What if you shined a flashlight...
Thursday, June 10, 2004 by I.R. Brainiac | Discussion: WinCustomize Talk
Reply #82 Saturday, June 12, 2004 4:54 AM
By the way, I'm working on me social skills OC, how do you think they're coming along ?

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

Reply #84 Saturday, June 12, 2004 12:25 PM
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.
Reply #85 Saturday, June 12, 2004 1:24 PM
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.
Reply #86 Saturday, June 12, 2004 1:26 PM

Reply #87 Saturday, June 12, 2004 1:30 PM
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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Reply #88 Saturday, June 12, 2004 1:31 PM
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.

Reply #89 Saturday, June 12, 2004 1:33 PM
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.
Reply #90 Saturday, June 12, 2004 1:37 PM

Reply #91 Saturday, June 12, 2004 1:41 PM

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)

Reply #94 Saturday, June 12, 2004 1:54 PM
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 +
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

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.
Reply #96 Saturday, June 12, 2004 10:22 PM
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?????"

Reply #97 Saturday, June 12, 2004 10:31 PM
( image hosted by angelfire
)
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Reply #98 Saturday, June 12, 2004 11:54 PM
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

Reply #99 Sunday, June 13, 2004 1:20 AM

Reply #100 Sunday, June 13, 2004 1:24 AM
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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Reply #81 Saturday, June 12, 2004 4:48 AM
Personally, I wouldn't let him 'probe' anything... 