J.C.MacSwell

I see only two obvious stable positions for the system, stone on the bottom and balloon at the surface. In between I don't see how you can easily tune the weight/volume to a stable condition, though you could tune the temperature and temperature gradient of the water to get that affect.

Yeah, my thing on the scale gained mass...so of course it weighs more. At that point I'm not really weighing a photon though... Picture trying to chase one down with a scale. If you tried to time it so that you were at 99.9%c as it went by you would have redshifted most of the energy out of existence in your new frame...so by succeeding in doing this you would have lost most of what you were trying to weigh and still no further ahead!

Hi Janus I often don't understand it until I have it clear in my head from more than one frame and I'm not there yet but: At what point is it as high as 3.73? Past 2am here so the brain is a little foggy, but I see it as very close to 2 as described in your last line and never much above. Except with an acceleration involved I don't see it and with none specifically defined even at the turn around I don't see a point where it is 3.73. Thanks JC

...and if you take weight as force affected by gravitation, then photons could be considered to have "weight", again with blue being "heavier" than red, though I'm not sure if that would be considered "weight". If you had something on a scale, and it absorbed a photon it would weigh more...and more if it was blue than if it was red.

He had to have more than one son. There is no requirement that he reproduced with more than one woman. Polygamy and the fact that males can have more offspring does explain the 50,000 year gap, but you cannot necessarily "blame" the current Adam.

Yeah, might be better to add a few more invincible parts, just to keep it interesting...

According to who? Aristotle?...or Vilas Tamhane? (the one who wrote that no theory was sacrosanct!) Admittedly our former and more intuitive views of space, and especially time, took a beating as SR was established... but something had to give and SR seems to have held up quite nicely as it has yet to be proven wrong. Feel free to try to prove it wrong, but Vilas Tamhane believing it irrational or impossible does not count.

Then why do you, like a broken record, continue to base your objections on the same incorrect premises? Where is it that you are asking "what if I am wrong?" You have offered nothing where current theory fails to agree with experiment, and instead cling to ideas that are clearly wrong. What is so sacrosanct about your beliefs that they should hold up despite evidence to the contrary?

Sadly, it is not uncommon. You have to check the air (as well as have other safety procedures in place) before any tank or confined space and rusting certain depletes the oxygen.

I don't understand this statement, even if it's "own frame" is it's rest frame. I assume I am missing the context. When switching frames anything not invariant is still mathematically dependent. I assumed that was what Tar meant by "staying in tune" (I could be wrong but I hope he did not mean that no time dilation was possible)

If you cannot keep your own examples straight it is going to be pretty tough to learn anything.

Assuming they were the same age prior to becoming part of the Earth and Sun, then yes. The oldest (least accelerated in lowest gravitational field, spending it's "life" in the cmbr isotropy) defines the age of the Universe. (correct me if that is wrong) You are right that it is not easy to separate out SR and GR effects when doing experiments.

As long as "apparent" is understood in the context that your observation is apparent as well, then I think that is fine. If you think that your view is somehow "real" in a context that the others is not, then you cannot support this scientifically. As for whether the rod contracts (or expands, if the relative speed of the observer decreases), I would say it depends, again, on what is meant by "contract" or even "physically contract". It cannot mean precisely what we mean in our daily usage as the mechanism is different from that of any type of everyday usage. But the length or distance gets measured as shorter when applying a consistent set of physical laws.

No math: How can your measurement of the rod, which remains stationary in it's rest frame not contract if you accelerate in that direction? Please answer using accepted laws of physics, or at the very least assumptions that have not been proven to be incorrect.

Every process works in such a way that the exact same events take place in each frame, even non-inertial frames. Only the "look" and timing is different.

Any elementary physics text that includes Special Relativity. Sorry Tar, but it would only break your imaginary laws, your conjectures, not accepted physical laws. It is not simply a photon lag phenomena that physicists "forgot" to account for, or a 100 year old conspiracy to ignore it.

Keep in mind the kinetic energy of the 3,000 lb weight at the end of the second. It is not an insignificant part of the energy in this case.

Which frame would that be? I personally use a number of them everyday and would find it very inconvenient not to switch.

1) 21,000 ft lb of energy 2) 1500 ft lb/hr

Sounds like potential energy. Power is rate of work or energy.

...and the bolded will be true for Betty and Fiona on Dock at rest in the original frame only. No synchronization of acceleration is possible for Bert or Frank.

A "perfect" vacuum would not even have photons in it. Nothing would remain that could define a temperature.

Frames generally speaking* do not have their own independent reality. We may shift around mathematically in the definitions of each, in both time and space...but we still exist...we are still "here" in the past, present or future of whichever frame you choose. (assuming the frame is physically legitimate) They are all real in that sense. *you can define a frame to exclude us, but in that sense the frame is just limited not our reality

I made it up to make a point as others were claiming that a set distance between 2 points (or an object of non zero dimension) could be maintained while accelerating and at the same time the 2 points could at all times share a rest frame. I'm sure there are a few similar paradox themes around that are similar though I don't recall one directly for that purpose. It's just the way simultaneity is broken with acceleration in SR-when one moves into the others past. Edit: I read the Wiki and interestingly it looks like it's the same Bell from Quantum physics that came up with "Bell's Inequality", so this could be "Bells Inequality II", although it originated earlier with someone else who was pointing out the actual physical contraction required to accelerate (or stresses produced as I mentioned earlier)