I found the videos extremely helpful. I'm just a novice and struggled with MTW, etc. on my own without much success. I appreciated the way he (eigenchris) used simplified notation in the beginning then added more details as needed, rather than bombarding the reader with everything all at once. I...
In the first sentence of Chapter 2 in Ben Crowell's "General Relativity" he states:
"The geometrical treatment of space, time, and gravity only requires as its basis the equivalence of inertial and gravitational mass".
This is stated as if it's an obvious fact, but I don't understand why. Why...
Slightly off topic for a physics forum, but an interesting sf novel written back in 1970 by Poul Anderson explored the issues of forward time travel using relativistic speeds: https://en.wikipedia.org/wiki/Tau_Zero
Perhaps the answer that the OP was looking for is that the reason light travels at the speed it does, is because the universe is apparently constructed with a speed limit. Light, being massless, can travel faster than anything else, but it cannot travel faster than the speed limit. Physicists...
Thanks, that helped. So I guess, in a sense, it is the field itself that is "flowing". Or maybe not. Perhaps it's best not to press too hard on the fluid analogy and just trust the formalism.
Hi. I've been reading PF for quite a while and have decided to ask my first question. Please be gentle. (I'm a retired computer programmer, not a student)...
I've been learning Gauss' divergence theorem and I understand what "flux density" is when considering things like fluid transport or...
A star chart and small binoculars are a great way to start out. Learn the names of the bright stars and constellations. Find the planets. You'll be amazed at the number of (non-stellar) objects you can see without a telescope.
Bing. The light bulb finally goes on. I've struggled to understand this for quite some time, and was starting to get close, but your post makes it so clear now. Thanks Ben!