The observer tag has no wiki summary.
15
votes
8answers
2k views
How can anything ever fall into a black hole as seen from an outside observer?
The event horizon of a black hole is where gravity is such that not even light can escape. This is also the point I understand that according to Einstein time dilation will be infinite for a ...
8
votes
5answers
568 views
Isn't the uncertainty principle just non-fundamental limitations in our current technology that could be removed in a more advanced civilization?
From what I understand, the uncertainty principle states that there is a fundamental natural limit to how accurately we can measure velocity and momentum at the same time. It's not a limit on ...
6
votes
8answers
2k views
Would time freeze if you can travel at the speed of light?
I read with interest about Einstein's Theory of Relativity and his proposition about the speed of light being the speed limit for anything with mass. So, if I were ...
10
votes
13answers
1k views
What are the mechanics by which Time Dilation and Length Contraction occur?
What are the mechanics of time dilation and length contraction? Going beyond the mathematical equations involving light and the "speed limit of the universe", what is observed is merely a phenomenon ...
4
votes
5answers
503 views
Time Dilation - How does it know which Frame of Reference to age slower?
Okay, I'm asking a question similar to this one here: Time Dilation - what happens when you bring the observers back together?. Specifically, I am curious about a specific angle on the second part of ...
4
votes
3answers
182 views
Black hole formation as seen by a distant observer [duplicate]
Possible Duplicate:
How can anything ever fall into a black hole as seen from an outside observer?
Is black hole formation observable for a distant observer in finite amount of time? ...
131
votes
14answers
41k views
A mirror flips left and right, but not up and down
Why is it that when you look in the mirror left and right directions appear flipped, but not the up and down?
9
votes
2answers
207 views
Is the uncertainty principle just saying something about what an observer can know or is it a fundamental property of nature?
I ask this question because I have read two different quotes on the uncertainty principle that don't seem to match very well. There are similar questions around here but I would like an explanation ...
12
votes
2answers
279 views
What does a sphere moving close to the speed of light look like?
What shape does the viewer in a reference frame with $v=0$ perceive? I suppose that since the sphere moves in one direction only (oX only, not oY) its section would change into an ellipse, where the ...
4
votes
2answers
600 views
How can time be relative?
I don't understand how time can be relative to different observers, and I think my confusion is around how I understand what time is.
I have always been told (and thought) that time is basically a ...
3
votes
2answers
211 views
What do you feel when crossing the event horizon?
I have heard the claim over and over that you won't feel anything when crossing the event horizon as the curvature is not very large. But the fundamental fact remains that information cannot pass ...
2
votes
1answer
102 views
Would dense matter around a black hole event horizon eventually form a secondary black hole? [duplicate]
Possible Duplicate:
Black hole formation as seen by a distant observer
Given that matter can never cross the event horizon of a black hole (from an external observer point of view), if a ...
-1
votes
3answers
166 views
Does the Lorentz transformation not apply to light?
Since you would know that light always travels at the constant velocity with respect to all frame of reference ....according to relativity whenever we are traveling at speed of light our time with ...
4
votes
1answer
193 views
Falling into a black hole
I've heard it mentioned many times that "nothing special" happens for an infalling observer who crosses the event horizon of a black hole, but I've never been completely satisfied with that statement. ...
4
votes
2answers
131 views
Effect of gravity at near-lightspeeds
Let's say I'm in a space station, hurtling towards our galaxy nearly close to the speed of light. From my reference frame, I see the galaxy coming towards my ship at the same speed.
I pass the Sun, ...
2
votes
3answers
182 views
If time slows down when you move faster, does this give you an “effective speed” different from your proper speed?
Suppose you're travelling at 0.9c toward the sun, and you tag past the Earth and start a clock. Would Lorentz contraction/time dilation cause you to get to the sun faster than (about) 9 minutes ...
1
vote
4answers
174 views
What is the exact mechanism by which time dilates?
What is the exact mechanism by which time dilates for a fast moving object?
Can the time dilation be explained by any theory other than relativity?
1
vote
1answer
141 views
How does a strobe lamp stop a fast moving object?
A strobe lamp can be used to seemingly stop a fast moving object when calibrated.
Commonly used in quality assurance during production to inspect otherwise non-observable assembly line activity.
What ...
0
votes
0answers
36 views
Can a black hole actually grow, from the point of view of a distant observer? [duplicate]
Possible Duplicate:
Black hole formation as seen by a distant observer
I've read in several places that from the PoV of a distant observer it will take an infinite amount of time for new ...
