How can a solid object move faster than the speed of light?
553694
You are assuming there is an absolute reference to measure their speeds against. All speed has to be measured against some standard. But, for the sake of your discussion, let's assume you have two large asteroids in space that are motionless relative to each other. You launch super SciFi spaceships from each, aiming near to the other so they will pass. Each spaceship accelerates to 60% of C (speed of light). You are asking if they won't see the other zoom by at 1.2C.\n\nYou are forgetting that as they move to 60% of C, time is also affected. (google for the twins experiment). Time slows to an extent that they will never see anything approaching at C or in excess of C.\n\nHope this helps.\n\nChuck Taylor\nhttp://groups.yahoo.com/group/lunar-observing/
1170536
I will attempt an answer that is somewhat factual.  \n\nThe theory does not stipulate that nothing can travel faster than the speed of light.  It stipulates that matter can not approach the speed of light.  In fact a hypothetical partical called a tachyon has been named that has a speed faster than the speed of light.  That partical has an imaginary mass. \n\nThe entire work comes from the equations developed by Einsten,\n\nE= MC^2/ sq rt (1- c^2/v^2)
72176
If you're asking about some mass being accelerated up to and beyond the speed of light, no it is NOT possible. Einstein theorized that the faster an object moves, the greater will become its mass. This increased mass would require more energy to accelerate it even more, which in turn would increase its mass, which would require more energy to go faster, etc., etc.,. Ultimately to get this object up to the speed of light would require infinite energy, and that's impossible. This isn't just theory anymore either; mass increase versus velocity has been observed countless times in modern particle accelerators.\n\nOf course there are plenty of sci-fi novels, TV shows and movies (like Star Trek and warp drive) where things move faster than light, but unless someone can find a way around Einstein and all the evidence that he was right we'll never be able to attain FTL travel.\n\nBy the way...worm holes don't provide a way to MOVE faster than light. So-called worm holes, if they exist at all, are nothing more than short cuts; going through a worm hole you'd still have to obey the speed limit imposed by Einstein.\n\nPersonally I hope that some day some radically new branch of physics is found that would allow us to get around Einstein, but right now it doesn't look too good.
15796
Its not proven but heres how eistine put it.\n\nThe faster you travel the more you weigh. Since light is the fastest moving thing in the universe if you went faster then that you would way infinite pounds and that would be impossible so you cannot go faster than the spped of light
883877
Going faster than light speed violates the laws of special relativity.  You simply cannot start at rest or any velocity less than light, reach light speed, then get faster.  However, it does not violate special relativity if your starting velocity is faster than light.  This is how tachyons are hypothesized.  When a tachyon forms, it immediately starts which a velocity faster than light.  Therefore it can never slow down to the speed of light or less.  If tachyons exist, they'll give off a certain type of radiation so they won't be invisible. \n\nSo in other words, it will never be possible for us to make some spaceship or anything that can go faster than light, which means no "warp drives" or anything like that.
1042298
No it can't.\n\nLaser light goes at exactly the speed of light.
811109
You misunderstand Einstein's Theory of Special Relativity. It doesn't say that you can't have something move faster than the speed of light. Only "information" can NOT move faster than the speed of light. By information, I mean any "signal", like electromagnetic waves (which includes light, radio waves, etc. etc.). Any material object within the Universe are also restricted by Special Relativity, since material objects also carry "information".\n\nFor the Universe or the fabric of spacetime to be expanding faster than the speed of light is NOT a violation of Special Relativity, and the Universe will not be moving backwards in time.\n\n--------------------------------------------------------\n\nEdit - Ok, here let me clarify why I said that Special Relativity (SR) does NOT apply to the expansion of the Universe:\n\nVelocity of something depends on which definition of distance we use. So, if we assume that the distance of an object at time t is the distance from our position at time t to the object's position at time t measured by a set of observers moving with the expansion of the Universe, and all making their observations when they see the Universe as having age t, then the velocity (change in D per change in t) can definitely be larger than the speed of light. This is not a contradiction of special relativity because this "distance" is not the same as the spatial distance used in SR, and the age of the Universe is not the same as the time used in SR.\n\nIn the special case of the "empty Universe", where one can show the model in both special relativistic and cosmological coordinates, the velocity defined by change in cosmological distance per unit cosmic time is given by v = c ln(1+z), where z is the redshift, which clearly goes to infinity as the redshift goes to infinity, and is larger than c for z > 1.718.\n\nFor the "critical density Universe", this velocity is given by v = 2c[1-(1/sqrt(1+z))], which is larger than c for z > 3. \n\nFor the "concordance model" based on CMB data and the acceleration of the expansion measured using supernovae, a flat Universe with Omega = 0.27 (this would be our Universe), the velocity is greater than c for z > 1.407\n\nAll this just means that for any expanding universe, there will be a value of z (i.e., redshift or cosmological distance) that will give the appearance of galaxies moving at velocities greater than c.
