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

  • 12:21: One possibility is looking for radio-Cherenkov from the Moon.
  • 12:26: So yeah, using the entire moon as a neutrino telescope.

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

  • 01:31: You put the first box in a rocket and send it to the moon, while you keep the second box with you on Earth.
  • 01:38: While that box is closed, the ball on the moon has a 50-50 chance of being black or white.
  • 01:44: You open your box and you instantly learn the color of the ball on the moon.
  • 02:18: Opening the box causes the observed ball to have to choose a color state, which then forces the ball on the moon to choose the opposite.
  • 02:26: ... have an effect that travels faster than light, with the ball on the moon switching from a superposition state to a defined state as soon as ...

2022-06-01: What If Physics IS NOT Describing Reality?

  • 12:09: ... observer-centric interpretations truly believe  the moon isn’t there when nobody looks. To this,   Bohr and Wheeler and ...

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

  • 06:57: ... the Greek titan of that name, and   has nothing to do with the moon of Saturn. Gaia  is able to identify the stars from this ...
  • 15:22: ... that even a system with  lots of gas giants could have habitable moons.   Now that’s true. There’s a good reason to restrict ourselves to ...
  • 16:02: ... Nicholson and others remind us that  the Earth’s moon is exceptionally large,   and such large moons are probably ...
  • 16:41: ... even happened - all of the   evidence is from cratering on the moon,  and biases in the analysis of that data   may have led to ...

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

  • 02:52: ... know that Earth's days ARE getting longer,  but it's because of the moon, not the ...

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

  • 07:06: You can point at, say, the moon by ensuring that a line drawn from your outstretched finger intersects would intersect the moon.
  • 07:13: ... course your wouldn’t be pointing at the moon of the present - it would be the moon of the past, because you’re ...
  • 15:41: Tidal squeezing should indeed help keep the planet’s interior hot, just like it does on the volcanic moons of Jupiter and Saturn.

2022-02-10: The Nature of Space and Time AMA

  • 00:03: ... between the peaks and the troughs of that wave due to your relative moon and you've all experienced that when you've heard a a siren on street ...

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

  • 04:17: And I would hope so, because this is essentially  how we calculate the trajectories that place people on the moon or land robots on comets.

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

  • 16:26: And for that matter, what about Jupiter. don’t read this asks about impacts on the Moon?
  • 17:05: ... for looking for impact evidence on the Moon - yes, in principle these impacts leave weird-shaped craters that we ...
  • 17:14: Oromandias asks whether the scenario of the Neil Stephenson's book Seveneves is plausible - in which a primordial black hole destroyed the moon.
  • 17:33: The black hole could never deposit enough energy on its passage through the moon to break it apart.
  • 17:38: It would need to grant the entire moon enough energy to overcome its own self-gravity.

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

  • 11:22: But in 2019 it became somewhat clear this dimming was probably due to the debris of a tidally disrupted moon-size body.

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

  • 03:00: ... greater than about 10^19 kilograms - or around 15% the mass of our Moon. Meanwhile, if primordial black holes had masses smaller than around a ...
  • 05:13: ... talk specifics. We’ll say our black hole has the mass of the Martian moon phobos - 10^16 kg like a large asteroid. That gives it an event horizon ...
  • 10:16: ... the tiny scar of the PBH passage. But the same can’t be said of the moon. Without any real atmosphere or tectonic activity, our moon’s surface has ...
  • 11:02: ... an asteroid hits the moon, it stops very quickly, making something of a big round explosion, ...
  • 12:01: ... one crater to the other, though we’d need to actually go back to the moon to test that ...

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

  • 05:51: ... around the size of the earth, this new guy is barely 25% bigger than the moon, making it the smallest known white ...
  • 13:41: ... there we have it- ZTF J1901+1458 - Zee - is a moon-sized, highly magnetized white dwarf probably formed when two low mass white ...

2021-07-21: How Magnetism Shapes The Universe

  • 00:56: And it governs the formation of every major structure in the universe, from the smallest moon to the largest cluster of galaxies.

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

  • 04:45: ... of geochemical processes. The red patterning on the surface of Jupiter’s moon Europa could be slime colonies, but could also be ...

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

  • 06:20: ... of black holes with masses around that of a larger asteroid or small moon, we’d need truly ridiculous numbers of them to get all the dark matter we ...
  • 08:52: ... mini-galaxies has allowed us to rule out MACHOs between roughly the moon’s mass to 10 or so times the mass of the Sun as a main contributor to dark ...

