Frames Definition and 610 Threads

hi folks! I have a question which had been haunting me for quite some time... can an observer sitting in a accelerating reference frame deduce that he is accelerating without establishing any contact with the outside world( i am alluding to outside the frame ambience)?

Do two observers in different reference frames necessarily agree on the energy of another object in a third reference frame?

A question that led to an interesting answer was posed in a newsgroup recently that I thought I'd share here. Someone proposed a scenario where there were two rocket ships that would travel at constant speed along a circle in opposite directions. They would pass each other twice per revolution...

I can make a local inertial reference frame in a gravitational field by creating a frame that is small but close to the source of curvature of space-time. Alternatively I can make a local inertial reference frame by creating a frame that is large but a long distance from the source of curvature...

Hey everybody, this is my first post! :biggrin: I've always had a problem understanding why, if a space-explorer left on a ship, traveled at nearly the speed of light for a while, and then came back to earth, he might have only aged a few months whereas the people of Earth would have aged...

Moving in Frames?? okay, so let's say I ran 3 miles. At one point, I must have been halfway between start and finish right? From the halfway point, I must have existed halfway from there and the remaining 1.5 miles also. And halfway between THAT point and the finish. Then halfway from THAT...

Suppose 2 inertial frames with relative relativistic velocities. To discuss phenomena in other frame, we need to use Lorentz Transform for length and time. I got question: do we have to also use LT to talk about permittivity and permeability of other IRF? This seems strange. Permittivity has...

1. Let clock A and clock B be of identical construction, and let them both not be subjected to any force. Let them be at rest with respect to each other. Thus, the relative velocity v is equal to zero. Therefore, using Newtonian mechanics or SR, the clocks tick at the same rate. For the...

If you take two identical radioactive samples, place one on Earth and another on a near-lightspeed spaceship, and compare them some time later, will the one left on Earth have undergone comparatively more radioactive decay than the one on the spaceship? If the experiment is repeated by...

What determines whether a boat goes upstream, downstream, or straight across? Is it be the angle that the boat is pointed, the speed of the boat and the speed of the river?