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Cannot understand why light cannot go faster than 186K miles a second?

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Simple answer and analogy please.

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  1. C is the universal speed limit. It may seem to be very fast, but in fact it moves at a snails pace. If you could focus on one star in the Andromeda Galaxy, and that star was moving at the speed of light, you would detect almost no displacement over your life time.


  2. i have to say that whilst watching the 666 th episode of the sky at night it was stated that the universe is expanding faster than the speed of light so i supposse thats why we can only see darkness after a certain distance ???

  3. i would be the first one to say going faster than the speed of light is not possible....and for many reasons. least of all the most apparent, or at least most apparent to me - which is; if you did go 100% the speed of light you would cease to exsist...an interesting question is... if you did go the speed of light and became non existent, could you then dip just back under the speed of light (99.9%) and recompose? freaky to think about. physical cosmology and the propagation of light in the universe is of enormous interest in our generation and epoch. as a life long cosmologist i have, as indeed many others have, searched for such answers and reputable data to show other wise. alas, nadda! (yet!) - lol - but we must keep in mind that for eons humans of earth said flying was something man would never do because he was not meant to. well look now, clearly we are meant to.... humans of earth said the world was flat. eratosthenes proved them wrong with only sticks and his noggin'. humans of earth said we would never travel faster than the speed of sound (earth based sound waves)- and we did that as well. i think it is highly possible that we may one day figure this out as well. as far out in left field as it is and seems (countless scientist would disagree (myself included lol)) we can not discount in any way, shape, form, or fashion where fundamental insights may arise from. there-by giving us knowledge, previously unavailable on earth....and with such knowledge the key to relativistic velocities. also consider what kind of material your craft would have to be comprised of to with stand potential self induced cosmic rays. quite intense to say the least... but in our day and age.... i would not hold your breath....lol

    p.s. also keep in mind we have gone just about the speed of light via data transmissions... which to me is quite incredible.

    p.s.s. think of anaxagoras, leuccipus, and democritus. much of atomic democritean philosophy is fundamentally sound. this was over 2000 years ago. few agreed with such proclamations in his time. relativistic space travel is possible, thank you albert! - but not any time soon.

  4. We can only discern light at the speed of light.

    There are various forms of radiation that are also called light.

    I must believe that there are particles that travel faster than light.

    I cannot provide an analogy, as quite frankly there are more things in the Universe than we are even aware of.

    To describe something so far unfound is impossible to visualise.

  5. Without getting into Theology ("It's not faster than that because God said so ) is it not the characteristics of the photon.We understand light in terms of photons and the fastest observed light particle travelled at said rate.Hence 186Kmps.

  6. well actully that is a theroy that nothing can travel faster then the speed of light but like every thing theroys can be wrong.

  7. Ah, if anyone could answer this question and the others like it (why does the electron have the charge it does, the proton the mass it has, etc) then they would be explaining to you the Grand Unified Theory and physics would have it's answers, as far as we know today these "universal constants" are as they are because that is what they must be in the type of universe in which we happen to exist. We at this moment have no way of predicting the values of these constants and must at this time assume they were randomly chosen, for want of a better word, (or circumstances led to) at their values at the moment of creation with no deeper reason.

    Weirder than relativistic mass increasing with speed for objects with mass, as far as the light is concerned it isn't moving at all but is simultanously at all points along its path from relativistic time dilation.

  8. There's no reason why, its just that that speed it the fastest anything can move without mass.

  9. Why?

    Sorry, there is no simple answer.

    It is the nature of space/time, that nothing can travel faster than light.

    One might say that space/time is not rigid enough to

    transmit energy any faster, but the analogy is poor at best.

    (Please don't ask how 'nothing' can have rigidity.)

    You do know that where space is 'bent' by gravity, the speed is slower.

    If you figure out a better answer, with predictable side effects,

    there's probably a Nobel Prize in it for you.

  10. To complete your question, you should also ask why light can't travel slower than c (186,000mps). Light is composed of two perpendicular waves- electric and magnetic- each propagating the other as it moves in a straight line. This pure energy wave simply propagates at c, no more no less. The moment something tries to slow it down, like a brick wall, the wave goes from c to 0mps in a nanosecond. It becomes absorbed. Without speaking in volumes about the subject, it is what it is.

  11. A somewhat correct analogy is to say that light travels at the speed of reality.  If you were to travel any faster you would violate causality - that is, to time travel.

  12. simple answer - Light is that which nothing is faster than.

