Comments by "Dr Gamma D" (@DrDeuteron) on "Kyle Hill" channel.

  1. and it would hella radioactive. Like the piece he is holding would have around 10^40 neutrons in it, with 11m 1/2 life: 10^24 Watts of beta decay. Not to mention the neutrons themselves
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  2. It will converge on a single word, like Malcovich
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  3. there are some protons and electrons left in there.
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  4. don't forget to boycott electricity.
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  5. You don’t seem to know anything about the LHC
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  6.  @nocare  Have you solved the Schrodinger equation for the Coulomb hydrogen atom? (it's college level QM). It only includes electricity. The ground state is a perfectly spherical orbital. I mean perfect. Now solve the bound state for a proton moving at 0.99c and an electron moving at 0.99c. There is electricity, and magnetism, as moving charges are currents. The ground state is not spherical. It's ellipsoidal: the orbital is flattened in the direction of motion. Lorentz contraction is real, atoms are flattened.
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  7.  @StephenGillie  most ppl don’t know what happens at the LHC, so I’d hardly call that ad hominem. The Higgs is all about gauge theory and spontaneous symmetry breaking, and Einstein was not a fan of that. He wanted a geometric field theory of everything al la Kaluza Klein, and that’s just not happening.
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  8. Imagine if they had social media at the time, with their out of touch corporate twitter account
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  9. I’d say it’s hybrid, the matrix algebra is linear, but the response to the sum of the sums is not
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  10. Bro: you did The Hoff dirty (0:04).🤣
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  11.  @nin2494  the barn doesn't look like it shrunk. It is shrunk.
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  12. No we don’t.
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  13.  @StephenGillie  the only reason it smashes protons is because you can put them in a high energy ring. They'd prefer electrons, but they don't work at that energy. LHC smashes quarks, that just happens to b in protons. They are not studying proton structure, that was HERA at DESY.
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  14. I disagree with sagans retort that such claims require such evidence. A lot of physics revolutions had rather mundane evidence.
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  15. Hanford is contaminated with gravitational waves.
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  16. musical taste is indeed relative.
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  17. no. the PEP is derived from the spin-statistics theorem (or so I am told). The SST is derived from (anti)commutators of field operators for (fermions) bosons being zero outside the light cone, so...you could say the finite speed of information (aka: casualty) is the cause of the PEP.
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  18. The problem is twofold: One, the speed of light 💡 is fast. Mass of a paper clip times its square is 20 kilotons of TNT 🧨 , or a fat man. Two, Avogadro’s number is just so darn big.
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  19. Once it decides very very is a better modifier than very, well have very very very very very ….. very verbose output
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  20. See "Born Rigidity". Such a material that cannot break, breaks realtivity. (Hence: there is no such material).
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  21. this is a good question. The answer depends on how you stop the ladder (it's actually better to do the train/tunnel versions here because trains have brakes). If the engineer sends a brake signal to the back of the train (at c), the front stops and the back continues to pile in and its destroyed. If you preprogram the (infinity powered) brakes to engage all at once (in the tunnel frame), then the train stops fitting in the tunnel....now it's not moving and has to un-Lorentz contract: that stress blows it up. Meanwhile the ladder frame sees the front stop before the back, and the train is compressed as the back piles in. You call also put the preprogrammed stop signal to be simultaneous on the train. The then tunnel frame sees the back brakes come on first and the train is stretched out and ripped apart (the back never makes it to the tunnel). For further investigation, see "Born Rigidity": infinitely rigid object violate relativity, and various relativistic strains must exist.
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  22. I think ppl felt the same way about printing: we just can’t have commoners reading
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  23. Chandrasekhar disagrees.
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  24. those LANL guys knew what they were dealing with. If the blue glow is from neutrons, you're done. Gamma's you have a shot. Betas: not too bad, alphas: fuggeddaboutit.
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  25.  @the_retag  I suppose "fuggetaboutit" is ambiguous.
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  26. Kyle is a good narrator…I think it’s the hair.
