Traveling the Speed of Light

[Nezill]

2 posts up.
c is constant, the speed of light is not.
light can be slowed down, e.g. when it passes through glass or air it is infact travelling slower than when it passes through free space.
light is thought of a wave and particles, the particle-wave duality theorem or whatever, my brains on summer holiday. i may just have dig out some of my notes.

The Light is bent and to its own inertial frame it is traveling at about 300,000 km/s. It may appear to us to be going slower, but it's really just traveling more "distance."

 

[kirovman]

The Light is bent and to its own inertial frame it is traveling at about 300,000 km/s. It may appear to us to be going slower, but it's really just traveling more "distance."

Yes, I think that has to do with Fermat's Law. You can derive an optical path length, n x L (n=refractive index, L=actual length)
Light will go somewhere by the least possible optical path length.

Did that half a year ago, so it's not very fresh in my mind.

 

[Nezill]

I just did a report on the Theory of Relativity, so this is all fresh in my mind.

 

[DavE0r]

Basing my hypothesis on the Higgs boson view point (which is one of the more credible i have heard over my time), creating an atom that had 0 higss bosons would then make this atom instantly travel at the speed of light, ok let me explain.

Lets say 'bob' our wourthy test subject (fool ) weighs in at 90kg. He wants to move lets say over to the other side of the shop he's in. He is going to require a certain ammount of energy to move his mass to that point.
So saying this, if he than drastically lost weight, he would require less energy (working on the theory of E=mc2) to perform the same movement. Now, if we had something lets say an atom of steel, that had all the higs bosons removed, and the atom then had a mass of 0, it would require 0 energy for this to move. (already stated above by TigerRei) So this means that the atom would then move on its own instantly at the speed of light. But it would not move off in a single direction persey, as in foreward or something, i think it would move off in "all" directions at the same time, because it would not need any outside force to make it move, such as something with a mass.
Well...i hope i got that across right

 

[Grumpy]

Brain Damage is so close with his info.

One way to accelerate beyond lightspeed (in spoken terminology only, because you wouldn't actually be moving at all), would be to hold yourself and your ship within a bubble of spacetime that was stationary relative to your ship but capable of moving throughout the universe. Since your ship is not actually moving relative to its own spacetime bubble, there is no increase in mass due to acceleration.

You do not need to be able to travel faster than c to get from A to B faster than light The trick is, you have to fool the Universe into looking the other way while you sneak in through the back door

 

[Brian Damage]

Well, that makes me think: What if we one day found a way of altering physical laws within a certain area?

It's basically altering reality, so I dunno if we'd ever be able to do it, but it'd be nice to be able to select a region of space and say, "Okay, spacetime continuum, we're allowed to go faster than light here, understand?"...

 

[holy_cheese]

we cannot alter physics laws. (they may not be right, but what ever law is correct, we cannot alter. everything is as it is and we cannot do a damn thing about it)
although it is possible to reach a point B from A faster than light, if you find a spot where space is curved.
Cosmic strings, the space around a cosmic string is bent. take a cross section of a cosmic string, the space around it isn't flat, it would be a cone. much like a pizza with some slices missing and then pulled together to make a cone, so instead of travelling through the middle you can travel around and over the missing slices and arrive at B faster than light would if it travelled in a straight line through the middle.

 

[Muhahahaha]

That is an interesting point that was made earlier, though. That it is only impossible to ACCELERATE to the speed of light, since you would need an infinite force, but that it is not impossible to go at the speed of light or faster by some other means. Obviously I have no idea how else you would do that, but I just found it to be an interesting clarification.
I wonder if HL2 uses Einsteinian physics or Newtonian physics? That would be interesting to know. It makes little difference for the game, I suppose, but there are slightly different equations for moving objects according to Einstein, which reduce to Newton's equations at very low speeds. Also, if some developer were to code stuff for the game and messs with the speeds of people or vehicles or something (hopefully in some infinite-like level), would it allow them to go the "speed of light" or not?

