Recent content by johnny_bohnny

Can anybody explain this fact in terms of space-time diagram, why are events that are close in space but far in time timelike separated, how can we see that from the diagram with simultaneity surfaces?

I was looking at some space-time diagrams with the simultaneity surfaces for moving inertial observers in SR and looking at the picture an interesting thought came up to my mind. It is known that the causal structure of the universe is preserved in SR, and that cause always comes before the...

The question seems very straightforward, you said that the coordinate speed can be as low as we can imagine. So I asked why it isn't so low in our everyday lifes, and I mentioned the example that the light from the Sun takes 8 minutes to reach us. In which conditions is the light much slower...

I can't edit my previous post for some reason, so I will post a new reply, I hope it isn't a problem. It is often said that the light from the sun takes 8 minutes to reach us, of course people take its velocity to be c in this case. If the speed can be as low as few meters per second, this...

So could you explain to me the example I mentioned in my previous post, for instance I have an object in front of myself and I'm a non-inertial frame. If I was inertial, the speed of light would be c and I could deduce how many time units have passed before the light from the object hit my eyes...

Ok, thanks for the answers, even though I feel I need time and knowledge to really get to know them. So for instance, if a rocket is traveling from Earth to the Sun, will it travel by geodesic or not? Since the only things that travel by geodesic, if I understand correctly, are free-falling...

But traveling with geodesics still makes you accelerate, right, and therefore experience different time dilation at each point of the curve?

Hello guys, I just had to ask a quick question about the nature of light. In different synchronization parameters regarding inertial frames (other than 1/2) light can take value between c/2 and infinity. So far, so good for inertial frames. But considering non-inertial frames, what are the...

How will the path not be curved since spacetime itself is curved?

I have many questions regarding this topic, so I'll ask some and I hope I will get some answers. The first one is connected to the motion in GR. For instance, if somebody would travel from the Earth to Sun, he would do in a curved path, right? How is this different from the classical 'distance'...

It would be great if you could give me some examples, cause this is very fuzzy for me, I haven't had almost any experience with GR. In curved space time the shortest path between two points is a curve, in flat space-time it is a line. But can that curve contract in some way, like a line can in SR?

@Pervect, thanks for the great answer. I was wondering how exactly the SR effects that I mentioned correspond to curved space time. Will a curve in space get length contracted relative to a moving frame, or not, how do effects from flat space-time transmit to curved space-time?

SR is a theory based on flat space-time, and all of its effects are there in a flat space-time framework.My question is, how is SR compatible with GR, since GR uses curved space-time? Or to say it better how are time dilation, length contraction and relative simultaneity manifested in curved...

I was just thinking about this, and from a perspective of an inertial frame, it's easy to see how distances contract, times dilate, simultaneity varies between observer and the speed of light is exactly c in each case. But what about non-inertial frames? In the presence of gravity almost...

Can anyone please explain the previously mentioned effect and its applications on Earth and other objects with mass, because I still haven't found a relevant answer.