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  27.  @sorrenblitz805  not true. Electron LINACs can make a lot of ozone, so when you shut the beam off and wait 15m for the oxygen-15 to decay (2m 1/2 life), and then go in: it smells, but is safe.
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  28.  @logicplague  you can't see my reply? I used the "d" word for fermionic matter that has its fermi-sea filled up (kT notwithstanding).
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  29. Hmmm..kind of like the president
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  30. 1/4 lbs of Cs-137 is 4 moles, and Avogadro's number is really huge: 2.4e24 atoms, 1.7e15 decaying each second, emitting over 100 watts, and with radiation: macroscopic numbers kill you
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  31. your emotional appeal for fact based discussion was good.
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  32. pretty sure the strongest material in the universe is your hair product.
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  33. Stop...you'll get it banned!!!
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  34. This is unfair. Neutrons see Kyle's golden main and say, "oh heyal no, I'm going back to the U236."
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  35. but there is no t_1. The leading and trailing spaceships have different elapsed times at fixed t. Meaning the premiss of your entire argument is flawed.
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  36.  @massimilianodellaguzzo8571  If the changing speeds are simultaneously equal (at different positions, same time) in the Earth's frame, then in any moving frame, the velocities are never equal. The rope breaks in ALL frames.
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  37. one long ship is not constrained to have uniform acceleration in the Earth's reference frame. The two ships in this paradox are, by definition.
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  38. Isn’t this Oblers paradox with bullets instead of E X B?
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  39. that explanation violates basic relativity. There is no drag from motion. If there were, you could define an absolute rest frame (the one with no drag). No matter how fast you go, space-time looks the same.
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  40. The question is: would you prefer the faculty of Harvard or the first 4000 names in the Boston phone book to curate for you?
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  41.  @stranger6822  It's a William F Buckley, Jr. quote.
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  42. but the ships are not in the same comoving reference frame, so everything concluded based on that is false.
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  43.  @dpsamu2000  well, atoms (nuclei actually) do Lorentz contract into flattened-disks with time-dilated internals in an accelerator.
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  44. That is called a "failure to abstract". No relation to "Terrell Rotations"?
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  45. well, people "test" the theory of relativity. Not sure they're trying to disprove it...unless they are crackpots.
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  46. you left something out: we make steam [to make high pressure fluid to make high speed flow] to turn turbines.
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  47. the statement that "ship 2 perfectly matches the speed of the 1st" violates relativity. So you are guaranteed to get the wrong description.
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  48. it's called "Superluminal Motion" (wrt to jets). It is indeed an illusion, as the time difference between observing matter at two points is less then the actual time (in the Earth's frame) between the light signals being sent...basically b/c of the finite speed of light. Wikipedia derives it.
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  49. In a thought experiment, one does not take measurements by observing light-speed limited signals. In order to assign coordinates to an event, one choses a frame-of-reference, which then splits spacetime into 3D space filled with imaginary synchronized unbiased clocks, the time of any event is then assigned the reading on the clock with the same position. If find it quit irritating when I find people complaining about the limitations of visual observations in a thought experiment.
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  50. This is a video about Special Relativity. There is no need to go outside of SR just to cause problems.
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  51.  @robertmitchell8728  but there is zero motivation to complicate SR, which is not a theory, it's a fact. If you've ever split an atom you would know that. Moreover, GR has correctly predicted: 1) gravitational time dilation 2) space stretching (Shapiro delay) 3) Frame dragging 4) gravitation waves 5) black holes 6) universe expansion all of which have been observed.
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  52. Does anyone simulate all possible action to identify corner case?
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  53. you're moving at relativistic speeds right now, in the frame of an UHECR (gamma=1B). Do you feel 2 nanometers tall?
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  54. we make anti particles daily. Now proper neutral anti-atoms, in a container, that is hard and expensive (probably a mole of dollars for a macroscopic amount). See: CERN: ATRAP.
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  55. it's not a nuclear accident, it's a radiological accident.
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  56. timestamp?
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  57. Red Rocks State Park. nice.