676715
The speed of light is the upper limit of speed in our space-time universe. Nothing here can be faster. And no car or any other macroscopic object can be equal to the speed of light. But the question is a thought experiment, hence, a good one indeed. Questions like this were raised by Einstein and Relativity became part of modern physical theory.\n\nSince the speed of light is an upper limit, the light from the headlamp of the relativistic car cannot be faster than the car. You won't see them in front.
144969
It's something along the lines that mass increases with speed. The closer you get to the speed of light the more mass you achieve, which requires more energy to move you. This increases exponentially, always getting closer to the speed of light, until you are essentially immovable, you can't get any heavier so can't move any faster. I heard this explained in a college class once and probably totally got it wrong, but it's in that vein.
164037
The speed of light is much, much faster than the earth's rotation.
15648
There is this wonderful little thing called a "Rest mass", and should something have an imaginary rest mass (i.e. tachyons) its lowest speed possible is the speed of light.  However, this is one wacky hypothetical construct that has no proof nor anything to disprove it.\n\nAlso, the spacetime continuum itself can move faster than the speed of light; it has happened before, less than a second after the big bang.  This wonderful thing called inflation happened, and spacetime grew obscenely fast.  This is also why spacetime is mostly flat.
512775
The comment about a worm hole (or warping for that matter) is only partially true.  The object that travels through a worm hole or a space warp still can only travel (assuming it has a mass) at the speed of light through that worm hole or space warp.  It only "appears" to travel much faster than that from an "observer" not in the worm hole or warp.\n\nThe difference is the "effective" speed can be much faster than light; however, the object can only travel the speed of light.\n\nAn example; lets say that you have a car that travels at 100 mph (~160 km/hr) and you "created" a worm hole (or space warp) to travel from New York to LA.  You would still only drive at 100 mph, but the travel time form NY to LA would be fractions of a second thus for an observer from say Dallas would "see" your car one moment in NY and a faction of a second later "see" your car arrive in LA.\n\nFor people that might not understand a worm hole is like folding the map of the US in our example and if you can "fold the map" in the right way such that NY and LA are right on top of eachother it would only take a fraction of a second to travel from NY to LA in your car.
53622
Well, its absolutely impossible to travel at or faster then the speed of light, but lets pretend you can so i can actually give you an answer to the question. The speed of light is actually the ultimate speed limit to the universe, nothing can travel faster than light, so although you would expect the light to be going at twice the speed of light (you plus the speed of light)it can't because it is physically impossible for even light to travel faster than the speed of light so it would be going slower than you and not reach any path in front of you. Of course, if you turned on your headlights before you started moving, the light would be one step ahead of you.\n\nOf course, still, nothing can go faster then the speed of light because in the formula for time dialation(time slows down for an object moving close to the speed of light) t'=t/sqrt(1-v^2/c^2) where t' is the time passing for an outside observer, t is the time that passes for the object going at the high velocity, v is velocity, speed is the speed of light and ^2 is squared. (note: this formula is definately correct, it's part of einstein's theory of relativity and I've had to derive it myself for class in the past) so if v was bigger than c, you would have a number greater than one and therefore a negative number under a square root, which is impossible.
