Speed of electricity

[PhysicsWiz]

Electricity is an energy, hence it has no mass therefore its can travel faste than "C" (speed of light). But, electrons cannot. Since electrons have a mass when they reach 10% of or more than the speed of light, then its mass will increase meaning a greater force is required to keep a steady speed. If it had a infinite speed then it would also have an infinite mass.

[jinydu]

Actually, the formula for relativistic mass is:

M = m*gamma

where M is the relativistic mass and m is the rest mass. Gamma is a dimensionless number that approaches infinity as the object approaches the speed of light. Einstein once remarked that the speed of light corresponds to a state of infinite energy.

Since electrons have a mass when they reach 10% of or more than the speed of light,

Electrons always have mass. At rest, their mass is about 9.1093826*10^-31 kg. http://physics.nist.gov/cgi-bin/cuu/Val ... ctron+mass

Also, massless energy (such as light and gravitational waves) is supposed to travel at the speed of light.

[PhysicsWiz]

I do agree with the tube of marbles 2 light years long, if you push 1 end the other would feel it instantly, but only if the marbles are rigid objects.
If they are not, then it would take time for each marble to compress and un-compress after a force has been applied.

[never done physiscs]

Light distorts energy to get to earth but energy is a measurement, but measurement is a concept. A concept is used to describe something that dose not exist so energy cannot exist just like numbers so how can light distort energy to et to earth so light must be the result of the concept of energy so how can light really exist? just thought i would ask.

[quickfur]

I do agree with the tube of marbles 2 light years long, if you push 1 end the other would feel it instantly, but only if the marbles are rigid objects.
If they are not, then it would take time for each marble to compress and un-compress after a force has been applied.

Realistically speaking, there's no such thing as a perfectly rigid object. The marbles in the tube are made of atoms, and when you push the marbles, the atoms are pushed together. The electrons in adjacent atoms will then repel, and push the atoms apart again. This produces a compression wave along the axis of the tube. But this can't propagate faster than light because electron repulsion takes place via photon exchange, and photons travel at light speed (obviously).

Intuitively speaking, you can interpret this as "atoms can't feel other atoms pushing against them faster than light can travel".

[jinydu]

Light distorts energy to get to earth but energy is a measurement, but measurement is a concept. A concept is used to describe something that dose not exist so energy cannot exist just like numbers so how can light distort energy to et to earth so light must be the result of the concept of energy so how can light really exist? just thought i would ask.

Why do you claim that a concept is used to describe something that does not exist? It seems much more reasonable to me that a concept describes something that does exist, or is at the very least a useful way to think about things that do exist.

[never done physiscs]

A concept is described in the dictionary as " Something formed in the mind" so if it is formed in some ones mind it can only be true to that one person so for it to exist it would have to posses a form to be true to every person and could not be called a concept but fact or something along that line. Just as numbers, letters or words etc but I will agree that without these simple concepts our life would be a lot more difficult and something’s would be impossible [/img]

[jinydu]

WordReference.com says that a concept is:

"an abstract or general idea inferred or derived from specific instances"

Thus, you can say that concepts are formed in someone's mind, but they are not formed out of nowhere. Instead, they are formed by generalizing from specific instances. For example, having many experiences with pairs of objects leads a person to form a concept of the number 2.

Just because a concept is formed in the minds of individuals doesn't mean that it doesn't have objective existence. Sometimes, the specific instances are known to everyone. One example would be heat. Everyone has experienced heat (or lack of it), and it would be difficult to imagine anyone without a concept of heat. Thus, heat can safely be said to have an objective existence.

[never done physiscs]

So what your saying is that how you experience heat will be the same as very one else. How can u suggest that the way that your body reacts the same way that others do in the world around? Let’s take physicswiz for an example what he may experience as pain may be different than some people, that some people could find pain pleasurable which has resulted in S&M, this is why I think every person has a different taste in music, art and food as they may experience the world in a different way through their sense. So to sum up what is there to say that the way you experience your sense is the same as the next person you see?

[jinydu]

I didn't say that all concepts are necessarily the same for everyone. I only said that this is probably the case for some concepts. Numbers are probably the most clear-cut example I can think of. It's difficult to imagine someone with no concept of number.