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  58. the two ships only have simultaneous acceleration in the Earth's reference frame. Let's say the front and rear ships flash a (fast) light bulb at the same time according to Earth (With the event's labeled F and R). On earth t_F = t_R, as specified. In a frame moving along with either ship: t_F < t_R. The front ship flashes 1st. If that flash occurs when they reach 99.00000000% the speed-of-light, Earth says: they are moving at the same speed; however, someone in either rocket says: the front ship is moving faster than then the rear one. Paradox: resolved.
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  59. There are no practical reasons in thought experiment. "Practical" is a problem from real experiments and engineers.
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  60.  @nowaaru  search for k shell peak …irs when the X rays energies surpass the binding energy of the inner shells so the absorption cross section goes up on….uh, quantum, jumps. See the particle data booklet chapter 2: the passage of charged particles through matter. …though that’s not X rays, and the pdb is more concerned about much higher energy gamma rays which are photo electric effect at low energy, Compton scattering at medium energy, and pair production at high energy. Search “radiation length”
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  61.  @morgenstern7865 that’s an easy calculation. I think a golf ball size piece of neutron Star as 1 g of a gravity asteroid around 10 meters? If so, it’s around 1,000,000g at the surface. Not something you want in the lab. White dwarf is about mass neutron/mass electron times weaker…..so still… not good.
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  62. but in the reference from an ultra high energy cosmic ray (which is a valid inertial frame): you are moving at 0.99999999999999999c right now.
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  63. The problem with radioactive material is that Avogadro's number is really, really, big.
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  64. Let's just solve it. Earth (Ship) is unprimed (primed): x_r = at^2/2 x_f = x_r + L at later time, with v = at, the Lorentz transform is: x'_r = g(x_r-vt) = g(at^2/2 - at^2) = gat^2(-1/2) x'_f = g(x_f + L) = x'_r + gL So it looks like x'_f -x'_r = gL... which shows Lorentz dilation in the ship rest frame (the ships move apart in their frame if they're equally space in the Earth frame). Of course you must also compute the times, since: t_f, t_r = t. but in the ship's frame(s), they are not simultaneous: t'_r = g(t - vx_r) = g(t - (at)(at^2)/2) = gt(1 - (at)^2/2) t'_f = a(t - vx_f) = t'_r- gL(at) --> exactly matches gravitational time dilation due to acceleration "a". so that in the ship's frame, the front ship is in the future w.r.t. the rear, according to Earth. Since v = at in the Earth's frame for both ships, the front ship is moving faster than the rear in their frame. Bam: Paradox resolved.
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  65. what's that in REM/hr?
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  66.  @alexanderx33  thx. Milli rem is preferred ofc, but not by auto spell
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  67. The dangerous physics of rock climbing can be summed up with: g = 21.9 mph/s
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  68. Star Wars dog fight scenes were taken shot for shot from a WW 2 ball turret gunners v luftwaffe fighters.
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  69. we can't "do without" relativity, rn. Without it, GPS wouldn't work, nor would interplanetary navigation.
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  70. a space ship can't go the speed of light.
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  71. Beta radiation does make it through thick plastic, but not tritium decay....it is just so low energy.
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  72. TMI was the beginning of global warming
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  73. You were right, until you said "This is not a paradox". It is a famous relativity paradox, and has a history of stumping experts.
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  74. there was a 20,000 Ci Co-60 source where I worked. It was shielded in a 20 foot iron doped concrete container. Had to be moved with a 100' crane.
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  75. A 5 kg plutonium pit in a modest nuclear weapon, after going supercritical for 100 ns, weighs around 4,999 grams with 1 gram of mass turned into very, very, very, bright X-rays still trapped^1 inside the imploding high explosives. [1] but not for long.
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  76. Do wonder why Bell chose a string when he could have very well said "metal chain"?
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  77. you have a major misunderstand of special relativity. A major consequence is that you cannot move with respect to space. That's why c is always c: it propagates at c in spacetime, and no matter your velocity spacetime looks the same. There is no absolute rest frame. Ofc, in general relativity, ppl take about spacetime moving (frame fragging), and falling into blackholes at c....so, there that.