122048
Peple I know you want the points, but can you please not just make up answers out of whole cloth like that?\n\n>>>>>Massive objects cannot go the speed of light.\n\nYeah, they can. They can't accellarate to the speed of light but they can be created at lightspeed and continue on.\n\n>>>>>> However if they could, no you could not see, becuase the light could not go furthur then the builbs at the front of your car\n\nNonsense. The speed of light is constant for all frames of reference. From the FOR of the bulbs the light would be seen travelling away from it at lightspeed. \n\n>>>> You'd be seeing the light go by your side.\n\nNo, you would not be seeing the light by your side. You would still be seeing all light in the universe travelling away form you or towards you at the speed of light, just as you do at your current velocity\n>>>>>The light would not shine out in front of you because you are going the same speed.\n\nIncorrect. Light always sines out in front at lightspeed in the observers FOR. It makes no difference if that FOR is stationary or lightspeed itself.\n\nYou quite obviously made that answer up.\n\nws, this question seems to get asked here every couple of days. You can go back and have a look and see it answered quite well several times.\n\nIn brief,\n\nLight is funny stuff. Light always travels at the same speed relative to you, it doens't matter how fast you travel. \n\nIf you are sitting still and a person is going past you at light speed you can both look at exactly the same light beam, and it will be travelling at lightspeed compared to both of you.\n\nIf you are going at lightspeed and turn on the headlights the light will move away fomr you at lightspeed. If it strikes something it will be refelected back at lightspeed. If someone is sitting completely still beside you he will also see that light move away form him at lightspeed, and get reflected back at lightspeed.\n\nIt's weird stuff light, it doesn't behave like anything else. The answer to any question that asks how fast light is moving towards you or away from you is always "lightspeed". It doesn’t matter what else we add to the question, the answer is always 'lightspeed".\n\nSo if the light leaves the bulbs at lightspeed and gets reflected back at lightspeed does that mean you could see?\n\nProbably not. \n\nAlthough light doesn't change speed relative to the observer it does change wavelength. The faster you travel towards a light source the bluer it will look. \n\nAny object that your headlights strike will reflect the light back to you at lightspeed, that's OK. But because you are travelling towards the object at lightspeed the light will be shifted way, way towards the blue end of the spectrum. It would all be ultraviolet an X-rays. The human eye simply can't see those wavelengths. So plenty of light would be reflected back, but it wouldn't be visible to you. As a result it would all look dark.\n\n\n>>>>> if the interior light inside your car was on at\n>>>>> the time would you see that?\n\nYes. Because both you and it are travelling at the same speed it woulnd't be red shifted at all. Similarly because you and the interior of the car are travelling at the same speed you would be able to see the light reflected off that just fine as well.\n\nEverything in the universe that is travelling as fast as you will look normal.Everything outside will appear black.
120276
The first thing you have to understand is that the speed of light in a vaccum is constant, no matter how fast you're moving, nor how fast the source of the light is moving. This is bizarre. If someone standing on a conver tosses a ball to you at 5 mph while you're standing on the corner, you'll see the speed of the ball as being 5 mph relative to you. But if you're driving at 15 mph and they throw it at you at 5 mph, the speed of the ball relative to you will be 20 mph. This is how most things work. But with light, no matter the speed of the source or yourself, you'll always measure the speed of light as being 299,792,458 metres per second.\n\nEinstein accounted for this by postulating his special theory of relativity, which says basically that the reason for this is because if you move really fast, three things happen: 1) time slows down, 2) mass increases, and 3) length in directions parallel to the direction of movement contract. If you take those three hypotheses, you'll also note that the concept of things being "simulatanous" is a relative term, meaning two observers moving at the same velocity (or moving at no speed relative to one another) will agree on which events are simultaneous and which are not. However, observers at different velocities will have different concepts of what is and isn't simulataneous--and yet THEY'RE BOTH CORRECT. It's pretty mind-blowing, but if you take all of these notions together, you get a consistent view of reality.\n\nThat's Einstien's SPecial Theory of Relativity. About a decade later he formed his far more complicated general theory of relativity.\n\nThe general theory says that Newton's view that gravity operates by exerting a force on a falling object is incorrect. Rather, by general relativty, a free-falling object that is in a vacuum has no forces acting on it at all. The movement of falling objects isn't due to force, but rather the curvature of space-time--massive objects actually curve the surrounding universe. In Newtonian physics, we regard there being three spacial dimensions (up/down, left/right, and backwards/forwards) and a single dimension of time. In general relativity, there are four dimensions of space-time. In Newtonian physics, a foce makes the earth orbit around the sun. In general relativity, the earth and the sun curve the surrounding space-time continuum, and both bodies move in a straight line through curved space, resulting in the perceived sense that one body is circling about the other. In Newtonian physics, light should not bend to gravity, because gravity affects massive bodies, and light has no mass. But in fact, light does bend around stars and such.\n\nGeneral relativity has been likened to a stretched sheet of elastic material, like a trampoline. Heavier objects sink more, and make the sheet curve about them, and light obejcts rolling across are deflected by this curving.\n\nGood luck understanding all that. Hope your head doesn't explode.
25198
You can't be in a vehicle going the speed of light, because as objects accelerate they gain mass and a car going the speed of light would be insanely massive.
737000
Time travelling is a very difficult topic.\n\nYou can supposedly travel into the past if you travel faster than the speed of light but this involves getting a source of infinite energy as when matter gets closer and closer to the speed of light its mass will dramatically increase.\n\nThis is said to be very unlikely but general relativity says it may be possible on highly unusual circumstances.\n\nWormholes, permitted by general relativity,  could be possible only if it is traversable.\n\nIf you read general relativity and objects at speed of light you get time, space and gravity based dilations where light appears to be bent by gravity and arrives at an object at different times.\n\nYet again the object has to be travelling at 0.99c or faster!!\n\nI says time travel will never happens but i wish it would.