However, I do agree with you that pain may be experienced differently for different people. In fact, I would say that of all concepts, feelings probably have the lowest level of objective existence. As I know from my real life experience, pain is a purely personal feeling, that cannot be seen, heard or felt by others. If someone claims that I am feeling pain, I have no way to prove him right. If someone claims that I am not feeling pain, I have no way to prove him wrong.

Unlike pain, concepts in Physics tend to have a precise. Morever, they tend to be measureable/detectable by anyone willing to observe/experiment. Furthermore, everyone should get the same result when measureing/observing the same thing, within a range of experimental error, and assuming they've followed the process correctly. For example, everyone with a working thermometer agrees on the amount of thermal energy a particular beaker of water has. This lends credence to the idea that the concept of thermal energy has an objective existence.

[djuforeo]

Electrons don't, but electricity in a cable does.

Each electron pushes the next, so whether it is the electron that was pushing or the one that came out, it doesn't matter, so there you go infinity described by finite..ness.

This is why when you are talking to someone across the country, you don't talk, and then hear a pause, you talk and there's an immediate response Bob.

Maybe this occurs because electricity travels close to the speed of light (3 x 10 ^ 8 )? So it would seem that you hear someone talking on the phone to you almost instantaneously?

[jinydu]

Yes, the reason the time delay is not noticed is because the speed of light travels so fast (compared to the size of the Earth).

However, if you listen to tapes of the Apollo missions, you should notice a small but noticeable delay (should be about 2-3 seconds) in the communications.

The communications delay with spacecraft in the outer Solar System is even more pronounced. The delay for the Voyager space probes is several hours.

[elpenmaster]

say i take a quark, and i push one side of it somehow. the other side of it is a finite distance away, but wouldnt that other side move instantly? light would take an finite time to go from one side of the quark to the other, yet if you pushed one side of the quark, the other side would move instantly. i am assuming that quarks are rigid bodies. if this doesnt work because of some technical rule, try it with protons or something :?

[RQ]

Yes, elpenmaster, that is a good thought. However, each plank length of that quark moves at a finite time over a finite distance, the smaller the distance the smaller the time with respect to the same force and reference frame, never reaching 0 however with respect to the uncertainty principle and against 0/0, as 0 distance can be covered in 0 time. Thus the quark would take a small smaller difference of speed than that of light, adding up to eventually, if you pushed a quark the size of a TV, over a long distance, enormous length differences between that of light and the object, in this case quark, being pushed.

[RQ]

So what your saying is that how you experience heat will be the same as very one else. How can u suggest that the way that your body reacts the same way that others do in the world around? Let’s take physicswiz for an example what he may experience as pain may be different than some people, that some people could find pain pleasurable which has resulted in S&M, this is why I think every person has a different taste in music, art and food as they may experience the world in a different way through their sense. So to sum up what is there to say that the way you experience your sense is the same as the next person you see?

You never know, maybe people experience everything the same way.

However there is no concept that conceives the science that conceives IT. This is a paradoxical proposition that our minds created the universe, as it is plain that this universe created our minds (materialistic and physical ones). If you want to talk about the soul as not being part of this universe, then I don't see how it can create our universe, or what it has to do with our physical minds in perfectly observable, non-conceptual existences right under, or above our noses.

Perhaps this is more of a trend towards imagination that you are suggesting, because I don't really see how our thinking that a universe exists, makes it exist. It is however much more evident and scientifically accepted that this universe with all its properties and dimensions act in specific ways, which we record as the laws of the universe, eventually trying to make a GUT or Grand Unified Theory. Whether these laws we conceive are correct, is only under the subject of continuous experimentation, and when one fails, it is either discarded, or modified, thus never really achieving a GUT without proving the givens we've assumed in my mind.

It is also important to see that there is no consistent proof of x=x, and thus it is the biggest given in all of mathematics. It is merely a matter of accordant observation that this given is fact in our universe, but it may not be this way in parallel universes, if they exist, since science is an application of math with the added properties, and science is math, but math is not science.

[mghtymoop]

i would debate the existence of a truly rigid body, everything is to some point elastic, technically if you take a so called rigid body and make it long enough you would be able to observe a time lag between one end being moved and the opposite end subsequently moving. oh, and as for comments about electrons moving at light speed, i'de really hate to see that happen given that an electron moving at one quarter light speed would have a momentum similar to that of a semi trailer travelling at 100 km/h, see electrons are very big, and light speed is very fast, make sence

[PWrong]

Electrons are very big? Not when I last checked.

