Search PBS Space Time

What are you looking for?

	2022-12-14: How Can Matter Be BOTH Liquid AND Gas? 19:37: ... Factor in the relative distance of the center of the Milky Way and you get that ...
	2022-11-23: How To See Black Holes By Catching Neutrinos 11:47: ... kilometers, which should approximately increase the detection rate by a factor of ...
	2022-11-16: Are there Undiscovered Elements Beyond The Periodic Table? 11:01: There are so many factors at play that the only way to figure this out is to simulate the nucleus.
	2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations? 04:42: There are a bunch of other factors that cause this peak, which we go into in our episode on galactic habitable zones. 05:44: The number of hard steps is a big deciding factor in how fast the universe can spawn intelligent life. 08:49: So there are two main deciding factors of our birth rank: the number of hard steps and the maximum lifetime of habitable planets. 04:42: There are a bunch of other factors that cause this peak, which we go into in our episode on galactic habitable zones. 08:49: So there are two main deciding factors of our birth rank: the number of hard steps and the maximum lifetime of habitable planets.
	2022-10-12: The REAL Possibility of Mapping Alien Planets! 01:25: ... of the brightness of the exoplanet   by a factor of a trillion, and a magnification of the surface details by a ... 04:36: ... first place. And the planet's surface area would be expanded by a factor of around 100 billion.   If only it were possible to remove ...
	2022-09-28: Why Is 1/137 One of the Greatest Unsolved Problems In Physics? 04:26: And the energy of that ground state electron  is smaller than the rest mass energy of the electron by a factor of 137 squared. 05:42: These factors multiply a sort of base probability  to make the interaction more or less likely. 11:20: ... example, the speed of light is the translation  factor between the dimensions of space and time in relativity; it’s also the ... 05:42: These factors multiply a sort of base probability  to make the interaction more or less likely.
	2022-09-21: Science of the James Webb Telescope Explained! 04:11: ... and the expanding universe has stretched the light by more than a factor of ... 16:46: That said, there are various plans to build so-called Higgs factories that don’t involve just building bigger and bigger colliders.
	2022-08-17: What If Dark Energy is a New Quantum Field? 10:08: ... we happen to live in a period of the universe where these are within a factor of a few of each other, at exactly the time when the acceleration ...
	2022-06-30: Could We Decode Alien Physics? 15:41: ... a single civilization   in a million years or less is a strong factor  to consider when pondering the Fermi paradox.   We did an ...
	2022-06-22: Is Interstellar Travel Impossible? 01:49: There are two factors that make interstellar travel difficult. 08:02: Interstellar space is quite a bit less dense than the upper atmosphere - by a factor of around 10^16. 08:26: ... Factoring in the relative densities, particle masses and speeds, the heat ... 01:49: There are two factors that make interstellar travel difficult.
	2022-06-01: What If Physics IS NOT Describing Reality? 14:22: ... Milky Way   could potentially host life based on various  factors like abundance of necessary elements   and there not being too ...
	2022-05-25: The Evolution of the Modern Milky Way Galaxy 16:02: ... common. The large moon has been proposed as  an important factor in the appearance of life,   which may have first appeared in ... 07:58: ... a few  hundred lightyears thick, and is the main star   factory of the Milky way. It’s home to the spiral  arms and the big, bright ...
	2022-05-18: What If the Galactic Habitable Zone LIMITS Intelligent Life? 05:24: ... not so fast. There is another factor to consider.   Stars have habitable zones, but so do ... 09:26: ... factors make the core the worst place in  the galaxy. The extreme density ... 13:03: ... factor that may explain the  apparent absence of technological ... 07:36: ... for life yet. However these   stars were incredible atom factories, rapidly  burning their way up the periodic table   and ... 06:28: ... spread through the galaxy   in supernova explosions. So a big factor  in determining the galactic habitable zone   is that enough ... 05:24: ... on the galactic habitable zone. Moiya,   what are some of the factors that make  a region of the galaxy habitable or ... 09:26: ... factors make the core the worst place in  the galaxy. The extreme density ... 07:36: ... for life yet. However these   stars were incredible atom factories, rapidly  burning their way up the periodic table   and ...
	2022-05-04: Space DOES NOT Expand Everywhere 03:48: ... z, but here adding the dimension of time. And this thing is the scale factor, which represents the overall size of the universe, and this is the thing ... 04:26: ... and its growth represents the increase in the scale factor over ... 07:45: ... Now the distance between those lines represents the growing scale factor. Let’s zoom in ... 14:34: ... to start their train of reasoning with statements about external factors that they couldn’t directly observe. Unfortunately, practitioners of ...
	2022-03-23: Where Is The Center of The Universe? 00:44: At least, once you factor out the selection biases of needing to be somewhere moderately hospitable. 06:34: ... of this expanding hypersphere is represented in the math by the scale factor - and the scale factor increases as time ...
