and it's shrinking.
  • 05:36: But now it's the last thin sliver of the sun that's twinkling.
  • 05:43: The sun's final crescent contracts to a last spark on one side of the moon, like a diamond ring.
  • 05:54: It's the one time you can stare safely straight towards the sun.
  • 05:58: ... red from a specific electron transition in the hydrogen of the sun's upper ...
  • 06:12: Really, they're extra sunlight peeking through lunar valleys.
  • 06:18: What shows up next is the ghostly light of the corona, the sun's outermost atmosphere.
  • 06:24: The corona is always there, but its faint glow is normally overwhelmed by the glare of the sun's surface.
  • 06:30: Right next to the black sun, you'll see the bright star Regulus and its constellation, Leo.
  • 06:41: Mercury orbits so close to the sun that it's hard to catch in a dark enough sky.

2017-04-05: Telescopes on the Moon

  • 01:34: And three, on earth, sunlight is scattered to make our blue sky.
  • 04:23: When exposed to the sun, temperatures rise to around 125 Celsius, well, above the boiling point of water.
  • 04:37: ... Yutu was experiencing a massive temperature differential between its sunny side and shaded ...
  • 05:17: Hit by sunlight, tiny regolith particles build up electric charge, and so repel each other into dust fountains in the low lunar gravity.

2017-03-15: Time Crystals!

  • 02:49: Cups of coffee cool down, planets orbit the sun, the universe expands.
  • 11:54: Yet it's estimated that a system with an Earth-like planet orbiting a Sun-like star has around a 1% chance of transiting from our perspective.

2017-03-01: The Treasures of Trappist-1

  • 01:11: The star, TRAPPIST-1a, is an ultra cool dwarf star, about 10% the sun's diameter and less than 10% its mass.
  • 01:20: It's also much colder, about 2,500 Kelvin compared to the sun's 5800 Kelvin.
  • 04:20: It would look pink on the sky to us, but there will be no day and night so an eternal sunrise.
  • 04:39: That could be OK for habitability if they have sufficiently thick atmospheres to mix the heat from their sun globally.
  • 05:24: For comparison, our sun and moon span around half a degree on the sky.
  • 05:29: On the inner planets' sunny side, the star will provide about as much visible light as our sun.
  • 05:53: Out here on Earth, our distance and our magnetosphere protect us from most of the sun's coronal mass ejections.
  • 06:12: The TRAPPIST-1a's winds may have eroded its planet's atmospheres, just as the sun did with Mars.

2017-02-22: The Eye of Sauron Reveals a Forming Solar System!

  • 00:44: Fomalhaut is an A-type star about twice as massive and much hotter and brighter than the sun.
  • 04:16: This is believed to have happened some tens of millions of years after the sun first formed.
  • 08:44: For example, our sun has long since left its birth siblings behind.

2017-02-15: Telescopes of Tomorrow

  • 01:16: Webb will begin unfolding its 18 hexagonal mirrors on its journey to the sun-earth system's second Lagrange point about a million miles away.
  • 04:19: It also sports a 5-layer sun-shield to block as much sunlight as possible.

2017-02-02: The Geometry of Causality

  • 14:54: ... first generation of stars, perhaps thousands of times the mass of the sun. ...
  • 15:05: But by now, some of those have grown to billions of times the mass of the sun.

2017-01-25: Why Quasars are so Awesome

  • 01:05: They have a supermassive black hole, millions to billions of times the mass of the sun.
  • 03:59: Take a black hole of millions to billions of times the mass of the sun.

2017-01-11: The EM Drive: Fact or Fantasy?

  • 11:09: SunPower Guru argues that SITI is pointless, because there's no good reason to think that aliens would use, for example, radio.