 

[ratm9200]

Just a few questions that formed while reading this thread:

what if you were traveling .99999999999999c and fired a gun? the laws of physics as we understand them now say that the bullet has mass and therefor cannot travel at or above the speed of light.

Can anyone here (or anyone) actually comprehend how time slows down as light speed is approached or do you just accept that that is what happens? It accept it, but i dont understand how its possible.

We say that distance = rate X time, but if you were traveling .75c for 10 seconds. Would you count the 10 seconds relative to you (who's time is "slower") or relative to a bystander who is still (whos time is "normal")? Either way, does this mean that distance is relative?

Now, my own theory. While it seems that it is possible for some objects to travel faster than the spped of light, it will never be possible for humans to travel faster then the speed of light. But i have an idea for teleportation (sort of). In the distant future, if the human body is compley figured out, i think it would be possible to send them through signals. My idea would be to have 2 machines (there would be more if they were being used for travel but for the purpose of this explanation there will be 2) that each have a stockpile of the matter (plus anything else that is discovered) that is needed to make up a person. When a person enters machine a, they are completly broken down. The matter is then transfered to the machines stockpile. The machine would send a signal (which would travel at the speed of light) containing information to rebuild you exactly as you were when you left. Machine b would use the material in its stockpile to completly rebuild you. So, in a way you would have traveled at the speed of light. Of course this will not be possible anytime soon, especially because of rebuilding memorys and such. Anyway just an idea I formed.

 

[Nezill]

That is an interesting point that was made earlier, though. That it is only impossible to ACCELERATE to the speed of light, since you would need an infinite force, but that it is not impossible to go at the speed of light or faster by some other means. Obviously I have no idea how else you would do that, but I just found it to be an interesting clarification.
I wonder if HL2 uses Einsteinian physics or Newtonian physics? That would be interesting to know. It makes little difference for the game, I suppose, but there are slightly different equations for moving objects according to Einstein, which reduce to Newton's equations at very low speeds. Also, if some developer were to code stuff for the game and messs with the speeds of people or vehicles or something (hopefully in some infinite-like level), would it allow them to go the "speed of light" or not?

The game would allow something to go past the speed of light, whether your processor and the pixels on your screen could process it tho is another thing. The Physics in the game mimic real life physics and are not built off of any theories etc.

 

[holy_cheese]

:
what if you were traveling .99999999999999c and fired a gun? the laws of physics as we understand them now say that the bullet has mass and therefor cannot travel at or above the speed of light.

this is the old "in a car, throw a brick" ok here goes, your in a car travelling at 100km/h throw a brick forward out the window at 20km/h it hits the guy standing on the side of the road at 120km/h (neglecting air resistance) WRONG!!! it hits the person at 119.99999999........999...........99999 keeps going km/h still hurts but not quite 120km/h. this is thanks to dear old einstein, cheers mate. Any ways, same goes for things at large fractions of light speed, but to a much larger degree.
although since everything is relative, and take the example of light, travel at 0.9c shine a torch infront of you, the light goes c away from you but also passes someone else who is stationary at c aswell.........

Can anyone here (or anyone) actually comprehend how time slows down as light speed is approached or do you just accept that that is what happens? It accept it, but i dont understand how its possible.

to the best of my understanding it works some what like the doppler effect. But im not entirely sure. I just know that time dilation is definately real and has already been measured by astronauts who have been in space being a couple seconds or so younger than what they would have been if they stayed on earth.


Onto my own theory, since everyone seems to have thier own theories, i don't want to fell left out :cheese: :
I belive that the speed of light is directly related to time, or atleast relative time, the faster you go, the faster the world you return to has travelled.
Also i believe that c will never be reached by man, that is c in flat space not through curved space. Beyond c i belive is a mirror, i won't say universe, ill say reality, where everything is as it is here in this universe, just moving at c or above/below (mirror thingy)


well enough of the long winded post.