The mass of an electron is 9.11*10^-31 kg, and the speed of light is 3*10^8 ms^-1
That would make the momentum (9.11*10^-31) * 1/4*(3*10^8)
=6.83*10^-23 kgms^-1 (sorry to anyone who doesn't use metric)

That's not quite as much momentum as a semi trailer. However I agree with you about the rigid body. It's no more plausible than travelling faster than light is.

Incidently, quarks don't move like ordinary objects, and I don't think they actually come in contact with each other. At that level, the "pushing" force is just another part of electromagnetism. So an atom can "push" another atom without actually touching it.

Also, a subatomic particle like an electron doesn't even move continuously. An electron can only exist at discrete energy levels. For instance, on some kind of atom, the levels might be 2.3, 3,6 and 7.2
This means the distance between the electron and the nucleus can only be one of these three values. It somehow moves up and down without ever existing in between two levels. :?

In closing, quantum mechanics is very wierd. If any of that is wrong, I probably failed my physics exam. I don't think it is though, as I'm paraphrasing my textbook directly.

[mghtymoop]

using newtons laws to calculate the momentum of a subatomic particle travelling at immense speed, interesting idea, though not quite correct, try again, this time using modern physics

[6th former]

And, even if there were no gaps, the fastest the signal can possibly travel is the speed of light.

I disagree with that. Imagine a very long pole suspended in space, hundreds of miles long. If someone pushes one end of the pole, the other end moves instantly, right? Now, imagine a tube hundreds of miles long in space, with the whole tube filled with marbles the radius of the inside of the tube. If someone were to push the marble at one end, the marble at the other end would come out instantly, wouldn't it?

I dont have the time to read all the rather complex and somewhat longwinded post in this topic as I have got A-levels to and such like.

Based on my knowledge of GCSE Physics and Chemistry, neither of which I am going for A-level, I would say that even if you did push the rod at one end there would be slight compression of the rod, and so there would be a time lag between the push, as atoms never actuially touch under normal circumstances, unless fusion is taking place, but anyway, normal circumstances. Therefore surely there is always going to be some 'play' there, soom for movement. Push one end, atoms push against each other, slighty compressing and expanding as the movement travels along the object, thus meaning a lag time from push at one end to effect at the other.

But you know, just GCSE physics/chemistry fluffing around in the mind of an A-level student...........

[mghtymoop]

what an arrogant little bugger 6th former must be, doesn't have time to read the thread but as he/she reckons they're a a-level student it gives them the qualification to make somewhat belated comments, ha, get a life mate

[PWrong]

6th Former, you're right, but we've been saying that for a while now. And you don't really need to mention the fact that you're an A-level student 3 times in one post. We're all smart people here. By the way, what's GCSE?

using newtons laws to calculate the momentum of a subatomic particle travelling at immense speed, interesting idea, though not quite correct, try again, this time using modern physics

What do you mean by modern physics? If you use relativity, the speed would increase the mass of the particle, so the momentum would be greater. But relativity doesn't apply at the subatomic level, unless you want to use string theory, . Anyway, I have no idea how to use relativistic equations.

[jinydu]

6th Former, you're right, but we've been saying that for a while now. And you don't really need to mention the fact that you're an A-level student 3 times in one post. We're all smart people here. By the way, what's GCSE?

I can answer that one. GCSE stands for General Certificate of Secondary Education. Its a series of exams that British students take 2 years before the end of high school. A Level is what they take in the final 2 years of high school. If I remember correctly, they choose 4 courses for the first year of A level (called AS), then drop one and take 3 courses for the final year of A level.

using newtons laws to calculate the momentum of a subatomic particle travelling at immense speed, interesting idea, though not quite correct, try again, this time using modern physics

What do you mean by modern physics? If you use relativity, the speed would increase the mass of the particle, so the momentum would be greater. But relativity doesn't apply at the subatomic level, unless you want to use string theory, . Anyway, I have no idea how to use relativistic equations.

