What is the difference between time-like and space-like separation?

  • Thread starter Thread starter azatkgz
  • Start date Start date
Click For Summary
Time-like separation refers to events that can influence each other, allowing for a causal relationship, where one event can occur before the other in all reference frames. If two events are time-like separated, an object can travel between them at a speed less than the speed of light. In contrast, space-like separation means that no causal connection exists between the events, as they cannot influence each other without exceeding the speed of light. Events that are space-like separated do not have a definitive temporal order, as observers may disagree on which event occurs first. On a spacetime diagram, time-like events fall within each other's light cones, while space-like events are outside of these cones.
azatkgz
Messages
182
Reaction score
0
Please,can you simply explain the meaning of terms time-like,space-like,time-like separated,space-like separated.I searched in web for an hour but all explanations are very complicated.I didn't understand anything.

IS the time-like separated means just difference in time of two points in some frame at dx=0 at this frame?
 
Physics news on Phys.org
If two events are time-like separated, then an object can travel from the first event to the second event with a velocity v<c.

Events separated by a time-like interval are always arranged in the same order in time. That is, if an observer O deduces that event A happens before B, then another observer O', moving relative to O, will also come to the same conclusion. There is a before and after. And there is a possibility that that event A will influence event B. (Cause and Effect.)

In a space-like interval, an object can be present at both events only if it travels at a velocity v>c. Since no object with mass can travel at such a speed, the two events are not causally connected. Also, there is no particular order between A and B(in time) if they are space-like separated.

On a spacetime diagram, for time-like events A and B, B will be within the light-cone of A and vice-versa. For space-like intervals, one event is outside the light-cone of the other.
 
Thank you very much.It seems to that I understood something.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 38 ·
2
Replies
38
Views
3K
Replies
5
Views
2K
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 29 ·
Replies
29
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 76 ·
3
Replies
76
Views
3K