	2022-02-16: Is The Wave Function The Building Block of Reality? 11:50: ... Sasso laboratory, a main source of noise, cosmic muons, was reduced by a factor of nearly 1 million. Then, they further shielded the crystal with layers ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... described mathematically as the growth of something called the scale factor which is just a multiplicative factor that that um that essentially ...
	2021-12-29: How to Find ALIEN Dyson Spheres 09:46: ... 1% of its star's light could shift the visible-to-infrared color by a factor of more than ...
	2021-08-03: How An Extreme New Star Could Change All Cosmology 04:37: ... determines how bright the star appears to us - but there’s another factor at play there - how far away the star is. Measure the star’s brightness ...
	2021-07-21: How Magnetism Shapes The Universe 13:29: ... this, but Stephen is SO generous and amazing that scientists have to factor in his personal magnetism when they calculate the Earth’s geomagnetic ...
	2021-06-23: How Quantum Entanglement Creates Entropy 13:44: ... the 42% is no longer   accurate - presumably it’s lower by a factor of more than 3, due to all the new debris   and the fact that ...
	2021-06-16: Can Space Be Infinitely Divided? 04:30: ... Heisenberg. Or close enough - A proper  derivation gets you a factor of 1 over 4 ... 06:39: ... how big this uncertainty is. Space is stretched   by a factor equal to the effective mass times the gravitational constant ...
	2021-06-09: Are We Running Out of Space Above Earth? 10:29: This will increase the number of satellites in orbit by a factor of more than 10.
	2021-04-13: What If Dark Matter Is Just Black Holes? 02:02: In other words, most of the physical universe needs to be vast swarms of black holes that outweigh all the atoms in the universe by a factor of four.
	2021-04-07: Why the Muon g-2 Results Are So Exciting! 04:07: But the electron dipole moment is different from the classical one by this factor g. 11:10: ... of course this was a systematic error, some unknown factor influencing the measurement that is not a new particle, the g-2 team ...
	2021-02-24: Does Time Cause Gravity? 00:27: Our GPS satellites tick faster by a factor of 1-in-a-billion - enough to thrown their position accuracy off by 11km per day.
	2020-10-13: Do the Past and Future Exist? 15:37: ... we can ask whatever advanced civilization to kindly shut down their factories so we can more carefully analize the atmosphere for much more ...
	2020-10-05: Venus May Have Life! 15:09: ... the last catch - a few of you noticed I used the expression “factor a prime number” - which is dumb, because the factors of a prime number ... 15:22: What I meant was factoring the product of two primes INTO those primes. 15:09: ... used the expression “factor a prime number” - which is dumb, because the factors of a prime number are just itself and ...
	2020-09-28: Solving Quantum Cryptography 00:10: ... math problem is prime number factoring, and the new era of quantum computers may lay bare your indiscretions, as ... 00:39: ... purchase, every login—is secured by the fact that it’s a lot harder to factor out prime numbers than it is to multiply them ... 00:58: ... computers will take thousands to billions of years to find those factors, depending on the key ... 01:08: ... an algorithm - Shor’s algorithm - that could use a quantum computer to factor a prime number in, well, a human lifetime, or a human ... 01:51: ... tolerance” and/or support vastly more quibits to do the sort of prime factoring required for ... 02:07: One option is to match quantum decryption with new quantum encryption techniques to replace prime factoring. 03:13: Prime factoring is an example of what we call a one-way function. 04:07: ... current dominant encryption protocol uses prime factors instead of colours, and this is the RSA protocol after Ron Rivest, Adi ... 04:28: But prime factoring is only one example of a one-way function. 04:40: ... you try prime factorization using a classical computer you’re stuck using an algorithm similar to ... 05:01: This is laborious—it takes an insane amount of time to factor large numbers this way. 05:05: Or you could run an insane number of computers in parallel to each check every different factor. 05:24: It turns out there’s a structure to factorization that can be exploited by quantum computers. 06:13: That doesn’t help us immediately - for the powers of large numbers, guessing the period is as hard as guessing the factors. 07:23: ... you tried to use a quantum computer to guess the factors of a prime number, you’d read out one of the guesses but it’s no more ... 07:38: ... of trying to hold possible prime factors in our quibits, our array of qubits holds these repeating moduli of ... 08:15: Once you read out that period you can determine the prime factors. 08:20: So far, quantum computers are stuck under 100 qubits and none have managed to factor a number higher than 21 with Shor’s algorithm. 08:53: The answer is to find one-way functions that don’t have a known exploitable quality like the periodicity of prime factoring. 13:05: Well, one important factor in this question is the age of the alorgithm. 05:01: This is laborious—it takes an insane amount of time to factor large numbers this way. 00:10: ... math problem is prime number factoring, and the new era of quantum computers may lay bare your indiscretions, as ... 01:51: ... tolerance” and/or support vastly more quibits to do the sort of prime factoring required for ... 02:07: One option is to match quantum decryption with new quantum encryption techniques to replace prime factoring. 