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 Subject: speed of light, why not? Category: Science Asked by: chefmarius-ga List Price: \$10.00 Posted: 17 Mar 2006 13:56 PST Expires: 16 Apr 2006 14:56 PDT Question ID: 708532
 ```I'm no scientist, but what I would like to know is this. As far as I know Einstein "proved" that u cannot reach the speed of light, u can only approach it,I think its "c" now, speed of light equels 300 x 10 to the power of 6. why can we go faster than that, why is it IMPOSSIBLE? Is it not just technology that is keeping us back? I know that they say we will be as flat as you can possibly get it, but if you accelerate slowly and eventually pick up the speed, and combined with depresurization, we will be okay? but appart from that, what is physically keeping us from going past 299 792 458m.s? Technology? I think so!! pls explane why not!!```
 Subject: Re: speed of light, why not? Answered By: hedgie-ga on 09 Apr 2006 12:57 PDT
 ```This is actually a FAQ - it was answered here sevweral times Is it not just technology that is keeping us back? No I know that they say we will be as flat as you can possibly get No, you will not be flat, and time will not stop. Ignore most of the comments. Here is your answer: why http://answers.google.com/answers/threadview?id=708752 why not http://answers.google.com/answers/threadview?id=708752 e=mc squared wrong? http://answers.google.com/answers/threadview?id=605720 After you read it, you may post RFC```
 Subject: Re: speed of light, why not? From: cadre-ga on 17 Mar 2006 15:16 PST
 ```The energy required for this would become very large. It is defined as: E=ymc^2 Where y is: 1/[root(1-v^2/c^2) v is the speed of the moving object. As a mass carrying object approaches the speed of light, its energy becomes infinite. From the value of gamma (y) you can also deduce, that v cannot equal c. When v=y, then we have 1/0, which is not mathematically defined. There are other effects when approaching c. Lenght contraction. All seen by an observer. The problem is the notion of what the speed of light is. Everywhere in the universe, everything is moving in respect to all else. Then, it is difficult to determine, who/what is moving in respect to whom/what and at what speed.```
 Subject: Re: speed of light, why not? From: cadre-ga on 17 Mar 2006 15:25 PST
 ```Actually, if you are interested in actually travelling very fast, it is possible. Relativity says, that at the speed of light or very close to it, time is less of importance, to the traveller at least. Lets say you could venture to the next galaxy in a couple of years close to c. For an observer, it is actually the speed he observes which counts. So if light travels a million years to a neighbouring galaxy, roughly that time would pass on earth. Not a nice prospect.```
 Subject: Re: speed of light, why not? From: kottekoe-ga on 17 Mar 2006 21:41 PST
 ```I don't quite understand Cadre's comment, but perhaps he is talking about the fact that you can, in principle, travel to distant galaxies in a short period of time if you can travel close to the speed of light. From your point of view, it is because of the Lorentz contraction that shrinks the distances that you must travel. From the point of view of someone back on earth, it is because of the time dilation that makes your clock run much slower. If you could accelerate continuously at 1 g (10m/sec^2) (a very big if!), it would take about a year to get close to the speed of light and you would have traveled a reasonable fraction of a light year. With each successive year, the distance traveled would grow exponentially, so it would only take a matter of 10's of years to go to astoundingly great distances. If you tried to go back home, unfortunately, you would find all your loved ones long since dead. Of course, the energy required to achieve these velocities is virtually unthinkable, but it is important to understand that in spite of relativity's unbreakable speed limit, there is no limit on how fast we can get to distant spots in the universe and time travel is possible, but only into the future, with no hope of return.```
 Subject: Re: speed of light, why not? From: rracecarr-ga on 18 Mar 2006 19:09 PST
 ```I did the calculation once and I seem to recall that, accelerating at 1 g, you can get anywhere in the universe within 1 year (by your clock, of course) not 10s of years as kottekoe suggests.```
 Subject: Re: speed of light, why not? From: rracecarr-ga on 18 Mar 2006 20:12 PST
 ```Kottekoe is right as always. At 1 g, you can get anywhere in the observable universe in about 23 years (if we give the observable universe a size of 10^10 light years). I think what I was remembering is that if a spaceman accelerates away from the earth at 1 g, and you want to shoot them with a laser, you can't wait too long, or the laser will never catch up to the spaceman, even though it travels at the speed of light. The cutoff time is a little under a year.```
