Popular theory states that we cannot travel at the speed of light because time would slow down for us making it unreachable.
But doesn't light travel at the speed of light? Or is that the distance light travels in a year, not to be confused with the speed of light?
If light is made up of something, and can travel at the speed of light, why couldn't we?
Brad
The way I understand it, the problem isn't that time slows down, according to e=mc^2, when you hit the speed of light, the object becomes infinitely massive...
The distance light travels in a year is, cleverly, called a lightyear, and that's just a measurement of distance, not speed.
IP: Logged
02:18 PM
Hank is Here Member
Posts: 4446 From: Hershey, Pa Registered: Sep 2000
Popular theory states that we cannot travel at the speed of light because time would slow down for us making it unreachable.
But doesn't light travel at the speed of light? Or is that the distance light travels in a year, not to be confused with the speed of light?
If light is made up of something, and can travel at the speed of light, why couldn't we?
Brad
Nothing with mass can travel at the speed of light. The reason is because your speed is added to your mass. So the faster you go, the heavier you get. The heavier you get, the more energy it takes to accelerate. As you get closer to the speed of light, your mass becomes infinite. Infinite mass requires infinite energy to accelerate. The end result is that nothing with mass can ever go as fast as the speed of light.
These effects are not noticable until reaching speeds close to the speed of light. You will not be able to measure an increase in your mass traveling down the road at 70 mph.
Light, can go at such speed because it has no mass.
Originally posted by Doug85GT: Nothing with mass can travel at the speed of light. The reason is because your speed is added to your mass. So the faster you go, the heavier you get. The heavier you get, the more energy it takes to accelerate. As you get closer to the speed of light, your mass becomes infinite. Infinite mass requires infinite energy to accelerate. The end result is that nothing with mass can ever go as fast as the speed of light.
These effects are not noticable until reaching speeds close to the speed of light. You will not be able to measure an increase in your mass traveling down the road at 70 mph.
Light, can go at such speed because it has no mass.
I can understand that.
This is where I start having a real problem.
We can use light to move objects such as with a solar sail. So light can move mass. I know photons are supposed to not have mass, but they are there, so they have to take up some room. How can something that doesn't have mass exist?
Brad
IP: Logged
02:34 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
yup - as above - it is due to ever increasing energy needed to accelerate, which makes the matter seem infinitely dense
and - no, light does NOT actually always travel at the speed of light - it is usually slower. a great example is a prism. it breaks light up due to the speed changes while inside the prism. same thing with a rainbow. light travels slower within water. and, what light is made of still highly theoretical. heck - still not sure if it is wave based or ray based. experiments have showed it both ways. which makes little sense to common perspective. tho - electrons & other atomic components have also been shown to exist this way as well.
IP: Logged
02:38 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Originally posted by twofatguys: I can understand that.
This is where I start having a real problem.
We can use light to move objects such as with a solar sail. So light can move mass. I know photons are supposed to not have mass, but they are there, so they have to take up some room. How can something that doesn't have mass exist?
Brad
solar sail? if this is what I think it is - it is not light which is moving the object - it is all the other energy being put out by the sun - "solar wind" basicly the sun being a huge continuous explosion means there is output.
IP: Logged
02:40 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
if you have Netflix - stream the series "Turning Points in the Physical Sciences" the last 2 episodes cover the above pretty well - but the whole series (5 episodes) is well worth watching
IP: Logged
02:46 PM
Doug85GT Member
Posts: 9472 From: Sacramento CA USA Registered: May 2003
We can use light to move objects such as with a solar sail. So light can move mass. I know photons are supposed to not have mass, but they are there, so they have to take up some room. How can something that doesn't have mass exist?
Brad
Light (electromagnetic radiation) is still energy. When it strikes a surface it will push very slightly against that surface. You can read more here:
A recent experiment* at NEC Research Institute, Princeton, N.J., U.S.A., clearly demonstrated superluminal propagation of a light pulse through a specially engineered medium. Superluminal implies faster than the speed of light, and in this experiment the peak of the light pulse arrives at the output end of the medium even before it has entered the medium.
We can use light to move objects such as with a solar sail. So light can move mass. I know photons are supposed to not have mass, but they are there, so they have to take up some room. How can something that doesn't have mass exist?
Brad
Ummm...electricity? Same thing , or not? Can't see it, can't touch it...sure does exist though Magnetic forces? Nick
IP: Logged
04:23 PM
Tuna Helper Member
Posts: 458 From: Ft Wayne, IN, USA, Earth Registered: Aug 2010
We can use light to move objects such as with a solar sail. So light can move mass. I know photons are supposed to not have mass, but they are there, so they have to take up some room. How can something that doesn't have mass exist?
