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	2022-10-12: The REAL Possibility of Mapping Alien Planets! 04:36: ... cluster. If the alignment is close enough, we can see an Einstein Ring, like this   galaxy being lensed by an intervening galaxy. The ... 10:07: ... point back at the Sun and take an image  of the faint einstein ring surrounding it.   You might note an issue here. The last thing ...
	2022-06-30: Could We Decode Alien Physics? 16:39: ... didn’t get to it 60 years earlier, Tony  - the Tee Jet has a nice ring to it.    Regarding shielding against interstellar ...
	2022-06-01: What If Physics IS NOT Describing Reality? 14:22: ... The  galactic habitable zone is defined to be a   ring around the disk, not too close to the core  and not too far out. It ...
	2022-05-04: Space DOES NOT Expand Everywhere 07:12: ... Lose another dimension of space so the universe becomes an expanding ring instead of a ,sphere, with grid points instead of gridlines. But then we ... 07:58: ... galaxy causes gridlines to be pulled together on a sphere, then on the ring it causes points to be pulled together, and they maintain that ... 09:38: ... the present and define a grid of space - or a grid of points on our 1-D ring universe. Then we rewind the universe and every single one of those ... 07:58: ... points to be pulled together, and they maintain that separation as the ring expands. So on our expanding cone, we see distant gridlines diverging, but nearby ... 07:12: ... we can add the dimension of time into our picture so that the expanding ring traces a sort of cone, and the points trace lines. This is nice because you can ... 09:38: ... the present and define a grid of space - or a grid of points on our 1-D ring universe. Then we rewind the universe and every single one of those points traces ...
	2022-02-23: Are Cosmic Strings Cracks in the Universe? 00:58: ... - a pair of field strengths, and so   the new minimum formed a ring around the old minimum,  resembling an item of festive Mexican ... 10:09: ... them  towards us. We can see multiple images or even a   ring surrounding that lens. A cosmic string would also deflect light ...
	2021-12-29: How to Find ALIEN Dyson Spheres 06:03: Partial Dyson spheres could take the form of equatorial rings of collectors, or swarms that don’t fill the entire spherical surface.
	2021-12-20: What Happens If A Black Hole Hits Earth? 18:16: ... may be that the so-called ring-down - the waves produced as the merged object settles back into a spheroid - ...
	2021-11-17: Are Black Holes Actually Fuzzballs? 06:01: ... a black hole’s mass into a single point, it gets distributed around the ring structure of these ...
	2021-08-18: How Vacuum Decay Would Destroy The Universe 01:31: ... at every point. As a   simplistic example, imagine a rubber ring at each point. If you compress the ring in one ... 02:18: ... like the deformed ring, a quantum field  wants to return to its equilibrium ... 01:31: ... shape. But each ring is also connected   to its neighboring rings, and so it can transfer its oscillations, causing a wave to ...
	2021-07-21: How Magnetism Shapes The Universe 10:59: If you thought the 27 km ring of the large hadron collider was big, try the 300,000 light year ring around the Milky Way.
	2021-06-09: Are We Running Out of Space Above Earth? 08:08: They quickly smear out in a ring around the Earth, making tracking and avoidance that much more difficult.
	2021-04-21: The NEW Warp Drive Possibilities 09:45: ... is in front and behind the spaceship, while the exotic matter is in a ring around the direction of ...
	2021-03-16: The NEW Crisis in Cosmology 10:08: ... way galaxies are scattered across the universe and use those rings as a sort of standard ruler.   These “baryon acoustic ...
	2021-02-17: Gravitational Wave Background Discovered? 00:00: ... in what is known as a quadrupole wave if the wave passes through a ring of points those points would move in and out like this okay so imagine ...
	2021-02-10: How Does Gravity Warp the Flow of Time? 06:05: But first, let’s try this - build our lab into a giant, ring-shaped space station.
	2020-12-15: The Supernova At The End of Time 14:35: John Ring correctly summarizes that observers in a reverse-time universe wouldn't know the difference.