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  78. That burn goes all the way through. And 500 rad whole body is ld50 40x is terrifying
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  79. The tethered ships do not behave like one ship because they are stipulated to follow different trajectories. Every aspect of each ship don't snap because they are not stipulated to follow identical trajectories with respect to Earth.
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  80. the string is at rest in its frame, and sees the ships pulling on it, since relative to Earth, the front ship is in the rear ship's future, and is therefore going faster due to constant acceleration.
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  81. Even with a sawed off, you still worry about bears. You just worry less.
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  82. there is no reason to be terrified. If you work with sources, you'll trained how to handle them. BTW: smoke detectors, glass, concrete, bananas, earth, and the sky are sources of radioactivity.
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  83.  @Dingusdongus257  maybe it was Sam Brinton…but he’s into puppy play.
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  84.  @goosecf  it would be gamma rays, so no: you can’t see it coming, even if you could see it.
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  85. found Rogans Smurf account.
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  86. The flaw in your argument is when you say, "Since the two ships and the string at all times have identical velocities..". What is simultaneous in the Earth's frame is not simultaneous in the ships' frames. Two identical earth times at the front ship and rear ship (t_f = t_r), when transformed into the ships frame satisfy: t'_f < t'_r, so the front ship is faster then the rear ship under uniform acceleration in Earth's frame.
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  87. In the Earth's frame, the front and back of the spaceships don't have the same acceleration. If 2 LED lights are illuminated simultaneously (in the ship's frame) at the nose and tail, on the Earth's frame, the tail light comes on first. This is not a delayed light effect, as it is true if the rocket is leaving earth, and if the rocket is approaching earth. The relativity of simultaneity is what drives SR paradoxes. The Lorentz transform is linear, it has a slope (the Lorentz factor) and an intercept (clock bias). Clock bias is at the root of the paradoxes that appear to be caused by the Lorentz factor.
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  88. don't damn neutrinos. Without them, the Sun could not shed "electron number", which is required when you turn 4 protons and 4 electrons into 2 protons, 2 neutrons, and 2 electron.. aka, the PP cycle which powers the sun and gives us life.
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  89. so my question is about the case. A gamma source would be in lead, while a beta-only would be aluminum. (alphas can be safed in a ziplock bag, while neutrons go in a 55 gallon drum of borated wax). The lid didn't look heavy enough, the way he moved it, but the metal looked like new lead. Oxidized lead is darker.
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  90. you are correct. Each sees the other Lorentz contracted and moving slower through time.
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  91. idk if it helps, but Jeff Goldblum's hair is crap compared with yours. And ARIA, ..well I won't say nothin ...yet.
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  92. it is actually shorter in the barn frame. The length is the distance from the front to the back of the ladder, the thing is, according to the ladder frame, the barn measures the front position of the ladder first and then moves towards the back and measures the back position later, so ofc it's shorter: you moved your coordinates between measurements (in the ladder frame).
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  93. but we know a single ship Lorentz contracts in the Earth's frame, so declaring it to a "a single entity" that Lorentz contracts contradicts the set-up of the problem, in which the distance between front and back remains constant (in Earth's frame).
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  94.  @jpe1  well, if you replace the ladder with a long spacecraft, the mission planners can certainly predict the ladder/door collision and preprogram the camera to snap simultaneously. so the question then is, in which frame are we defining simultaneous? Once you do that, run the clock backwards to figure out which photons are hitting the CCD at that moment. I suspect in the ladder frame, the front isn't even in the barn yet. You'll see a normal sized latter with with a relativistic beaming barn approaching.....but I didn't draw a Minkowski diagram to verify that.
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  95. the string broke because the separation between the ships increased, in the string's reference frame.
