Science a GoGo's Home Page
Posted By: Flat Scan Faster than light travel in the cinema - 12/01/08 05:37 AM
So, I was reading a graphic novel today where one of the characters moves faster than the speed of light while on earth. I remeber in a movie I saw that the mention moving to light speed while in planetary orbit and how dangerous it is and I was wondering if anyone knew a point of reference for this or some applicable info. Thnx
Posted By: redewenur Re: Faster than light travel in the cinema - 12/01/08 07:43 AM
Hi, FS.

Not sure that I understand your question exactly, but you may or may not be aware of this relevant aspect of relativity:

When an object moves, its mass increases. The faster it moves, the greater it's mass, and so the greater the energy required to make it go faster; as it approaches the speed of light, its mass rises toward infinity. To reach the speed of light, at which point it would have infinite mass, it would require infinite energy. That, of course, is not possible, and so it can never reach that speed.

Particles at facilities like LHC (CERN) are accelerated, at great cost in energy, to near light velocity, and gain many times their 'rest' mass. But even an electron cannot reach the speed of light (in a vacuum). That too, as small as it is, would require infinite energy.
Posted By: paul Re: Faster than light travel in the cinema - 12/03/08 12:27 AM
I still have a hard time with the increasing mass part there.

ie..

if I had a vacume tube 186,000 miles long.

and at one end a laser , at the other end a photo cell.

when the laser is turned on wouldnt it hit the photo cell exactly one second later?

now if the vacume tube is mirrowed and the laser is tilted slightly so that the beam would strike the mirrowed surface of the vacume tube , wouldnt the beam become both difused in strenght and speeded up? each time the beam strikes the mirrowed surface?

by the time the laser reaches the other end where the photo cell is wouldnt it be traveling faster than the speed of light?

if I point a flashlight at a mirror isnt the beam of light reflected off faster than the speed of light?

the light from the sun takes several minutes to reach the earth
and if you multiply that time in seconds by 186,000 miles per second you get the correct distance to the sun from the earth correct?

now why have we appended mass to the equation when we are dealing with high speeds?

I dont think that the mass of an object changes at any speed it can be accelerated to just because it has achived a certain speed.

if the object were entering into a lower or higher gravitational
boundary different from its own then it could shrink or expand but its mass should remain intact.

an object might be attracted to gravitional bodies and this might cause the objects shape to change as it changes its direction.

I believe that any object can be accelerated faster than what we labled the speed of light as long as an object is accelerated above any resistance to acceleration it will continue to accelerate.





Posted By: Iztaci Re: Faster than light travel in the cinema - 12/03/08 09:40 AM
Mass is energy at rest. Energy is mass in motion. The thoroughly proven equation E=MC2 is the expression of this mass/energy equivalency.

If you fire a hollow-point bullet 200 grains in weight, at 1000 feet per second, into a mud bank from a distance of ten feet, you will create a crater several inches in diameter. If you fire a hollow-point bullet the same weight at 2000 feet per second from the same distance into the same mud bank, you will create a crater significantly larger than the first one. It's the same with any mass at various speeds. Think of the damage a 1957 Chevy traveling at 60mph hitting a brick wall incurs. Then think of the damage traveling at 120 mph. Then think of two Chevys, each at 120 mph in a head-on collision. At increased speed, the mass in the mass/energy equivalency increases relative to the speed. It's a manifestation of relativity you can observe anytime. You can feel it in your hands when you clap them together. The harder you clap the more heat you feel.

It's not necessary to "understand" these phenomena. In truth, no one really does. But the theory can be deduced and proven by observation. In the case of mass/energy, the truth is in the result.