 

[R@mmstien]

Sometimes i think, What if we already have the power to travel at the speed of light... it would be right under our noses and we wouldnt even know. I think Traveling at the speed of light we just be a realization of how we normally percieve things. It could be one answer, just one that would help us realize and maybe even just convert to pure energy with nothing but that answer.

 

[.nails]

Sometimes i think, What if we already have the power to travel at the speed of light... it would be right under our noses and we wouldnt even know. I think Traveling at the speed of light we just be a realization of how we normally percieve things. It could be one answer, just one that would help us realize and maybe even just convert to pure energy with nothing but that answer.

Someone decipher that :rolling:

 

[kirovman]

Put simply:
Time Dilation, Length Contraction and Relativistic mass all change, just to keep the speed of light constant for all observers in all frames of reference.
If you want to understand it better, do a special relativity course. It's not too difficult, the maths can get tedious at points, but once you've studied it a bit, and done a few problems involving calculations, you can get a good feel for it.

 

[holy_cheese]

Time Dilation, Length Contraction and Relativistic mass all change, just to keep the speed of light constant

wow, that explained so much better than any of our half a page rambles. atleast for me it just went click.

 

[Grumpy]

Hmmm, the good part of all this is the theoretical ideas popping up. A few scientist I know could do with a trip here to see the crazy stuff put forward, it may get them out of a rut and back to solving a few problems by coming up with rediculous but actually doable solutions. This is where scientific advancement fails, you believe everything that is taught and for the rest of your life cannot get your brain to allow silly idea to be postulated Why is c set at what it is, what are the underlying mechanics of the process where light and thus c come into being. There is more going on beneath the Quantum Strata to pop c into being than tea in China, yet we just say it is so..baaaa !

 

[Mouldy Punk]

I don't actually understand where the idea of time coming into any of this came from. We can travel much faster than the speed of sound, that doesn't involve time, it just means you can go further in the same amount of time. Surely the same applies to light speed. You will just get their quicker, that is the only relevance to time...or atleast that's what I think. If you were travelling at the speed of light people wouldn't be able to see you, or it would be delayed, fair enough. Just like planes that travel past the sound barrier, you see them, but you locate the sound of the jet engines behind them. Just like there is a bang when you "break" the sound barrier, I assume there will be a flash when you "break" the light barrier. The only possible problem with accelerating to the speed of light that I can think of is the human body limitations. If we gradually accelerate and deccelerate we will probably be ok though, but the G's would crush us otherwise....wait...that's a point. The faster we go the more mass we have? Surely G's crushing us would make us have less mass.

The way I see it, light is just sound, but at a much much much much much much higher wavelength...I remember seeing a diagram once. Sound has wider waves than light. Meaning (in my head) they are pretty much the same thing, but light is faster. Surely if you just keep on excellerating you will break the sound barrier, then the light barrier, the feck knows what next and viola you will be travelling faster than the speed of light. How does time come into this? Time doesn't exist. We just measure something we think is their with clocks. 60 seconds to a minute, 60 minutes to an hour, 24 hours to a day etc, they are only measurements, to make a hand click round a notch every so often doesn't mean a thing.

Just my outlook. I'm pretty sure most of that made no sense what so ever so make what you will of it.

 

[kirovman]

I don't actually understand where the idea of time coming into any of this came from. We can travel much faster than the speed of sound, that doesn't involve time, it just means you can go further in the same amount of time. Surely the same applies to light speed. You will just get their quicker, that is the only relevance to time...or atleast that's what I think. If you were travelling at the speed of light people wouldn't be able to see you, or it would be delayed, fair enough. Just like planes that travel past the sound barrier, you see them, but you locate the sound of the jet engines behind them. Just like there is a bang when you "break" the sound barrier, I assume there will be a flash when you "break" the light barrier. The only possible problem with accelerating to the speed of light that I can think of is the human body limitations. If we gradually accelerate and deccelerate we will probably be ok though, but the G's would crush us otherwise....wait...that's a point. The faster we go the more mass we have? Surely G's crushing us would make us have less mass.