2017-01-04: How to See Black Holes + Kugelblitz Challenge Answer

  • 01:43: At around 15 times the mass of the sun, the dark object in this system can't be anything but a black hole.
  • 05:12: It has enough energy to produce a black hole with a mass of 100,000 suns and an event horizon that almost reaches the moon's orbit.
  • 09:23: The Dyson sphere absorbs all of the energy from the shell, so it immediately gains the entire mass equivalence, 100,000 suns worth.
  • 09:53: ... the original mass of the sphere isn't going to add enough to the 100,000 suns of the near Kugelblitz to appreciably increase the size of the event ...
  • 10:41: ... there's the slight problem of having blocked out the sun, but hey, we just built an infinitely strong Dyson sphere and charged it ...
  • 10:53: Maybe we can just build a mini sun inside after we blast the aliens and save spacetime.

2016-12-14: Escape The Kugelblitz Challenge

  • 04:47: This blast has a mass-energy equivalence of 100,000 suns.

2016-11-02: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers

  • 04:46: For 100 light years, we have 512 G-Type stars: that's the same type as our sun.
  • 05:05: So that means there are around 100 such planets orbiting stars like the sun within 100 light years.
  • 07:21: ... we instead need to ask, "How large a sphere centered on the sun would also contain 100,000 stars?" There should be, on average, around ...

2016-10-19: The First Humans on Mars

  • 09:52: A star's core needs to be more massive than around three times the mass of the sun in order to collapse into a black hole.

2016-10-12: Black Holes from the Dawn of Time

  • 03:39: PBHs could have been formed at a few grams to tens of thousands of times the mass of the sun, depending on which formation model you go with.
  • 06:17: ... or a much smaller number of really big PBHs around 20 to 100 times the Sun's ...
  • 08:07: Even a close encounter with a black hole as massive as the Sun or higher would be pretty catastrophic.
  • 13:21: ... the hordes of octopodes rise from sunken R'lyeh to harken his coming, these silly grammatical quibbles will seem ...

2016-10-05: Are We Alone? Galactic Civilization Challenge

  • 02:43: Around 11 billion of those are Earth-like planets around Sun-like stars.

2016-09-29: Life on Europa?

  • 07:05: Ultimately, their energy and nutrients come from sunlight-powered microorganisms, like algae and plankton, at the ocean's surface.

2016-09-14: Self-Replicating Robots and Galactic Domination

  • 10:44: In a recent episode, we asked whether it's even possible, or a good idea, to build a Dyson swarm to capture all of our sun's energy.
  • 11:01: Well, a full Dyson swarm interior to Earth's orbit would, indeed, block sunlight and freeze our planet.
  • 11:14: However, it is conceivable that you could cause the solar collectors to fill up as they transited the sun, leaving a gap for sunlight.

2016-08-24: Should We Build a Dyson Sphere?

  • 02:09: The sphere would not be habitable, having only a tiny gravitational pull at its surface, and that would be towards the sun.
  • 02:20: Any small bump would cause one side to fall into the sun.
  • 02:49: ... in diameter and each with its own independent stable orbit around the sun. ...
  • 03:03: Build enough of these, and you can read the entire sun in all directions, absorbing its entire energy output.
  • 05:16: ... fully encompass the sun, we'd probably need to devour Venus, Mars, and a good number of asteroids ...
  • 06:06: Once complete, the Dyson swarm would harvest a good fraction of the sun's energy, so trillions of times the current energy output of the planet.
  • 06:31: The advantage of using sunlight is that the sun is already making it.
  • 06:39: Only 0.7% of the rest mass of the ingoing hydrogen fuel at the sun's core is converted to energy.
  • 08:07: And we only need 1 billion Kugelblitzes to equal the sun's output.
  • 08:30: The Dyson sphere/swarm can absorb at most the entire energy output of the sun.
  • 08:50: ... 600 million kilogram Kugelblitz, it takes something like 10% of the sun's energy output each second, focused into a single attometer at a single ...

2016-08-10: How the Quantum Eraser Rewrites the Past

  • 11:08: And they're at least several times the mass of the sun.
  • 12:25: The increasing temperature of the sun will cause all of Earth's oceans to evaporate in a billion years, plus or minus, depending on the model.
  • 12:48: As for the death of the sun and Andromeda's collision with the Milky Way, OK.