  13. light can go faster than 186,000 miles a second. in laboratories scientists have made a beam of light travel at 300c, or 300 times the speed of light in a vacuum.

    i would say it has to do with the mass of the photon. there are several particles with no mass, all of them travel at the 186,000 miles a second. there is really no reason why except that its apparently an inherent property of space-time. its like asking why cause comes before effect, or why the charge of the electron is negative and the proton is positive, it just is.

  14. The speed of light is a function of two universal constants:

    1.  The electrical permittivity of free space, ε0.

    2.  The magnetic permeability of free space, μ0.

    These two values are properties of space itself, and, like other universal constants, are completely arbitrary.  The speed of light in a vacuum is equal to:

    c0 = 1 / sqrt(ε0 * μ0)

    FYI:

    Space is not at all like water.  There is no friction traveling through a vacuum, even at 99% the speed of light.  "Jesus in a microwave" is talking nonsense.

    Water is a WRONG way to describe it.  It is an utterly incorrect analogy, and a misleading one.  Also, the 'ether' does not exist.  It was a failed theory to describe how light propagates through empty space.

    Furthermore, a bowling ball moving at 100 mph has almost exactly the same mass as the ball at rest.  The different at such a low speed is almost undetectable.

    Take a physics class before you decide to propagate what turns out to be blatant misinformation.

  15. Einstein's very famous E=MC 2 very neatly explains why nothing can travel faster than light.

    In a nutshell it tells us that energy and mass have an equivalency, are two forms of the same thing in essence - and that the one can be converted into the other. As an object of mass accelerates it basically increases in size and needs to covert more and more energy to stay in motion. As it reaches light speed it's size becomes infinitely big and therefore needs an infinite amount of energy to keep going.

    The universe itself is not infinite in size and can therefore not a) contain anything of infinite mass and b) does not have an infinite amount of energy available. Therefore, it is impossible for anything to travel faster than light.

    (Although, to be pedantic, quantum physics does suggest that certain subatomic particles may already be travelling ftl, but for our purposes it's true to say that nothing can accelerate to a speed faster than light).

  16. Analogy..wave equation for stretched string..

    y''=c^2*L(y).. L=laplacian op=d2/dx^2 in one dimension..y=displacement..c=speed..prop... to tension/linear density ..ie props of medium

    Maxwell's equations.. (all the stuff about Gauss' law, Faraday's Laws and Amperes circuital theorem put in maths terms!)

    CurlE=-dB/dt  (faraday)

    CurlB=uo*e0*dE/dt (ampere law)

    Curl(curlE)=-d/dt(curlB)= -uo*eo*d2E/dt^2

    Now Curl(curlE)=div(div.E)-div^2(E)

    div(divE)=0 from Gauss Equn

    >-uo*eo*d2E/dt^2=-div^2(E)=-L(E) (where L=laplacian)

    >d2E/dt^2=L(E)/(uo*eo)

    If we compare this with our string equation..then 1/rt(uo*eo) corresponds to wave speed, where uo=mag permeability and eo= permittivity of free space..or the respective 'coupling consts' for the mag and electric fields resp.

    A similar equation gives the variation of the B-field as it travels in free space.

    So the speed of light in  a vacuum is constrained by these constants in the same way as the speed of waves in a string are determined by its properties of tension, density.

    Naturally light travels slower in a refractive medium and particles can exceed the speed of light in glass or a semiconductor medium. In an other universe with diff initial conditions light speed may well have a different value.

    Last bit..although material particles cannot REACH the speed of light, there is nothing in physics to disallow particles with imaginary mass travelling faster..just as Absolute zero cannot be achieved..but states with negative absolute temperatures can be 'prepared'

  17. It is possible (and this is just the speculation of a high school student, so take it with a grain of salt) that it can be explained by the anthropic principle. There could be other universes out there, or past universes, in which the value of the speed of light is/was greater or less than 186,000 mps. If that were the case, then the laws of physics as we know them would be entirely void, as the value c (the speed of light) effects basically every aspect of our universe in some form or another. It could be that in a system in which the value for c is different than 186,000 mps, the laws of physics would not permit the necessary conditions for the evolution of intelligent beings who could  ask the question "Why is the cosmic speed limit the value that it is?", would be impossible.

    Summary: we exist to observe that light travels at 186,000 mps, solely because it does so.

  18. Terry R: "To complete your question, you should also ask why light can't travel slower than c (186,000mps)"

    If you are a physics teacher you should know to be more careful about such pronouncements.

    The speed of light in a *vacuum* is always 186,000 miles/sec...never more or less.

    However, light can be slowed down considerably.  Several years ago some scientists slowed it down to about 38 miles/hour (see link).  They did this by shining light through a Bose-Einstein Condensate.  Light slows down to a lesser degree in other materials as well.