As for reflected light accelerating after the bounce; why should it? Does a rubber ball bounce back faster than it is thrown to the floor? No, it doesn't, because a portion its motion/energy is released as heat and sound, and some is used in the minuscule amount the floor is compressed in the impact. Otherwise the ball would keep on bouncing indefinitely. It is the same with light in that some of its energy is drained off as heat when it impacts a surface, and some is lost in refraction. Here again, the truth is in the result.
Posted By: redewenur Re: Faster than light travel in the cinema - 12/03/08 11:46 AM
Originally Posted By: paul
now why have we appended mass to the equation when we are dealing with high speeds?
...
I dont think that the mass of an object changes at any speed it can be accelerated to just because it has achived a certain speed.
...
I believe that any object can be accelerated faster than what we labled the speed of light as long as an object is accelerated above any resistance to acceleration it will continue to accelerate.

The facts do seem absurd but, in this matter, whatever we think or prefer to believe based on our intuition is irrelevant. Such is the nature of two major scientific revelations of the 20th century - relativity and quantum mechanics - that our intuition is of little or no value.

As Iztaci said above "the truth is in the result". If observations continue to support the theory, without contradiction, then they represent the best scientific 'truth' we have. To date the observations continue to support the theory on a daily basis.

Posted By: paul Re: Faster than light travel in the cinema - 12/06/08 06:03 AM
Quote:
If you fire a hollow-point bullet 200 grains in weight, at 1000 feet per second, into a mud bank from a distance of ten feet, you will create a crater several inches in diameter. If you fire a hollow-point bullet the same weight at 2000 feet per second from the same distance into the same mud bank, you will create a crater significantly larger than the first one. It's the same with any mass at various speeds. Think of the damage a 1957 Chevy traveling at 60mph hitting a brick wall incurs. Then think of the damage traveling at 120 mph. Then think of two Chevys, each at 120 mph in a head-on collision. At increased speed, the mass in the mass/energy equivalency increases relative to the speed. It's a manifestation of relativity you can observe anytime. You can feel it in your hands when you clap them together. The harder you clap the more heat you feel.


that has nothing to do with anything other than the speed
upon impact. nothing in that has anything to do with what I was speaking of.

mass is the amount of matter that makes up an object.

MASS

you are speaking of the different amounts of force that an
object can apply in a collision or upon impact.

what I have a problem with is how people seem to think that the mass of an object will grow as the object speeds up , and even infinitely as it reaches or achieves the speed of light.

Quote:
As for reflected light accelerating after the bounce; why should it? Does a rubber ball bounce back faster than it is thrown to the floor? No, it doesn't, because a portion its motion/energy is released as heat and sound, and some is used in the minuscule amount the floor is compressed in the impact. Otherwise the ball would keep on bouncing indefinitely. It is the same with light


how we measured the speed of light using " MIRRORS "

we use light bouncing off of mirrors to determine the speed of light , but who really knows , if light does speed up when it is reflected off of a mirror or not.

when Danish astronomer Olaus Roemer determined c as 136,646 miles per second without using mirrors he was probably right.

I can remember reading somewhere that light becomes difused and increases in speed when reflected off of a mirror , of course that was before the speed of light was such a big factor in life , and it may just be that too many peoples reputations were on the line to correct the mistakes in the books.

think about a laser , why do they bounce light back and forth between mirrors to intensify light for a laser.

how can you intensify light by bouncing it between mirrors
when each time it bounces it becomes difussed?

if light can be can be slowed down by sending it through a dence medium such as water , glass , diamonds ...etc.

then to follow suit with everything else in nature there should
be a way to speed light up , such as mirrors by decreasing its intensity you proportionately increase its speed.


I will have to check into how the all knowing NIST determined the speed of light and see if they used mirrors or any other method that could have provided accelerated results.

.
Posted By: Iztaci Re: Faster than light travel in the cinema - 12/06/08 07:33 AM
In the early days of lasers, experimenters used to mirror both ends of a ruby rod with one end slightly less mirrored than the other. Then the chromium atoms were stimulated to higher levels of excitation releasing more and more photons (light waves). As the light was reflected back and forth, new waves joined in and were therefor forced to pack tighter and thus "cohere": line up hill to hill and valley to valley thus increasing the packing density (intensity)of the beam. At a point, the intensity became such that the beam broke through the less mirrored end of the ruby rod in a coherent beam. That's the lase.