	2020-10-27: How The Penrose Singularity Theorem Predicts The End of Space Time 03:18: ... central point of infinite gravity is spun out into a   ring - but it was a singularity nonetheless. The Kerr solution was still ... 08:49: ... central singularity, while in Kerr  black holes space ends at the ring ... 03:18: ... central point of infinite gravity is spun out into a   ring - but it was a singularity nonetheless. The Kerr solution was still ... 08:49: ... central singularity, while in Kerr  black holes space ends at the ring singularity. ...
	2020-08-24: Can Future Colliders Break the Standard Model? 00:28: ... will accelerate particles in a 100 kilometer circumference underground ring encircling ... 02:29: The key to doing this is to store the particle beams in a ring so that they can be collided at your leisure. 02:37: To that end, the particle storage ring was invented by Gerard K. O’Neill in the mid 1950s. 02:53: Its four meter ring collided electrons and positrons. 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility. 04:29: km circumference ring beneath the Swiss and French countrysides. 14:49: Think of the case of the rotating black hole - the singularity is a ring, and relatively few geodesics - free-falling paths - hit the singularity. 14:57: Most pass through the ring. 04:29: km circumference ring beneath the Swiss and French countrysides. 02:53: Its four meter ring collided electrons and positrons. 00:28: ... will accelerate particles in a 100 kilometer circumference underground ring encircling ... 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility.
	2020-08-17: How Stars Destroy Each Other 08:29: That gas forms an enveloping ring around the whole system, which then falls onto the neutron star.
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 08:00: ... around the outside of the chamber direct the anti-protons to a storage ring called the Antiproton Decelerator, where they are slowed down by pulses ...
	2020-06-30: Dissolving an Event Horizon 02:57: Inside, we found that the rapid rotation has spun the point-like singularity into a ring of infinite density. 03:04: The time machine is on the other side of that ring, by the way. 03:09: The same rotation that f orms the ring also drags the fabric of space into a vortex which counters the inward pull due to the singularity’s mass. 03:51: Instead, there’s a smooth run of normal - albeit rapidly spinning space all the way down to the singularity ring. 04:00: The NAKED singularity ring. 12:20: Each ring you pass as you go down that funnel represents crossing 3-D spherical shell.
	2020-06-15: What Happens After the Universe Ends? 13:28: Penroses proposes that the collisions of super massive black holes in the previous universe may leave rings on the sky in the next.
	2020-05-18: Mapping the Multiverse 04:54: The singular, central point has been spun out into a ring of infinite density. 05:14: ... through the inner horizon, or you can plunge through the singularity ring. ... 06:24: But within a Kerr black hole, the singularity is a ring, and the trillion balls would fall towards the disk bounded by that ring. 06:33: Only the ones exactly on the equator hit the ring and, those geodesics do end - same infinite squish as in a Schwarzschild black hole. 06:58: Before we take that outward ride, let’s push a little harder and try to get through the ring. 07:04: With a lot of speed - and I mean a LOT - it’s possible to overcome the anti-gravitational field in the middle of the ring and punch through. 07:17: ... ring is like a portal to a new, very different region of spacetime - and ... 07:34: For one thing, the ring singularity becomes entirely repulsive - as though it had negative mass. 07:50: For one thing, the lack of event horizons above you means the ring is a naked singularity, as well as being repulsive. 07:58: Surrounding the ring on this side is a toroidal region in which it’s possible to accelerate to infinite speed. 08:43: We’ll come back to how it can be avoided in the math - for now, let’s whip once around back to our own past and hop back through the ring. 09:39: Extending the Kerr metric from ring singularity into the future leads to something else. 13:35: They just don’t have the ring singularity leading to the bizarro-verse, so Kerr is more fun than Reissner-Nordström. 07:34: For one thing, the ring singularity becomes entirely repulsive - as though it had negative mass. 09:39: Extending the Kerr metric from ring singularity into the future leads to something else. 13:35: They just don’t have the ring singularity leading to the bizarro-verse, so Kerr is more fun than Reissner-Nordström.
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... telescope okay so it's a 10 inch Dobsonian you can see the I mean the rings of Saturn are amazing with that telescope it's also a plan holder by ...
	2020-04-22: Will Wormholes Allow Fast Interstellar Travel? 03:45: ... time frozen for the moment and add back the 3rd spatial dimension. The ring of the wormhole is actually a sphere the size of the Schwarzschild event ...