2021-03-16: The NEW Crisis in Cosmology

  • 08:03: ... ESA’s Gaia mission has given us. Parked in an orbit just past the moon,   Gaia scans the sky year after year, mapping the structure and ...
  • 17:08: ... fields - star destroyers,   the death star, forest moons, ice planets - must be hard to recalibrate every time. Who knew ...

2020-10-05: Venus May Have Life!

  • 00:23: ... Earth have tended to focus on the Martian subsurface and the ocean moons Enceladus and Europa and even the methane lakes of ...
  • 00:59: It’s the brightest thing in the sky besides the sun and moon, hanging just above sunrise and sunset.

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

  • 14:30: ... enough epicycles he could have created a working model centered on the moon, or on the library of Alexandria, or on his ...

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

  • 05:59: ... of aesthetic pleasure when he realized that the motions of both the moon and an apple could be explained by one piece of high-school ...
  • 09:23: Same with Newton’s gravity, derived from observations of apples and the moon, but it predicts the motions of galaxies.

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

  • 00:00: ... but other things they just sort of gave up on like why doesn't the moon fall down well you know presumably that's just off limits for physics ...

2020-06-08: Can Viruses Travel Between Planets?

  • 06:03: Perhap more promising are the ocean moons of the gas giants.

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

  • 11:02: ... beyond that date we have to look beyond the Earth. We believe that the moon formed at the same time as the Earth - both coallescing after a giant ...

2020-01-20: Solving the Three Body Problem

  • 03:18: ... centuries since Newton, predicting the motion of the planets and the moon was critical for nautical navigation. Now it’s essential to space ...
  • 04:29: ... around the Earth. It can also be used to approximate the orbits of the moon relative to the Earth and Sun, or the Earth relative to the Sun and ...

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

  • 13:28: ... Juice points out that the formation of the moon due to a giant impact would also have increased the amount of iron in ...
  • 13:40: ... Earth's rocky crust to be thrown into orbit before congealing into the moon. ...

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

  • 05:48: ... our solar system: 1) it has a very dynamic interior and 2) a very large moon. ...
  • 07:10: Which brings us to the moon.
  • 07:12: Earth’s moon is ridiculously gigantic - no other rocky planet in our system has anything like it.
  • 07:27: The debris thrown up during this collision became our moon.
  • 07:36: It may also be that our moon and the event that formed it was critical to the development of life.
  • 08:16: And the moon’s later tidal influence may also be an important factor in enhancing ongoing tectonic activity.
  • 08:22: And a final possible result of our weirdly large moon is that it enabled the first appearance of life.
  • 08:45: Without a large moon tides are half the size, so fewer tidal pools.
  • 08:59: OK, so Earth is weirdly dynamic and has a weirdly giant moon, but there’s more.

2019-09-23: Is Pluto a Planet?

  • 01:44: ... Mercury, Venus, Mars, Jupiter, and Saturn, but also the sun and the moon - basically anything that moved relative to the background ...
  • 04:21: Or do we drop Mercury, which is, after all, only 50% larger than our own moon and smaller than Saturn’s moon Titan.
  • 09:02: A planet must: One - be in its own orbit around the Sun, not around another planet like a moon.
  • 11:57: For example, the moons of Jupiter and Saturn are active worlds that may prove to be the only other homes for life within our solar system.

2019-09-16: Could We Terraform Mars?

  • 15:39: Can you believe it’s been 50 years since we landed on the moon?

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

  • 00:00: Thank you to Draper and its Hack the Moon initiative for supporting PBS Digital Studios.
  • 09:11: Thank you to Draper and its Hack the Moon initiative for supporting PBS Digital Studios.
  • 09:16: You know the story of the Astronauts who landed on the Moon.
  • 09:27: Hack the Moon chronicles the engineers and technologies behind the Apollo missions.
  • 09:33: ... is full of images, videos and stories about the people who hacked the moon If the size of the Universe is enormous, why haven’t we seen other signs ...