On the contrary, Special Relativity (SR) works great at the subatomic level. In fact, some of the key experiments (such as the muon experiment, see http://landau1.phys.virginia.edu/classe ... lwhat.html) that led to the acceptance of SR were carried out on sub-atomic particles. Experiments involving subatomic particles accelerated to very high speeds routinely rely on the equations of SR. Its General Relativity (GR) that may have some problems at very small scales, because some of its ideas conflict with the ideas of quantum mechanics.

[PWrong]

Oh, sorry 6th former, I thought A level meant you were getting straight A's.

[monkeymeister]

Tying this back to the orginal question...

Electricity, after reaching its final point moves at an infinite (seemingly) speed if it's in a cable and it can be stored with 100% accuracy if there are no cut cables.

If an electron pushes another electron in a cable stored with 100% accuracy and no friction the electron at the other end will move instantaniously but that does not mean it will move faster than the speed of light. The first electron can not be moved faster than speed of light therefore it can only push the next electron at the speed of light so if there were no gaps inbetween electrons then the last eletron of the cable would move out at about 299,792,458 meters a second. Just like when you push a marble in bobxp's scenario

Imagine a very long pole suspended in space, hundreds of miles long. If someone pushes one end of the pole, the other end moves instantly, right? Now, imagine a tube hundreds of miles long in space, with the whole tube filled with marbles the radius of the inside of the tube. If someone were to push the marble at one end, the marble at the other end would come out instantly, wouldn't it?

Yes, the marble at the top would move instantly but only as fast as the first marbe was pushed[/code]

[jinydu]

As I've stated many times, I really don't think adjacent particles, whether they are marbles or electrons, move instantly.

Remember that all masses are ultimately made of subatomic particles. Furthermore, subatomic particles like electrons, protons and neutrons are not billard ball like objects. They do not interact by bumping into each other the same way that billard balls do. In the example of electrons in a cable, Electron 2 accelerates away from Electron 1 when Electron 1 approaches because of the increased repulsive electromagnetic force exerted by Electron 1. However, information about changes to Electron 1's electromagnetic field do not travel through space instantaneously. Instead, this information travels at the speed of light, which is not surprising because (according to particle physicists), the information is carried through photons. Thus, the overall signal will still travel no faster than the speed of light.

If you still don't believe this, read my earlier post on page 1 of this thread, where I proved that instantaneous communication violates the Special Theory of Relativity.

[houserichichi]

While it's not the exact same situation, the Superluminal Scissors Experiment may help shed a little light on the subject.

Give it a good readthrough, hopefully it opens up opinions on this balls-through-tubes thing that was going around here. Nothing moves infinitely fast, information can't be transmitted faster than light anyways as far as relativity is concerned. Thus, if we have a lightyear long tube filled with rigid balls (I think I saw that movie :wink: ) then pushing one ball causing the last ball in the tube to move instantly would defy physical laws. There has to be some kind of warping (whether it be of the tube or of the balls, ridig as they may be) so that it takes at least a year for the last ball to move (with respect to the initial force exerted on the first ball, that is).

Geez, hope I'm not wrong or I might look silly.

[RQ]

Yes, but since electrons in a wire are not balls, and are much less massive, they move at enormous times their regular speed in a cable, and this is the reason why we don't need light computers to take over.

The momentum of particles with no mass is not p=mv, but m/sqrt 1- v^2/c^2 I think, if not correct me.

[jinydu]

Yes, but since electrons in a wire are not balls, and are much less massive, they move at enormous times their regular speed in a cable, and this is the reason why we don't need light computers to take over.

The momentum of particles with no mass is not p=mv, but m/sqrt 1- v^2/c^2 I think, if not correct me.

Actually, the equation for momentum is p = Mv.

M = relativistic mass
m = rest mass

They are related by the formula:

M = m*Sqrt(1/(1-((v^2)/(c^2))))

[RQ]

The momentum of light is not p=mv, because light has no mass, but it has pressure as conducted experiments have shown.

[jinydu]

The momentum of light is not p=mv, because light has no mass, but it has pressure as conducted experiments have shown.

Oops, sorry about that. I thought you were talking about particles with mass. However, light does have momentum. The momentum of a photon is given by:

p = hf/c

where h is Planck's constant, f is the frequency of the photon, and c is the speed of light.