03:13: Prime factoring is an example of what we call a one-way function. 04:28: But prime factoring is only one example of a one-way function. 08:53: The answer is to find one-way functions that don’t have a known exploitable quality like the periodicity of prime factoring. 01:51: ... tolerance” and/or support vastly more quibits to do the sort of prime factoring required for ... 02:55: Enter post-quantum cryptography, or quantum resistant algorithms - which might replace our vulnerable prime factoring-based cryptography. 04:40: ... you try prime factorization using a classical computer you’re stuck using an algorithm similar to ... 05:24: It turns out there’s a structure to factorization that can be exploited by quantum computers. 00:58: ... computers will take thousands to billions of years to find those factors, depending on the key ... 04:07: ... current dominant encryption protocol uses prime factors instead of colours, and this is the RSA protocol after Ron Rivest, Adi ... 06:13: That doesn’t help us immediately - for the powers of large numbers, guessing the period is as hard as guessing the factors. 07:23: ... you tried to use a quantum computer to guess the factors of a prime number, you’d read out one of the guesses but it’s no more ... 07:38: ... of trying to hold possible prime factors in our quibits, our array of qubits holds these repeating moduli of ... 08:15: Once you read out that period you can determine the prime factors. 00:58: ... computers will take thousands to billions of years to find those factors, depending on the key ...
	2020-09-08: The Truth About Beauty in Physics 12:25: ... results from the hidden workings of our brains - many factors contribute subconsciously to this qualitative sense of ... yes, that ...
	2020-08-24: Can Future Colliders Break the Standard Model? 08:01: ... is currently in a long upgrade process, with the final result being a factor of a couple increase in power - but more importantly a factor of 5 ... 09:43: But why build a Higgs factory?
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 09:19: ... The exact energy of one of these states is determined by many different factors: the precise mass and charge of the particles, their orbital angular ...
	2020-06-30: Dissolving an Event Horizon 09:51: ... electrons have very tiny masses for comparatively large charge - just factoring the electrons mass, it should be easy to send a black hole over the ... 14:40: ... THINK the idea is that when you rescale both space and time by the same factor, you also rescale the interaction probabilities to that the interaction ... 09:51: ... electrons have very tiny masses for comparatively large charge - just factoring the electrons mass, it should be easy to send a black hole over the ...
	2020-06-15: What Happens After the Universe Ends? 02:01: This is perhaps the simplest conformal transformation - just multiplying or dividing all dimensions by the same scaling factor.
	2020-06-08: Can Viruses Travel Between Planets? 00:42: And it’s increasingly believed that they are critical factors in the process of evolution, perhaps even in pre-cellular days. 15:01: ... masses of the Cavendish experiment are very close together, you need to factor in the Casimir force between them to get an accurate measurement of the ... 00:42: And it’s increasingly believed that they are critical factors in the process of evolution, perhaps even in pre-cellular days.
	2020-05-27: Does Gravity Require Extra Dimensions? 10:53: ... larger than the size-scale of those dimensions - depending on other factors - most importantly depending the strength with which gravity interacts ...
	2020-05-11: How Luminiferous Aether Led to Relativity 16:07: Well that’s easy - the universe has expanded by a factor of 1100 since the CMB was released.
	2020-05-04: How We Know The Universe is Ancient 07:40: ... to us than they really were. In fact he got distances wrong about a factor of two too small. Overnight the universe doubled in ...
	2020-03-31: What’s On The Other Side Of A Black Hole? 03:14: ... projection, the separation of lines of longitude are multiplied by a factor that depends on their latitude - and that multiplication factor becomes ...
	2020-03-24: How Black Holes Spin Space Time 12:36: ... influenced by hull shape, ship mass, power plant output, and many other factors. And World of Warships captures the feel of complex motion dynamics ...
	2020-02-18: Does Consciousness Influence Quantum Mechanics? 15:49: ... like the speed of light and the gravitational constant are just scaling factors and so varying them shouldn't lead to quantum particles - but perhaps ...
	2020-02-11: Are Axions Dark Matter? 12:47: ... number of possible configurations of particles in the universe - 10^90 factorial. Now, I assume Ethan got that number by imagining swapping around every ...
	2019-12-17: Do Black Holes Create New Universes? 07:00: ... stars and so far fewer black holes would form - and of course these factors also seem to be essential for ... 10:33: Now perhaps the extra .17 can be factored into the uncertainties of the theory... 10:59: ... black hole production, and it’s just a happy coincidence that the same factors also favor ... 15:09: And by similar, I mean within a factor of a few. 10:33: Now perhaps the extra .17 can be factored into the uncertainties of the theory... 07:00: ... stars and so far fewer black holes would form - and of course these factors also seem to be essential for ... 10:59: ... black hole production, and it’s just a happy coincidence that the same factors also favor ...
