# faster than light?

#### nate

##### New Member
faster than light?

I was thinking, if you send a space shuttle into space, get it to go 20,000mph and stop the thrust from the engines, wouldnt you continue to go 20,000mph? If so then why cant you thrust and continue to use the engines to get past the speed of light if you had an unlimited amount of fuel?

#### astralsailor

##### Junior Member
Re: faster than light?

yeah i been thinking about it to...
There would be no gravity problems so...
tought time does not work this way
Time is not "Events" Events are caused do to memories
Time is what we call memories that falls on a line or in a loop line
we dont call the "Future" memories because we are told to think that it has not happend yet
So i guess if you would go faster then the speed of light
You would only arrive in other timeline.
The best way to travel back in this time line is probeble remembering
or Astral traveling

To deal with Time one has to understand that Time is memories
and clairvoiance(precognity) is memories from what is to come
If one wants one can do anything..
"The greatest illution of all is that humans has limitations"

#### gl100

##### Member
Re: faster than light?

If so then why cant you thrust and continue to use the engines to get past the speed of light if you had an unlimited amount of fuel?

Well if you went faster than the speed of light, you'd get ahead of your headlights and couldn't see. Actually, I believe your mass continues to increase thus requiring more and more energy to achieve greater speed. Unlimited fuel does not necessarily give you unlimited increased thrust. Maybe somebody here with more physics can shed some light on this.

#### thenumbersix

##### Member
Re: faster than light?

wouldn't the mass of the fuel stored onboard also increase ?

#### Tenshi

##### New Member
Re: faster than light?

It's impossible to travel at, or faster than, the speed of light.

Why? Because the faster that something travels, the more massive the object becomes, and when it reaches a certain speed (just over three-quarters the speed of light, or thereabouts) the object acquires infinite mass, therefore needing infinite energy to propel it through space, and it is impossoble to get infinite energy.

#### Tenshi

##### New Member
Re: faster than light?

<div class='quotetop'>QUOTE(\"gl100\")</div>
Well if you went faster than the speed of light, you'd get ahead of your headlights and couldn't see. Actually, I believe your mass continues to increase thus requiring more and more energy to achieve greater speed. Unlimited fuel does not necessarily give you unlimited increased thrust. Maybe somebody here with more physics can shed some light on this.[/b]

Actually, I think, according to Einstein, if a car travelled at the speed of light and it had its headlights shining, you will still see the light shining normally as if the car was travelling at a normal speed.

A similar situation occurs when you roll a ball along the carpet of a passenger train travelling at 100 miles an hour. You don't perceive the ball as travelling faster than 100 mph. Just see it as travelling at about 3 mph.

#### Harte

##### Senior Member
Re: faster than light?

<div class='quotetop'>QUOTE(\"nate\")</div>
I was thinking, if you send a space shuttle into space, get it to go 20,000mph and stop the thrust from the engines, wouldnt you continue to go 20,000mph? If so then why cant you thrust and continue to use the engines to get past the speed of light if you had an unlimited amount of fuel?[/b]

Nate, the speed of light ? is a constant and unattainable to anything that has mass.

Below is a quote from http://www.timetravelforum.net/showthread.php?t=1234 that states some of the consequences of c being constant. Since I'm quoting myself here, a I took the liberty of making a few changes and addenda to the original for the purposes of clarity.

It turns out that any light measured under any circumstances always travels at the same speed relative to any observer. That's what Einstein meant when he said the speed of light is constant.

If you are in a ship moving at high speed and you shine a light along the direction of movement, no matter how you measure it your measurement will show that the light is moving away from your source at the speed of light ?.
If you are outside the ship and at rest with respect to the ship and you somehow measure the speed of that guy's flashlight beam, no matter how you measure it your measurements will also show the beam to be moving at the speed of light?. How to reconcile these two facts?

Lets forget that c is constant and just talk about the measurements taken of the speed of this beam of light.

If you are the guy inside the ship, you measure the speed of the beam to be, let's say, m.
If you are the guy at rest outside the ship but looking in the window, you would expect your measurement to be the speed of the beam plus the speed of the ship carrying the beam, but when you make your measurement, you find that you also measure the speed of the beam of light to be m.

