Is it really impossible to travel faster than light?

Discussion in 'General Science & Technology' started by Railton2, Jun 2, 2010.

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  1. Railton2

    Railton2 Registered Senior Member

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    Hey!

    I'm not sure if this thread is in the right forum or what. If not, will you please move it to the right forum please?

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    I also want to tell you that this is only a thought. Not any scientific prove.
    I am only seventeen years old, and I am going in 10th grade, so I don't have any education in science/physics. So please don't call me a crazy scientist, even though how crazy these things sound. I am only posting this to get some answers on my speculations

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    Is it really impossible to travel faster than light?


    In order to make matter escape from the event horizon at a black hole, then the matter MUST have a speed faster than light.

    A black hole is an area in space, so dense with matter, that the gravitational field is so intense that not even light can escape.

    If all matter and energy was created at the same time as big bang. Then there MUST have been a black hole a few planck seconds after the big bang, since all the matter in our universe was so dense at that time.

    Doesn't that mean that all the matter in our universe was in the event horizon, at a black hole, at that time?
    Why didn't all the matter crumple into the singularity?
    How did all the matter escape with a speed slower than light?





    I also have an other strange thing, that I need an answer too. I'm really bad at explaining, that's why it's so long, sorry

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    Lets say it's possible to travel with 99,9% of the speed of light. Accordingly to Einstein's theory of relativity it isn't possible to exceed the speed of light. But it also tells us that if we move at a speed 99,9% of light, then the time almost stops.

    Lets imagine that I travel with a spacecraft that could reach that high speed and flew only for a second. Wouldn't the time on earth go faster compared to the second I travelled with my spacecraft?

    For me, my travel would only take one second. But if time goes slower at that speed, wouldn't the earth's time then go faster?

    If the time on earth goes faster than the time in my spacecraft. Wouldn't it then look like - watching from earth - I have used more than one second to travel that distance?


    Lets say we have a set a timer, that starts when I take off. One timer on earth and one timer on my spacecraft.
    If I take off with the speed 99,9% of light and stop exactly when my timer says one second. What time would the timer on earth then be?
    Wouldn't it be more than one second, as the time on earth goes faster?

    If it is more than one second. Lets say two in this example. Then looking from earth it would have looked liked, I have travelled the same distance in two seconds. But I have really travelled the distance at the speed 99,9% of light. But according to the timer on earth it only looks like I have travelled with half the speed.
    Lets say I travelled 300.000 km in this example.
    According to the timer on the spacecraft it must say that I have used a speed of 300.000 km/s (lights speed) because 300.000/1 = 300.000.
    But according to the timer on earth it must say that I have used a speed of 150.000 km/s (half of lights speed) because 300.000/2 = 150.000

    Doesn't that mean, that I need to travel faster with my spacecraft to reach the speed of light, looking from the sight of earths time?

    Is light really travelling with 300.000 km/s or is it an illusion that looks like it travels with 300.000 km/s, but actually is much more faster?




    Thanks for reading and I really hope you understand and can answer my questions.

    Sincerely,
    Mark Railton


    PS: I am only seventeen years old, and I am going in 10th grade, so I don't have any education in science/physics

    Have a great day!
     
    Railton2, Jun 2, 2010
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  3. Danny G

    Danny G "Listen.. you smell something" Registered Senior Member

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    17 years old with questions like that, you will go a long way my friend, and welcome to SCIForums.

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    The way i see it, if you orbit the earth in a rocket that is traveling at %99.9 light speed, then time is slowed down, but not for you and not for the earth, bu the relative gap in between. You may leave earth and start your orbit around earth and do it for one month, then slow down and return, what has been one month for you ,will have been 10 years for the people on earth. (maybe not ten years, but a lot longer).

    Oh, Thankyou for restoring my ever dwindling faith in the youth of today

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    Danny G, Jun 2, 2010
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  5. Dywyddyr

    Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    So far as we know.

    What makes you think matter was around at that time?

    Wasn't the entire thing including space itself also expanding rapidly?
     
