# Search results

1. ### Lorentz Contraction Physical Reality

See below You spoiled the fun:cry: And I should have said equal AND constant, correct. Thanks.
2. ### Lorentz Contraction Physical Reality

Simple thought experiment I read and would like to hear what others think will the result will be: Let two spaceships A and B accelerate along a straight line. Observer C does not accelerate. The accelerations, as judged by C, are constant for both ships. Each ship is equipped with a...
3. ### Can you determine absolute motion?

No. Re-read the example. Light reaches Point A and Point B on the train at different times, t1and t2. But if a third train were introduced and it was moving at some constant velocity other than the original train, then light would reach its Point A and Point B at some other times, t3 and t4...
4. ### Can you determine absolute motion?

See: http://www.bartleby.com/173/9.html Einstein's scenario decribes certain reasoning behind relativity's view of light, therefore asking 'Is Einstein wrong in his scenario or is relativity's view of light wrong', is akin to asking 'did Barry Bond's hit a home run or did Barry Bond's bat hit...
5. ### Can you determine absolute motion?

I believe you are slightly incorrect. Yes, light always travels at c and yes, you can't "add" a speed to it as you've stated. But saying 'light would hit the receptors at the same time' is misleading. Refer to 'Relativitey', Albert Einstein, Chapter 9. In Mr. Einstein's train example, imagine...
6. ### On the interpretation of a spacetime diagram

Right. My apologies. My brain is not working this morning.
7. ### On the interpretation of a spacetime diagram

You are correct. I did miss a part to my explanation: I observed Rod A, B and C from my planet and determined their constant velocities of 0.2c, 0.6c, and 0.1c respectively. So because Rod C is moving at 0.1c and Rod A is moving at 0.2c (both in constant velocity RF), would Rod C not say 'Rod...
8. ### On the interpretation of a spacetime diagram

Maybe think of it this way: We have (1) 'stationary' rod, call it Rod A. Now let's say this 'stationary' Rod A is in a lab on earth. Obviously it is moving at some constant velocity because the earth is moving at some constant velocity, let's say equal to 0.2c. We have (1) 'moving' rod...
9. ### Magnetic or Electric Field or Electromagnetic Field?

Cool. Thanks for the follow up. It will be interesting to re-read this section in the new 3rd edition.
10. ### Magnetic or Electric Field or Electromagnetic Field?

So if this statement is false, why is it bolded? Clearly he is trying to make the point that understaing the statement as true is very important (hence the bolding of the text). Sorry just wondering why he would do this. As for my background, I took 1 1/2 years of physics at my university...
11. ### Magnetic or Electric Field or Electromagnetic Field?

Glad you have the book as well. Now I may get more in depth with my questions and they should be easier to follow. I follow you up to here. I was trying to get more at what makes causes the charge Q to accelerate up to point P in Sharon and Bill's reference frame. In Bill's RF, a magnetic...
12. ### Magnetic or Electric Field or Electromagnetic Field?

'Physics for scientists and Engineers' - Chapter 34 -Randall D. Knight I don't have it avaiable to me at the moment but will recite the exact quote soon.
13. ### Magnetic or Electric Field or Electromagnetic Field?

Good point. Well if Sally stopped moving with the charged particle and came to rest in Bob's RF, then they would both agree the charged particle was traveling through a magnetic field which supplied the force F. And vice versa...If Bob increased his speed until he reached a constant velocity...
14. ### Magnetic or Electric Field or Electromagnetic Field?

The physics textbook I was reading stated that the charged particle experienced the same force regardless of the RF as long as the RF was intertial.
15. ### Magnetic or Electric Field or Electromagnetic Field?

I think it matters and think it is very interesting. If someone walked up to Bob and said "You measured the force on the charge particle to be x. Did the particle travel through a magnetic field or electric field?" Bob replies "Magnetic of course". Next, Sally is asked the same question...
16. ### Magnetic or Electric Field or Electromagnetic Field?

Thanks for the resource. I will see into reading it. My physics textbook covers transformations of electric fields into magnetic fields. I guess I'm still stuck on first base though as I don't quite understand which exists for a given problem. As in my example, I can transform magnetic and...
17. ### Magnetic or Electric Field or Electromagnetic Field?

Bob Reference Frame: A charged particle moves through a uniform magnetic field with velocity V. No electric field is present and gravitational forces may be neglected. The charge thus experiences a force due to this magnetic field equal to F = qV x B. B is the strength of the magnetic field...
18. ### Light clock with something else than light

Impossible. A ball bouncing up and down cannot travel at a constant speed.
19. ### Moving though space but not time?

(1) Use the quote function, not the primitive @ key. (2) Don't be so offensive in your responses. Different levels of understanding are present (and welcome, from what I've see) on this forum.
20. ### Another SR train paradox

Yes, BART on a Friday afternoon
21. ### Another SR train paradox

Guys, Isn't this thought experiment just a version of Einstein's original though experiment that led him to SR? You know the one where he visualized someone dropping a rock out of a window of the train? To the person in the train, the rocks path is curved. To a person watching the train go...
22. ### Twin Paradox (by acceleration)

Speaking in terms of 2-D geometry, wouldn't the straight-line path between two points, A and B, always have a smaller distance than a bent path between A and B.
23. ### Relativistic Interception

In what case? If it's the case I gave in my example (ship traveling from earth to moon) than I assure you the distance is not 17 light years. When doing any type of calculation in life, ALWAYS ask yourself "Does my answer make sense?" It didn't take Apollo 11 (17) light years to reach the...
24. ### Relativistic Interception

What makes you think that?
25. ### Relativistic Interception

Well, it depends. If your first ship traveling at .9999c left earth and headed to the moon at Time A, and your second ship traveling slightly faster (.99999999c) left at Time B (1*10-8 after...let's say) later, then the second ship would arrive at the moon before the first. As for slower, you...
26. ### Massless particles ?

They could travel toward you too!
27. ### Relativity confusion

It's the only question I kinda understood. And whey I said 'see' I literally meant 'see'. For example, the would both see an apple fall, but they would disagree on when the apple fell.
28. ### Relativity confusion

A person on the planet moving close to c would see the events the same as the person on earth. They would simply disagree on when the events took place
29. ### Does c-invariance in SR postulate need inertial frames ?

I'm confused. Are you suggesting the speed of light varies? How can the speed of light ever differ from c (besides in some medium)?
30. ### Light Cones / QM

So we seem to be getting way off topic...I thought the conflict between Relativitey and QM was well established and that everyone was looking for some sort of unified theory? I assumed this fact in my original question. Is this not true?