	2019-12-09: The Doomsday Argument 03:03: He got a value that was a factor of 10 higher than what would be observed 10 years later when dark energy was discovered. 04:05: ... off by a factor of 2 - which considering the method, and the fact that dark energy could ...
	2019-12-02: Is The Universe Finite? 04:31: The combination of these factors determine the geometry.
	2019-11-18: Can You Observe a Typical Universe? 15:09: Much of the parameter space that the constants of nature could have taken eliminate one or more of these factors.
	2019-11-11: Does Life Need a Multiverse to Exist? 09:56: So there must be factors which bring that number down to nearly zero. 14:34: ... disagrees with a lot of these 'rare earth' type scenarios because the factors we talk about are needed for OUR evolutionary tree, but other types of ... 09:56: So there must be factors which bring that number down to nearly zero. 14:34: ... disagrees with a lot of these 'rare earth' type scenarios because the factors we talk about are needed for OUR evolutionary tree, but other types of ...
	2019-11-04: Why We Might Be Alone in the Universe 02:40: ... rare earth hypothesis posits exactly this - that a range of factors made Earth exceptionally unusual and uniquely able to produce ... 08:16: And the moon’s later tidal influence may also be an important factor in enhancing ongoing tectonic activity. 10:04: ... are a few other possible rare Earth factors - we may have an unusually hospitable atmosphere and water content and ... 11:08: ... are many factors that shaped Earth’s formation and development - what if the Cambrian ... 11:54: It’s very possible that a combination of extremely unlikely factors means it’s extremely rare for planets to spawn intelligence. 02:40: ... rare earth hypothesis posits exactly this - that a range of factors made Earth exceptionally unusual and uniquely able to produce ... 10:04: ... are a few other possible rare Earth factors - we may have an unusually hospitable atmosphere and water content and ... 11:08: ... are many factors that shaped Earth’s formation and development - what if the Cambrian ... 11:54: It’s very possible that a combination of extremely unlikely factors means it’s extremely rare for planets to spawn intelligence. 10:04: ... are a few other possible rare Earth factors - we may have an unusually hospitable atmosphere and water content and may ...
	2019-09-30: How Many Universes Are There? 03:34: The scale factor – or radius of the universe – increased by a factor of at least 10^26 in less than 10^-32 seconds. 03:50: Well, a scale factor or radius increase of 10^26 means a volume increase of that cubed – so 10^78. 04:44: And our number of new bubble universes should multiply by the same insane factor each second. 08:58: ... argument goes like this: if the number of new universes increases by a factor of some impossibly large number every second, then the vast, vast ...
	2019-09-16: Could We Terraform Mars? 05:34: ... maybe double the current amount of CO2 in the atmosphere – which is a factor of around 100 times too low to make a ... 17:32: ... to have transitioned between two stable or semi-stable states that are a factor of 10^27 different in ...
	2019-08-26: How To Become an Astrophysicist + Challenge Question! 10:46: ... the horizon and flatness problems That is all distance is increased by a factor of 10 to the power of 26 Every 10 to the power of negative 32 seconds ...
	2019-08-06: What Caused the Big Bang? 00:09: ... inflationary expansion multiplied the size of the universe by a larger factor than in the following 13 and a half billion years of regular ... 03:48: ... and monopole problems inflation needs to expand the universe by a factor of 10 to the power of 25 in less than 10 to the power of negative 30 ...
	2019-07-18: Did Time Start at the Big Bang? 03:27: ... about the size of an expanding infinite universe in terms of the scale factor That's the distance between any two points in space at some moment in ... 04:20: So when I talk about rewinding the expansion, I mean running the clock backwards to track a shrinking scale factor. 04:28: One way to do that is to keep halving the scale factor. 04:38: ... and dense as you like But it'll still be infinite, spatially, the scale factor is incredibly small But an incredibly small number times infinity is ... 05:07: That last tiny step is a doozy The scale factor goes from incredibly small to zero.
	2019-06-06: The Alchemy of Neutron Star Collisions 02:47: ... star merger that formed these elements must have been an important factor here is that neutron star mergers are rare all short-lived r-process ... 13:02: ... a factor of a hundred at the beginning of re-ionization. And so electrons were ...
	2019-05-16: The Cosmic Dark Ages 04:29: ... the universe was around 1/1000 of its current size. It expanded by a factor of 100 before the epoch of reionization started, and it’s expanded by a ... 13:43: ... computer security protocols under development that don't rely on prime factoring. Thanks everyone for emphasizing this. Quantum cryptography may indeed ...