1. Higher Intensity does not necessarily equate to increased Velocity.
2. Neither reflection nor refraction increases velocity. It decreases it. Whatever you read "somewhere" was either wrong or you misread it.
3. Going to NIST will do you no good until you spend some time with Physics 101.
4. Reflecting light from mirrored surfaces is only one of many ways used in measuring the speed of light, all of which give the same value. Many methods predate NIST by centuries and are in agreement to within a few m/s. All of which prove 136,646 miles per second to be incorrect.

Posted By: redewenur Re: Faster than light travel in the cinema - 12/06/08 04:49 PM
Originally Posted By: paul
mass is the amount of matter that makes up an object.

That idea served well for a couple of hundred years, and still does for most practical purposes. But it's actually more complicated. For objects moving at higher and higher relative speeds, it becomes less and less accurate. What you're referring to is nowadays known as 'rest mass' (it might help you to understand if you look that up).

Originally Posted By: paul
what I have a problem with is how people seem to think that the mass of an object will grow as the object speeds up , and even infinitely as it reaches or achieves the speed of light.

As I'm sure you know, Special Relativity has been around for over 100yrs. It's demonstrated every day in the world’s particle accelerators. It's not just a case of what some people (like Einstein) seem to think.

Maybe this will help:

The famous equation E = mc^2 means that a body's relativistic mass is proportional to its total energy.
It also means m = E/c^2.

Here's a version that includes momentum:

m = (SQRT(E^2-(pc)^2))/c^2

Where
m is mass
E is the total energy of the system
p is the total momentum of the system
c is the speed of light.

Which shows that the mass, m, increases as the momentum, p, increases.

If it's not immediately obvious, maybe you could try typing the right side of that equation into a spreadsheet and using any numbers you like for the variables. You'll find that an increase in p gives an increase in m.

You have doubts. No problem. But base your doubts on sound knowledge. Read all you can about it from recognisably reputable sources. Whatever you do, don't just take the word of forum posters like me.
Posted By: paul Re: Faster than light travel in the cinema - 12/06/08 09:03 PM
I believe that what you are speaking of is kinetic energy

kinetic energy --> the energy a object has due to its movement.

if the kinetic energy of a moving object is what you are speaking of then you are correct , but lets just say the kinetic energy increases to avoid confussion.

still I cannot agree that the mass of an object changes due to its speed , the overall energy of an object does change of course with increasing speed , but this is all that changes
otherwise physics would need to be re-written in whole to compensate for the added mass of an object with increasing speeds.

I have read about these things that I myself refer to as science fiction , these things are abundant today and lead many people in wrong directions.

and since this thread is in the sci fi forum I suppose it is at home here.

E=Mc^2

bullfeathers!!!

first off you believe that nothing can travel faster than the speed of light as you refer to it.

and then you want me to believe that you can get energy by propelling mass at 186,000 mps times 186,000 mps !!!

so which is right

nothing can travel faster than the speed of light
or
mass can travel faster than the speed of light

dont forget that you will need an infinite supply of energy to begin with if the mass you are propelling increases infinetely.

because as the mass increases with velocity you will need to add
more and more force to cause the mass to gain velocity , not just the initial force for acceleration but an additional force for each grain of mass that is added due to acceleration.

in other words what we have here is the method that was used to
try and prove that nothing can travel faster than the speed of light , how could it if its mass grew as its speed increased?

yes that should work lets write books about it !!!

lets fill our scientist heads full of this type of garbage so
that they will leave energy alone !!!

hopefully none of them will be capable of thought processes that would un-cover our mistakes.

.
© Science a GoGo's Discussion Forums