The way I see it, light is just sound, but at a much much much much much much higher wavelength...I remember seeing a diagram once. Sound has wider waves than light. Meaning (in my head) they are pretty much the same thing, but light is faster. Surely if you just keep on excellerating you will break the sound barrier, then the light barrier, the feck knows what next and viola you will be travelling faster than the speed of light. How does time come into this? Time doesn't exist. We just measure something we think is their with clocks. 60 seconds to a minute, 60 minutes to an hour, 24 hours to a day etc, they are only measurements, to make a hand click round a notch every so often doesn't mean a thing.

Just my outlook. I'm pretty sure most of that made no sense what so ever so make what you will of it.

When you travel towards the speed of light, Common sense or Classical Mechanics as you know them break down. Time is an intrinsic part of speed (units of speed, metres per second anyone?). Special Relativity will explain it to you, take a physics class, it will not make sense in the realms of common sense, but not much physics does these days.
As I have said before, time and length are 'warped' (dilated or contracted) to the appropriate scale in order to keep the universal constant, c constant for all observers
Also sound speed is mearly a measure of how fast air particles can travel, but light speed, it is the universal speed limit.

Time DOES EXIST, maybe it is not tangible, we measure lengths of it, but I suppose you could say the natural unit of time is a planck time length (very small), like we measure lengths of string. By using that arguement spatial dimensions don't exist, and therefore neither do you. That's a matrix philosphy arguement, so let's not speak of it.

 

[GeorgeWLucas]

Gordon Freeman is cool. He has a crowbar and he goes WHACK!

 

[Person]

I don't actually understand where the idea of time coming into any of this came from. We can travel much faster than the speed of sound, that doesn't involve time, it just means you can go further in the same amount of time. Surely the same applies to light speed.

Not so if you ask Einstein. Two events occuring at the same time for an observer need not occur at the same time for another observer (relativity of simultaneity). This creates no paradox as long as you travel below speed of light, you can't prove what really happened when. But if you exceed speed of light, you can be there before an event already occured for another observer, and therefore you can change the past. Weird stuff.

 

[Mouldy Punk]

Oh yeah, didn't think of that...if you go faster than the speed of light, you can get somewhere, see something, before the guy who is already there sees it. So light speed could be linked with time travel, just accelerating will affectively make you accelerate through time.

 

[antaydos]

kirovman, am I glad you're hear to reply as often as you are.

Not so if you ask Einstein.

Not so if you ask ANYONE WHO'S TAKEN THE LOWLIEST INTRODUCTORY PHYSICS COURSE.

Oi. I saw a couple people mentioning that you can reach point B from point A faster than a light signal if you find a curved area of space. Duh. That's the same thing as saying "I can get there faster if I just make the light go through this huge elaborate maze of mirrors on its way there". You're cheating by sending the light on a wild goose hunt during the course of the race.

Know this: Travelling the same path as a beam of light, you will always lose.

A lot of other people are saying that we probably can move faster than the speed of light, and that we simply haven't figured out the means to do so yet. Sorry, but you're very wrong. You seem to be under the impression that the postulate of nothing moving faster than light speed was chosen at random with no mathematical or logical reasoning. Not true. The speed of light is constant in all reference frames. Under any kind of transformation of coordinate systems or Lorentz transforms or what have you, it will always be the same. AS SUCH, it is the fastest moving entity in the universe, and its speed can never be equalled by anything other than itself.

The notion that nothing can move faster than light is a very simply derived idea from one of the most solid and profound bases of physics to have ever been written. It's not something that's been thrown out at will. Nobody said "Hmm... well let's make physics easier and say that nothing can move faster than light. Nobody will know. Screw 'em."

It just IS.