Later you talk to the astronaut after he has returned, and say something like \"I measured the speed of your beam to be m, since to me, m is the speed of the beam plus the speed of your ship, then the measurement you took must be quite a bit less than m, correct?\" To which he replies \"You are a liar, sir. My measurement was m, your's must have been greater than mine, that is your measurement had to be m plus whatever my ship's speed was.\"

Let the speed of the ship = s and c = speed of light. Then you would expect your measurement to be the astronaut's measurement (m) plus the ship speed (s). Instead, your measurement is m, much slower than m+s.

Speed is measured in units of distance divided by time (d/t). Since the speed (d/t) you measured is less than it should be, the only way to account for this is that either d has decreased (constriction of length) or t has increased (dilation of time). In fact, it has been proven experimentally that both of these outlandish things happen at any speed. It's just that they aren't very noticeable until you get to speeds which are at least a fair percentage of c.

If you are the voyeur looking in on the astronaut's light experiment, if you look at his clock you will see (part of) the reason his measurement of his light beam is the same as yours. His clock will appear to be running slowly to you, which is why you measured his light beam going slower than you expected(traveling at speed m instead of speed m+s as you would expect.)

Exact amounts of length constriction and time dilation for any given speeds can be easily calculated from Einstein's field equations. Google that for more info.

In addition to the constriction of length and dilation of time, as you increase velocity, your mass increases. At c, the dilation of time completely stops the flow of time, the constriction of length shrinks your ship's length (measured along the direction of travel) to zero and the mass of everything goes to infinity. (All these things appear only to the observer, the traveler will notice none of them.) Infinity is a hard thing to deal with so let's talk about traveling at just a hair under the speed of light.

At this very large speed, the mass of your ship is huge. The mass of your fuel is huge also, but both masses grow by equal percentages with any increase in speed. Remember, the thrust applied by your engine at full throttle is not subject to relativistic effects. Since the thrust remains constant as you accelerate, but the mass increases at the same time, eventually you reach the point where your engine is unable to put out enough thrust to accelerate anymore.

Several years ago I remember reading about a new concept regarding thrust for a space ship called the ion drive. I forget exactly how it works, but the drive puts out charged particles at high speeds and the action-reaction results in a force of 1 newton ([1 kg-m]/s^2) being applied to the engine. The drive ran off solar power so no fuel was involved. A drive like this could be attached to an unmanned ship with maneuvering rockets for steering and set in orbit around the sun. Depending on the weight of this apparatus, the thing could approach lightspeed after enough time went by. It would be interesting, but dangerous and expensive, to see what would result from such an experiment.

Harte

#### astralsailor

##### Junior Member
Re: faster than light?

<div class='quotetop'>QUOTE(\"Tenshi\")</div>
It's impossible to travel at, or faster than, the speed of light. ?

Why? Because the faster that something travels, the more massive the object becomes, and when it reaches a certain speed (just over three-quarters the speed of light, or thereabouts) the object acquires infinite mass, therefore needing infinite energy to propel it through space, and it is impossoble to get infinite energy.[/b]

And now if i could only convert my self to energi
Yes offcourse i should had remembered that from reading so much about it... Thanks for reminding me

#### thenumbersix

##### Member
Re: faster than light?

If speeding ourself up to the speed of light increases mass, does slowing us down decrease it ?

#### Harte

##### Senior Member
Re: faster than light?

<div class='quotetop'>QUOTE(\"thenumbersix\")</div>
If speeding ourself up to the speed of light increases mass, does slowing us down decrease it ?[/b]

This is a beautiful question that was actually answered in my previous post. Remember that I said that the traveller would notice none of these effects?

If you slow down, you will lose mass from the point of view of someone that is already travelling slower than you. But only by his measurement.

Einstein said that no reference frame is preferable over another. There is no central reference point we can use to determine our speed. There is no object in the universe that can be said to be at rest. The universe has no point that is it's center. When we talk about the observer that is at rest, we mean some guy that was going the same speed as the astronaut before the astronaut accelerated.

Harte