2016-08-03: Can We Survive the Destruction of the Earth? ft. Neal Stephenson

  • 08:25: A supernova explosion within 30 light years would destroy the ozone layer, leading to a horrible hard ultraviolet bath and the worst sunburn ever.

2016-07-27: The Quantum Experiment that Broke Reality

  • 11:18: ... a star?" Well, the lowest mass stars are around 7.5% the mass of the Sun, while Jupiter is 1/10,000 of a solar ...
  • 11:45: Well, the Sun and other stars don't need rocky cores because they are massive enough for all of that gas to collapse by itself.
  • 12:04: For typical interstellar clouds, the Jeans mass is quite a bit smaller than the Sun's mass but still much, much larger than Jupiter's.

2016-07-20: The Future of Gravitational Waves

  • 00:43: These oscillations echoed the final 1/10 of a second of the end spiral and merger of a pair of black holes, each around 30 times the mass of the Sun.

2016-07-06: Juno to Reveal Jupiter's Violent Past

  • 00:32: It's by far the largest and most massive thing in our solar system after the sun.
  • 00:37: It may only have 1,000th of the sun's mass, but it weighs more than all the other planets combined, two and 1/2 times more.
  • 01:11: It likely grew as fragments of rock and ice clung to each other in the disk of debris and gas surrounding the infant sun, the protoplanetary disk.
  • 02:15: That's 5.2 times Earth's average distance from the sun.
  • 02:49: Even the sun feels Jupiter's tug.
  • 02:51: The center of mass of the sun-Jupiter system lies just above the solar surface, and both the sun and Jupiter circle this point.
  • 03:10: I'm talking about the rare long period comets that orbit the sun with periods of hundreds to many thousands of years.
  • 05:13: In this model, Jupiter first formed closer to the sun at around 3.5 astronomical units.
  • 06:56: ... the inner solar system would have sent such planets spiraling into the sun, leaving only a limited amount of material to then build the current crop ...
  • 10:38: So many of you, including Neil deGrasse Tyson, point out that the sun is actually white and not yellow.
  • 10:46: ... the sun usually appears white to our eyes and so to our brains, and since the ...
  • 11:05: The sun does emit a bit more light in the yellowy green part of the electromagnetic spectrum compared to the blue and the red parts on either side.
  • 11:19: A more color sensitive eye or electronic detector would see the sun as yellowish green.

2016-06-22: Planck's Constant and The Origin of Quantum Mechanics

  • 00:23: In fact, you can see the effect of this quantum behavior and even measure the Planck constant just by observing the color of sunlight.
  • 02:43: For example, along with the sun's temperature, it sets the color of sunlight.
  • 02:49: If the Planck constant were 25% smaller, the sun would be violet, all else being equal.
  • 03:42: The sun is yellow because its 6000 Kelvin surface produces more photons in the green yellow part of the electromagnetic spectrum than anywhere else.
  • 04:13: It was Sir Isaac Newton who first analyzed this heat glow in the 1660s when he used a prism to split sunlight into its component colors.
  • 09:10: ... of an object's heat glow, for example, by observing the color of the sun. ...
  • 10:38: ... blackbody spectrum, the Planck constant can be read in the color of the sun and the stars, in the brightness of the different colors of the ...

2016-06-15: The Strange Universe of Gravitational Lensing

  • 02:11: ... catch an eclipse of the sun and to measure the tiny change in the position of nearby stars due to ...
  • 02:28: Their light paths were slightly deflected, making them appear a bit further from the sun.

2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners!

  • 06:01: So it's true that high sunspot activity can increase solar irradiance.

2016-05-25: Is an Ice Age Coming?

  • 02:07: Earth's motion around the sun changes, and with it, the intensity and distribution of sunlight.
  • 02:46: ... the absolute maximum eccentricity, Earth's most distant point from the sun-- the Aphelion-- is about 30% further than the closest point, the ...
  • 03:10: The Southern Hemisphere is closer to the sun in summer and further in the winter, so more extreme seasons.
  • 03:18: ... the difference in sunlight intensity due to this difference in distance from the sun is much less ...
  • 04:37: Because then the highest latitudes, where glaciation begins, never get much sun.
  • 08:05: As ice cover increases, Earth starts to reflect more incoming sunlight.
  • 08:13: More ice means less absorbed sunlight, lowering global temperature and allowing even more ice to grow.
  • 08:42: First, low obliquity means less overall sun at high latitudes where the glaciers start.
  • 08:49: Second, high eccentricity means one hemisphere experiences a bad winter at Aphelion, further from the sun.

