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Everything posted by swansont
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But when you say double-slit experiment, it implies the basic experiment - it does not imply quantum eraser. Similarly, a quantum eraser experiment does not imply delayed choice. These are all distinct experiments and should be properly identified. The use of polarization is used to identify the path, but not in a way that compromises the interference, as shown by the fact that you get interference when you don’t know the path. You can do which-path experiments where the path is identified by looking at an entangled photon created before the interference. So the which-path information has nothing to do with altering polarizations in the double-slit path.
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Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
It's not one length. Go back to the example of kinetic energy you have ignored. In my frame, the train is at rest, and thus no kinetic energy. In your frame it is moving, and has a KE of, say 10^7 Joules. How can it have two values of kinetic energy? (answer: because KE is a frame-dependent quantity) -
Requirement for two "nows" to grasp the idea of Simultaneity
swansont replied to tar's topic in Relativity
AFAIK they were strapped into the seats, so the beam would be going perpendicular to the plane's motion. But that would have no measurable effect on the outcome according to SR. No radioactive decay is involved. It would be transverse in this case. But if you're thinking about some preferred frame, then you have to account for the fact that trips at one time of day would be in one direction, and trips 12 hours later would be in the opposite. The time dilation was far larger than the measurement error from those clocks. If you think that the accelerations played a large part, that's one more thing that's up to you to demonstrate. From an relativistic point of view, the effect is minimal. The gravitational drop in the several millisecond travel of a thermal cesium beam is quite small. External electric and magnetic fields are shielded; these would have a large effect on the clock's performance if they were not. Yes; the earth's rotation is taken into account in the analysis. The motion about the sun is not as the effect is (or was, for those clocks and such a short experiment) too small to measure Can you calculate the angular speed of this to show that it's "rapid"? The gravity to show its hugeness? (hint: how long does it take for us to compete 2*pi of a revolution?) Feel free to show this. This is a graph from the Hafele-Keating results (Science, New Series, Vol. 177, No. 4044. (Jul. 14, 1972), pp. 168-170) Fig 2 from p169. Seems to me the scatter in the timing signal is smaller than ∆t. (edit: and they cite the experimental error in their results) It's likely you would need to show some model demonstrating that you would expect a result before anyone does this experiment. Not if relativity is correct -
Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
Who was doing the measuring? The answer is frame-dependent -
A rational explanation for the dual slit experiment
swansont replied to Marius's topic in Quantum Theory
Um, about that... https://physicsworld.com/a/the-double-slit-experiment/ -
I stored my belongings for several months after I finished grad school and went home to live until I got a postdoc. Cheaper than moving it across country and back. They were fenced in and my unit had a lock. And I wasn't storing anything that had a high resale value.
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A rational explanation for the dual slit experiment
swansont replied to Marius's topic in Quantum Theory
Is that more or less irrational than expecting quantum behavior to be exactly like classical behavior, when quantum mechanics was developed because the behavior did not follow classical physics? The descriptions we give are hampered by the fact that people like to hold on to familiar, classical ideas, like particles and waves. Quantum particles behave like quantum particles, but that doesn't help bridge the gap of understanding, so we use the observation that they have elements of both wave behavior and particle behavior, and one will be present depending on how you are looking at them, similar to the example Markus has provided above. QM has more example of trying to explain some effect using classical terminology (I'm thinking of tunneling as a prime example). They are more like analogies than actual models, and always have limitations. -
If the Universe is infinite, will we be reborn?
swansont replied to FindingMeaning's topic in General Philosophy
You also have an infinite combinations of initial conditions. How could you guarantee that you would recreate the exact conditions required? What if one of the influences was the temperature of the CMB, which could not be replicated at a later time? There are probably many variables that would not be the same. Composition of the matter available for star and planet formation, for another example - they would tend to have more heavy elements in them as we cycle through generations of stars. -
Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
Contradictions are not simple. It's not surprising that they arise because we are discussing special relativity, which is not Newtonian, and you can't mix-and-match models in this way. (it can lead to contradictions) It could be that whatever questions/confusion you have arise from such contradictions. What is needed is a self-consistent picture of what is going one. Newtonian physics is, and so is SR. The latter matches observation, the former fails to do so under situations like we are discussing. Are you going to address my example of kinetic energy, and whether that is an illusion for Bob? The issue is that length and time are absolutes in a Newtonian world, so we aren't used to thinking of them as variables. But you can derive the effects, as Einstein did, based on c being invariant — which is another thing that we're not used to in Newtonian physics — and you can also look at the experiments that confirm it. Most of them involve time, because time is easier to measure at the precision demanded by such experiments. -
It’s a basis of one of your speculations and not relevant here. You refer to maths but there are no equations in that paper.
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Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
1. That’s how this works. People see I’ve raised the issue, and they refrain from being repetitive. and 2. That’s not an actual rebuttal of the issue, it’s dodging it. So if nothing moves, how can there be time dilation or length contraction? -
! Moderator Note Do NOT bring your speculations into other threads.
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Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
The part where you said “Nothing moves in a block universe.” Or maybe where you said Bob is moving. Which it? Issues were raised, AFAICT you’ve ignored them. -
Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
How is this possible unless Bob is moving relative to the earth? -
Requirement for two "nows" to grasp the idea of Simultaneity
swansont replied to tar's topic in Relativity
Explain why clocks at different speeds, and/or gravitational potentials, are observed (as in, there is experimental evidence) to run at different rates. -
I’m not censoring anything. I’m reminding you that if you make claims you need to back them up, which is part of the rules. IOW, WAGs are not “conversation” If you will take care to notice, none of your material I quoted mentions God. If this is mere confusion on your part, you should pay attention. Your attempt at testable predictions falls well short of the rigor we require.You admit you aren’t a scientist, so how much “support” do I need that your posts lack rigor? You admitted as much when you said “I believe the best way to work out the details of a theory or hypothesis is through argument.”
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Physicists failed to ascertain the nature of regular matter for only slight less time. That dark matter and dark energy need to be investigated is a relatively recent discovery. And AFAICT there’s no connection to philosophy here. ! Moderator Note Then please refrain from making non-mainstream scientific claims. If you make them, you will be expected to back them up
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Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
You made a claim about relativity. -
Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
“Bob goes close to light speed in his ship” sounds like Bob is moving. That’s an interesting delusion. -
Length contraction in a block universe must be an illusion
swansont replied to 34student's topic in Relativity
So how is Bob moving?