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physicsnoob12
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why does light travel so fast?
physicsnoob12 said:but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.
physicsnoob12 said:but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.
No matter how fast we live, the speed of light is allways the same. And you, the observer, will allways move with zero speed relative to youself, so it allways would seem that the light moves at the speed of light and you are at rest.Because we live so slow.
physicsnoob12 said:why does light travel so fast?
The_Duck said:Because we live so slow.
cryptist said:This question is about philosophy, not physics.
physicsnoob12 said:but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.
Asking that "why light travels at c instead of another speed or instantaneously" is a philosophical question and nothing to do with physics. It is a universal constant. Like pi for example..epenguin said:I think it is about physics not philosophy and the solution is of the type of The_Duck's.
physicsnoob12 said:but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.
I have given a very crude version of what would be a physical argument. When you say the speed of light is so many m/s like any other physical measurement it is a comparison. You can make it into a comparison with e.g. the size of atomic structures and the times of atomic events. As light is more fundamental than the atom the most meaningful comparison is the other way round. It is asking why atoms have the size and frequencies they do, more exactly try an explain why the size is such that light can get back and forth between two adjacent atoms in the time it takes for x flips of a Cs nucleus or something like that, thousands of things like that. Physical questions.cryptist said:Asking that "why light travels at c instead of another speed or instantaneously" is a philosophical question and nothing to do with physics. It is a universal constant. Like pi for example...
Not sure what your point is here but yes that is mathematical, once we define pi as twice the circumference of the unit circle. The mathematics answers of is the answer to any 'why' question.cryptist said:Like pi for example..
If that's not philosophical, then I can ask you; why pi is 3,14... and not something else? Then is this mathematical?
cryptist said:Pi is the ratio of the circumference of a circle to its diameter. It is 3,14... Asking "why it is 3,14... and not something else" is not a mathematical question. It is a philosophical question. There is no single living thing that can answer why pi is 3,14...
And this is the same case. Pi is a mathematical constant, c is a physical constant. Therefore, asking why speed of light is c is not physical question but philosophical.
Physics and mathematics (in fact any positive science) do not ask "why" questions.
physicsnoob12 said:why does light travel so fast?
epenguin said:Puzzling and contradictory IMHO.
It was mathematically proved that pi when defined as you have is that decimal. So it was a mathematical question answered. The mathematical proof is the answer to the why. In ordinary parlance - maybe you can argue deeply that you cannot give a logical sense to the word 'why' that applies here.
epenguin said:Your 'therefore' is completely unwarranted since math and physics are of completely different status and nature - it is not like statements about physics carrying over to chemistry.
epenguin said:At first your use of the word 'philosophical' suggested to me you were one of those scientists who used 'philosophical' as equivalent to 'pointless, unworthy of an adult's attention'. But when I saw 'positive science' I thought you might come from a very definite philosophical position. Unless you just copied the expression. In any case just one position.
epenguin said:Would you say the Boltzmann constant is just what it is, asking why it has that value is a philosophical question?
physicsnoob12 said:why does light travel so fast?
physicsnoob12 said:but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.
epenguin said:Would you say the Boltzmann constant is just what it is, asking why it has that value is a philosophical question?
cryptist said:Every constant in science has a meaning. But "why it has that meaning" is something else.
physicsnoob12 said:The problem here is that some people are solving this by just saying " it just does" but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does" we have to to a crack at the question.
physicsnoob12 said:The problem here is that some people are solving this by just saying " it just does" but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does" we have to to a crack at the question.
There is a most profound and beautiful question associated with the observed coupling constant, e the amplitude for a real electron to emit or absorb a real photon. It is a simple number that has been experimentally determined to be close to 0.08542455. (My physicist friends won't recognize this number, because they like to remember it as the inverse of its square: about 137.03597 with about an uncertainty of about 2 in the last decimal place. It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it.) Immediately you would like to know where this number for a coupling comes from: is it related to pi or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed his pencil." We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out, without putting it in secretly!
— Richard P. Feynman (1985)
epenguin said:Well the Boltzmann constant comes in a bit everywhere at least in bulk matter theory. So it can have the appearance of a fundamental constant. But if you analyse it it is nothing but a property of water, its solid/liquid/gas states. If you can predict the energy of its melting and boiling you have it. So a property of atoms in the end. I suggest the speed of light is a property of atoms in the same kind of way.
Oldfart said:Reading through this fastinating thread makes me wonder: Do at least some of you believe that it is beyond human capability to ever mathematically derive the speed of light, i.e., to explain why it must travel at the speed that it does? And if so, why?
The whole point of the enlightenment and modern, as opposed to medieval and greek science, is that we can say "it just does".physicsnoob12 said:but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does"
I don't think any of the reasoning that you mentioned was ever intended to get you a law describing how things fall. Explaining why and describing how are not equivalent tasks.NobodySpecial said:none of this reasoning gets you to a law describing how things fall.
cryptist said:I don't think it is contradictory and I don't think the mathematical proof is the answer to the why. "Why" has more deep meaning. Of course we know pi is 3,14... and not something else. But why it is? Can you answer? All you can say is that "Because for any circle circumference over diameter gives 3,14..". Then "Why for any circle circumference over diameter gives 3,14...?". You can ask these but you cannot find an answer. That's why there is a thing called philosophy :)
I don't think math and physics have completely different status. Physics derived from mathematics. Physics can be considered as applied math. (I think
No, I never use "philosophical" as pointless or unworthy. I know the boundaries of philosophy and science, so I am not saying that "Do not discuss why does travel so fast! It is pointless." , I am saying "Quantum Physics forum is not the right place to discuss this kind of why questions". Because it is philosophy.
Every constant in science has a meaning. But "why it has that meaning" is something else.