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  96. It specified in the set-up that they do not act as a single body. The only specification is that they have the same acceleration profiles, and hence the same velocity profiles, with respect to time as measured in the Earth's frame. If you boost those profiles into the average-ship-frame, you get two different time coordinates for each. Colloquially, the from ship's clock is running ahead of the rear ship's clock (it's a clock bias/offset, not time dilation), hence, the front ship is moving a little bit faster than the rear, and it tears the string. Conversely, for one large ship accelerating uniformly in its own reference frame, Earth will see the nose cone's velocity profile lagging the tail's profile as the ship Lorentz contracts.
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  97.  @SynetheSage  I don't find the infinite energy argument compelling. It's more of a side effect. The fact of SR is: no matter how fast you move relative to someone else, say 99.9% c along "x", you're still at rest in your frame, and c is c in all directions. So which way do you go 0.1%c to reach c? x is the same as -x is the same as y and z. It's the nature of hyperbolic spacetime.
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  98. At can't be more rigid than "Born Rigidity" allows. Perfectly rigid matter would allow you to send signals backwards in time :-(
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  99. An absolute cloying affectation, made worse b/c Kyle is a very good narrator. It started during the Regan era, where pronouncing "Nicaragua" became a litmus test for politics.
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  100. Didn’t a darpa ai sim blow it self up because it maximized the score by minimizing damage from the adversary?
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  101. if I had a nickel for every time I used the chaos hand move to get some strange.....
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  102. no, because you're moving through Lorentz contracted space...until you stop and realize you didn't age over a very looooong trip.
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  103. simultaneity is relative, so you can't just say "they accelerate at the same speed" without specifying a reference in which to match velocities and times.
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  104. the fireball is a lot hotter than surface of the sun, more like 20x hotter than lightning (which is already much brighter than the sun)...but it's quickly hidden behind the opaque shockwave....which is heating air to >100,000K, so it's really bright, too.
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  105. The string is a physical manifestation of the local (inertial) length coordinate. Since the ships remain with constant separation in Earth's frame, they must spread out in their local rest frame, breaking the string. Since the string breaking is relativistically invariant (it can't break in one frame and not in another), it brings home the fact that Lorentz contraction is real physics, and not a matter of "perspective", as some like to incorrectly argue.
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  106. That the two ships travel at the same speed at the same time (for Earth) is neither "appearance" nor is it a "hypothesis", it is a "stipulation". So any analysis you do where it is not stone-cold-fact is garbage.
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  107. There are no inertial frames at "c", so the question "how does a photon experience time" is not askable, and any apparent insight gained from considering it is based on a fallacy, and is probably misleading.
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  108. And his technical accuracy.
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  109. 🚨 with emergency stop buttons under them every 20 feet or so is standard in accelerators. So is double door 🚪 key 🔑 interlock during operations, preceded by a closed search of all spaces by search experts …which can take hours per arc in large place like DESY or CERN
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  110. I suppose some people don’t like to be told what to think. I wonder if AI will ever have that problem
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  111. Ppl misuse the telephone and the mail. Even books (maybe more so) Never had a Nigerian prince send me a telegraph, though
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  112. or, the plane of simultaneity from the rear ship sees the front ship in the future (relative to Earth's plane of simultaneity), thus the front ship is moving faster.
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  113. Light doesn't have a rest frame. Such questions cannot be answered, so we don't ask them.
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  114. if the nose and tail have same acceleration w.r.t to the launch pad: then, yes.
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  115. infinite tensile strength violates special relativity. See: Born Rigidity.
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  116. the PEP is the whole point of degenerate matter.
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  117.  @logicplague  I checked from another account and I believe I was censored for using the word (which I can write here, duh: D generate) which in quantum mechanics means all low energy states (with multiplicity > 1) are filled... that is, you achieve the maximal spatial packing consistent with the Pauli Exclusion Principle. Since the minimum size of a state goes as 1/m, the ration of the size of a white dwarf to a neutron star is roughly (mass neutron) / (mass electron)....around 2,000. Very cool.
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  118. It can join fusion power and high Tc superconductors in the museum of hype, while quantum computing waits in the wings
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  119.  @ingerasulffs so close
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  120. AI is stupid af. draws weird picture tho.