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    Dywyddyr, Jun 2, 2010
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  7. Kernl Sandrs

    Kernl Sandrs Registered Senior Member

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    You can't in a local sense, but if there were ever a device such as the Alcubierre drive, then yes. I was watching a bit on the science channel about time travel. Suppose you're on a train which goes around the equator. This train is traveling at 99.99% the speed of light. Then a little girl stands up on the train and runs forward. Wouldn't her forward speed be added to the speed of the train? Yes. But time will always slow down just enough to protect the light-speed barrier. And lets say you get on this train on January 1, 2050. Then the train accelerates to 99.99% the speed of light, and you stay on that train for 1 week, then when you get off the train it will be January 1, 2150. So from your perspective you have only been on the train for one week. But to everyone else on Earth who is watching the train go by, it has been 100 years. And a train going around the earth at near-light speeds is pretty fast. The train would go around the planet seven times in one second.



    http://en.wikipedia.org/wiki/Alcubierre_drive

    http://en.wikipedia.org/wiki/Faster_than_light


    Keep in mind that those links are Wikipedia. A few months ago I got on there and changed Lincolns birthday to 1912. Granted they changed it back, it's still not incredibly reliable at all times. It's best to get info from various sites.
     
    Last edited: Jun 2, 2010
    Kernl Sandrs, Jun 2, 2010
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  8. Skeptical

    Skeptical Registered Senior Member

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    When it comes to time dilation effects, do not forget acceleration. If you travel at 99.9% of light speed, you have to accelerate. If you accelerate at a steady one gravity, it will take you a full year to reach that velocity.

    If you accelerate a lot faster, you will turn into raspberry jam, since your body cannot tolerate great acceleration.

    Time dilation relative to another observer can occur only if there is acceleration. If you accelerate to 99.9% of light speed, then one second for you will be a much longer time period for someone back on Earth. Then when you decelerate back to the speed you started with, time will pass again at a 'normal' rate. But the only reason you can experience that double change in the rate of time passing is because you have gone through acceleration twice.
     
    Skeptical, Jun 3, 2010
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  9. Doreen

    Doreen Valued Senior Member

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    Just wanted to make the distinction between traveling at or beyond the speed of light
    and
    getting somewhere in a time shorter than it would have taken at the speed of light.

    Perhaps there are short cuts.
     
    Doreen, Jun 3, 2010
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  10. phlogistician

    phlogistician Banned Banned

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    Hmmm, short cuts, as in bending space, and wormholes? Theoretically possible, but in practice the energy expenditure has been calculated, and it takes more energy than their is in the Universe (at current understanding) so not a method we can harness.
     
    phlogistician, Jun 3, 2010
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  11. Fraggle Rocker

    Fraggle Rocker Staff Member

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    You would probably receive answers that are more expert and detailed in the Physics & Math subforum.
    I think you mean "proof," not "prove." It's really a question, and questions are always welcome here so long as they are respectful--not only respectful of the membership, but respectful of science itself.

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    But you have a good grasp of the concepts. You're off to a great start!
    Yes, given what we know about how the universe works, which by now is rather a lot. However, questions like these can sometimes fall into the realm of cosmology. Cosmology is, specifically, the study of the structure of the universe and the way it works. Microcosmology is the study of the minutiae of the universe: how electrons, photons, etc. interact, how they are comprised of combinations of quarks, leptons and bosons, and whether the quarks, leptons and bosons themselves can be deconstructed even further. Macrocosmology is at the other end of the scale of time and distance, the study of dark matter, black holes, the Big Bang, the expansion of space, and the Really Big Questions such as: Is our Hubble Volume (the part of the universe we can see, which was created by the Big Bang) all that exists in the universe or have there been other Big Bangs? Will our Hubble Volume expand forever or will it one day collapse in a Reverse Big Bang?

    Obviously microcosmology and macrocosmology cannot be separated, and both are defined by universal constants such as the speed of light. It is almost as obvious (to me anyway) that cosmology is something more (or less) than a science: an awkward combination of physics (which is a science), mathematics (which is merely a tool of science) and philosophy (which is neither, but nonetheless guides the way our species examines the universe).