2016-05-04: Will Starshot's Insterstellar Journey Succeed?

  • 01:31: A spacecraft is propelled as the light from the sun-- or from a giant laser-- accelerates a sail of reflective material.
  • 01:57: Light sails need no onboard propellant and the power generation stays back at home, whether it's the sun or an Earth-based laser.
  • 02:35: Well in that case, light from the sun just won't cut it.
  • 02:46: Accelerating on sunlight alone would make it a many millennium mission.

2016-04-27: What Does Dark Energy Really Do?

  • 03:55: Take a white dwarf, the leftover core of a dead, low-mass star like our sun, and let it cannibalize some of the material from a binary companion.

2016-04-13: Will the Universe Expand Forever?

  • 11:15: But recent work has suggested that it might actually be formed in lower-mass stars like our sun after they enter the red giant phase.
  • 12:06: The Sun has orbited the Milky Way around 18 times since it formed.
  • 12:21: It collapsed into the Sun's sibling stars, which are also scattered across the galaxy by now.

2016-04-06: We Are Star Stuff

  • 04:55: Our sun, and in fact every star in the prime of its life on what we call the main sequence, shines by forging hydrogen into helium.
  • 05:05: ... the case of the sun, when that process is finished, it'll puff out to become a red giant ...
  • 05:36: ... the largest stars, any bigger than around eight times the sun's mass, reach the ends of their lives, they become super giants, and their ...
  • 08:47: ... a white dwarf, a remnant of a low mass star like the sun, has a binary partner star and manages to accrete, to steal from it ...

2016-03-30: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners!

  • 00:59: And that distance measurement allowed scientists to calculate the FRB power output as that of 500 million Suns.

2016-03-16: Why is the Earth Round and the Milky Way Flat?

  • 07:18: And this hydrostatic equilibrium keeps stars like our sun extremely spherical and happily burning away for billions of years.
  • 07:31: The Earth and the Sun, for that matter, rotate on their axes.

2016-03-02: What’s Wrong With the Big Bang Theory?

  • 10:51: For example, the solar system is better described with the Schwarzschild metric, dominated by the sun's gravitational field.

2016-02-17: Planet X Discovered?? + Challenge Winners!

  • 00:48: And presumably is just one of many such rocks orbiting the Sun in the vast Kuiper Belt, out beyond Neptune.
  • 01:31: ... a year-length, of 15,000 Earth years, and an average distance to the Sun of 700 astronomical ...

2016-02-03: Will Mars or Venus Kill You First?

  • 01:35: ... the solar wind, the constant stream of energetic particles from the sun, to whittle away at Mars' ...
  • 05:27: This is when a magnetic storm on the sun's surface sends out a blast of extremely high energy particles, most notably protons and electrons.
  • 06:06: ... these blasts typically take days to reach Mars from the sun and are preceded by some visible indication like a solar flare, whose ...
  • 08:03: ... the interaction of the sun's magnetic field with Venus's think atmosphere actually induces something ...

2015-12-16: The Higgs Mechanism Explained

  • 08:42: For the sun, that's 3 kilometers.

2015-12-09: How to Build a Black Hole

  • 02:17: ... a bowl of neutrons the size of a city, with a mass of at least 1.4 suns and the density of an atomic ...
  • 08:26: It's three times the mass of the sun.
  • 12:08: Max Shifter asked about the plausibility of directing a killer asteroid into the sun.
  • 12:13: So even the largest asteroid hitting the sun would barely make a splash.
  • 12:18: ... problem is that changing its velocity enough to hit the sun, or even to fall into Earth's orbit-- which was another suggestion-- ...

