Tagged Questions
0
votes
3answers
78 views
Mass in special relativity
I have just got a query about how this equation works if its right.
We have Newtonian Physics saying $F=ma$,
According to the 'Mass in special relativity' the mass changes according to
$$m= ...
-1
votes
1answer
81 views
Why is this thought experiment flawed: A vast lever rotating faster than the speed of light [duplicate]
If there were a vast lever floating in free space, a rigid body with length greater than the width of a galaxy, made of a hypothetical material that could endure unlimited internal stress, and this ...
6
votes
0answers
87 views
Status of experimental searches for tachyons?
Now that the dust has settled on the 2011 superluminal neutrino debacle at OPERA, I'm interested in understanding the current status of experimental searches for neutrinos. Although the OPERA claim ...
0
votes
3answers
106 views
Stuff can't go at the speed of light - in relation to what? [duplicate]
We all know that stuff can't go faster than the speed of light - it's length becomes negative and all kinds of weird stuff happens.
However, this is in relation to what? If two objects, each moving ...
0
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3answers
158 views
Is there absolute proof that an object cannot exceed the speed of light?
Have any known experiments ruled out travelling faster than the speed of light?
Or is this just a widely accepted theory?
5
votes
3answers
397 views
Does entanglement not immediately contradict the theory of special relativity?
Does entanglement not immediately contradict the theory of special relativity? Why are people still so convinced nothing can travel faster than light when we are perfectly aware of something that ...
0
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2answers
159 views
Has anyone ever measured the one way speed of light perpendicular to the Earth at the Earth's surface?
1 - Has anyone ever measured the one way speed of photons traveling perpendicular to the Earth at the Earth's surface?
2 - Given our current understanding of Physics is there any way both the upward ...
5
votes
2answers
242 views
What if a faster-than-light particle is found?
What will be the consequence (severe ones) on laws of physics if a particle that travels faster than light is discovered?
I am looking for a more general answer so that a high school student would be ...
0
votes
1answer
44 views
How the effect travel's? [duplicate]
Let us assume that we placed lot's of ball touching each other in a hollow cylindrical tube, now if we push one ball at the end the ball at the other end move's instantly. So how do the information ...
6
votes
3answers
315 views
Can something travel faster than light if it has always been travelling faster than light?
I know there are zillions of questions about faster than light travel, but please hear me out. According to special relativity, it is impossible to accelerate something to the speed of light. However, ...
13
votes
4answers
453 views
Thought experiment regarding an object approaching a mirror
Here's a thought experiment I came up with in class today when my mind drifted (I however highly doubt I'm the first to think about this since it is pretty rudimentary) :
Let's say superman ...
5
votes
2answers
308 views
Does quantum mechanics allow faster than light (FTL) travel?
Let's suppose I initially have a particle with a nice and narrow wave function[1] (I will leave these unnormed):
$$e^{-\frac{x^2}{a}}$$
where $a$ is some small number (to make it narrow). Let's also ...
3
votes
2answers
112 views
Extended Rigid Bodies in Special Relativity
I was reading Landau & Lifhsitz's Classical Field Theory and I noticed that they mention that an extended rigid body isn't "relativistically correct".
For example, if you consider a rigid rod ...
9
votes
2answers
705 views
Is the “How to break the speed of light” minute physics video wrong?
I am referring to this video, on YouTube, by minutephysics, which has quite a lot of views.
In the video it states that if you flick your wrist while pointing a laser that reaches the moon, that the ...
0
votes
0answers
30 views
Relatively faster than light [duplicate]
Possible Duplicate:
Travelling faster than the speed of light
If one spaceship travels in one direction at 3/4 of the speed of light and another spaceship travels in the opposition ...
4
votes
2answers
415 views
Is 2.5x speed of light possible between two objects?
These news are in Finnish:
http://www.hs.fi/ulkomaat/Kaukaisin+havaittu+galaksi+et%C3%A4%C3%A4ntyy+maasta+valoa+nopeammin/a1305618680897
The main excerpt is:
"Distant galaxy moves away from us as ...
-1
votes
1answer
85 views
Faster than light due to reference position [duplicate]
Possible Duplicate:
Travelling faster than the speed of light
Please try to follow and clarify me I've been curious about this for a long time as it seems a bit paradox due to the rule that ...
10
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4answers
2k views
Einstein's special relativity beyond the speed of light
Could someone with access to this paper which claims to have new transformations between frames with relative motion faster than light which are supposedly consistent with special-relativity, say what ...
0
votes
1answer
86 views
Wavefronts and phase velocity faster than $c$
Lets assume we have parallel wavefronts in a glass of water:
and we put an inclined rod on the water surface:
related to a very small inclining, Vy velocity is greater or much greater then Vx ...