    Getting back to your question, there are several asterisks in the statement: Nothing can travel faster than c, the speed of light. It hinges largely on the philosophy component of cosmology: What exactly is the definition of the word "travel"? We have irrefutable evidence that our Hubble Volume (I much prefer that to the word "universe," which is ambiguous since it is also used to mean the entire space-time continuum, which for all we know may be entirely empty everywhere but here) is only about thirteen billion years old. Yet we also have (as far as I know) irrefutable evidence that the most distant stars are something like a hundred billion light years away. Inconsistency Alert! How can those stars have traveled 100B LY in only 13B years???

    The answer is--and I am not kidding, this is exactly what the cosmologists tell us--that the space between the stars is expanding. Since space is empty, there is no matter there, so technically, nothing is moving, so this does not violate the rule about traveling faster than c. As I said, this sounds more like philosophy than science! That's a more polite word to use than weaseling.

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    Furthermore, it has recently been discovered that if you take a mated pair of electrons and separate them by any arbitrary distance, when the state of one changes the other one will change state to match and establish balance, instantly. No one has yet managed to move one of the electrons to another planet or galaxy to verify this phenomenon under extreme conditions, but it seems to be true at the distances we are capable of creating, which provide sufficient precision to verify the phenomenon. Again, philosophy comes into play here: all that is moving from one electron to the other is information, which is not a "thing," so it's still true that nothing is traveling faster than c.

    I hope you have a headache now! There's no reason that you should be any less confused by all this than the rest of us. Welcome to the wonderful wacky world of cosmology! "Nothing can travel faster than the speed of light," but that sentence has so many asterisks and footnotes that it might as well have been written by a lawyer instead of a scientist.
    I'm not a cosmologist, but I suspect they might answer that question by saying that the particles did not travel, but rather that the space between them expanded. I'm just guessing, not to mention being a big wise-ass.
    You're forgetting the fact that the spacecraft must first accelerate to c. Acceleration requires force by definition: f=ma; force is defined as the mass of the object multiplied by the acceleration. It takes energy to exert force on an object, and the energy in the universe is finite, so acceleration cannot be infinite. In practical terms, you cannot safely accelerate a spacecraft with humans on board very much faster than g, the acceleration of gravity, which = 32 ft/sec^2. Do the arithmetic and you'll discover that at this rate of acceleration, it will take an entire year to reach the speed of light. So questions involving nearly instantaneous achievement of c for human observers are meaningless.
    Yes. But please remember to construct your examples using speeds less than c. (I see you doing this pretty consistently, so this is just a reminder.) Only things with no mass, like photons, can actually travel that fast. To accelerate an object with mass to the speed of light would require infinite energy; in other words, it's impossible.
    Remember that acceleration is not instantaneous, so in addition to your one second you have to include the time it takes to accelerate plus the time it takes to decelerate. In addition, in order to compare these two clocks, the ship must return to earth, so you have to add that time too. Your one second is such a tiny fraction of the total time (one year contains approximately 30 million seconds) that the measurement you seek will be almost impossible to perform with enough accuracy to illustrate the Theory of Relativity.
    Yes indeed. Time and velocity appear different to two different observers. Their measurement is relative to their speed and acceleration. That's why this is called the Theory of Relativity. I hope this helps!
    The essence of the Theory of Relativity is that light always travels at 300M meters/sec (in a vacuum anyway, denser material can slow it down) regardless of your frame of reference. This is why c is a universal constant. This is the essence of relativity: no matter where you are, no matter how fast you're moving, light always appears to you to be traveling at c. This requires major finagling in the measurement of time, which is where all the complexity come in. It is not time that is a constant, but c.

    BTW, most of our members are American so you will see the comma/period convention reversed from your customary use: pi=3.14159; c=186,000 miles per second. Not to mention, to hell with the metric system. Brits will send their grandchildren on field trips to America, where we lovingly preserve the yards, gallons, acres, ounces, barrels, horsepower, degrees Fahrenheit, and other quaint elements of British culture which they abandoned. Although we don't weigh ourselves in stones and we've always had decimal currency.