	2020-01-06: How To Detect a Neutrino 02:47: ... beam line accelerates protons around a two and a half mile circumference ring, using giant electromagnets, ♪ (𝘳𝘩𝘺𝘵𝘩𝘮 𝘣𝘶𝘪𝘭𝘥𝘴) ♪ to around 99.997% the ...
	2019-10-15: Loop Quantum Gravity Explained 15:49: ... universe - or in the case of a rotating black hole, an infinite density ring. ... 17:07: Especially given that I kept saying a struck black hole rings like a bell.
	2019-10-07: Black Hole Harmonics 02:48: As those vibrations give up their energy – in this case to sound waves – the vibrations fade. The bell rings down. 04:39: OK, so a black hole can ring like a bell when struck – in that case a black hole merger is the biggest hammer strike of all. 12:59: ... gravitational wave spectroscopy, we can now listen to the harmonics of ringing black holes, and through them better understand the fundamental nature ... 02:37: This final phase is called the ring-down – an expression comes from the analogy with a bell. 04:46: But what does the ring-down of a black hole really look like? 04:57: ... in order to see the overtones you’d need to look at the tail end of the ring-down, when the black hole was approaching a more spherical ... 05:20: The problem is, at the tail-end of the ring-down the LIGO signals are probably too weak to detect the overtones. 05:37: They looked for overtones in the ring-down from right at the point of black hole merger. 06:45: ... when the ringdown begins some of the overtones are actually stronger than the fundamental ... 07:12: Similarly, the overtone structure of a black hole ringdown can identify the fundamental properties of that black hole – namely its mass and spin. 08:04: looked at the merger and ring-down signal from the largest black hole merger we’ve seen. 08:22: ... team analyzed the harmonics in the gravitational wave ring-down from this event and claim a likely detection of at least one overtone – ... 09:13: ... the mass and spin derived from the ringdown are consistent with the estimate that was previously obtained by ... 09:24: ... is important, because the overtone analysis ONLY looked at the ringdown, so this tells us that all information on the nature of the final black ... 10:08: ... define everything – including the nature of the oscillations during ring-down. ... 08:04: looked at the merger and ring-down signal from the largest black hole merger we’ve seen. 12:59: ... gravitational wave spectroscopy, we can now listen to the harmonics of ringing black holes, and through them better understand the fundamental nature ... 02:48: As those vibrations give up their energy – in this case to sound waves – the vibrations fade. The bell rings down.
	2019-09-03: Is Earth's Magnetic Field Reversing? 06:21: As a result, the starting magnetic field gets wound up into rings around the axis of rotation – into a torus shape. 06:56: Now we have exactly the conditions of an electromagnet – organized rings of current, which produce our giant dipole field. 06:21: As a result, the starting magnetic field gets wound up into rings around the axis of rotation – into a torus shape. 06:56: Now we have exactly the conditions of an electromagnet – organized rings of current, which produce our giant dipole field.
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 16:21: ... can't actually see the event horizon telescope" doesn't have such a nice ring to ... 16:53: Belodri writes from Austria to inform us that their phone ring is now me saying Zwicky.
	2019-05-01: The Real Science of the EHT Black Hole 06:17: What we’re seeing here is the black hole shadow inside the bright ring of the photon sphere. 06:36: We only see light that escapes directly towards us, so the photon sphere looks like a photon ring. 08:14: The ring is the photon sphere, blurred due to the fact that this observation is incredibly difficult and the EHT is “only” the size of the Earth. 08:24: In principle this could be a very narrow ring. 10:01: ... asymmetry in the ring tells us the rotational direction of the vortex, so combine that with ...
	2019-03-06: The Impossibility of Perpetual Motion Machines 15:07: ... the baryon acoustic oscillations frozen into both the CMB and in galaxy rings were blurred out quite a bit because the universe took a moment to ...
