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Speed of Light

11/15/2017 11:23 PM

Assume/Imagine a spaceship travelling at the speed of light. Two lasers are mounted on top of the craft. The 2 lasers are mounted in such a way that,

  1. Pointed forward
  2. Pointed Backward

What will happen to the laser coming out of the torch

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#1

Re: Speed of Light

11/15/2017 11:29 PM

Nothing.

Your perception of the laser light might change.

Are you inside the spacecraft?

Outside the spacecraft?

Etc?

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#2

Re: Speed of Light

11/16/2017 12:47 AM
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#3

Re: Speed of Light

11/16/2017 1:01 AM

You can imagine whatever you want, cause no matter what, it will not happen if your asumption is false.

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#4

Re: Speed of Light

11/16/2017 1:04 AM

Take a physics class including red/green-shift calculations. Do not assume 100%c.

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#5

Re: Speed of Light

11/16/2017 2:39 AM

"There was a professor named Bright

Who travelled much faster than light

He left one day

In a relative way

And came home the previous night." - Anonymous Poster #0

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#10
In reply to #5

Re: Speed of Light

11/16/2017 9:23 AM

Such a brilliant rhyme, my darling. Impressive.

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#19
In reply to #10

Re: Speed of Light

11/17/2017 3:18 AM

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#24
In reply to #19

Re: Speed of Light

11/17/2017 8:07 AM

He'd go with everyone!

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#6

Re: Speed of Light

11/16/2017 5:07 AM

Both laser beams will travel away from the spaceship at the speed of light.
If you try measure their velocity from any other point, it will still be the speed of light or you won't be able to even see what's a happening...
Del
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#12
In reply to #6

Re: Speed of Light

11/16/2017 9:59 AM

"If a man in a forest says something and there is no woman there to hear him... is he still wrong?

"

Go ask Mrs. Cat, I'm sure she will have an answer!

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#7

Re: Speed of Light

11/16/2017 6:03 AM

Your question is 112 years too late.

einsteins-special-relativity-for-dummies

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#16
In reply to #7

Re: Speed of Light

11/16/2017 2:28 PM

Or was Einstein 112 years early? Can you tell this in your inertial frame of reference?

Humans.

Lovely inspiring thought, lacking the power to see beyond the kitchen window, yet making biscuits of wonder perfectly suitable for the tea ceremony. How will we ever reach out and touch the stars? We already have. We are the stars (dust).

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#8

Re: Speed of Light

11/16/2017 8:05 AM

Speed is relative, you have to specify speed in relative to some reference, for example, the earth. Nothing except light can travel at the speed of light relative to anything else, and light always travels at the "speed of light" relative to everything.

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#9

Re: Speed of Light

11/16/2017 9:22 AM

There is something in the eyes that would probably help explain light.

Questions like

  1. how do you perceive light?
  2. does optical sensory conforms hi-tech light technology?
  3. What type of conversion there exist converting photons to neural transmission?

so on and so forth...

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#11

Re: Speed of Light

11/16/2017 9:57 AM

What torch?

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#13

Re: Speed of Light

11/16/2017 10:30 AM

It's all relative.

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#14

Re: Speed of Light

11/16/2017 10:47 AM

Depends if the lasers are able to operate in that ambient temperature range. It's pretty cold up in space.

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#15

Re: Speed of Light

11/16/2017 2:22 PM

Huge Doppler Effect, one will be reduced to a low frequency virtually nil, since you specify v=c. The other will be very high frequency. I think your laser will blow up in the "head wind" of interstellar gases.

This is in the supposition that something scatters the beams in order for stationary observer in other frame of reference to actually observe the beams.

Otherwise if directly behind the craft, does the beam ever make it out of the event horizon? If directly ahead of the craft, how can the beam propagate fast enough to reach observer before the craft. I suspect a collision of immense energy takes place.

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#17

Re: Speed of Light

11/16/2017 11:29 PM

"Assume/Imagine a spaceship travelling at the speed of light. Two lasers are mounted on top of the craft. The 2 lasers are mounted in such a way that, 1. Pointed forward 2. Pointed Backward What will happen to the laser coming out of the torch"

Thank you all for your valuable comments. The above question I asked is just to understand "what is light".