 Subject: Re: speed of light, why not? From: kottekoe-ga on 18 Mar 2006 22:26 PST
 ```Racecar: Cool, I never knew that constant acceleration with a head start could keep you ahead of a light beam. Thanks for the kind words and for teaching me something new.```
 Subject: Re: speed of light, why not? From: robjewell-ga on 19 Mar 2006 15:08 PST
 ```The reason the light won't catch the spaceman is counterintuitive. As pointed out above, as you approach the speed of light your mass would increase exponentially. The closer you are to a massive object the slower time seems. That is why while you can't travel faster than the speed of light from your own perspective, you can travel what appears to an observer to be more than 1 light year in 1 year. This is because space is also relative and affected by mass in a similar manner to time. You think you are 3 meters from a tree because you are not that massive. If you were, you would be much closer. Very strange. Since light has no mass it doesn't gain this advantage and is stuck dealing with space being the size our usual non-massive selves think it is. So the rocket man is traveling slower, but has to cover less distance to get there. Space is actually smaller for him. One more thing to think about, chefmarius-ga , is that theoretically if we did get any object with mass, no matter how small, to travel very close to the speed of light then it would approach the top of the asymptote. Then it would as massive as the entire universe and all the mass would occur at the same point. At this point all time would stop and everything would be one big black hole frozen in time. Thankfully, it would require more energy than we will ever be able to produce (I hope) to do this.```
 Subject: Re: speed of light, why not? From: kottekoe-ga on 19 Mar 2006 17:08 PST
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 Subject: Re: speed of light, why not? From: aamirash-ga on 20 Mar 2006 07:19 PST
 ```The energy required for this would become infinite. If we use the entire energy of this universe even then we can not acquire that speed.It is defined as: E=ymc^2 Where y is: 1/[root(1-v^2/c^2) v is the speed of the moving object. As a mass carrying object approaches the speed of light, its energy becomes infinite. From the value of gamma (y) you can also deduce, that v cannot equal c. When v=c, then we have y=1/[root(1-1/0)], which is not mathematically defined. There are other effects when approaching c. Lenght contraction. All seen by an observer. The problem is the notion of what the speed of light is. Everywhere in the universe, everything is moving in respect to all else. Then, it is difficult to determine, who/what is moving in respect to whom/what and at what speed.```
 Subject: Re: speed of light, why not? From: cadre-ga on 20 Mar 2006 17:31 PST
 ```kottekoe-ga Would it interest you to comment upon Speed of Light/Relativity by ocoeeriver-ga? Perhaps I will get a better insight into this question. Thanks.```
 Subject: Re: speed of light, why not? From: aamirash-ga on 20 Mar 2006 22:02 PST
 ```The energy required for this would become infinite(Very Very Large). The entire energy of this universe is less then the required energy.Energy required to move an object at speed v is: E=ymv^2 Where y is: 1/[root(1-v^2/c^2) Where m is the mass of the object at rest. v is the speed of the moving object. If v=c then E=ymc^2 As a mass carrying object approaches the speed of light, its energy becomes infinite. From the value of gamma (y) you can also deduce, that v cannot equal c. When v=c, then we have y=1/0, which gives E=1/0=Infinite. There are other effects when approaching c. Lenght contraction. All seen by an observer. The problem is the notion of what the speed of light is. Everywhere in the universe, everything is moving in respect to all else. Then, it is difficult to determine, who/what is moving in respect to whom/what and at what speed. Therefore apart from technology lack of energy is also responsible for it.```
 Subject: Re: speed of light, why not? From: chefmarius-ga on 21 Mar 2006 12:00 PST
 ```thanx for the comments, but robjewell-ga, you say that we cannot get anything to the speed of light, but here in south africa in a town in stellenbosch, there is a rotator with 4 blades (almost looking like a fan) and apparently this blades move to the speed of light and they through in this "ball" of something and then this breaks offcourse, giving off a huge amount of energy, then the scientist i think study what happens inside this ball, and the atoms etc, also in the states, there is a tunnel, where they work with a certain object that goes through this tunnel, reaching the speed of light, bearking and then the whole studying happens of this thing again. am I wrong with this? o you mind explaing "This is because space is also relative and affected by mass in a similar manner to time." thanx```