    EDIT:  cobirch2 - "light can go faster than 186,000 miles a second. in laboratories scientists have made a beam of light travel at 300c, or 300 times the speed of light in a vacuum."

    Not true.  There are some tricks that seem to imply a speed faster than light and they can even work (e.g. quantum entanglement).  However, no information can be carried in this fashion.  Light speed in a vacuum is the max speed you can manage that at.

  19. Think about trying to run through water! Its really hard and u eventually reach a top speed! Space is like water, if u travel fast enough it starts to feel sticky and slow things down! At light speed, flying through space becomes like trying to fly through a brick wall!

    You can travel faster than light by stretching space, but if you do this, the distance between objects also increases so u never actually get anywhere faster!

    Mass INCREASES as you travel faster! Not decrease! This is because enegy has mass! So if a bowling ball is moving at say, 1000 000mph, it could have maybe twice the mass it has at standing still! At the speed of light, your mass would be HUGE!!!!! Infinatly huge.

    And 'lithiumdeturide', i didnt say space is like water physically, its just a way to describe it! And i think you'll find if u research it, space has substance and texture! Its called the 'ether' and its tangable! Hence how gravity works etc

  20. Because there is a limit to everything. Nothing can get colder than 0 kelvin, nothing can have mass, volume, or density of 0.

  21. Just to tell you when you go faster mass increases not decrease.

  22. Its not simply that light itself cannot go faster than 300,000 kilometers per second, no form of ordinary matter can. this limit ,when reached, is the limit of speed in the universe where time slows down to zero around the object moving,in this case a photon. any faster and the energy gained from the increase would create a space time dent that would lead into the past due to the huge concentration of energy neaded to move faster than light. so you would be literally be going backwards through time if you went faster than light so we can assume that we ould not see anything,from our reference frame, that goes faster than light.

    mass increases as speed increases due to energy being absorbed by the object as its speed increases which is then converted to matter as given in the equation E=MC^2 which allows energy to be converted to matter and vice versa.

  23. My personal opion is that was light exceeds it's constant speed then the time-space fabric gets twisted something like a worm hole, one beautiful info IF EVER studied is that black holes before theyu devour particles reach 99.9% of light speed but what actually is the speed of the particles once inside the black hole cos theory has it light cannot escape them, so an interesting assumption is that light exceeds that spped and bends the fabric of space and shoots out in either a different dimension or at a different point in the universe

  24. Light simply cannot go faster than c.

    No information can.

    Nothing, zip, nada.

    It's a physical constant.  As for why it has the value it does--who is to say?  It's like asking why the specific heat of water is what it is, or the density of iron.

    P.S. The first poster has it wrong.  The energy//mass equivalence means that the more energy an object has (i.e. the faster it moves, kinetic energy), the more massive it becomes, therefore the more energy that would be needed to make it move faster.

  25. It baffles me almost as much as your question as to why many people cannot answer EXACTLY what you have asked (this applies across ALL OF YAHOO ANSWERS AND IS VERY FRUSTRATING). DID YOU ASK WHY OTHER MATTER CANNOT TRAVEL FASTER THAN, OR EQUAL TO  LIGHT ? NO !!! DID YOU ASK IS IT POSSIBLE TO GO FASTER THAN THE SPEED OF LIGHT ? NO !!! DID YOU ASK IS LIGHT THE FASTEST MEDIUM AVAILABLE ? NO !!! IT GOES ON BUT YOU GET MY POINT !!! Now my answer -  We don't know why light cannot (or does not) travel faster than it does. Therefore an analogy cannot exist. However I can offer other unknowns as analogy and perhaps this will help you understand the limits of human intellect, technology and understanding of many complex issues. This question is of the same nature as why are the physical laws the way we find them and not something else ? If any of the constants of nature or physical laws were different from the way we have found them so far, our universe would be so utterly transformed that it would not contain organic life at all. Our existence is balanced on the razor's edge between reality and nothingness. We are so tuned to nature as we find it that even the slightest change would have made our existence unlikely. So, we find the speed of light to have the velocity it has and obeying the rules of special relativity and we do so because it is what it is, without knowing WHY it is. By some perverse process, had it been otherwise we would not be here to wonder about it ! This sentiment of course applies to the entire laws of physics that we encounter. BY THE WAY, THERE ARE A LOT OF INACCURACIES IN MANY OF THE ANSWERS SHOWN HERE INCLUDING WHAT YOU HAVE TYPED IN YOUR ADDITIONAL DETAILS, I COULD EXPLAIN BUT I WOULD BE DEPARTING FROM WHAT YOU HAVE ASKED AND OPENING MANY OTHER QUESTIONS IN THE PROCESS.......

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