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 01:21: For example, a quantum computer can calculate the prime factors of large numbers extremely quickly. 01:27: This is bad because prime factoring is a cornerstone of internet cryptography. 02:32: It's a mathematical process that can't be undone with the public key - only with its prime factors, which only you have. 02:41: All of this works as long as the public key can't be easily factorized back into its two primes. 02:47: ... is another type of one-way function - it's much, much harder to factorize large numbers than it is to create them by multiplication in the first ... 03:01: Once quantum computers can factorize public keys quickly the entire public key system falls apart. 01:27: This is bad because prime factoring is a cornerstone of internet cryptography. 02:47: ... is another type of one-way function - it's much, much harder to factorize large numbers than it is to create them by multiplication in the first ... 03:01: Once quantum computers can factorize public keys quickly the entire public key system falls apart. 02:47: ... is another type of one-way function - it's much, much harder to factorize large numbers than it is to create them by multiplication in the first ... 03:01: Once quantum computers can factorize public keys quickly the entire public key system falls apart. 02:41: All of this works as long as the public key can't be easily factorized back into its two primes. 01:21: For example, a quantum computer can calculate the prime factors of large numbers extremely quickly. 02:32: It's a mathematical process that can't be undone with the public key - only with its prime factors, which only you have.
	2019-05-01: The Real Science of the EHT Black Hole 04:09: Another important factor is that any two telescopes can only measure the angular separation in one direction on the sky.
	2019-04-24: No Dark Matter = Proof of Dark Matter? 00:03: ... in a galaxy like this the dark matter would outweigh the stars by a factor of 400 the team has since found a second galaxy in the same group that ...
	2019-04-10: The Holographic Universe Explained 11:04: In good string-theorist style, Maldacena defined incorporated that scale factor into be a new spatial dimension.
	2019-03-28: Could the Universe End by Tearing Apart Every Atom? 04:32: ... constant. So now the pressure term is A, negative and B because of this factor of 3 it's a bigger influence than the density so this whole party in the ...
	2019-03-20: Is Dark Energy Getting Stronger? 13:57: What we have here is a tantalizing clue that our accepted understanding the factors that drive the expansion of the universe may be off.
	2019-02-20: Secrets of the Cosmic Microwave Background 07:42: ... to the speed of sound times the amount of time that they had to collapse Factoring in the expansion of the universe over that time that size should be ...
	2019-02-07: Sound Waves from the Beginning of Time 03:21: ... fact, dark matter outweighs baryons by a factor of five, Which means it was, by far, the dominant gravitational ... 07:03: And now over thirteen and a half billion years later, the universe is expanded by a factor of 1,100.
	2019-01-24: The Crisis in Cosmology 02:15: Until the new millennium, the best we could do was to estimate H0 within a factor of 2,... 05:55: ...is a hell of a lot better than the old factor of 2 uncertainty. 07:21: ...now stretched by a factor of 1,100 by its near 14 billion year journey... 07:40: The blue regions are a factor of 100,000 cooler than the red regions,...
	2019-01-09: Are Dark Matter And Dark Energy The Same? 09:15: ... with a negative cosmological constant should have a sinusoidal scale factor. ...
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... connected to quantum spin but for any particle with mass motion doesn't factor into it it's not the same as olicity it's best to think of quantum ...
	2018-12-06: Did Life on Earth Come from Space? 00:37: ... when a media is slave to advertiser demands well this is definitely a factor when both the media outlet and the writer live or die by that month's ...
	2018-10-25: Will We Ever Find Alien Life? 07:13: ... current number of communicative civilizations by combining a series of factors. ... 07:23: ... are astrophysical factors like the rate of star formation and the fraction of these stars that ... 07:47: The biological and sociological factors are so poorly understood that estimates of the number of civilization vary between none to tens of thousands. 07:57: ... now that we have a much better understanding of the astrophysical factors and are also pretty sure that there aren't tens of thousands of advance ... 09:37: That is perhaps it's one of the biological factors of the Drake equation that keeps the number of aliens low. 11:46: Depending on the destruction probability-- let's call it the wacko factor-- you might expect civilizations to last from decades to thousands of years. 07:13: ... current number of communicative civilizations by combining a series of factors. ... 07:23: ... are astrophysical factors like the rate of star formation and the fraction of these stars that ... 07:47: The biological and sociological factors are so poorly understood that estimates of the number of civilization vary between none to tens of thousands. 07:57: ... now that we have a much better understanding of the astrophysical factors and are also pretty sure that there aren't tens of thousands of advance ... 09:37: That is perhaps it's one of the biological factors of the Drake equation that keeps the number of aliens low.
	2018-10-10: Computing a Universe Simulation 04:50: Again, the Bekenstein bound is the event horizon surface area in Planck areas with an extra factor of a quarter that Stephen Hawking figured out. 05:55: ... cetera, and not just atoms, you need to scale up the surface area by a factor of 10 billion and the radius by a factor of ... 09:09: ... can do 3 by 10 to the power of 82 logical ops per second, a factor of 10 to the power of 20 slower than the computational speed of the ... 09:20: ... its own evolution at maximum speed, our black hole computer would take a factor of 10 to the power of 20 longer or 10 to the power of 30 years to ...
