Recent content by stone1

There is something (among many things of course) that confuses me with the uncertainty principle as it pertains to position and momentum of a photon. If one shoots a photon of red light, for example, at a screen, one can see where exactly the photon hits the screen so position is known. Also...

Here is a way to travel faster than light -- fall into a black hole. To an outside observer you will pass the light speed limit and your light will not be seen again. You can also rent a spaceship and go far enough so that the expansion of the universe carries you away faster than light. So...

Not if time is only in our minds and if "increasing entropy" and "time" are the same thing (the second law is as much about "increasing entropy" as it is about "time"). Saying that entropy should increase in both directions of time is like saying that time should flow into the future both when...

This last discussion helps me even more. I guess the motivation of my question is the following: If one were to actually measure the speed of light, one would need a specific initial position in timespace (A) of the photon and a specific end position in timespace (B). Then one needs to calcualte...

This is probably a crazy question, but what happens to a photon when it hits an antiparticle? Say the same type of antiparticle that Hawking uses to derive his Hawking radiation. Does the photon disappear? Is its energy/frequency reduced?

Thanks a lot. That helped.

So you are saying that one can measure the speed of a photon with infinate precision, correct? Also, is the exact speed of light (the actual number) derived from theory or is it based on empirical observations?

I appologize if my questions make no sense (very likely as I do not have a physics background). 1. The uncertainty principle states that precision of measurement is identified only down to the Planck's constant. If this is so, how can one measure the speed of light with infinite precision? ANd...

Also, when does gravity become zero? It is zero inside and not zero outside the sphere. But what is the gravity exactly at the sphere?

I find this topic fascinating. What would happen if the hollow sphere is not perfect, but randomly vibrates? Would the vibrations cancel each other out? Or would the object inside the sphere be subject to vibrations as well?

Thanks a lot sylas, I see what you mean.

Would someone with a mathematical understanding of the redshift please answer this question. Given the mathematics of the redshift, is it fair to say that we are surrounded by a black hole (or more like a black boundary that acts like a black hole)? All light is redshifted by the black boundary...

But what is the source of the aging difference? How can you say who moved? From your persepctive, your wife moved and so she should come back even younger than you? Is the acceleration/deceleration the source of the difference? You accelerated/decelerated while your wife's frame of reference is...

or you could move so far away from the original object that space expansion kicks in and you can move relative to the original object at speeds higher than c.

Let me first say I am just a layman interested in physics, so my question may not be quite correctly posed. One thing that majorly confuses me is that you are talking about different types of velocities. Experiments show redshift for regular velocities - if an object moves away from us (no space...