2015-11-18: 5 Ways to Stop a Killer Asteroid

  • 03:50: ... raising to launch the Sentinel infrared telescope, that will orbit the sun and look outwards, tracking hundreds of thousands of ...
  • 05:53: The sun's light will push harder on the more reflective side, slowly pushing it just far enough off course to miss us.

2015-11-05: Why Haven't We Found Alien Life?

  • 00:26: ... Milky Way and probably billions of them are Earth-sized planets around sun-like ...
  • 09:33: ... all of the sun-like stars and Earth-like planets that will ever form over the full past and ...

2015-10-15: 5 REAL Possibilities for Interstellar Travel

  • 02:57: The sun does this pretty well, so let's build an engine that works like a mini star.
  • 06:55: ... the moon and powered by massive Helium 3 reactors or in orbit around the sun powered by vast solar ...

2015-10-07: The Speed of Light is NOT About Light

  • 06:13: The Earth is whizzing around the sun, the sun around the Milky Way.

2015-09-30: What Happens At The Edge Of The Universe?

  • 08:03: For example, the predictions GR makes for planetary orbits can give us a mass for the Sun.
  • 08:09: And that mass predicts the deflection angle for light passing the Sun perfectly, that is its gravitational lensing effect.

2015-08-27: Watch THIS! (New Host + Challenge Winners)

  • 03:19: ... our planetary system, it'll be a white dwarf remnant, and after the sun ejects its outer layers, there's a planetary ...

2015-08-19: Do Events Inside Black Holes Happen?

  • 04:52: For simplicity of presentation, let's pretend that the Sun is a perfect sphere.
  • 05:05: ... if I replace the Sun with a spherical black hole that's around six kilometers across-- and ...
  • 05:19: So as far as Earth is concerned, that black hole generates the same spacetime geometry out here that the Sun does.
  • 05:27: In that respect, the black hole certainly behaves like an object, an object with the Sun's mass.
  • 05:48: A black hole that mimics the Sun has a Schwarzschild radius of 3 kilometers.
  • 06:18: I think this idea of suckage is rooted in a misunderstanding of the region that used to be inside the Sun but is still outside the black hole.
  • 13:33: ... are gravitational effects from the Sun and Moon that do the same thing, but they're highly, highly masked by ...

2015-08-05: What Physics Teachers Get Wrong About Tides!

  • 00:07: So if gravity from the Moon and the Sun is really responsible for tides in the ocean and water is water, then why don't we see tides in lakes?
  • 02:10: Assumption two-- let's ignore the Sun.
  • 02:16: The Sun's effects are going to work analogously, anyway.
  • 07:25: First, the Sun-- its effects on tides are analogous to those of the Moon, but they're only about a third as big.
  • 07:31: The Sun is more massive, yes, but it's also much further away.
  • 07:33: Now, when Earth, the Moon, and the Sun all line up in space, the effects are additive and you get extra-large spring tides.

2015-07-29: General Relativity & Curved Spacetime Explained!

  • 07:40: So for example, say you stick the energy distribution of the sun into the Einstein equations and turn a crank.
  • 07:46: What comes out is a map of the geodesics in the sun's spacetime neighborhood.

2015-07-08: The Leap Second Explained

  • 01:34: Thus, 12:00 PM on our clocks is continually getting ahead of when the sun is directly over us.
  • 01:40: ... and we insert leap seconds to force our clocks back into sync with the sun. ...

2015-06-24: The Calendar, Australia & White Christmas

  • 00:16: ... degrees, so that different parts of the planet will receive more direct sunlight at different times of ...
  • 00:25: In June, the northern hemisphere gets more direct sunlight, so it's northern summer and southern winter.
  • 00:33: Now, from one spring equinox to the next spring equinox, Earth does not actually move a full 360 degrees around the sun.
  • 00:43: That means that one cycle of seasons is completed about 20 minutes earlier than a full 360 around the sun.
  • 00:57: Since Earth's axis is tilted, one half of that bulge is a little closer to the sun than the other half at any given moment.
  • 01:04: So the gravitational pull of the sun is slightly stronger on the slightly closer half, causing a net torque on the Earth like this.
  • 01:29: ... Earth's axis precesses in the opposite sense of Earth's orbit around the sun, so that the equinoxes and solstices backtrack along Earth's ...
  • 02:55: But a full trip around the sun takes around six hours longer than a whole number of days.
  • 05:13: But by then, maybe we won't care about locking things to the sun and the seasons so much.
  • 06:04: ... maybe putting planet-sized geometric objects in orbit around the sun. ...
  • 06:52: He also points out that if we put enough of them around the sun that we could cover viewing angles from most star systems.