Brad
A better question is how can a photon that has no mass cause a solar sail to move? Without mass it has no inertia right?
A better question is how can a photon that has no mass cause a solar sail to move? Without mass it has no inertia right?
How can a magnet #1 push magnet #2 away from itself without magnet #1 ever moving?
You're forgetting about wave energy. Magnetic waves are energy.. light waves are energy.. radio waves are energy. Given a sufficient amount of any of these, you can cook your dinner. Given that, capturing that energy and using it to drive linear motion doesn't seem that "difficult" (Difficult of course being a relative term).
IP: Logged
04:30 PM
Tuna Helper Member
Posts: 458 From: Ft Wayne, IN, USA, Earth Registered: Aug 2010
Popular theory states that we cannot travel at the speed of light because time would slow down for us making it unreachable.
Brad
My understanding is this, if one was to travel at near the speed of light, and look behind them, time would appear to slow down as the light would not enter your eye as fast as it would normally. If you were to look to the side things would appear normal, and if you look forward things would appear in fast forward. I believe that if you were to travel faster than light and look behind you you would see nothing. Now, this is assuming that one were not traveling in any kind of vehicle. If you were, would things inside appear normal, while things outside appear fast or slow?
Ummm...electricity? Same thing , or not? Can't see it, can't touch it...sure does exist though Magnetic forces? Nick
Electricity is different from magnetic forces. Electricity is the act of outer electrons freeing themselves from one atom and moving to the next. Molecules which have "free" electrons on the outer shell make up good conductors (copper, steel, gold).. Molecules that don't have free electrons on the outer shell don't make good conductors (Glass, Plastics, etc).
Magnetic forces is wave energy..
IP: Logged
04:34 PM
Tuna Helper Member
Posts: 458 From: Ft Wayne, IN, USA, Earth Registered: Aug 2010
From a layperson's point of view, it reads like a group of people made up a rule, and went with that. But there are three or four groups, and each one has a different set of rules.
Then if something happens to break one of those rules, all the groups change just a bit.
My understanding is this, if one was to travel at near the speed of light, and look behind them, time would appear to slow down as the light would not enter your eye as fast as it would normally. If you were to look to the side things would appear normal, and if you look forward things would appear in fast forward. I believe that if you were to travel faster than light and look behind you you would see nothing. Now, this is assuming that one were not traveling in any kind of vehicle. If you were, would things inside appear normal, while things outside appear fast or slow?
Isn't this also the whole traveling back in time theory? The faster you go the slower time is to you as an individual up to the speed of light. IF one could somehow travel faster than light time would (to them) go backwards. In theory that is.
I've always liked this explanation From Carl Sagan:
quote
NOVA: How is the speed of light connected to time travel?
Sagan: A profound consequence of Einstein's special theory of relativity is that no material object can travel as fast as light. It is forbidden. There is a commandment: Thou shalt not travel at the speed of light, and there's nothing we can do to travel that fast.
The reason this is connected with time travel is because another consequence of special relativity is that time, as measured by the speeding space traveler, slows down compared to time as measured by a friend left home on Earth. This is sometimes described as the "twin paradox": two identical twins, one of whom goes off on a voyage close to the speed of light, and the other one stays home. When the space-traveling twin returns home, he or she has aged only a little, while the twin who has remained at home has aged at the regular pace. So we have two identical twins who may be decades apart in age. Or maybe the traveling twin returns in the far future, if you go close enough to the speed of light, and everybody he knows, everybody he ever heard of has died, and it's a very different civilization.
It's an intriguing idea, and it underscores the fact that time travel into the indefinite future is consistent with the laws of nature. It's only travel backwards in time that is the source of the debate and the tingling sensations that physicists and science-fiction readers delight in.
IP: Logged
05:57 PM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
------------------ And they said one to another, "Behold, for here comes the dreamer. Come now, let us slay him and we shall see what then will become of his dreams." ~ Genesis 37: 19-20
Time and space are part of the same fabric. The faster you move through one, the slower you move through the other. Sitting in front of your computer, you are moving through time at the speed of light but are stationary in space (not counting the movement of the earth, solar system, galaxy etc.). As you move faster through space, your speed in time slows down. When you near the speed of light, time is nearly at a standstill.
This has some other strange implications. Say you are going 99% the speed of light and a light beam goes past you. How fast is the beam of light moving past you? Answer: at the speed of light. It will appear to be moving at its same speed because time has slowed down for you by 99%.
Magnetic forces?