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

  • 00:00: Thank you to Draper and its Hack the Moon initiative for supporting PBS Digital Studios.
  • 07:47: Thank you to Draper and its Hack the Moon initiative for supporting PBS Digital Studios.
  • 07:52: You know the story of the astronauts who landed on the Moon.
  • 08:04: Hack the Moon chronicles the engineers and technologies behind the Apollo missions.
  • 08:08: Brought to you by Draper, the site is full of images, videos, and stories about the people who hacked the moon.

2019-03-13: Will You Travel to Space?

  • 10:21: Either just off the Moon or on the Moon.
  • 10:24: ... slightly just off the Moon. People who stay at our hotel will be able to will have these lovely ...
  • 10:35: And then we can have little spaceships that can whisk them around the moon and back in the evenings for dinner.
  • 10:41: ... Yeah, so you can program it just to go a few hundred feet above the Moon's ...

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

  • 00:37: ... on earth that have compositions suggesting they originated from the Moon or Mars many chunks of Earth have also been ejected into space most of ...

2018-11-21: 'Oumuamua Is Not Aliens

  • 08:31: ... in order for our spotting of a more moon to have been likely, interstellar space needs to contain something like ...

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

  • 00:26: ... PLAYING] NASA put humans on the moon, sent probes throughout and even beyond the solar system, and drove a ...

2018-07-04: Will A New Neutrino Change The Standard Model?

  • 12:38: Some of you also wondered whether mining the Moon could be more efficient than mining the asteroid belt.
  • 12:43: Well, the moon is definitely an option for mining, and it's going to have some useful heavy elements from crashed asteroids.
  • 12:53: ... get stuff off the Moon, you have to contend with its admittedly low gravitational field compared ...
  • 13:01: Also, mining the moon is going to have a lot of political complications compared to asteroids.
  • 13:06: For one thing, our moon is protected from exploitation by the Outer Space Treaty, which prohibits nations from claiming any sovereignty there.

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

  • 08:15: ... accessible orbit close to the Earth, perhaps even in orbit around the Moon. ...

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

  • 04:26: That's roughly 10 times the distance from the Earth to the moon.

2018-03-07: Should Space be Privatized?

  • 04:54: Grant enterprises, like the Apollo moon landings, inspired generations.
  • 05:30: There appears to be a new model emerging for some of these moonshot ventures.
  • 07:00: Then, it's back to the moon.
  • 07:02: And then, the moon again.

2018-02-21: The Death of the Sun

  • 08:32: All the planet's orbits will have expanded, and to the moons of Neptune, Uranus, and even Saturn, may provide brief refuge.
  • 08:47: ... moons may be a final temperate vantage point to watch the sun's inevitable ...

2017-11-22: Suicide Space Robots

  • 04:47: This orbiter studied Saturn and its moons and rings for 13 years.
  • 04:59: This moon is a world covered in ice.
  • 05:37: One day, we'll land probes on the moon and even drill into it's ocean.
  • 06:18: The Galileo probe was deorbited into Jupiter to protect its moons, in particular Europa, which boasts of vast ocean under its own icy crust.

2017-08-16: Extraterrestrial Superstorms

  • 07:56: ... crash into them to avoid contaminating potentially life-bearing moons like Europa and to peek under the gas giant's cloud ...

2017-07-19: The Real Star Wars

  • 01:21: The Space Race had begun, and it inspired some incredible advances in science and exploration, culminating in the moon landing in '69.

2017-06-07: Supervoids vs Colliding Universes!

  • 03:03: Think 40 full moons.

2017-05-17: Martian Evolution

  • 14:15: In fact, it's the moon's orbit around the Earth that results in the shadow's movement.
  • 14:20: The moon orbits the Earth once a month, which means it moves about 0.5 degrees per hour.
  • 14:31: So it takes one hour for the moon to fully eclipse the sun and another hour to move past it.
  • 14:39: So the shadow actually moves as the moon moves.

