What if you shined a flashlight...

Thursday, June 10, 2004 by I.R. Brainiac | Discussion: WinCustomize Talk

while going the speed of light?Would it shine any further?(or would the light just collect at the source and get REALLY hot)
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Fuzzy Logic
Reply #81 Saturday, June 12, 2004 4:48 AM

Just how far does IR intend to extend his probe - and whose next ???

Personally, I wouldn't let him 'probe' anything... 

Alternate Setting
Reply #82 Saturday, June 12, 2004 4:54 AM
Who knows maybe he comes from a place where there is no chocolate and seeks to take all he can find, maybe even the very means of chocolate production. Of course if thats all he wants I'm sure no-one here will object

By the way, I'm working on me social skills OC, how do you think they're coming along ?



[Message Edited]
UBoB
Reply #83 Saturday, June 12, 2004 9:57 AM
A problem:

An egg travels on a 12m-long conveyor belt at a speed of 2 m/s. Use the Special Theory of Relativity and the binomial theorem to calculate the difference in the time the egg takes to hatch, compared to that of an identical egg which remains stationary. Does this difference correspond to an increase or a decrease in the time ?

Aleatoric
Reply #84 Saturday, June 12, 2004 12:25 PM
Jafo,

The reason that the motion of the emitter is irrelevant is exactly because of relativity. There is no privileged frame of reference.

For the photon to 'care' about the motion of the emitter, you'd first have to specify what the motion of the emitter is relative to, in a frame of reference that would affect the photon.

Example: Two observers, a and b, both moving relative to one another at one half c. From the point of view of a, he is standing still while observing that b is in motion. Conversely, b observes that she is standing still, and that a is in motion. As far as the photons are concerned, the emitter is always standing still, regardless of what constant velocity the emitter may be travelling at with regard to some other observer.

I.R. Brainiac
Reply #85 Saturday, June 12, 2004 1:24 PM
klaatu barada nikto(or nikta depending on local galactic dialects)

glass in old castles has already flowed much more than an 1/8 of an inch.These are some times less than 200 years old.(they were however very thick glass and that would presumably allow a greater flow.) Many have completely separated from the top of the window frame and are twice as thick on the bottom as the top.
I.R. Brainiac
Reply #86 Saturday, June 12, 2004 1:26 PM
ok maybe there isnt enough energy to melt the "electric torch",but I bet the bulb would burn out.
werewolf
Reply #87 Saturday, June 12, 2004 1:30 PM
ok, so I'm in an enclosed vehicle (a plane for instance) traveling 600mph. I throw a ball in the same direction of travel. Someone inside the plane clocks my throw at 60mph. Someone outside the plane (just accept it would clock it at 660 mph?

If I were outside the plane, people would get a good laugh because the instant I released the ball, it would just go straight backwards and hit me in the face.

So, now I'm in an enclosed vehicle (a spaceship) traveling at the speed of light. It's dark, I turn on a flashlight and, pointing it in the same direction of travel, shine it at the control panel and it is illuminated. Yes? Same principle as the ball in the airplane?

I go outside the spaceship to see if the lettering on the side is still there, it's dark, I turn on the flashlight, point it in the same direction of travel, and there is no illumination. Yes?


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[Message Edited]
Aleatoric
Reply #88 Saturday, June 12, 2004 1:31 PM
I.R.

Until relatively recently (last couple of hundred years at most), pane glass was blown, not rolled. As a result, there were substantial variations in the thickness of the pane, even within a single pane. Most likely reason for the apparent flow would be that the glass was deliberately installed with the thicker part on the bottom. That glass can flow is indisputable, but the rate of flow is so slow that even a thousand years won't make a significant difference.

UBoB
Reply #89 Saturday, June 12, 2004 1:33 PM
BTW, answer to post #83:

t = t0/(1-u^2/c^2)^1/2 » t0[1+(-1/2)(-u^2/c^2)] = t0(1+u^2/2c^2) from binomial theorem, where t0 = 12/2 = 6 s is the proper time interval for hatching.

So the time difference is t - t0 = t0 (0.5 u^2/c^2) = (6)(0.5)(22)/(3x108)^2 = 1.33 x 10^-16 s

The positive sign indicates that this is an increase in the time.

Hus
Reply #90 Saturday, June 12, 2004 1:37 PM
So what you're saying is, if I'm travelling at the speed of light...I'll get to my destination REALLY quickly...but I can't see the whole way there unless I have an electric torch?
UBoB
Reply #91 Saturday, June 12, 2004 1:41 PM
My father always told me it's better to travel light.
Alternate Setting
Reply #92 Saturday, June 12, 2004 1:42 PM
12m-long conveyor belt at a speed of 2 m/s


Actually no - after 6 seconds the egg plummets off the end of the conveyor belt, and smashes long before getting the chance to hatch and ponder its existance (see hitchhikers guide to the galaxy for relevant tract)
UBoB
Reply #93 Saturday, June 12, 2004 1:44 PM
Aleatoric
Reply #94 Saturday, June 12, 2004 1:54 PM
werewolf,

Inside or outside of the plane, the final velocity of the ball would be 660 mph (not accounting for the wind, but if we account for that, you'd have been blown off the plane before the ball could come back for you ).

