# Search results

1. ### Is Mass Relative?

well it seems that you change in mass would be equal to your change in energy, potential or kinetic, then that divided by the speed of light squared plus your rest mass? Is there a mass that stays invariant no matter what reference frame you observe it from?
2. ### Is Mass Relative?

So mass is not a set number at all then. If you were travelling next to an object at the same velocity, and you measured its mass, and then some how measured it while you were at rest and the object was still moving, their masses would differ?
3. ### Is Mass Relative?

Ok this may or may not sound like a very stupid idea. But having read the Black Hole War by Leonard Susskind, he makes a claim that as the Earth gets closer and closer to the center, squeezed by gravity, it loses potential energy. The lost potential energy is then radiated as heat, and therefore...
4. ### Question on Black Holes

Ok, that makes a lot of sense. Thank you for clearing that up!
5. ### Question on Black Holes

Actually JesseM, that makes perfect sense to me now. I somewhat thought that may be it, but I understand now that the ever increasing redshift causes it to disappear to plain sight. Its really interesting how black holes work and its odd to think how many contradictions to everyday life occur...
6. ### Question on Black Holes

But that doesn't make sense. If someone at a great distance never see's the particle cross at the event horizon, then it never disappears completely does it? so wouldn't the black hole illuminate, or at least be visible from all the particles that has fallen into it?
7. ### A problem with time travel.

Hmmm, this is an interesting problem. Take into account a Minkowski diagram (the three spacial dimmensions on the X axis plotted as a funtion of time on the Y axis). If you move back into time, which would be moving down in a verticle line, you yourself stay in the same position it seems at a...
8. ### Question on Black Holes

Well, I'm currently reading The Black Hole War by Leonard Susskind, and one thing to me seriously doesnt add up. It says that when someone falls into a black hole, and observer from the outside would not see them fall into the singularity, but they would seem to stretch out and move slower and...
9. ### New to this kind of math

wow thats a good amount of reading. Thank you! what i really hope to get out of this is the ability to write a good proof and understand why stuff works. Its odd because i used to hate proofs in geometry freshman year, but now i really want to learn to write some. I always wonder why stuff works...
10. ### New to this kind of math

Well, first of all I'm extremely interested in math. I'm a junior in highschool right now and im taking the highest math i can for my grade, which is pre-calculus honors and im also teaching myself single variable calculus. I have read some of Road to Reality by Roger Penrose, which teaches some...
11. ### Anyone have a good Physics Book?

well id like Quantum mechanics, but mostly string theory and things along that line. even nuclear/particle physics.
12. ### Anyone have a good Physics Book?

I've read a lot of the "popular" physics book, i.e. Brief History of Time, Relativity, Elegant Universe, etc. I want something more, perhaps explaining why things work with math and what not. Maybe not so popular, yet intriguing none the less. Does anyone have any ideas?
13. ### 1-dimensional strings

a one dimensional string was thought of as a zero dimensional point particle because of how small it was, and the more advanced mathematics behind the theory of strings. And energy is not a mathematical construct, its a real thing. You can have pure energy. Energy and mass are the same thing...
14. ### Physics Careers in Physics?

thats actually great advice. thank you for that, gmax. And you are exactly right. I love physics and reading about advanced stuff. It teaches me to think logically and creativity and view this world as something more than what i see. Hopefully i can make some money doing that as well, but i...
15. ### Any good Physics Interactive Programs out there?

Does anyone know of a good physics interactive computer program to mess around with, and perhaps even learn something? maybe even a mathematics program as well would be cool. if you have any ideas, i'd appreciate you sharing!
16. ### Physics Careers in Physics?

well i can get through it without the math. its like understanding how a computer runs but not knowing the parts that make it up. I vaguely understand some of the "simpler" math behind it, and im reading Road to Reality by Roger Penrose which explains a lot of the math, but most of it i am...
17. ### Video lectures of Structure and Intepretation of Computer Programs

I'm thinking berkley. did you happen to try iTunes for any of the videos? they have some cool physics lectures i downloaded a while ago free. so they may have something that your looking for.
18. ### Physics Careers in Physics?

Ok, I know there are probably plenty of posts on the site about this sort of thing, but I'd like to hear what you guys think. I'm a junior in high school and i really love physics. I consider myself "advanced" in the subject, for I read book after book about physics, string theory, particle...
19. ### Massachusetts Physics Internship?

Well I am in AP-Physics, which is a college course basically. I also read heavily on the subject, and am active on these boards. So maybe if I could possibly prove my worth to them? Why not! Thank you for your information!
20. ### Massachusetts Physics Internship?

so this just for undergrads, not highschool kids? because I'm only a junior :(
21. ### Massachusetts Physics Internship?

Does anyone know where I would be able to get a physics internship in massachusetts or anywhere relatively close by? (i.e. New England, New York, Pennsylvania etc) It would be greatly appreciated if anyone had an information.
22. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

The wooden block obviously. One, it has more final mass than the steel one, because it has the bullet plus the mass of the wooden block. And did we agree that the wooden block would have more velocity? because that would further corroborate my thinking. it would be much easier if we had actually...
23. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

because in an elastic collision that repels a bullet, thereby causing it to go back in the oppisite direction with an almost equivalent speed, the kinetic energy must be conserved. if the bullet was stopped and all the kinetic energy was transfered into the steel block, then maybe it could have...
24. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

"One hits a steel block, and bounces off. Both blocks are on a frictionless table. The steel block is a perfectly inelastic collison which causes the bullet to bounce of with the same v, and the block moves away with the same v." if it is an elastic collision, then kinetic energy must be...
25. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

no because it repelled the bullet. the steel block has no velocity. the wooden block does. If the steel block did move, and it also repeled the bullet at the same velocity, then it would have spontaneously gained energy, which is impossible.
26. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

Hmmm, I would want to say no. For an inelastic equation, where the bullet would go into the wooden block, the equation is m1v1 + m2v2 = (m1 + m2)vf. which is different from an elastic equation where everything remains constant. m1v1 + m2v2 = m1fv1f + m2fv2f (sorry my notation is a bit...
27. ### The Bulk and time.

Well I'm not really knowledgable about Brane Theories. I know a lot about string theory, but not so much about branes. However, it seems that your question is really dealing with the time dimension. Its interesting to think of multi-time dimensions, however, you cannot think of time in the same...
28. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

do you happen to have all the information?
29. ### 2 Bullets, same mass, same v, fired at wood and steel block, which block has > v?

ahh we just did this in physics. what you would have to do is the mass of the bullet times the velocity of the bullet plus the mass of the block times its initial velocity (which would come out to zero) and set it equal to the mass of the bullet and block added together and your variable would...
30. ### My idea on what happened to all the antimatter.

yea that actually sounds pretty interesting. But we can create anti-particles, so that would break times one-directionality right?