PeterDonis's latest activity

What I meant was, we have a large number of results of momentum measurements on the particles that were prepared as I described, and we...

What do you mean by "sample" here? What I described was preparing a large number of particles in the same state, and measuring the...

Here are some more things to consider as food for thought: In RocketGirl's rest frame, the Earth is moving in the minus ##x'##...

If by "the Copernican view", you mean the view that the Sun is the center of the universe, what makes the Sun special? The Sun itself is...

No. No. What is the case is that using a frame with the Sun at the center (or to be more precise, with the barycenter of the Solar...

Actually, as my post #15 indicates, you can use the time dilation formula to get the correct answer for that particular question...

This is actually correct--if you correctly understand what "a smaller amount" means here. If you look at the numbers I gave in post #14...

Here, I'll give you the correct answer to this question: 1.77 years. I got it by a simple Lorentz transformation, with ##v = 0.8##...

Unfortunately, Brian Greene is notorious for only giving you part of the story. His pop science books and TV shows are even worse. I...

Maybe this is jumping ahead... but I think the quicker you get to this topic (below), the better off you'll be. Have you tried to draw...

No, she does not know that. What she knows is that Earth and Proxima Centauri are 4.25 light years away in the frame in which Earth and...

Suppose I prepare a large number of particles in the same state (i.e., same wave function), and then I measure the momentum of each one...

Yes, but we can still use them mathematically to help understand how actual physically realizable states like wave packets work. This...

That product is what appears in the quantum uncertainty principle. But each ##\Delta## by itself is not constrained by that principle...

This intuitive picture works nicely for position and momentum. But the uncertainty principle is not limited to position and momentum. It...