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  121. It falls apart b/c relativistic mass is not a thing (anymore). No matter how fast the string moves, it's still just string at rest in its rest frame.
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  122. that is a major pitfall of learning relativity. Lorentz contraction is not a result of visual perspective. It's because a space slice of spacetime at equal time in the moving frame is contracted w.r.t. to the non-moving frame. Since the distance btw the ships is constant in the initial rest frame, they pull apart in the moving frame. The paradox is resolved when you remember the slice of contracted space is not simultaneous in Earth frame.
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  123. cut, but just a sliver off the back. Light is faster than the ladder, always.
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  124.  @spacemanspiff2137  When confused, I just do the Lorentz transformations. Step 1 is define "Events" in one coordinate system. Put the ladder entering the barn, at the entrance, at (t=0,x=0) in the barn frame and (t'=0, x'=0) in the ladder frame. Define other events. Transform them with the (linear) equations and ponder. All will be revealed. Think about Minkowski diagrams. Eventually, some degree of intuition is developed.... I first studied this in 1985, so it takes a while.
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  125. check on the Helium Flash: it takes a lot of energy to convert degenerate matter into normal matter, and then there is gravity's binding energy (about 20% of the baryonic mass).
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  126. The difference between the speed of light an a particle beam is m2/2E2, os LEPs electrons were faster than LHCs protons, but lower energy. Ofc fermilabs neutrino beams are the fastest fermions in the world.
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  127. no that';s right. we can go back to newspapers and radio. let AI burn the fossil fuels arguing with itself.
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  128. Suppose you've reached 99% c going Galactic North and coast for a bit. Now you are ready for the final push.The speed of light in every direction is still 299,792,458 m/s....so in which direction should you go to try to break it?
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  129. No. Transverse dimension aren't weird.
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  130. relativity is not about "perspective" in the traditional sense. In the non-traditional sense (a coordinate diffeomorphism)?....that's a different....perspective.
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  131. but they don't. The stipulation that they accelerate equally in Earth-frame means they're on two separate trajectories.
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  132. The claim that 2 ships act as 1 is false.
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  133. You can't say "the whole thing moves at the same speed" without specifying a frame of reference. If the acceleration is constant in the Earth's frame, then the speeds are always the same. That means the speeds are different in either ships' rest frame, because the times in the 2 ships are different (by (v2-v1)*(x2-x1)/c^2, for small |v2-v1| ).
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  134. you cant think of anything more au currant?
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  135. solar or sidereal revolutions. btw: the correct answer is 1: 3 rotations and 1 revolution. Nice work college board of woke dopes.
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  136. we all want Kyle's follicle brilliance, but alas....
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  137. If they were a single entity (in their restframe), they would notice nothing. But: Earth would see the two ships accelerating differently (violating the set-up in the paradox). The rear ship would be 'faster' than the front ship, and that speed difference would account for the Lorentz contraction of the string.
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  138.  @johnbennett1465  The problem with your analysis is when you say "all 4 marks are accelerated at the same rate"...or v1(t1) = v2(t2) = v3(t3) = v4(t4) = v with t1=t2=t3=t4. If that holds in the Earth frame, then in the ship frame t1' > t2' > t3' > t4', so that position 4 reaches "v" before 3 (and so on). The relativity of simultaneity is the root of all SR paradoxes.
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  139.  @johnbennett1465  But they are not accelerating at the same rate in their own rest frame. In fact, in your example, there is no frame in-which they are all accelerating at the same rate. In the Earth's frame (1+2)/2 accelerates at the same rate as (3+4)/2 (the COM of the ships remain equally spaced for earth), but (2-1) and (4-3) are Lorentz contracted by gamma. For the ships' frames, (2-1) and (4-3) are fixed (the rest length of the ship), with the COM's separating: (3+4)/2 - (1+2)/2 expands by gamma. There is no compensation for speed-of-light delays, as that is totally unnecessary and of no use in thought experiment.
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  140. please use American to pronounce ferreners' names.