	2019-02-20: Secrets of the Cosmic Microwave Background 02:05: ... collapsed into galaxies We still see them today Interwoven patterns of rings drawn in galaxies on the sky but those rings are not the whole story ... 14:23: ... oscillations should have produced bubbles, spheres rather than rings on the sky That's right, they definitely would have produced 3D ... 02:05: ... collapsed into galaxies We still see them today Interwoven patterns of rings drawn in galaxies on the sky but those rings are not the whole story ... 14:23: ... oscillations should have produced bubbles, spheres rather than rings on the sky That's right, they definitely would have produced 3D ... 02:05: ... collapsed into galaxies We still see them today Interwoven patterns of rings drawn in galaxies on the sky but those rings are not the whole story Today ...
	2019-02-07: Sound Waves from the Beginning of Time 07:09: So those rings should be 150 mega parsecs across, 500 million light years. 07:22: Well, crazily, we can still see those rings, not made of plasma or gas, but made of galaxies. 08:27: Those rings were further smeared out over the thousands of years it took for the universe to fully transition from plasma to gas. 09:46: Corresponding to the acoustic rings, everything is so hopelessly overlapping. 10:21: These are the galaxy pairs where one is at the center of the dark matter peak, and one is on the surrounding ring. 11:26: See, we know exactly how big those acoustic rings should be. 11:47: ... means we know how big those rings were when they formed, and we can see how big they are at different ... 11:57: These rings give us a standard ruler on the sky, spanning all of cosmic time. 12:39: I mean think about it. There are rings in the sky inscribed in galaxies, frozen echoes of the very first sound waves to reverberate across space-time. 07:09: So those rings should be 150 mega parsecs across, 500 million light years. 07:22: Well, crazily, we can still see those rings, not made of plasma or gas, but made of galaxies. 08:27: Those rings were further smeared out over the thousands of years it took for the universe to fully transition from plasma to gas. 09:46: Corresponding to the acoustic rings, everything is so hopelessly overlapping. 11:26: See, we know exactly how big those acoustic rings should be. 11:47: ... means we know how big those rings were when they formed, and we can see how big they are at different ... 11:57: These rings give us a standard ruler on the sky, spanning all of cosmic time. 12:39: I mean think about it. There are rings in the sky inscribed in galaxies, frozen echoes of the very first sound waves to reverberate across space-time.
	2018-10-18: What are the Strings in String Theory? 06:48: Niels Bohr came up with the first quantum model for electron orbits by thinking of them as ring-like standing waves around the hydrogen atom.
	2018-05-16: Noether's Theorem and The Symmetries of Reality 12:45: You could also check Appendix F in Lord of the Rings.
	2018-01-17: Horizon Radiation 12:56: Extremely large quakes can set the entire star ringing, which is observable in its effect on the extremely regular flashes of its pulsar jet.
	2018-01-10: What Do Stars Sound Like? 01:44: Stars ring like bells. 03:45: ... just as a single tap can set an entire bell ringing, a single traveling wave feeds its energy into standing pressure waves ...
	2017-11-22: Suicide Space Robots 04:47: This orbiter studied Saturn and its moons and rings for 13 years.
	2017-09-28: Are the Fundamental Constants Changing? 05:22: They have magnetic fields, just like a little bar magnet, or electric currents rotating in a ring even though there is no actual rotation. 13:41: ... to build something like an aragoscope with infinitely many concentric rings by using some sort of advanced diffracting ... 14:02: To do something similar with visible light, you'd need a nanofabricated structure with actual concentric rings. 14:09: ... problem then is that the focal length of the rings depends on their size, with smaller rings creating a focus closer to the ... 14:18: So this material would have to be cone-shaped so the smaller rings are closer to the detector. 13:41: ... to build something like an aragoscope with infinitely many concentric rings by using some sort of advanced diffracting ... 14:02: To do something similar with visible light, you'd need a nanofabricated structure with actual concentric rings. 14:09: ... problem then is that the focal length of the rings depends on their size, with smaller rings creating a focus closer to the ... 14:18: So this material would have to be cone-shaped so the smaller rings are closer to the detector. 14:09: ... that the focal length of the rings depends on their size, with smaller rings creating a focus closer to the aragoscope than larger ...