What if an observer is stationary?

  1. For pointed forward: Will the light velocity be doubled
  2. For pointed backward: Will the light velocity be zero

In addition to this, is it possible / sensible to compare the above scenario with a bullet coming out of a pistol, mounted on a spaceship whose speed is equal to speed of a bullet.

What would be the fate of the light and the bullet for a stationary viewer?

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#18
In reply to #17

Re: Speed of Light

11/16/2017 11:39 PM

Doppler effect - Wikipedia

Study the Doppler Effect.

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#20
In reply to #17

Re: Speed of Light

11/17/2017 4:51 AM

<...is it possible / sensible to compare the above scenario with a bullet coming out of a pistol, mounted on a spaceship whose speed is equal to speed of a bullet..> No, it isn't, because bullets don't usually travel anywhere close to the speed of light; speed of sound in air at [temperature/pressure], maybe. Plus, there is by definition no air in space. So the conjecture is absurd.

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#25
In reply to #17

Re: Speed of Light

11/17/2017 8:21 AM

Read post 6. Del has it right. The speed of light is constant, no matter your frame of reference. So both lasers will fire at the speed of light.

The problem is who is going to fire the lasers. The person on the spaceship, who according to you is already travelling at c, will have a time reference frame that is stopped, so it will take him to infinity to press the button.

As stated in another previous post, you should talk about approaching the speed of light, not travelling at c.

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#28
In reply to #17

Re: Speed of Light

11/17/2017 11:10 AM

What is light ? The absence of, which is impossible, because in the absence of light there still is light, although not in our visible spectrum. Like asking what is cold ? Even in extreme cold there is still heat or warmth.

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#21

Re: Speed of Light

11/17/2017 5:35 AM

I bought my time machine next Thursday, it broke down last Friday, the mechanic said they don't build em like their going to.

Bazzer

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#22
In reply to #21

Re: Speed of Light

11/17/2017 6:01 AM

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#23
In reply to #21

Re: Speed of Light

11/17/2017 6:03 AM

em 'em

their they're

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#29
In reply to #23

Re: Speed of Light

11/17/2017 11:17 AM

They spoke a different language, grammatically tomorrow.

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#30
In reply to #29

Re: Speed of Light

11/17/2017 11:39 AM

Thus, this thread was over before it began.

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#26
In reply to #21

Re: Speed of Light

11/17/2017 9:47 AM

Sounds like yur busted before you go anywhere.

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#27

Re: Speed of Light

11/17/2017 11:01 AM

Although the spacecraft is moving at the speed of light ( define light spectrum ? ) . What is the speed of the lasers ( define light spectrum ? ) Are the lasers mounted side by side ? What is the length of the craft ?

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#31
In reply to #27

Re: Speed of Light

11/17/2017 12:08 PM

The speed of light is the same no matter the spectrum. You are talking frequency.

It's like the speed of sound. The tone does not change the speed of sound.

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#32
In reply to #31

Re: Speed of Light

11/17/2017 2:04 PM

Same goes for rumors, the tone does not change the speed of the rumor.

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#33
In reply to #32

Re: Speed of Light

11/17/2017 3:04 PM

Ahhh Rumors excellent album.

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#34

Re: Speed of Light

11/21/2017 3:12 PM

There will be absolutely no change in the spacecraft or the lasers from pre- to post-firing.

Time dilation increases as speed increases, as speed approaches C, time dilation approaches 0. Traveling at the speed of light, time will stop in the inertial frame of the ship. If t is a fixed, unchanging value then there can be no change of state within that single fixed instant of t.

-----

Now if you change the chips speed from C to 0.99C, then the question can be answered.

From an observer within the ship:

The lasers will spear out from the ship, both traveling at the same speed (C) away from the ship.

From an observer on a planet the ship is passing near, as no maneuvers have been stated the ship will be considered to be traveling at a tangent to the planet, neither flying directly towards nor directly away:

The lasers will spear out from the ship, both traveling at the same speed (C) away from the ship.

This has been a quick lesson in relativity and inertial frames.

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