J.C.MacSwell

Hi Avner...this is an old thread! Particles carry momentum not force. For a boat and air particle initially at rest: If the force accelerating the particle is the same but opposite in each case, and for the same duration, the particle (and boat) will again be stationary...but the boat will be displaced to the left (not as much as the presumably lighter particle is displaced to the right) You may of course consider this displacement insignificant and ignore it If the force accelerating the particle is the same but opposite, but for more or less duration in each case, the boat will be in motion at some velocity, with momentum equal to but opposite that of the particle.

If it arrived at 1 foot up at 2s; from which direction would it arrive? If it arrived at the top at 60s; from which direction would it arrive?

A spring...to the degree that it is also a damper (almost insignificant for a good spring) . Only an ideal spring does not have any hysteresis. But I think you are after something else...

How do we know it's not reversing right now?

Espergalacanto

In a "perfect world" the perfect cosmological principal would hold: http://en.wikipedia.org/wiki/Perfect_cosmological_principle The Perfect Cosmological Principle states that the Universe is homogeneous and isotropic in space and time. In this view the universe looks the same everywhere (on the large scale), the same as it always has and always will. It is the principle underpinning steady-state theory and emerging from Chaotic inflation theory.[1][2][3] The Perfect Cosmological Principle is an extension of the Cosmological Principle, which accepts that the universe changes its gross feature with time, but not across space.

The unbolded is what Jacques is getting at. The bolded contradicts what was just stated. If the natural rate of expansion (assuming there is one) is being retarded by gravity, but that effect is reduced over time from the expansion, then the expansion will increase over time (accelerate) as it approaches that natural rate. The rate of acceleration will diminish but always be positive. Edit: not sure if that actually fits the data just that it is based on Jacque's assumptions

I think they are after a proof that regardless of any differences in the masses

This would be true if, and only if, the balls had the same mass.

The problem with this is that we only have information that there are 2 children, and that the youngest is a girl. You have no information on the sex of the elder. It's still 50/50 If you knew at least one was a girl and you asked if the youngest was a girl, that would be different. Note your first post: It depends on how the information came out, but based on the fact that it was information on this girl, you still have nothing to indicate any change in possibility for the other. edit: I reread Litenoumjuq's post looks correct

I wasn't arguing against any correlation (not sure what "entanglement" might suggest if there was none at all), just thought your analogy was suggesting a fixed or classical correlation with preset but unknown results which has been experimentally proven not to be the case. I think(?) we all agree that there is no hidden variable without non locality, where Juanrga goes further suggesting that neither is necessarily required. I have not read the text ( http://quantum.phys.cmu.edu/CQT/ ) beyond briefly scanning it over but don't yet see how non locality can be avoided (or supported given SR, so I really don't have a consistent picture of what is going on...I didn't think anyone did)

Not necessarily. The force will be equal but opposite in any case. Whether the stroller accelerates or not is dependant on whether the external forces on it balance.

Hi MigL This might be the link?: http://www.upscale.utoronto.ca/PVB/Harrison/BellsTheorem/BellsTheorem.html Quoting from it (bolded by me): "Imagine we take a coin and carefully saw it in half so that one piece is a "heads" and the other is a "tails." We put each half in a separate envelope and carry them to different rooms. If we open one of the envelopes and see a heads, we know that the other envelope contains a tails. This correlation "experiment" corresponds to spin measurements when both polarisers have the same orientation. It is when we have the polarisers at different orientations that we see something weird." This is why I stated earlier that the analogy seemed reasonable but in fact it can be shown, by doing the experiment in a certain way, that it does not hold up.

I'll be the guy to say "don't quit your day job"... Unless you have a substantial amount of money, enough to sustain the lifestyle you would be comfortable with, you are better to keep a job, arguably one that does not drain you mentally, but allow you to pursue your dreams in your spare time with no undue pressure to accomplish something you feel would be of great significance...just putting that out there Best of luck in any case, and I hope you enjoy your pursuit

No part of it. David Griffith in the video referred to, not the author of your text. As for "absence of nonlocal influences", what exactly does that mean? Does it mean 1. the wave function cannot be collapsed non locally FTL(so no non locality at all?), or does it mean that, 2. when or if it does, it cannot effect information or causality FTL? I believe that the 2nd is the most commonly accepted. Is it not? Is your author suggesting the first? I am not familiar with his approach but will have to look into it.

I don't have that text (edit: found this on line: http://quantum.phys.cmu.edu/CQT/) , but here is a non technical lecture by the David Griffiths I found while looking for info on Robert Griffiths and thought it was interesting with regard to the collapse of the wave function. His entanglement analogy is frisbees thrown with both left and right hand (warning: it is 53 minutes long!) He seems to say that non local effects are in fact indicated (consistently) by experiment, though without information or causality, and "barely" (he holds his fingers barely apart) compatible with SR (personally I don't see the compatibility)

Observing one collapses the wave function of the other, not merely exposing a pre-existing condition, like in your envelope analogy. Did I take your analogy out of context? from http://en.wikipedia.org/wiki/Alain_Aspect : "Stated more simply, the experiment provides strong evidence that a quantum event at one location can affect an event at another location without any obvious mechanism for communication between the two locations. This has been called "spooky action at a distance" by Einstein (who doubted the physical reality of this effect). However, these experiments do not allow faster-than-light communication, as the events themselves appear to be inherently random."

You are making the same argument Einstein made (so you are in good company!), but real experiments trump thought experiments. Note that "vast" distances have not been proven and it is said that information is not transferred superluminally, but you may want to check out the Aspect details. They certainly indicate a non local effect and no prior fixed correlation or hidden variable.

We do see the noon day Sun with our peripheral vision...

This seems like a very reasonable explanation (hidden variable theory)...unfortunately the Aspect experiments proved it does not work that way Using your example: it would be like them opening the envelope in such a way, say opening the left side facing the closure, they would find they could induce the head twice as often as the tail...and still the other envelope automatically has the opposite...quantum weirdness

1. Time dilation, and length contraction as well, is frame dependant, so you have to be careful what frame you are using. 2. You can't use the reference frame of the light. It does not have one. If something is 8.6 LY away in your reference frame, you would measure and calculate that the light will take 8.6 years to arrive.

You're all set then... ...just make sure your mother never traveled there first

Neither I nor ACG were debating that, but thank you all the same. You can always claim, correctly at some level, that nothing is direct. Nice, though, to see you admit the "indirect" varies. I hope that last part did not refer to black holes... ...if it's about higher dimensions we are skeptical...but back on topic...

in an inertial frame nothing can exceed the speed of light. The Earth frame is not an inertial frame, so that limit does not apply.

OK, so you are thinking that observing can only be visual, is that it? Even if you limited it to that (not correct), there are billions of times (please excuse the understatement) more visual evidence of air than black holes.