 

[lucidrains]

not possible

the concept that 'nothing is faster than the speed of light' is the base assumption for nearly all of advanced physics. it would be ridiculous to conjecture anything else, as we would have to rewrite all of physics, mathematical and theoretical, if it were not the case.

you're wondering why it is stupid to ask this question. but trust me, u need to understand a lot more physics before delving into the subject. otherwise, to a physicist, it would seem like fantastic musings that makes the slightest sense; pseudoscience, simply.

i got an A+ in physics III (light, optics, quantum mechanics) as a cornell undergraduate, so I do know my stuff.

 

[lucidrains]

nm

whoops, antydos' explanation is probably best read.

my bad for adding junk to the board.

 

[Nezill]

My theory is that time is the fourth dimension. Think about it, you stick your thumb into a 2d world, the 2d beings can only see a slice of your thumb, a 4d object pokes itself into our world, we only see a sliver of it.

 

[Mouldy Punk]

I always imagined the 4th dimension to be touch. But that's probably from those 4D cinema's in disneyland where they pour water on you and the seats rumble...

My theory about alot of things, just because we don't understand it, doesn't mean it doesn't happen/is impossible. Just because we don't understand how we could possibley reach the speed of light, doesn't mean we won't eventually get there. Just because we didn't understand that the world couldn't be anything but flat, doesn't mean it is flat. We don't have the knowledge at this moment in time to figure out how to make it possible to exceed the speed of light. Just because Einstein said it, doesn't mean it's true. Sure people have studied his work and "proved" him right, but has anyone tried to "prove" him wrong? We now know more than we did when Einstien was alive. It is more than possible that he is wrong. I'm pretty sure at one point it seemed impossible to travel at 50mph. Now that's a reality. I'm sure that someday we will reach light speed, unless we don't blow ourselves up before hand.

I have a question. If our mass would stretch to infinity when we reach the speed of light, where does all this extra mass come from? Didn't someone once say that mass cannot be created or destroyed, only manipulated? Surely our mass cannot grow or shrink. Unless it is our bodies digesting food etc.

 

[kirovman]

kirovman, am I glad you're hear to reply as often as you are.

Hey, cheers :cheers: It's good to read your enlightened posts too

Just because Einstein said it, doesn't mean it's true. Sure people have studied his work and "proved" him right, but has anyone tried to "prove" him wrong? We now know more than we did when Einstien was alive. It is more than possible that he is wrong. I'm pretty sure at one point it seemed impossible to travel at 50mph.

Einstein was a very clever man. Everything is just theory, nothing is 100% fact, but what we have are the best approximations of our age.
People thinking 50mph was too fast, well that's because of the laws of "common sense" before Newton's time. Newton came along and introduced his laws, which are widely regarded as correct. However his laws do not work at some limits, eg near light speed velocity, and so relativistic interpretations were developed.

And our 'facts' are based on rigourous testing and evidence, and are widely accepted. Yes, sometimes the 'facts' change, but look at Newton's laws. They are wrong, but they work in everyday life, they are good approximations. So we use them to launch rockets and stuff. Chances are relativity is wrong, but they are a good approximation in the circumstances. So changes to theories don't tend to affect the general case, only very specific cases, eg the specific case of near light speed velocities.

But wishful speculating is not going to change any of our facts. Building on top of what we have may do.
Light speed is not going to be broken by launching a ship and giving it more and more accelerative energy though. And nor by any other means I should imagine.

 

[holy_cheese]

Oi. I saw a couple people mentioning that you can reach point B from point A faster than a light signal if you find a curved area of space. Duh. That's the same thing as saying "I can get there faster if I just make the light go through this huge elaborate maze of mirrors on its way there". You're cheating by sending the light on a wild goose hunt during the course of the race.

erm, aint sending light on a goose chase take a circle, damn pizza, remove two slices, connect the sides together again you get a cone.
now here's how it goes, if light travels straight through the middel in effect travelling the entire distance from a to b. now if a body travelled around the side where slices were removed in effect travelling s greater distance but in less space.