2017-05-10: The Great American Eclipse

  • 00:52: A lunar eclipse is when the Earth's shadow falls on the moon.
  • 00:56: A solar eclipse is when the moon's shadow falls on the Earth.
  • 01:00: ... moon has to be on the opposite side of the Earth compared to the sun to catch ...
  • 01:08: And the moon has to be between the sun and the Earth for its shadow to hit us.
  • 01:13: So solar eclipses are always during new moons.
  • 01:16: But there's a new moon every month.
  • 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.
  • 01:33: Most months, the moon's shadow misses the Earth.
  • 01:36: Only when the moon crosses the ecliptic plane during a new or full moon can an eclipse occur.
  • 01:58: It'll be partial because the Earth won't completely covered the sun from the moon's perspective.
  • 02:03: Anyone who can see the moon will see that lunar eclipse.
  • 02:07: However, to see the solar eclipse, you need to be in the narrow path of the moon's shadow.
  • 02:17: The fun starts at 9:04 AM Pacific time, when the edge of the moon's shadow first reaches the West Coast.
  • 02:23: So that's the penumbra of the moon's shadow, where the sun isn't completely blocked.
  • 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.
  • 04:23: Such eclipses are called annular eclipses, because they leave a ring of bright sunlight around the moon's disk.
  • 04:40: Every year, the moon steals a little bit of Earth's rotational kinetic energy and drifts about 3.8 centimeters away from us.
  • 05:43: The sun's final crescent contracts to a last spark on one side of the moon, like a diamond ring.
  • 06:08: Below it, you see Baily's beads, sparkling around the rim of the moon.
  • 07:40: Bailey's beads and the red chromosphere flash along the edge of the moon, the diamond ring emerging on the Western side.

2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson

  • 07:17: ... true, even if you scale back, say, to a computer the size of the moon, or if you assume several more orders of magnitude in the computing power ...

2017-04-19: The Oh My God Particle

  • 10:12: Last week, we talked about the prospects of building telescopes on the moon.
  • 10:18: Acousticpsychosis wonders why we're so obsessed with going to Mars when the moon makes such a perfect nearer station.
  • 10:27: The moon is an incredible gift and we should make good and peaceful use of it.
  • 10:32: Ragdala asks, who gives permission for moon landings.
  • 10:36: In the case of the Moon Express program, the approval was from the US government.
  • 10:40: But you're right, no one owns the moon.
  • 10:57: ... of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, or, the Outer Space Treaty, which the United ...

2017-04-05: Telescopes on the Moon

  • 00:06: ... astronauts, that we no longer need manned missions to do science on the moon. ...
  • 00:16: Whether or not that's true, what about the science we can do from the moon?
  • 00:41: ... it descended onto the surface and became the first soft landing on the moon since the Soviet Lunar 24 in ...
  • 01:16: See, the moon has essentially no atmosphere.
  • 01:31: From the moon, the entire spectrum is accessible.
  • 01:40: On the moon, the stars are visible day and night.
  • 01:43: In addition, nights are especially great because they last a month due to the moon being tightly locked with the Earth.
  • 02:20: ... more light, increasing sensitivity, but when you're in space or on the moon, aperture size defines image ...
  • 02:47: We can think of it as a proof of concept for building a much larger telescope on the moon.
  • 03:16: But on a platform as stable as the moon, it may be possible to construct a telescope mirror right there.
  • 03:44: So Chang'E was named after the Chinese goddess of the moon.
  • 03:57: Poor little Yutu was ravaged by the moon's harsh environments.
  • 04:21: There is no such protection on the moon.
  • 05:00: Tiny shards of electrically charged glass-- in other words, moondust.
  • 05:11: This is the upper surface of the moon that has been pulverized by 4 and 1/2 billion years of meteor impacts.
  • 05:40: However, the greatest obstacle to putting a telescope on the moon is, of course, getting it there.
  • 05:46: But in that challenge, this evil moondust may actually be our friend.
  • 05:54: ... of epoxy and carbon nanotubes and combining it with a whole lot of moon dust to make a sort of ...
  • 06:06: Grind it into shape and coat it with aluminum, and it may be possible to build a 50 meter mirror on the moon.
  • 07:11: Pointing options are still limited, but by taking advantage of Earth or the moon's rotation, it's possible to scan a narrow arc across the sky.
  • 07:20: ... mercury is expensive, heavy, and likely to evaporate in the moon's low pressure Atmosphere Pete Worden, Director of NASA's Ames Research ...
  • 08:18: Maybe I'm biased by the cool factor, but this all sounds like a great reason to get back to the moon, both robotically and in person.
  • 08:28: ... The International Lunar Observatory Association in combination with Moon Express formed the first private enterprise to receive approval for ...
  • 08:49: And Moon Express has a manned base in the planning, useful if we really want a giant lunar telescope.
  • 08:56: The moon with its thin atmosphere, stable surface, and long nights is an astronomer's dream.
  • 09:03: ... we can meet its distant challenges with creative solutions, perhaps the moon will become the Earth's lookout tower, granting the clearest views of ...