	2017-09-20: The Future of Space Telescopes 07:00: All you get is the thin ring of light diffracted around the edge. 07:20: It's also possible to break the disk into a set of concentric rings so that you get many diffraction edges. 07:27: There are challenges to bring the light from each ring to the same focus, but fortunately humans are pretty smart and there are ways to do this. 13:14: [INAUDIBLE] wants to confirm that the gold in their ring may have been created in the collision of two neutron stars. 13:29: So yeah, your ring was forged in the death of a star or the birth of a black hole. 07:20: It's also possible to break the disk into a set of concentric rings so that you get many diffraction edges.
	2017-09-13: Neutron Stars Collide in New LIGO Signal? 05:37: ... hit that range in the final second before merger, while neutron stars ring at audible gravitational wave frequencies for at least several ...
	2017-05-10: The Great American Eclipse 04:23: Such eclipses are called annular eclipses, because they leave a ring of bright sunlight around the moon's disk. 05:43: The sun's final crescent contracts to a last spark on one side of the moon, like a diamond ring. 07:40: Bailey's beads and the red chromosphere flash along the edge of the moon, the diamond ring emerging on the Western side.
	2017-04-19: The Oh My God Particle 06:00: We build artificial ones on Earth using giant rings and powerful magnetic fields.
	2017-03-15: Time Crystals! 02:01: Wilczek came up with a simple model in which charged particles in a superconducting ring break what we call continuous time translational symmetry.
	2017-02-22: The Eye of Sauron Reveals a Forming Solar System! 01:26: But the surrounding ring is very real. 01:35: But the ring is brightest in the infrared. 01:46: We're seeing the heat glow of a giant ring of ice and dust 40 billion kilometers in diameter. 04:38: The Herschel and Alma images show very clearly that the ring has sharp edges, particularly that inner edge. 04:45: The leading idea is that newly formed planets carved out that ring with their gravity. 04:50: Check out Saturn's F ring. 05:22: So a planet passing along the inside of the dust ring overtakes each grain of dust and tugs them gently forward. 05:37: A planet passing along the outside of the dust ring pulls back on the dust. 05:47: Pushed outwards and inwards by the Shepherd planets, the dust ring boundaries sharpen between them. 06:07: In fact, it is very possible that we've actually found the planet that carves out the inner edge of that ring. 06:37: Or even cooler, it may be a planet with a giant reflective ring system. 06:42: If so, Fomalhaut really does seem to have a thing for rings. 09:10: The fiery eye of Sauron, wielding rings within rings. 05:47: Pushed outwards and inwards by the Shepherd planets, the dust ring boundaries sharpen between them. 05:22: So a planet passing along the inside of the dust ring overtakes each grain of dust and tugs them gently forward. 05:37: A planet passing along the outside of the dust ring pulls back on the dust. 06:42: If so, Fomalhaut really does seem to have a thing for rings. 09:10: The fiery eye of Sauron, wielding rings within rings.
	2017-01-25: Why Quasars are so Awesome 05:23: But viewed side on, that disk is obscured by a thick ring of dusty gas.
	2016-11-09: Did Dark Energy Just Disappear? 14:03: My point is that there are plausible options, and a giant rotating maglev ring city in a sealed taurus is actually plausible.
	2016-10-19: The First Humans on Mars 06:02: This is possible using a centrifuge, a rotating ring that results in the feeling of an outward force, a centrifugal force, with respect to the ring. 06:19: ... would still involve a large rotating ring, but with a sloped, slightly curved outer wall so that the centrifugal ...
	2016-09-29: Life on Europa? 02:25: Its geysers actually produce one of Saturn's rings. 02:29: And the Cassini spacecraft found that ring to contain salt. 02:25: Its geysers actually produce one of Saturn's rings.
	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.
	2016-06-22: Planck's Constant and The Origin of Quantum Mechanics 11:42: OK, a lot of you wanted to know why it is that the Einstein cross is a cross rather than a full ring. 12:05: We call that an Einstein ring. 13:01: Then you'll see an Einstein ring. 13:03: There are some cases where you see four individual quasar images connected by an Einstein ring. 13:10: That Einstein ring is actually the galaxy that hosts the quasar.
	2016-06-15: The Strange Universe of Gravitational Lensing 03:30: ... they are greatly magnified in brightness and stretched into arcs and rings. ... 08:46: ... light from any surrounding whirlpool of hot plasma to form a bright ring around the black ... 03:30: ... they are greatly magnified in brightness and stretched into arcs and rings. ...