2015-06-17: How to Signal Aliens

  • 02:17: Nowadays, lasers can produce high-power ultra-short pulses that can outshine the sun for less than a nanosecond.

2015-06-03: Is Gravity An Illusion?

  • 10:42: Earth analogs in Earth-like orbits around Sun-like stars are not going to be visible.

2015-05-27: Habitable Exoplanets Debunked!

  • 01:29: Plus, if you expand its orbit just a teensy bit, it would be in the sun's habitable zone.
  • 04:23: ... out the star's light, kind of like putting your hand over your eyes on a sunny day to help see your ...
  • 05:34: ... the atmospheres of Earth-sized planets in Earth-like orbits around Sun-like like ...

2015-05-20: The Real Meaning of E=mc²

  • 03:48: ... yes, since the sun is basically an enormous flashlight, its mass drops just by virtue of ...
  • 03:59: That's just a billionth of a trillionth of the sun's mass, and only 0.07% of the sun's mass over its entire 10 billion year lifespan.
  • 04:06: So does this mean that the sun converts mass to energy?
  • 04:10: All the energy in sunlight came at the expense of other energy, kinetic and potential energy, of the particles that make up the sun.
  • 04:17: ... more kinetic and potential energy contained within the volume of the sun manifesting as part of the sun's ...
  • 04:25: Those 4 billion kilograms that the sun loses every second is really a reduction in the kinetic and potential energies of its constituent particles.

2015-05-13: 9 NASA Technologies Shaping YOUR Future

  • 00:56: Next problem-- the space station orbits Earth so fast that each new sunrise happens every 90 minutes.

2015-04-29: What's the Most Realistic Artificial Gravity in Sci-Fi?

  • 05:17: ... in that novel has the same radius as Earth's entire orbit around the sun, around 93 million ...
  • 05:51: To sustain 1 g, the ring would need to complete the equivalent of one Earth orbit around the sun in only nine days.

2015-04-01: Is the Moon in Majora’s Mask a Black Hole?

  • 05:08: ... theoretical estimates say that you'd still need at least 1/10 of the sun's mass, give or take, to make ...

2015-03-25: Cosmic Microwave Background Explained

  • 02:09: You, a taco, the sun, everything.

2015-03-11: What Will Destroy Planet Earth?

  • 00:39: Now if you just want to split Earth in half, you get a bit of a discount-- only 16 million years worth of sunshine.
  • 02:15: But asteroids orbit the sun about 35 times slower than that.
  • 02:44: Well, Earth and Mars' field gravitational pulls not just from the sun, but also from the other plants-- and from big asteroids too.
  • 03:52: For instance, if Earth enters the sun.
  • 03:56: ... right, in about five billion years, the sun will begin its transition into a red giant-- inflating until it becomes ...
  • 04:21: See, the growing sun will also develop a stronger solar wind that sprays a lot of the sun's material out into space.
  • 04:27: In the process, the sun will lose a lot of mass and a lot of gravitational pull, causing Earth's orbit to actually grow.
  • 04:34: For decades, whether Earth will be swallowed by the sun or not has been too close to call.
  • 04:40: But the best recent simulations show that Earth will end up just inside the sun and fry.

2015-03-04: Should We Colonize Venus Instead of Mars?

  • 01:45: It's closer to the sun, which means about four times more available solar power then you have on Mars.

2015-02-18: Is It Irrational to Believe in Aliens?

  • 03:07: ... to Copernicus, is rooted in the democratic notion that our planet, our Sun, our galaxy, none of them are ...
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