	2018-10-03: How to Detect Extra Dimensions 10:10: ... other important factor here-- in order to determine how much intensity was lost by the ...
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 10:02: We talk about this more in our episode on the g factor.
	2018-09-12: How Much Information is in the Universe? 04:07: We only drop factors of 2.
	2018-08-15: Quantum Theory's Most Incredible Prediction 01:53: ... the theory and experiments behind one of these tests, measuring the G factor, or in simple English, measuring the anomalous magnetic dipole moment of ... 05:23: This difference between the quantum versus classical magnetic moments for the electron is called the G factor. 05:58: So measurements say the G factor is around 2. 06:45: This messiness messes with the interaction of the electron and the magnetic field to shift the G factor slightly. 09:04: ... field when we calculate the electrons magnetic dipole moment and it's G factor. ... 09:17: If we consider only the first interaction I showed along with similar primary ones, you calculate a G factor of exactly 2. 10:11: Over time, physicists have included more and more corrections refining the prediction of the G factor to increasing precision. 10:39: To actually measure the G factor with the same high precision as these calculations requires some cunning. 11:09: And the rate of this precession tells us the electron G factor. 11:15: The measured G factor agrees with the calculated value to 10 decimal places.
	2018-07-18: The Misunderstood Nature of Entropy 06:09: That microstate is a factor of 2 times 10 to the power of 107 less likely than one of the many smoothly mixed microstates.
	2018-05-16: Noether's Theorem and The Symmetries of Reality 04:07: ... the last classic example, if the factors driving the laws of motion are symmetric under rotation-- for example, ...
	2018-05-02: The Star at the End of Time 04:25: The heating core causes red dwarf fusion rates to increase by a factor of 10 or more, particularly towards the ends of their lives.
	2018-04-11: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!) 02:35: ... cuts and splices, and processes that data to build and control an entire factory of protein molecular machines, which in turn, power the entire ...
	2018-01-10: What Do Stars Sound Like? 05:48: The internal rotation of the star is also a key factor.
	2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor 10:11: And you have to divide that MV by the Lorentz factor. 10:14: That factor, the square root of one minus V squared on C squared, approaches 0 as velocity approaches the speed of light.
	2017-09-20: The Future of Space Telescopes 00:27: ... Telescope, will succeed the Hubble Space Telescope with more than a factor of five increase in collecting ... 02:24: ... to a million times fainter than the central star, but no where near the factor of 10 billion difference between the Earth and the ... 03:54: Configured right, glare is suppressed by a factor of 10 billion at 50 milliarcseconds from the star. 05:30: ... improve resolution by a factor of two, you need to double the diameter of the scope, which means the ...
	2017-09-13: Neutron Stars Collide in New LIGO Signal? 04:39: But that's a factor of 10 smaller than the 30 solar mass black holes that merged in the first LIGO detection.
	2017-08-02: Dark Flow 05:32: Once you factor out the Hubble flow, on average, those clusters seem to be drifting in the same direction.
	2017-07-19: The Real Star Wars 16:37: A few of you asked why it is that each additional vertex reduces the probability contribution of a given Feynman diagram by around a factor of 100.
	2017-07-12: Solving the Impossible in Quantum Field Theory 06:59: Every additional vertex in an interaction reduces its contribution to the probability by a factor of around 100.
	2017-06-21: Anti-Matter and Quantum Relativity 16:04: We will try to keep our accuracy to within a factor of a thousand next time.
	2017-05-17: Martian Evolution 06:49: ... Mars compared to Earth means it'll be harder to produce vitamin D. This factor is believed to result in the paler complexions found at high latitudes ...
	2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson 06:30: You can mess with any of those numbers and still remain within those few factors of 10. 12:00: With a little imagination, yet more mind factory universes can be conceived and simulated "usses" multiply exponentially. 06:30: You can mess with any of those numbers and still remain within those few factors of 10. 12:00: With a little imagination, yet more mind factory universes can be conceived and simulated "usses" multiply exponentially.
	2017-04-05: Telescopes on the Moon 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.
	2017-03-29: How Time Becomes Space Inside a Black Hole 12:55: ... has to be an integer factor, because if the EM field were pushing halfway through the time crystal ...
	2017-01-19: The Phantom Singularity 14:52: ... 999 out of 1,000, huh, that's odd, moments are due to some unaccounted factor that is totally within our current understanding of ...
	2017-01-11: The EM Drive: Fact or Fantasy? 06:05: The big one seems to be that thermal effects could still be a factor, in particular, deformation of the device or the scale due to thermal expansion.
	2016-11-09: Did Dark Energy Just Disappear? 06:35: ... fact, there are only two factors that can change the way our universe expands: there are things that tend ...
