All Questions
Tagged with faster-than-light visible-light
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Can the velocity of an image produced by a plane mirror be greater than that of light?
We are currently studying ray optics in school and it made me wonder if the velocity of an image produced by a plane mirror can theoretically be greater than that of light.
Using the relation $v_i = 2 ...
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Refraction of a Ray of Light [duplicate]
Why can no medium have a refractive index less than 1? Explain with Snell's Laws of Refraction of Light.
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1
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If I had a car which could go with a speed of light, could I drive it at night? [duplicate]
Just theoretically, when I turn on the lights in my super fast speed of light car, would I see the road if the light can't go faster than my car?
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But why can't i travel faster than the speed of light? [duplicate]
I'm laying in my bed right now. Am I traveling 0mph? Am I traveling 850-ish mph (south texas) as the earth rotates? Am I traveling 67,000mph as my planet orbits the sun? Am I traveling 560,000mph as ...
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How does change in Temperature affect Refractive Index/Optical Density of a medium?
In my school book its stated that:
With increase in temperature, the speed of light in a medium increases, so the refractive index of medium decreases.
I read in another answer that:
Refractive ...
- 1,168
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Speed of a train plus speed of light [duplicate]
Einstein postulates that the light travels at the same speed $c$ in every inertial frame of reference.
Now, if I'm within a train which goes right with velocity $V$ and throw a ball to the right with ...
- 165
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2
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Why can't light travel three days into the future then transmit that information back to us prior to us arriving at that position? [closed]
Example: If a football game between the Pittsburgh Steelers @ Tennessee Titans will happen in 3 days Sunday 10/25/2020 at 1pm, why can't light leave today 10/22/2020 and go to where the Earth will be ...
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That the laser hits the same point on the opposite side of the box implies it is moving faster than $c$?
In Greene's video: https://www.youtube.com/watch?v=2pV20KuDucs
In the video Greene describes a fairly well-known thought experiment. A person is in a rectangular box floating in space with a laser ...
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Exceeding the speed of light by means of a shadow, will we ever be able to transmit information faster than light? [closed]
I bumped into this:
Can a shadow move faster than the speed of light?
while trying to see if I could find out anything about what I'd been thinking for 2 years now.
Bear with me here, cause I'm only ...
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Self-acceleration of a light beam? Airy beam?
Can someone provide me with a quick explanation of an accelerating (or self-accelerating) beam of light? Something called an Airy beam is an example?
I get the impression that an accelerating Airy ...
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What if a spaceship going half the speed of light turned on its headlights in both directions?
If the spaceship, travelling at c/2 were to turn on only its forward facing headlights, then after one second (relative to us, the stationary external observers) we would see that the ship has moved ...
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5
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Is there a medium less dense than vacuum, in which light can travel faster than $c$? [closed]
Is there a medium less dense than vacuum, in which light can travel faster than $c$? If not, can we make it?
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2
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534
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Do Electrons revolve with super-light speed? [closed]
Faster the particle, smaller wavelength. In the electron microscope, we use electrons because of its smaller wavelength?
Does it mean electrons travel faster than light?
Or simply measuring its ...
- 21
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4
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213
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Observing an event in the past?
I'm writing a Sci Fi novel and I'm trying to come up with a (fairly) realistic or at least vaguely plausible mechanism for this person's ability to exist and function.
Hypothetically, would it be ...
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2
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Light and force
We know that photons also have momentum though they do not have mass given by the equation :
$E=pc$
Then why can't we apply force to light? I mean we can apply fore and increase its momentum and ...
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