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

  • 04:27: See, because the planets are so close to the star, they're probably tidally locked, like our moon.
  • 04:54: At closest approach, some will appear larger than the full moon, up to twice that size.
  • 05:24: For comparison, our sun and moon span around half a degree on the sky.
  • 10:18: ... a few years before Galileo made his famous observations of Jupiter's moons and the phases of ...

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

  • 04:52: Its clean lines are carved by what we call shepherd moons.

2017-02-15: Telescopes of Tomorrow

  • 00:06: Telescopes have come a long way since Galileo first fixed two lenses to a tube and discovered the moons of Jupiter and the phases of Venus.

2017-01-25: Why Quasars are so Awesome

  • 02:13: In an event known as an occultation, the moon passed right in front of one of the brightest of these radio blobs.
  • 02:30: ... registered the exact instant that the radio signal vanished behind the moon. ...

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

  • 10:39: ... if the 3,000 kilometer array can see an orange on the moon, an Earth-Mars interferometer could see that orange, well, crudely a ...

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

  • 03:22: EHT could currently detect an orange on the surface of the moon, if oranges were bright in microwaves.
  • 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.
  • 05:25: One-- Project Phoenix Egg is to build a giant Dyson sphere just outside the moon's orbit to absorb the incoming radiation.
  • 05:34: ... Disco Ball, proposes a satellite network orbiting the Earth at half the moon's orbit radius, capable of generating a reflective force shield to bounce ...
  • 08:24: The light shell passes the moon's orbit, and a true event horizon forms.
  • 09:11: Our other plan was to build a Dyson sphere just outside the moon's orbit.

2016-12-21: Have They Seen Us?

  • 02:05: ... presence by Nikola Tesla's first experiments, broadcast footage of the Moon landing, the "Phantom Menace?" To answer the question of who can see us, ...
  • 10:04: ... area and equivalent to a dish around three times the radius of the Moon's ...

2016-12-14: Escape The Kugelblitz Challenge

  • 04:59: So the kugelblitz event horizon forms just after the shell of light passes the moon.
  • 05:55: Plan A is to build an infinitely-strong Dyson sphere surrounding the earth just outside the moon's orbital radius.
  • 06:19: ... spherical force shield about halfway between the Earth and the moon. ...

2016-11-09: Did Dark Energy Just Disappear?

  • 13:47: Anyway, walking around in moon boots and lead bodysuits for your entire life is both unstylish, and it only helps bones and muscles.

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

  • 10:57: We recently talked about what life might look like in the ocean of Jupiter's moon Europa.
  • 12:03: For example, Saturn's moon Titan has lakes of liquid methane, and perhaps life could have formed in these.

2016-09-29: Life on Europa?

  • 00:00: [MUSIC PLAYING] This week NASA announced even more evidence of plumes erupting from the surface of Jupiter's moon Europa.
  • 00:58: The moon is increasingly looked at as our best chance to find extraterrestrial life in our solar system.
  • 01:24: But Europa isn't the only gas giant moon with a possible ice-covered ocean.
  • 01:29: Jupiter's moon Ganymede almost certainly has one, and Callisto may or may not.
  • 01:45: But the moon is extra exciting because of this reddish-brown gunk that covers the surface.
  • 02:21: Saturn's moon Enceladus may be just as promising as Europa.
  • 02:49: The same forces drive massive volcanic activity in its system moon IO, and so it's likely that Europa's rocky interior is also geologically active.
  • 05:12: ... this hypothesis, or even the existence of vents on Europa, if that moon's ocean is in contact with a warm, mineral-rich ocean floor, then perhaps ...
  • 07:38: NASA's Europa Clipper is expected to launch in the 2020s, and will vastly improve our knowledge of the moon.

2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate

  • 12:34: ... even if there are invisible probes hiding behind the moon put there by some utopian prime directive of bane civilization, there ...

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

  • 05:25: After several decades, it decelerates into a neighboring star system, and parks in orbit, or lands on a nice, big asteroid or gas giant moon.

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

  • 05:16: ... Venus, Mars, and a good number of asteroids and outer solar system moons, too, assuming we want to leave Earth ...

2016-08-17: Quantum Eraser Lottery Challenge

  • 04:27: So maybe we bounce them between Earth and the moon, like, 8,000 times.