	2016-11-02: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers 03:24: ... planets in that region -- that's "N (sub) ast" for "astrophysical factor" -- times the probability that a technological civilization will form on ... 05:59: Now there are several bio-technological factors that seem important in making technologically-capable life. 03:24: ... planets in that region -- that's "N (sub) ast" for "astrophysical factor" -- times the probability that a technological civilization will form on any ... 05:59: Now there are several bio-technological factors that seem important in making technologically-capable life.
	2016-10-05: Are We Alone? Galactic Civilization Challenge 00:19: ... number as a combination of astrophysical, biological, and sociological factors, each of which narrows the range of stars in our galaxy that may have ... 00:33: ... factors include the rate of star formation in the Milky Way, the number of ... 00:49: And finally, you need to factor in the average lifetime of the typical advanced civilization. 00:56: When Frank Drake formulated his equation in the early '60s, most of the factors going into it were hopelessly unconstrained. 01:31: In the last 50 years, we've learned a lot more about some of Drake's factors. 01:36: ... some progress with the biological factors, as we push the fossil record back closer and closer to the formation of ... 02:00: The sociological factors, and in particular, the average lifespan of a technological civilization, are still the subject of wild guesswork. 02:09: The area where we've made the most progress is in the astrophysical factors. 02:48: ... such a tight constraint on the astrophysics, but with the other factors being pretty hopeless, some researchers have decided to reframe the ... 03:03: ... universe, what would that say about the biological and sociological factors in the Drake ... 00:19: ... number as a combination of astrophysical, biological, and sociological factors, each of which narrows the range of stars in our galaxy that may have ... 00:33: ... factors include the rate of star formation in the Milky Way, the number of ... 00:56: When Frank Drake formulated his equation in the early '60s, most of the factors going into it were hopelessly unconstrained. 01:31: In the last 50 years, we've learned a lot more about some of Drake's factors. 01:36: ... some progress with the biological factors, as we push the fossil record back closer and closer to the formation of ... 02:00: The sociological factors, and in particular, the average lifespan of a technological civilization, are still the subject of wild guesswork. 02:09: The area where we've made the most progress is in the astrophysical factors. 02:48: ... such a tight constraint on the astrophysics, but with the other factors being pretty hopeless, some researchers have decided to reframe the ... 03:03: ... universe, what would that say about the biological and sociological factors in the Drake ... 00:33: ... factors include the rate of star formation in the Milky Way, the number of planets per ...
	2016-09-14: Self-Replicating Robots and Galactic Domination 05:34: It deploys initial solar panels and mining bots, and uses these resources to build a factory. 05:42: That factory includes larger solar power plant, a strip-mining operation, and perhaps more assemblers. 07:02: Given B, we should see replication factories in our own solar system. 05:34: It deploys initial solar panels and mining bots, and uses these resources to build a factory. 05:42: That factory includes larger solar power plant, a strip-mining operation, and perhaps more assemblers. 07:02: Given B, we should see replication factories in our own solar system. 05:42: That factory includes larger solar power plant, a strip-mining operation, and perhaps more assemblers.
	2016-08-24: Should We Build a Dyson Sphere? 04:40: Energy supply is the big limiting factor at the start, so it takes about 10 years to build the first collector.
	2016-07-20: The Future of Gravitational Waves 02:48: Two more factors help with the certainty.
	2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners! 06:13: The consensus is that this is much smaller than anthropogenic factors. 09:20: More precisely, for how many past and future doublings of the scale factor are they both at least 10% of the energy content of the universe? 10:36: And we can just use the scale factor of the universe as the side length of our box. 10:42: In fact, let's just use R for the ratio of past to present scale factors. 10:57: Put all of this into our original equation and rearrange, and we get this equation for the ratio of scale factors. 11:21: So you need to double that 0.36 about 1.5 times to get to the current scale factor of 1. 11:36: It will happen when the universe is larger by a factor of 1.57, or about 0.7 of a single doubling. 12:10: Now to do that, you need to integrate the first Friedmann equation over the scale factors that you got for the main part of the question. 06:13: The consensus is that this is much smaller than anthropogenic factors. 10:42: In fact, let's just use R for the ratio of past to present scale factors. 10:57: Put all of this into our original equation and rearrange, and we get this equation for the ratio of scale factors. 12:10: Now to do that, you need to integrate the first Friedmann equation over the scale factors that you got for the main part of the question.
	2016-05-25: Is an Ice Age Coming? 13:09: But photons also get spread out and they get red shifted, so they do lose energy inversely proportional to the increasing scale factor.
	2016-05-18: Anti-gravity and the True Nature of Dark Energy 03:32: a is the scale factor, sort of like the size of the universe. 03:41: It's the acceleration of the scale factor. 10:56: In the first Friedmann equation, we see it as an exponential change in the scale factor. 03:32: a is the scale factor, sort of like the size of the universe.