Newton's laws of motion dictate that velocities are simply additive, for an object 'a' being thrown from moving object 'b', the total velocity of object a is (a + .

Einstein elaborated on Newton's laws of motion by adding the relativistic effects, making the equation for calculating motion:

(a + * (c^2 / c^2 + ab)

Where a and b are small relative to c, the correction (c^2/c^2+ab) is very close to 1 and the sum of the motions are as described by Newton.

Where the values of a and / or b are a significant fraction of c, the correction factor becomes less than 1 and the total velocity is the sum of a and b times the correction factor, with the result that the total velocity is *always* less than c.

Since your hypothetical spaceship cannot actually reach the speed of light, let's say that it is travelling at a constant velocity of 99.9999% of the speed of light. When you shine your flashlight, the control panel will be illuminated in exactly the same manner as it would be if you shone the light on your keyboard at home right now. And if you measured the speed of light from your flashlight, you would measure its velocity as 'c'.

While the relativistic and quantum physical laws hold for the behaviour of photons *at* the speed of light, there's no meaningful way to determine what an observer such as you or I would observe if we were travelling at the speed of light, since that cannot occur. Given the zero time and distance solutions for a velocity at the speed of light, if we could reach that condition, it might be that we would 'see' everything in the universe at once (not sure if that would be a desirable outcome ).

You'll notice that I've limited my discussion to objects with a constant velocity (not accelerating). The special theory of relativity only considers objects that are not accelerating. To handle objects with acceleration (including responses within a gravitational field), one must invoke the general theory of relativity. By and large, the results will come out the same, although an object under acceleration *does* have a frame of reference of sorts, because of the acceleration.

BTW, the bulb wouldn't burn out either
Jafo
Reply #95 Saturday, June 12, 2004 9:38 PM

Aleotoric...

if both the photon and the emitter are travelling at the speed of light it is of importance to be aware that they travel at the SAME SPEED...the speed of light....relative to the emitter the photon does not move, ergo it does not emit [come out of the torch] at all.

The light will be 'off'.

There is no need for dissertations regarding Einstein, etc as if waving existentialistic quantum physics is a worthwhile endeavour.

The concept of cumulative or additive velocity is irrelevant 'IF' it is accepted that the speed of light is an absolute....and THAT is the crux of the argument.

Sure, if lightspeed was NOT an absolute it 'could' be possible for the photon to have its velocity added-to by the source....but then you'd have to ponder what accelerated light would look like to a static observer....we're not talking phase-shifting of light frequencies in this instance but an entirely different 'physics' and an entirely 'different' energy.

lovesblessing
Reply #96 Saturday, June 12, 2004 10:22 PM
So, would these caring or non-caring photons be encased in torpedoes? And would they come with cards attached or not, as the case may be?

And if these said caring or non-caring photons are going to be so cotton-picking fussy about their opinion, why not just use phasers and can Scotty make 'em go faster???? Huh? "Are we there yet?????"
CerebroJD
Reply #97 Saturday, June 12, 2004 10:31 PM
"Mr Sulu, ahead Warp Factor 2!"

( image hosted by angelfire )
[Message Edited]
Aleatoric
Reply #98 Saturday, June 12, 2004 11:54 PM
Jafo,

No offense, but I'm essentially correct on this one.

The reason for the 'dissertation' on Einstein (and quantum physics) was to demonstrate:

A. That I had done my homework on this (my education includes a minor in physics).
B. That according to the current state of our knowledge of physics, the scenarios I described are accurate and supported by direct observation and repeated experiments that verify our current interpretation of relativity and quantum mechanics.

No matter *what* velocity the emitter is travelling, if the conditions exist that will produce a photon emission, that photon *will* be emitted. And the photon in question will not be travelling faster than light. If the emitter is travelling at the speed of light (which is impossible for any object that has mass), then the emitted photon will also be travelling at the speed of light in whatever direction it is emitted, not any faster, and not any slower.

This behaviour is fundamental to both theories of relativity and there is no evidence whatsoever (at this time) that the tenets of relativity are incorrect. Even if we do find an area where relativity fails, the theory that succeeds it must still account for all that we currently test as accurate within relativity.

If we want to be pedantic about this, the original question presupposes an initial condition that *cannot* occur (a flashlight that is travelling at the speed of light). Therefore, any consideration of possible outcomes is mere speculation, and is best evaluated in the realm of philosopy.

Enjoy
I.R. Brainiac
Reply #99 Sunday, June 13, 2004 1:20 AM
Your light explanations seem sound enough,but the glass is a no brainer...the panes I have seen where not blown that way,they have "flowed" and actually gotten shorter,sometimes as much as a half an inch.(in only hundreds of years)
I.R. Brainiac
Reply #100 Sunday, June 13, 2004 1:24 AM
a philosophic bent was sorta included in my original question.Tho I certainly appreciate the relatavistic education.

alternate theory suggest that the light beam,having been accelerated already to lightspeed would then be instantly converted to blacklight and illuminate all the grateful dead posters in the universe.

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