	2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners! 01:03: A ring of gigantic magnets accelerates protons to up to 0.99999999 of the speed of light before colliding them from opposite directions.
	2016-04-06: We Are Star Stuff 08:27: ... gold in your ring, the nickel in your nickel, and, in fact, a lot of the iron in your ...
	2016-02-24: Why the Big Bang Definitely Happened 06:21: The fancy name is baryon acoustic oscillations which cause ring-like clustering of the CMB fluctuations.
	2016-02-11: LIGO's First Detection of Gravitational Waves! 06:48: ... see the slow ringing of binary white dwarf stars in our own galaxy, as well as the final ...
	2015-12-09: How to Build a Black Hole 12:28: Sam Gilfellan wants know how large an object we'd need to destroy in order to form a ring system around the earth. 12:35: ... if we want a ring system like Sam's, that has the same ratio of planet mass to ring mass-- ... 12:54: A ring system around the earth would be awesome. 12:35: ... want a ring system like Sam's, that has the same ratio of planet mass to ring mass-- of about 1 to 50 billion, then we'd need an object the same size as the ...
	2015-10-28: Is The Alcubierre Warp Drive Possible? 03:24: ... try to do this for the warp field, you find that you need to produce a ring of negative energy density in a band around the ship to produce the ...
	2015-05-06: Should the First Mars Mission Be All Women? 08:52: ... why we didn't bring up gravity gradient effects, namely that in a small ring-- this is not as a big a problem in large rings-- there would be a gravity ...
	2015-04-29: What's the Most Realistic Artificial Gravity in Sci-Fi? 03:17: ... surface or 10 meters per second squared, our earlier formula says the ring would need to rotate at 1.1 radians per ... 04:08: In this case, we're talking about the ring. 04:21: If he's actually running against the ring's rotation, he would tend to curve upward and could levitate just by sprinting, instead of jogging. 05:11: You can minimize these problems with a bigger ring, since that'll require less rotation to get the same 1 g of surface gravity. 05:17: ... let's look at an extreme example of a big ring, Larry Niven's "Ringworld." The ring habitat in that novel has the same ... 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. 05:57: That's slow for Coriolis purposes, but it's really fast in terms of mechanical stresses in the ring. 06:12: But if you go too big, the mechanical stresses will destroy your ring. 06:16: So do any franchises have a ring size that finds a good balance between these two? 07:12: ... space station on "Babylon 5." The key is that "Babylon 5" abandons the ring shape altogether and makes a cylinder instead, one about 8 kilometers ... 05:17: ... look at an extreme example of a big ring, Larry Niven's "Ringworld." The ring habitat in that novel has the same radius as Earth's entire orbit around the ... 07:12: ... space station on "Babylon 5." The key is that "Babylon 5" abandons the ring shape altogether and makes a cylinder instead, one about 8 kilometers long and ... 06:16: So do any franchises have a ring size that finds a good balance between these two? 04:21: If he's actually running against the ring's rotation, he would tend to curve upward and could levitate just by sprinting, instead of jogging. 02:49: ... as we gut check the physics of the following sci-fi examples-- "2001," "Ringworld," "Halo," and "Babylon 5"-- all which use rotation-induced artificial ... 05:17: ... let's look at an extreme example of a big ring, Larry Niven's "Ringworld." The ring habitat in that novel has the same radius as Earth's entire ... 05:31: ... achieve 1 g, Ringworld's rotational velocity would be small enough that, just like on Earth, ... 05:38: And to Niven's credit, he also correctly had hurricanes on Ringworld rotate vertically because the deflections would go like this. 05:48: But Ringworld has a different problem, namely composition. 02:49: ... as we gut check the physics of the following sci-fi examples-- "2001," "Ringworld," "Halo," and "Babylon 5"-- all which use rotation-induced artificial ... 05:38: And to Niven's credit, he also correctly had hurricanes on Ringworld rotate vertically because the deflections would go like this. 05:31: ... achieve 1 g, Ringworld's rotational velocity would be small enough that, just like on Earth, ...

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