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  141. Just say, "I don't get it" and try to learn. This self-esteem-movement inspired "there is no right answer" may work in gender studies, but it is an epic fail in physics.
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  142.  @TristynRusselo  we have the tech, it is proven.
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  143. Of course it will be verbose, as it ingests more verbose writing than terse, because reasons. Strunk and white is very short.
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  144. Simultaneity is reference frame dependent, so if they have the same (non-trivial) profile in Earth's frame, their profiles differ in all frame moving w.r.t. to Earth. Thus: your 3rd sentence asserts a contradiction, and all conclusions from it are wrong.
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  145.  @N3onDr1v3  said observer in 3rd paragraph would see ships moving apart. There are problems with his minkowski diagram. (1) He labels the time axis "y"...awkward (2) While he describes the resolution of the paradox qualitatively by showing the tilted line-of-simultaneity intersecting the worldlines further apart, he skips the fact that the tic marks are dilated by sqrt((1+v^)/(1-v^2)), which mitigates the effect...but doesn't cancel it out.
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  146. Moving a spot across the moon at >c is meaningless, because nothing is moving. It's not much different from: I am thinking about Mars. Now Venus. See: the place I was thinking about moved faster than the speed-of-light.
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  147. No. the nose and tail a single ship do not move at the same simultaneous speed in the initial rest frame, which violates the condition of the paradox, hence all conclusion based on that proposition are inconsistent.
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  148. "same time" according to who's clock? (Earth's...but do the front and rear ships' clocks differ from Earth's in exactly the same way?).
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  149. But the conditions are different. The problem stipulates that each rocket follows identical v(t) profiles in Earth's reference frame: so they must, by definition do that. No such constraint applies to the nose and tail of an individual rocket. Moreover, that a rocket undergoes length contraction implies it can not meet that constraint.
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  150. exactly one spaceship separation.
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  151. This is a thought experiment. Space is empty, and flat.
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  152. it was not a routine test.
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  153. Lorentz contraction is not "perspective", it's physical reality (in special relativity). The string snaps. Just do the Lorentz transformation, the ships spread apart in their (average) reference frame.
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  154.  @jgreen2015  no.
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  155.  @kalikiller1771  perception and light propagation are not helpful in analyzing this problem.
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  156.  @jgreen2015  but the ships aren't traveling with a relative speed of zero in their (average) frame. The front ship is faster b/c the relativity of simultaneity.
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  157.  @jgreen2015  No, their velocities are simultaneous in the Earth frame. In either of their frames, the front ship is in the future w.r.t. to the rear, relative to the Earth's timing,
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  158.  @jgreen2015  maybe you should just do the Lorentz transformation. If something is simultaneous in the Earth's frame (say, reaching 0.9c), then it simply cannot be simultaneous in a moving frame, since the relativistic invariant is s^2 =(ct)^2 - x^2. In this case, if the string length L, the invariant is s^2 = -L^2. In the moving frame, the spatial separation is (gL)^2 where g>1 is the Lorentz factor. The time separation then must satisfy: (cT)^2 - (gL)^2 = -L^2 so that: |T| = gLv/c > 0. If you need clarification, that's fine, but if you want to argue that I am wrong: please don't. Anyone here who thinks I am wrong, is wrong. I studied this stuff under the greatest masters at the time, not from a rando youtuber.
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  159.  @jgreen2015  it's different, which is why the set up to the problem specifies that two ships have the same velocity profile in the initial frame. That's why it's 2 ships and a rope, not a long ship.
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  160.  @jgreen2015  that's the point, they are going at different speeds. If they are accelerating, they can only go a the same speed in one reference frame, as t'=gamma*(t-vx/c^2) and "x" is different for each ship.
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  161.  @jgreen2015  it's not time dilation, it's simultaneity that is the problem. You don't understand the paradox. I just posted the Lorentz transformation showing your error. Figure it out.
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  162. "41%"...have you ever heard a doctor use that many sig figs?
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  163.  @druhu4590  you need at least 10,000 ppl in your study to distinguish 41% from 40%….. that study didn’t happen.
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