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

  1.  @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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  2. Does anyone simulate all possible action to identify corner case?
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  3. 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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  4. 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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  5. it's not a nuclear accident, it's a radiological accident.
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  6. timestamp?
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  7. Red Rocks State Park. nice.
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  8. 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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  9. There are no practical reasons in thought experiment. "Practical" is a problem from real experiments and engineers.
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  10.  @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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  11.  @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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  12. 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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  13. The problem with radioactive material is that Avogadro's number is really, really, big.
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  14. 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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  15. what's that in REM/hr?
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  16.  @alexanderx33  thx. Milli rem is preferred ofc, but not by auto spell
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  17. The dangerous physics of rock climbing can be summed up with: g = 21.9 mph/s
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  18. Star Wars dog fight scenes were taken shot for shot from a WW 2 ball turret gunners v luftwaffe fighters.
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  19. we can't "do without" relativity, rn. Without it, GPS wouldn't work, nor would interplanetary navigation.
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  20. a space ship can't go the speed of light.
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  21. Beta radiation does make it through thick plastic, but not tritium decay....it is just so low energy.
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  22. TMI was the beginning of global warming
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  23. 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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  24. 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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  25. 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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  26. Do wonder why Bell chose a string when he could have very well said "metal chain"?
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  27. 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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  28. That burn goes all the way through. And 500 rad whole body is ld50 40x is terrifying
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  29. 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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  30. 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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  31. Even with a sawed off, you still worry about bears. You just worry less.
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  32. 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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  33.  @Dingusdongus257  maybe it was Sam Brinton…but he’s into puppy play.
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  34.  @goosecf  it would be gamma rays, so no: you can’t see it coming, even if you could see it.
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  35. found Rogans Smurf account.
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  36. 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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  37. 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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  38. 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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  39. 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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  40. you are correct. Each sees the other Lorentz contracted and moving slower through time.
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  41. 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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  42. 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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  43. 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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  44.  @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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  45. the string broke because the separation between the ships increased, in the string's reference frame.
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  46. 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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  47.  @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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  48. 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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  49. 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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  50. 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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