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    Last edited: Jun 3, 2010
    Fraggle Rocker, Jun 3, 2010
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  12. phlogistician

    phlogistician Banned Banned

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    Ha, in the UK, we are flaccidly metric. Despite the fact that I've only ever been taught the metric system, I cannot estimate people's height in metres, only feet and inches.

    We decimalised our currency, but still use it to buy beer in pints, but spirits? No, we buy spirits by metric measure.

    We buy or petrol in litres, but then drive our cars on roads measured in miles, at speeds measured in miles per hour.

    We buy our groceries by metric weight, allegedly, although when I go to the deli, and ask for 'a quarter of ham', they know I want quarter of a pound, and then sell me the metric equivalent. In fact, we can still advertise prices of goods per imperial weight unit, as long as we have a conversion table for people wanting to know the metric, we don't have to have metric as the primary measure.

    It's all a bit half baked, with no sign of us ever fully adopting metric measures on all displays, signs, and transactions. Eccentric, us Brits, don't ya know?

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    phlogistician, Jun 3, 2010
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  13. Fraggle Rocker

    Fraggle Rocker Staff Member

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    Estimating metric units that precisely (one percent!) is indeed impossible. But gross estimates are not usually too hard: a meter is slightly longer than a yard, a kilo is a bit heavier than two pounds, a liter is little bigger than a quart, a hectare is about two and a half acres, a kilowatt is a horsepower and a half, etc. But converting between Fahrenheit and Centigrade temperatures (who the heck was that Celsius fellow anyway)--impossible! F=1.8C+32, no way to do that in your head. Might just as well go for Kelvin, at least when you're done the scientists will approve.
    You mean "gasoline?"

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    And if I'm not mistaken, you measure fuel consumption/economy inversely from our way: liters per 100km rather than our miles/gallon. Doing it our way, a larger number is better. The European way, a smaller number is better. I think that says something about the difference in psyche. In America, bigger is always better!
    In other words, better eccentric than Eurocentric?

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    Fraggle Rocker, Jun 3, 2010
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  14. phlogistician

    phlogistician Banned Banned

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    OK, tall people I can do, especially the friend of a friend. He's 6'6" tall, and called Peter, or 'Two Metre Peter', to his mates.

    Ah, US/UK pints aren't the same. So a UK Quart, is bigger than a litre.

    Ah, maybe in mainland Europe, but we are half baked, remember, so we do it your way still.

    Ah, OK, another oddity. Temperature, I estimate in Centigrade. Height, feet and inches, temp centigrade. Go figure. I wonder what younger Brits guesstimate in, ....
     
    phlogistician, Jun 3, 2010
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  15. Railton2

    Railton2 Registered Senior Member

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    Thanks alot for all the answers!

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    Fraggle Rocker?
    Should I post this thread in the Physics & Math subforum?



    Sincerely,
    Mark Railton
     
    Railton2, Jun 3, 2010
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  16. Railton2

    Railton2 Registered Senior Member

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    Thanks alot

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    Railton2, Jun 3, 2010
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  17. Stryder

    Stryder Keeper of "good" ideas. Valued Senior Member

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    Imperial is often used in Architecture. Metric for the most part is used when dealing with precision (I wouldn't suggest using imperial for say, designing a circuit board)

    As for Temperature, why not Kelvin(K)?
     
    Stryder, Jun 3, 2010
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  18. Fraggle Rocker

    Fraggle Rocker Staff Member

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    The numbers are too large. Cumbersome and not euphonious. We want to be able to say, "Fall is coming, it was forty-five last night," not, "it was two hundred eighty." Especially since most people toss in an "and" that is, technically, incorrect, making it "two hundred and eighty," six syllables instead of three.
     
    Fraggle Rocker, Jun 4, 2010
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  19. Dywyddyr

    Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    But amusingly annoying and confusing for other people.
    I had a week or so when I insisted on giving all temperatures in Kelvin, purely for the bugger factor.
    And even considering I worked for an engineering firm it threw enough people to keep me amused for the week.

    But you're right - it's not concise enough. There's few cases "in real life" where adding the extra 273 is worth the effort.
     
    Dywyddyr, Jun 4, 2010
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