	2016-05-11: The Cosmic Conspiracy of Dark Energy Challenge Question 03:38: We can think of that linear size as the scale factor of the universe. 03:43: ... the scale factor, the size of the universe, only needed to be around 20% smaller than it ... 03:55: Assuming a constant expansion rate, a constant increase in the scale factor, that means it was only two to three billion years ago. 04:30: That's 100 doublings of its scale factor-- so its linear dimension, not its volume.
	2016-05-04: Will Starshot's Insterstellar Journey Succeed? 08:10: Is the scientific payoff worth the money or is the awesome factor alone worth the investment?
	2016-04-13: Will the Universe Expand Forever? 04:48: That letter a is called the "scale factor," and it represents the size of the universe.
	2016-04-06: We Are Star Stuff 04:40: As well as providing us with all of their glorious entropy-resisting energy, stars are element factories, stellar alchemists. 10:04: Our universe is an element factory, producing building blocks capable of becoming you in all your stunning complexity. 04:40: As well as providing us with all of their glorious entropy-resisting energy, stars are element factories, stellar alchemists. 10:04: Our universe is an element factory, producing building blocks capable of becoming you in all your stunning complexity.
	2016-03-30: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners! 05:37: But our estimate of the total mass isn't accurate enough to bother factoring this in.
	2016-03-23: How Cosmic Inflation Flattened the Universe 06:17: ... needed to increase the size of the universe by a factor of at least 10 to the power of 26 in less than 10 to the minus 32 ...
	2016-03-16: Why is the Earth Round and the Milky Way Flat? 01:07: ... bridges, like the Verrazano-Narrows Bridge in New York, has to factor in the changing direction of down due to the curvature of Earth's ...
	2016-03-09: Cosmic Microwave Background Challenge 03:36: Within a factor of two or so is fine.
	2016-03-02: What’s Wrong With the Big Bang Theory? 07:52: ... exponentially accelerating expansion in which it increased in size by a factor of at least 10 to the power of ...
	2016-02-17: Planet X Discovered?? + Challenge Winners! 04:06: To determine the observed tick rate, you also have to factor in the travel time of light. 06:06: That's the Lorentz factor. 06:15: Combine these and you get what we call the Doppler factor, which looks like this. 06:20: The length of the observed second decreases by this factor for an approaching clock and increases for a receding clock.
	2015-10-22: Have Gravitational Waves Been Discovered?!? 03:16: ... make g-waves that lengthen or contract our space here on Earth by a factor of 10 to the power of minus 21 or ...
	2015-10-15: 5 REAL Possibilities for Interstellar Travel 01:43: This balance is factored into something we call the Wait Calculation, and we want to get this right. 05:20: Assuming we can scale up production of antiprotons by a factor of say 100 trillion, trillion, then pion rockets may be a possibility. 07:21: These tech issues need to be factored into the Wait Calculation. 09:25: We just have to increase the world's nuclear arsenal by a factor of 200, which we shouldn't do unless it's a question of extinction. 01:43: This balance is factored into something we call the Wait Calculation, and we want to get this right. 07:21: These tech issues need to be factored into the Wait Calculation.
	2015-09-30: What Happens At The Edge Of The Universe? 02:29: So we have to factor in the time interval, especially when space is changing.
	2015-08-05: What Physics Teachers Get Wrong About Tides! 01:50: So right up front, I want to make some assumptions to simplify the analysis and to remove unimportant factors from the picture.
	2015-06-24: The Calendar, Australia & White Christmas 04:14: Other factors could bring the south a white Christmas even sooner.
	2015-05-06: Should the First Mars Mission Be All Women? 00:54: Lots of factors disqualify you from NASA before you even begin including, currently, height restrictions.
	2015-04-09: How to Weigh a Fart 01:10: That number may be off by a factor of two or so, but I doubt it's off by a factor of 10.
	2015-04-08: Could You Fart Your Way to the Moon? 02:48: In truth, even starting out from low Earth order, you'd be short of Earth's escape velocity by a factor of about a billion. 07:19: A lot of factors come into play.
	2015-04-01: Is the Moon in Majora’s Mask a Black Hole? 06:34: Once you factor in tidal forces, I don't see how you avoid this conclusion.
	2015-03-11: What Will Destroy Planet Earth? 04:53: ... we're going to talk about anyway just because of the sheer awesomeness factor-- death by expanding ...
	2015-03-04: Should We Colonize Venus Instead of Mars? 01:17: Depending on the launch window, the round trip can be 30% to 50% shorter, which is a major factor for manned missions.
	2015-02-18: Is It Irrational to Believe in Aliens? 00:33: With probability statistics, we just need to get a handle on the factors at play in the emergence of intelligent life as we know it.

122 result(s) shown.

Help · About · Index