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

  • 11:49: In fact, impact by a primordial black hole was one of the hypotheses that Seveneves scientists proposed for the moon's inexplicable destruction.

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

  • 02:42: The moon explodes.
  • 07:56: Colonies on Mars, Venus, the moon, and in artificial habitations-- space arks-- are excellent insurance against global annihilation.

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

  • 12:43: For example, for every one orbit of Jupiter's moon Io, its moon Europa orbits twice and Ganymede four times.

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

  • 02:23: In the wake of its intense gravitational field, it drags with it its own mini solar system of at least 67 moons and a faint ring system.

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

  • 09:59: Flynn Kruchell would like to know whether he really can teleport to the moon.
  • 10:05: ... can't quantum tunnel to the moon, because to properly tunnel, you need to spontaneously find yourself at a ...

2016-06-01: Is Quantum Tunneling Faster than Light?

  • 02:13: There's an infinitesimal chance that I'm on the moon.

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

  • 05:06: This thing could burn Yuri Milner's tag on the surface of the moon and also accelerate a Starshot craft to 20% of the speed of light in a few minutes.

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

  • 00:23: It loves building spheres like stars, planets, and moons, and disks like spiral galaxies, solar systems, and some crazy stuff like quasars.
  • 02:53: And this type of dimensional egalitarianism is also shared by another effect, ultimately leading to the ball shapes of stars, planets, and moons.

2016-01-27: The Origin of Matter and Time

  • 11:59: Bruno JML would like to know in what reference frame Pink Floyd's "Dark Side of the Moon" syncs to when time breaks down.

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

  • 03:58: We think we know this because we flew to the moon and found evidence of it.
  • 08:54: After the Cambrian Explosion, it was only around half a billion years to go from jellyfish to moon landing.

2015-10-28: Is The Alcubierre Warp Drive Possible?

  • 05:25: Thicken the walls of the warp field, and you get the negative mass/energy requirement down to the equivalent of maybe the moon or even an asteroid.

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

  • 06:55: ... laser is going to have to be ridiculously large, possibly built on the moon and powered by massive Helium 3 reactors or in orbit around the sun ...

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

  • 13:33: ... are gravitational effects from the Sun and Moon that do the same thing, but they're highly, highly masked by the much ...

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?
  • 00:38: The moon's gravity is stronger at Point A and weaker at Point B than it is at Earth's center.
  • 00:42: ... net effect of this differential of the Moon's gravity across the Earth is to stretch the oceans out like taffy, ergo ...
  • 01:00: ... really is a gravity differential from the Moon at points A and B. And at least in this simplified model, there would be ...
  • 02:13: For simplicity, we'll focus only on the influence of the Moon.
  • 02:31: ... take a closer look at the Moon's gravity differential and how it manifests itself from the perspective of ...
  • 02:49: ... to a frame out in the ambient space, Block A accelerates toward the Moon more than Earth's center and Earth's center accelerates toward the Moon ...
  • 03:13: Remember, Earth itself is accelerating towards the Moon, so according to Newton, Earth's frame is non-inertial.
  • 04:14: ... tidal acceleration on objects due to the Moon's differential gravity along the Earth/Moon line works out to only ...
  • 04:46: For instance, a block at this location is going to be pulled this way by the moon.
  • 04:50: But of course, the whole Earth is pulled that way by the Moon, chasing after the block.
  • 05:59: ... the moon is turning the entire ocean into a planet sized hydraulic pump and the ...
  • 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.
  • 07:33: Now, when Earth, the Moon, and the Sun all line up in space, the effects are additive and you get extra-large spring tides.
  • 08:03: Well, location relative to the plane of the Moon's orbit is certainly part of it.

2015-07-15: Can You Trust Your Eyes in Spacetime?

  • 01:34: The moon doesn't orbit Earth.

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

  • 04:40: ... is also slowly spinning down due to its interactions with the moon, so that the mean solar day is getting longer, by about one to two ...

2015-05-06: Should the First Mars Mission Be All Women?

  • 00:47: Let's start with the physiological arguments for all-female missions beyond Earth's moon.

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

  • 07:33: But that would only give you 1 moon g.

2015-04-15: Could NASA Start the Zombie Apocalypse?

  • 04:29: I will report the best ones on the next episode of "Space Time." Last week's episode was about farting your way to the moon.