 Subject: Re: speed of light, why not? From: williamashley-ga on 22 Mar 2006 01:24 PST
 ```Crackhead! We are light! Einstein "proved", not to offend relatavists but I remind you science is 'theory' it is used to give engineers a reason to live. True doctors may shove a needle up your but and call you a ludite if you repeat this, but Einstein didn't 'proove' anything. He used a bunch of math to make an elite club of people that could remark and say THE MATH WORKS!!! Later Einstein said he made an error by establishing an universal constant that gave quantum mechanisists breathing room from psychotropic injection. "that u cannot reach the speed of light" for us to move at light speed we have to be light. The complex answer is not one that other physists may agree to cause it uses my own theories. Leptons are light (bosons) quarks are orbiting pairs and such of bosons when they colide they create light.. Biological humans are made of quarks.. quarks are in 'reverse' to light meaning they move nowhere at light speed but 'gravitate towards the center of the universe.' light.. does not it goes the other way. now the bosons have the capability to 'tow' if they have a greater number of 'leptons than half the number of quarks roughly no math here.. (there are different sized quarks) so to go at light speed you have to be leptons.. the bigger you are the slower you will be in one direction.. and the faster in the other.. Note this is my theory so if you tell this to your grade 10 science teacher they may not agree```
 Subject: Re: speed of light, why not? From: vtmemo-ga on 29 Mar 2006 10:13 PST
 ```Well, you've also got to worry about multidimensional analysis. Any dimension number (n) is not *determined* by it's lower dimension, (n-1). Then take into account the inherent finite energy nature of the universe - there is only so much energy in existence at any given point; this is part of the conservation of energy law. If you can't create it or destroy it, then you can only hope to contain it; the larger volume you try to contain it in, the larger the entropy of that energy. So basically, you have an almost infinite energy in a very finite space, which means it's tending to try to "get away" from you - the end result is a very simplified nutshell version (this shouldn't be used as a one-word answer, but it's an argument for it): You can't create energy, and you can't exceed the amount of energy in the universe. The faster you go, the more of the universe's energy you have - if at any point the sum of your energies changes, you've broken the first law of thermodynamics (and physics in general), and that's a no-no. So there *is* a theoretical "cap" to how fast any given mass can travel, and Einstein theorized that velocity as the speed of light - even to this day, we can't find anything that moves faster than "C". If you figure out how, you can probably just buy Google. :-P```
 Subject: Re: speed of light, why not? From: finite_knight-ga on 30 Mar 2006 07:15 PST
 ```Do remember that scientists used to think the world was flat, today scientists have made many discoveries about our universe. To say that the speed of light is unatainable just shows egotism to thinking we know our environment. We know tiny little aspects about our environment and we will continue to learn and explore and prove past theories wrong. Laws of thermodynamics may be wrong, but for now they work. Relativity and many other theories work for us right now and may no longer be applicable in 10, 20, 100 years. Science is not to prove what can and can't be done, science is to help us deal whith what is happening now and in the near future. Remember that everything is possible, it may not be plausible..... for now!```
 Subject: Re: speed of light, why not? From: manyvan2000-ga on 31 Mar 2006 09:43 PST
 ```The answer is simple. Its because science and technology is still in its primitive stage!! What we have learnt so far is not even one - zillionth of what nature has. We still, cannot even design an aircraft, which moves at the speed of light, that is *always* reliable and you are thinking about moving faster than light! We have to admit that we are still in the process of evolving and we still have a long way to even understand the very basics of nature.```
 Subject: Re: speed of light, why not? From: manyvan2000-ga on 31 Mar 2006 09:45 PST
 ```"We still, cannot even design an aircraft, which moves at the speed of light," sorry, it should be speed of sound..:)```
 Subject: Re: speed of light, why not? From: chefmarius-ga on 01 Apr 2006 03:49 PST
 ```vtmemo, can you tell me, if we cannot creat enery as you say, then how does an atom bomb work? is that not matter wich changes into energy???```