4
votes
7answers
410 views
Information relationship to Special Relativity
How do we write mathematically that "information" cannot go faster than light? And along a similar line of thought, how do we relate "information" with special relativity. Lastly, what is the ...
1
vote
0answers
200 views
Could someone transmit a signal with equally-tuned Casimir plates across the quantum field?
It seems, one could exploit the Casimir effect to send messages across arbitrarily-large distances with carefully-tuned Casimir plates.
Obviously, relativity would preclude FTL information transfer, ...
1
vote
4answers
832 views
Is it possible to transfer classical bits of information faster than light speed?
Is there any known, verifiable way to transfer classical information faster than light, using quantum entanglement or other phenomenon?
Does quantum teleportation, or other known phenomenon, allow ...
2
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5answers
424 views
Special Relativity Second Postulate
That the speed of light is constant for all inertial frames is the second postulate of special relativity but this does not means that nothing can travel faster than light.
so is it possible the ...
1
vote
1answer
211 views
Relative Speed vs speed of light [duplicate]
Possible Duplicate:
Travelling faster than the speed of light
Someting almost faster than light traveling on something else almost faster than light
I've got two questions which are ...
1
vote
1answer
172 views
Designing a plausible faster than light drive: the Space Skip Drive [duplicate]
Possible Duplicate:
Is the Portal feasible in real life?
I'm designing a plausible faster-than-light (FTL) drive for a SF universe. Here's what I have so far. I'm aware of existing ...
6
votes
3answers
508 views
Special Relativity and $E = mc^2$
I read somewhere that $E=mc^2$ shows that if something was to travel faster than the speed of light then they would have infinite mass and would have used infinite energy.
How does the equation show ...
1
vote
4answers
312 views
The speed of tachyons
The other day I was wondering: When a tachyon is coming towards you faster than the speed of light, will you see it before it hits you? Then I thought of course not, since the light waves aren't ...
3
votes
2answers
800 views
If I move a long solid stick can I send message fastest than light? [duplicate]
Possible Duplicate:
Is it possible for information to be transmitted faster than light?
I mean by using a perfect solid stick long enough and moving it forward and backward can I send ...
0
votes
2answers
145 views
light travels a maximum speed… /? [duplicate]
Possible Duplicate:
Is it possible for information to be transmitted faster than light?
we know that speed of light is an unconquerable term in physics..light takes about 1 year to travel ...
1
vote
2answers
136 views
What will happen if we use a speed greater than light speed and find a body'motion and energy relative to it?
In Einstein's papers, he used light speed as a reference speed. What if we use a greater finite speed and do the same calculations. Won't this greater speed then be the limit.
2
votes
3answers
364 views
If it turns out that neutrinos do travel at faster than lightspeed, how will the success of special relativity be explained?
As per in the title. If it turns out that neutrinos do travel faster than the speed of light, how will the success of special relativity be explained? My apologies if this has been asked before; I've ...
1
vote
1answer
220 views
speed of light flashlights question
This might be a silly question but I take the risk because it's been puzzling me for quite some time :
If you have 2 flashlights, one facing North and one facing South, how fast are the photons (or ...
15
votes
2answers
1k views
What happened to the idea of tachyonic or other superluminal neutrinos?
While hunting around for information about the recent OPERA measurement that hints at superluminal neutrinos, I discovered that this idea was actually considered back in the 1980s. Wikipedia lists as ...
6
votes
4answers
753 views
Double light speed
Let's say we have 2 participles facing each other and traveling at speed of light
Let's say I'm sitting on #1 participle so in my point of view #2 participle's speed is c+c=2c, double light speed? ...
10
votes
4answers
1k views
Travelling faster than the speed of light
Let's say I fire a bus through space at the speed of light. If I'm inside the bus (sitting on the back seat) and I run up the aisle of the bus will I in fact be traveling faster than the speed of ...
7
votes
7answers
926 views
Rotate a long bar in space and get close to (or even beyond) the speed of light $c$
Imagine a bar
spinning like a helicopter propeller,
At $\omega$ rad/s because the extremes of the bar goes at speed
$$V = \omega * r$$
then we can reach near $c$ (speed of light)
applying some ...
20
votes
12answers
2k views
Is it possible for information to be transmitted faster than light by using a rigid pole?
Is it possible for information (like 1 and 0s) to be transmitted faster than light?
For instance, take a rigid pole of several AU in length. Now say you have a person on each end, and one of them ...
7
votes
3answers
605 views
What are some scenarios where FTL information transfer would violate causality?
I've always heard people saying, "Faster than light information transfer can't happen because it would violate causality! Effects can precede their causes!"
However, I'm trying to think of a ...