2015-04-08: Could You Fart Your Way to the Moon?

  • 05:58: ... on the next episode of "Space Time." Last week I considered whether the moon in Majora's Mask might harbor a black ...
  • 06:43: ... Parrish Danforth all asked in one way or another why the shell of the moon wouldn't collapse and get sucked into the black ...
  • 07:09: Chronoflect asked whether Termina's moon could actually rip apart in the three day window of the game if it were the density of Earth's moon.
  • 07:40: Finally, Patrick Fadgen asked, how can the moon be seen all day long from Termina?
  • 07:44: ... seem to need the moon to orbit around the planet at the same rate that the planet spins on its ...

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

  • 00:00: [MUSIC PLAYING] In "The Legend of Zelda: Majora's Mask," Link needs to save Termina from an impending collision with that planet's malevolent moon.
  • 00:09: But what if I told you that the so-called moon is really a black hole?
  • 00:25: Link arrives in Termina, a province on a planet whose moon is on a three-day collision course with the surface.
  • 00:35: The approaching moon causes all kinds of havoc.
  • 01:05: Today I'm going to argue that the moon in "Majora's Mask" is not a moon at all, but instead of a rocky shell surrounding a miniature black hole.
  • 01:45: The root of the problem with both these other analyses is that they assume Termina's moon has the same density as our moon, and that's impossible.
  • 01:52: ... reasons I'll explain shortly, anything with the density of Earth's moon would be ripped apart if it got within 12,000 kilometers of Earth's ...
  • 02:09: OK, so how dense is Termina's moon?
  • 02:15: The key evidence appears in the scenes just before the moon hits, when loose rocks start flying upward off the surface of the planet.
  • 02:23: ... think this implies that the gravitational pull on the rocks due to the moon exceeds the gravitational pull from the planet itself, but that's not ...
  • 02:30: What has to beat the planet's gravity, in this case, to make the rocks levitate is something called the moon's tidal force.
  • 02:38: Rocks on the surface of Termina are being pulled towards the moon.
  • 02:41: But the planet is also being pulled towards the moon, chasing after those rocks.
  • 02:45: ... the rocks are closer to the moon, where the moon's gravity is stronger, they do accelerate towards the ...
  • 02:52: Now, on its own, this differential acceleration tends to separate rocks from the planet, even on the side of the planet opposite the moon.
  • 03:00: ... on the far side of the planet accelerate toward the moon even less quickly than the center of the planet does, so they would also ...
  • 03:09: ... Termina's point of view, then, the moon's tidal force manifests itself as an outward push off the planet's ...
  • 03:25: For instance, the tidal force from Earth's moon on you right now it's about 10 million times smaller than Earth's pull on you.
  • 03:31: That's why you don't levitate during a full moon.
  • 03:34: Of course, if you bring the moon closer, on Earth or on Termina, the tidal force from the moon will increase.
  • 03:45: I've worked out the algebra using that MatPat's measurement of a mere 30-ish meters for the radius of Termina's moon.
  • 04:00: ... Termina's moon really were only as dense as Earth's moon, its tidal force when hovering ...
  • 04:22: ... that requires Termina's moon to be-- wait for it-- between a billion and 100 trillion times denser ...
  • 04:37: This high density would help explain why Termina's moon is even still in one piece.
  • 04:40: After all, the planet also exerts a tidal force on the moon, which would rip Earth's moon apart if it got too close to us.
  • 04:48: So a trillion times the density of Earth's moon-- that's ridiculous.
  • 05:18: Termina's moon, even at these densities, only weighs about half as much of Earth's moon.
  • 05:32: So if it's not a neutron star, how can Majora's moon be so dense?
  • 06:20: And about a gazillion years later, poof-- moon-ish mass, submillimeter-size black hole.
  • 06:27: The moon in "Majora's Mask" is basically some super-dense crust with teeth and with a mini black hole in the middle.
  • 06:39: For example, gravity would be billions of times stronger on Termina's moon than on Earth.

2015-02-11: What Planet Is Super Mario World?

  • 01:14: Low gravity, for instance, is why astronauts in heavy spacesuits could jump so high on the moon.
  • 04:28: What you find is that all the major rocky bodies-- that means the moon, Mars, Venus, Mercury-- all of them have smaller g values than Earth does.
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