 Subject: Re: speed of light, why not? From: chefmarius-ga on 01 Apr 2006 03:54 PST
 ```vtmemo, can you tell me, if we cannot creat enery as you say, then how does an atom bomb work? is that not matter wich changes into energy???The device basically works when the detonated TNT compresses the Plutonium into a critical mass. The critical mass then produces a nuclear chain recation similar to the domino chain reaction. The chain reaction then promptly produces a big thermonuclear reaction. And there you have it, a 10 megaton explosion!```
 Subject: Re: speed of light, why not? From: pulpcatalyst-ga on 01 Apr 2006 05:06 PST
 ```i don't claim to know what i'm talking about, but after reading all these comments, it would all seem to come down to MATTER, it would appear that the concept (restrictions laid down) behind matter is what's causing the problems, i feel that we will eventuallly move on to this problem, and perhaps work on a way that could create a field that could encampass a object and allow the object to defy, or perhaps help bend the rules of current physics, i think this would also perhaps kill 2 birds in 1 stone, as elimating the problem with matter, should also help eliviate the power consumption requirements, however minipulating the laws of physics won't be easy, but doing it in space should help, after all we will no doubt see many things in space that go against our version of laws of physics, and as with all books, the laws of physics will no doubt be updated from time to time, i think we could probably create enough power to create a bubble if you will around a ship, that would eliminate if not most, all of the matter from space and sub-space (the mass would have to have 0% energy & gravitational Readings)```
 Subject: Re: speed of light, why not? From: robjewell-ga on 01 Apr 2006 13:13 PST
 ```do you mind explaing "This is because space is also relative and affected by mass in a similar manner to time." thanx Einstein said that both time and spacee were relative. That is the speed of time and the size of space. Several decades of testing seem to support this theory, although of course no one knows for sure. That is what they mean when they say if learning the theory of relativity doesn't scare you you didn't understand it. Example: The spaceman discussed travels near the speed of light fot 1 year. According to all his instruments he never reached the speed if light and traveled almost one light year. Now, on Earth, 50 years have passed. From Earth it also apears that the spaceman almost reached the speed of light, but not qiuite. From here he traveled at almost the speed of light for 50 years which means he traveled, say, 45 light years. The problem is that if he traveled 45 light years and from his perspective it was only 1 year then he should have traveled at 45 times the speed of light. But he didn't. What Einstein said is that space is smaller around him because all his energy is transferred into mass. Steven Hawkings measured time being slower near a massive object, like the Earth (atomic clocks at the top of a tall mountain actually ran slightly faster than at the bottom - see "A Brief History Of Time"). I don't know of any peer reviewed tests that show that space is effected the same way, but Einstein thought it was. If he was right, the example about the spaceman is accurate. If not, maybe we will find out that it works a different way in the future. Who knows.```
 Subject: Re: speed of light, why not? From: kottekoe-ga on 01 Apr 2006 22:54 PST
 ```The latest comment is referring to three things that have all been verified experimentally numerous times to high accuracy: time dilation (clock of moving observing runs slower as observed by stationary one), length contraction (a.k.a. Fitzgerald contraction, lengths measured by stationary observer appear smaller in moving frame in the direction of motion), and the gravitational red shift (clocks running slower near a massive object). All of this is perfectly consistent, without any paradoxes, and not doubted by any mainstream physicist. In science it is always correct to say that no one knows for sure, but special relativity is on as firm ground as the most cherished principals of physics, such as energy conservation. The ideas are hard to grasp and it takes some serious thought to understand them, but once you do, the mystery evaporates and it all makes perfect sense. Hawking did not measure the gravitational redshift. It was first observed by Pound and Rebka at Harvard in 1960. The slowing of time is seen every day by the long lifetime of relativistic muons, which have a much shorter lifetime when they are moving slowly. Both the gravitational and velocity effects on the ticking of clocks has been measured many times by flying atomic clocks in airplanes. These effects are big enough to require realtivistic corrections in GPS navigation.```