 

[Grumpy]

Not to mention the energy mass conversion which takes place when an object travelling at near c runs into a grain of salt. Going really fast and hitting ANYTHING really sux

 

[antaydos]

erm, aint sending light on a goose chase take a circle, damn pizza, remove two slices, connect the sides together again you get a cone.
now here's how it goes, if light travels straight through the middel in effect travelling the entire distance from a to b. now if a body travelled around the side where slices were removed in effect travelling s greater distance but in less space.

If you're trying to be taken seriously, PLEASE try to form a coherent sentence. I have NO idea what you just said.

And despite my previous post, people still seem to ignore everything I said. Ugh. I love when people who have no background in physics try to tell me I'm wrong about this.

 

[Grumpy]

I think we all understood you You cannot reach c due to constraints of energy and mass. In reality, the best speed a space vessel could safely hope for is about 135,000 Kph. Above that the dangers are too great, even that requires considerable time for acceleration and a large energy output. At that speed you need considerable mass dampening at the front for particle protection, redundant sensor arrays that would take up enormous volume. Life support for 40 people ( The minimal amount for a system to system journey ). In reallty, it would be like a sci fi story with massive trans generational vessels. I imagine with our level of technology, it would take 40-60 years to build such a vessel. So, I think we better find something better or hope they have some good books out by then to read on the way

 

[holy_cheese]

mainly to antaydos
i know that i sometimes ramble and i really couldn't care less if i was taken serious on a message board with a million different theories, all of which are probably wrong, even the ones i think may most likely be true.

if you would like me to clarify what i was trying to get at in more depth and more coherently ^_^ i can do so, if not, meh.

anyways no hard feelings.

 

[Sid Burn]

I think we all understood you You cannot reach c due to constraints of energy and mass. In reality, the best speed a space vessel could safely hope for is about 135,000 Kph. Above that the dangers are too great, even that requires considerable time for acceleration and a large energy output. At that speed you need considerable mass dampening at the front for particle protection, redundant sensor arrays that would take up enormous volume. Life support for 40 people ( The minimal amount for a system to system journey ). In reallty, it would be like a sci fi story with massive trans generational vessels. I imagine with our level of technology, it would take 40-60 years to build such a vessel. So, I think we better find something better or hope they have some good books out by then to read on the way

well, I think wormholes are our only hope to get to other starsystems in a few min or hours also... I think even with advance tech... noone can maintain that kind of speed. Though I think building a starship that can use wormholes would be almost impossible in our time even in the next centuries to come.

 

[Grumpy]

The ancient Egyptians believed you could travel to other worlds by playing with 5th and 6th dimensional space.

 

[Sid Burn]

The ancient Egyptians believed you could travel to other worlds by playing with 5th and 6th dimensional space.

But how could that be done!?

 

[kirovman]

In 1500s Britain they used to believe in witchcraft.

Have you got any sources about the ancient Egyptians and this?
I believe they were good mathematicians, built the pyramids pretty well. Must have had extraterrestrial help...or an evil genius pharoah's advisor to design them.

 

[Grumpy]

It is one of the mysteries of life, archaeologists do not like it when ancient cultures "seem" to know things they cannot possibly know. How did the Greeks know of not only Atoms but of that which they are composed of. These sorts of texts sadly usually are destroyed, or hidden away in vaults never to be read again. It is interesting also that 2 other cultures wrote of 5th and 6th dimensions as being real. Gotta love a good mystery, even better when the scientists have coronary occlusions over it

 

[ratm9200]

If you were traveling the speed of light, it seems it would take 4 years to a celestial body 4 lightyears away. But theoreticly, time stops when traveling the speed of light so wouldn't you arrive instantly? And if traveling light speed isn't possible, then traveling just under light speed, time would be going very slowly and should only take a couple of seconds to get there. Can someone tell me why im wrong?

 

[Grumpy]

I think it would still take 4 years, but it would take years to slow down safely

 

[itsmygame]

Now I'm confused. Stupid big words... D: