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Can something move faster than light?


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Poll: Can something move faster than light? (1 member(s) have cast votes)

Can something move faster than light?

  1. Yes (85 votes [58.62%])

    Percentage of vote: 58.62%

  2. No (40 votes [27.59%])

    Percentage of vote: 27.59%

  3. I don't know (20 votes [13.79%])

    Percentage of vote: 13.79%

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#290 Buffy

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Posted 01 June 2007 - 12:17 AM

...but what about the big bang fireball

The "radius" (misusing the term horridly to try to get it into a three-dimensional context, although its *extremely* important to realize that the universe has no intrinsic "radius") of the universe during Inflation did "increase" at a rate faster than the speed of light, but this was *expansion* of the universe, not *motion* through it.

People have a really hard time understanding expansion: that's why so many of them either draw incorrect conclusions as you have here, or simply deny that it occurs.

Popping balloons,
Buffy

#291 The Transhumanist

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Posted 01 June 2007 - 12:26 AM

I love blue cheese.


"We can already do this. They're called thumbs."
I can't believe you just said that, manipulate with out touching, lift water into then air.

"You are still lacking bovine meat with your claim."

I'll get some from the store (google)

"Oh, so you mean the energy from when water droplets form on the border of Rhode Island."

No the energy from the singularity, a knot in space time, all of the space time in our universe curved into 3 inches.

#292 Qfwfq

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Posted 01 June 2007 - 04:36 AM

But if there where to be two objects traveling at 0.6 c and at opposite directions. Then wouldn't one object see the other move away at 1.2 c?

If you analyse it with the Lorentz coordinate transformations it's not too difficult to compute that for each of those two objects the other will be travelling at [math]\norm\frac{1.2}{1.36}c[/math].

The "radius" (misusing the term horridly to try to get it into a three-dimensional context, although its *extremely* important to realize that the universe has no intrinsic "radius") of the universe...

Actually you shouldn't feel so horrible about it because it isn't really a misuse. The inverse of the scalar curvature is a radius, although in a fictuous sense as far as we know.

#293 PuGZ

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Posted 01 June 2007 - 05:22 AM

Speaking of moving faster than the speed of light, I absolutely love Cherenkov radiation - it's so pretty!

Cherenkov radiation - Wikipedia, the free encyclopedia
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#294 CraigD

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Posted 01 June 2007 - 08:29 AM

Hmm... well what if the train in the first picture where to be moving at c. What would stop the ball from moving faster than c in reference to the observer?

Perhaps time dilation?

Agen, you appear to have half-answered you own question. Accounting for time dilation and length contraction gives the following formula for addition of velocities (commonly called “Einstein velocity addition”): [math]v = \frac{v_1 + v_2}{1+(\frac{v_1}{c})(\frac{v_1}{c})}[/math].

For simplicity, this equation assumes all velocities have the same direction – it can be written in vector form for situations where this is not true, but is messier.

The derivation of it from the very similar formulas for time dilation ([math]t’ = t \sqrt{1 – (\frac{v}{c})^2}[/math]) and length contraction ([math]d’ = d \sqrt{1 – (\frac{v}{c})^2}[/math]), while algebraically simple, is hard (for me, at least) to understand and explain. This top-google ranked UC page does a credible job of it – for some reason, it seems to take me hours (which I don’t just now have) to visualize this well enough to explain it.

But if there where to be two objects traveling at 0.6 c and at opposite directions. Then wouldn't one object see the other move away at 1.2 c?

The velocity addition equation is applicable here, giving the result that on observer on either of the two objects would see the other moving away at [math]\frac{.6+.6}{1+ .6 \cdot .6} = \frac{15}{17} \dot= .88235294[/math]. Playing with the formula will show you that, for any 2 velocities [math]v_1[/math] and [math]v_2[/math] not greater than [math]c[/math], the formula gives a [math]v[/math] not greater than [math]c[/math].

Some complain that relativity is difficult to visualize without using algebra. I don’t find this to be the case. Having done the math, or had it done for and presented to you by a trusted person, it’s possible to visualize its implications in pretty intuitive, graphical form. I doubt, though, that Special Relativity could have been developed, or would have been accepted, without the algebra, and am sympathetic to arguments that you can’t really understand it without mastering its technical details.

#295 CraigD

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Posted 01 June 2007 - 09:35 AM

Dune is an exaduration of the real thing, the real thing is creating artificial bacteria that can slightly manipulate micro objects, and injecting them into a human embryo. Each new generation the embryo's will become more manipulative of objects, until they are able to curve the very fabric of our universe.

One of the rule you agreed to when you joined hypography was to back your claims up with evidence. Do you have any for you claim that injecting bacteria into human embryos will cause the offspring to have Psychokinesis? Do you have any evidence or theory that moving objects purely with “mind force” – no muscles, machines, or ordinary means – has ever occurred, or is possible? Certainly, brain activity can effect very special “objects”, such as electrons in EEG recorders, but evidence that it can apply measurable force to ordinary objects such “apples, bananas, and water” is lacking.

Although many people believe such evidence exists (a belief promoted by a large, profitable, “entertainment” industry), if examine all such rumors and leads with sufficient scientific care (being expecially careful not to confuse fiction stories with actual accounts), you’ll almost certainly be forced to conclude that the evidence is nonexistent.

Adding bacteria to a human being – or any similar animal – would almost certainly be either inconsequential, or cause disease. In terms of number of cells, human beings are already mostly bacteria, with bacterial cells outnumbering somatic (body) cells by a factor of about 10 to 1 (source: wikipedia article “Bacteria in the human body”). Because bacteria cells are very small compared to somatic ones, they make up only about 3% of the mass of a human or animal. Adding more would at best just slightly alter the complex bacterial balance within the body, or at worst, upset it, resulting in disease.

If there is an explosion the size of the big bang, the fireball would expand faster than light, do the math.

As the one making the claim, it’s your responsibility, Gardamorg, to do the math, or provide a reference or link to it. When considering scenarios such as the early inflationary universe predicted by some big bang models, the math tends to be no easy thing to do. In no model of which I’m aware does any fermion travel faster, or any gauge bosons slower, then the speed of light – though in many, the speed of light is not constant.

#296 DougF

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Posted 07 June 2007 - 01:45 PM

IN Start Trek for the ship to get from point A to point B the ship had a machine that condensed the space behind the ship and expanded the space in front of the ship. So the ship would not actually move, the space around it would. Do yall think that this is possible?

I suspect it is physically possible – that is, not forbidden by any quality of nature / physical law. However, I doubt that it’s achievable without tremendous advances in our understanding of physics, and, were such advances achieved, other technological options would render such a machine undesired.

Current physics suggest that physically reasonable “warp bubbles” require not only strong gravity of the kind that can be produced by very dense matter, and is thus in principle possible, but of a kind produced by dense exotic matter with negative mass. There are some tantalizing experiments that suggest that such matter may be possible, but the physics is very tentative and cutting edge.

If STrek-type warp bubbles are possible, so may be distorted spaces such as wormholes. If wormholes are possible, so may be all sorts of counterintuitive violations of causations. This rabbit hole is very deep

By nearly any current calculation, even if warp bubbles and wormholes are possible, their energy requirements are staggering – galaxies worth of available energy to produce effects capable of moving small objects interstellar distances.

For more, read (more than just the wikipedia article) about the Alcubierre drive.

I voted yes to this thread, :)
What we thought not to be possible yesterday is in use today!
Shields, ( in the works)
warp bubbles, ( in the works)
the folding of space, true.
traveling faster than the speed of light. ( in the works maybe someday)
TIME TRAVEL, (who knows I doubt I'll live that long, but then again maybe)
:)

Magnetic Radiation Shielding: An Idea Whose Time Has Returned?
Geoffrey A. Landis
Magnetic Radiation Shielding: An Idea Whose Time Has Returned? - G.Landis (1991)
Force Fields and 'Plasma' Shields Get Closer to Reality
Trek-Like 'Cold Plasmas' Shield, Cloak
Helicon Double Layer Thruster
ESA accelerates towards a new space thruster
Plasma bubble could protect astronauts on Mars trip
Plasma bubble could protect astronauts on Mars trip - space - 17 July 2006 - New Scientist Space
Einstein's warp effect measured.
Two scientists appear to have beaten a $600m Nasa mission to be first to measure a phenomenon predicted by Einstein's theory of relativity.
BBC NEWS | Science/Nature | Einstein's warp effect measured
But new, highly mathematical research may have brought us one step closer to being able to explore the Universe in a starship capable of traveling faster than the speed of light.
BBC News | Sci/Tech | Warp drive possible
Astronomers have confirmed that Einstein's predictions of space and time warps are correct.
BBC News | Sci/Tech | Warp speed five, Mr Einstein!
TIME TRAVEL
BBC - Science & Nature - Space - Time Travel

#297 Guest_chendoh_*

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Posted 09 June 2007 - 07:56 AM

My apoligies on my late reply

Because the speed of sound is not a fundamental physical property of the universe.

Oh, an why not?
Do you see events?
and, hear them as well?
When the begining started...Should not, there have been sound?

It's an entirely different set of problems - it doesn't require brand new physics to go faster than sound, just brand new thrust.

Hmmmm....I wonder what gave Light its thrust?
Isn't sound more physical, than light?

That said, I like to believe it's possible. There are a few steps to breakthrough technologies like this.

1) Theoretically it's possible, but it would never happen.
2) Okay, we can make it happen with ungodly (but achievable) amounts of energy/technology/unobtanium.
3) Nature already does it.
4) We pull it off.

I'd say we're at step 1 with the whole FTL thing - see Alcubierre, Kip Thorne.

TFS

I agree

#298 Guest_chendoh_*

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Posted 09 June 2007 - 08:15 AM

One of my first Sigs:

:doh: The only thing faster than light is your mind...:cup: -chendoh

#299 von Faulkenstein

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Posted 10 June 2007 - 03:13 PM

When teaching Einstein's SR, I felt that particles could not travel faster than light but now, I have read that in some situations, this is possible. That such particles would have to always travel faster than light--light still being the constant barrier. Also, that this was related to different "frames of references", etc. Any new ideas?:D

#300 Qfwfq

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Posted 11 June 2007 - 03:36 AM

Oh, an why not?

The speed of sound is a fundamental property of the air, air isn't quite as "universal" a thing as space-time.

If we mean c by "the speed of light" then it is a fundamental property of space-time and of dynamics; the speed of sound is not this and neither is the speed of light inside a piece of glass.

and, hear them as well?

You can't hear events in a vacuum.

Hmmmm....I wonder what gave Light its thrust?

A photon in the vacuum, like any massless particle, is constrained to travel at a velocity of c.

Isn't sound more physical, than light?

You could say just as physical, but why more?

#301 Agen

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Posted 11 June 2007 - 04:05 AM

A photon is a massless particle.


Do you consider that a fact?

#302 Qfwfq

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Posted 11 June 2007 - 08:33 AM

When you quote somebody you should not alter their wording. Editing is OK for excerpting or giving emphasis to show exactly what you are aiming at, but you should make obvious what you have changed. Paraphrasing can be acceptable, only if you're absolutely sure it will be found amusing.

#303 CraigD

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Posted 11 June 2007 - 09:34 AM

Do you see events?
and, hear them as well?
When the begining started...Should not, there have been sound?

Nifty questions, though that third one is reminiscent of the old “if a tree falls in the forest, and no one is there to here it, does it make a sound?” saw.

Before we can meaningfully compare sound, or, more precisely, sound signals, to light signals, we need to reach a theoretical consensus on what sound is. With the occasional fringe exception, we should already agree that light is composed of one of the four ”fundamental”, or “gauge” bosons, the photon. We know a light signal has arrived because some of the photons interacts with, significantly changing the state of, some fermions comprising the “ordinary matter” in such things as photographic film, electronic detectors, and our eyes. For the most part, the photons we’re aware of interact with electrons (one of the fundamental fermions) around atoms.

Sound is a more complex phenomena, in which nearby fermions interact with one another by exchanging bosons. For the most part, this interaction involves electrons in one atom exchanging magnetic photons with electrons in another atom, those electrons exchanging them with the fermions in its nucleus, then repeating this chain of interactions with another atom. Because the photons involved in these interaction have no interactions outside of them by which we could detect them, they’re called “virtual” – they exists, but can’t be directly detected.

So a startling (or, at least it was for me, when I first understood it) similarity between light and sound signals is that they both involve photons interacting with fermion. The difference is one of degrees – essentially, in quantum electrodynamical terms, differences in the quantum wave functions of the photons distinguishing virtual magnetic photons from “real” electromagnetic radiation photons. In an extreme cases, such as a large volume of space containing only a few atoms, the difference is only in the energies of the photons – the “speed of sound in (near) vacuum” in this case would be identical to the speed of light in vacuum, and would be greater than the signal speed of light in materials with high refractive indexes – though such sound would be very difficult (but not impossible) to detect.

Isn't sound more physical, than light?

Because the speed of sound, and the signal speed of light in non-vacuum, depends on complicated factors involving the arrangement of the fermions with which the photons interact, it’s sensible to say that both are “more physical” (or at least “more fermionic”) than the speed of light in vacuum. I think it’s more meaningful to say that these speeds are less fundamental than the speed of light in vacuum, which, according to Maxwell’s equations, depends only on 2 fundamental universal quantities, the permittivity and permeability of free space, [math]\varepsilon_0[/math] and [math]\mu_0[/math], as given by [math]c= \frac {1} {\sqrt{\varepsilon_0\mu_0}}[/math].

Hmmmm....I wonder what gave Light its thrust?

A photon in the vacuum, like any massless particle, is constrained to travel at a velocity of c.

I think Qfwfq is, as usual regarding modern physics, correct.

My less matter-of-fact, more zen-esque answer to chendoh’s question is: a photon (light) is not given force (thrust), it is force.

#304 von Faulkenstein

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Posted 11 June 2007 - 09:43 AM

Take some galaxies that are said to travel at velocity greater than "c" (speed of light) but this is really the space not the galaxies, which carries them along.:eek2:

#305 CraigD

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Posted 12 June 2007 - 10:35 AM

A photon in the vacuum, like any massless particle, is constrained to travel at a velocity of c.

A photon is a massless particle.

Do you consider that a fact?

I consider it a matter of formal theoretical definition that the rest mass of a photon is zero. Because, as Qfwfq notes, photons are theoretically forbidden from appearing at rest in any inertial frame, this zero rest mass is not a physically realizable quality. At their theoretically required speed of c, photons have measurable momentum. In principle, then, they can be considered to have a finite relativistic mass at speed c, with all the effects that implies, though measuring effects more subtle than the pressure due to their momentum is difficult with current experimental technology.

#306 snoopy

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Posted 13 June 2007 - 12:14 PM

Its theorised that the particles inside a photon travel at above c and that they average out to c.

Photons are all but massless or must have a vanishingly small mass but electrons can make quantum leaps from one side of the universe to another and this to my mind is travelling faster than light.

The problem of inertia too suggests `force carriers` in excess of the speed of light.

We have only been doing Physics properly for a couple of hundred years I think it is conceit to imagine we know all there is to know about the universe.

Maybe after doing Physics for a million years we might know pretty much everything.

I have said b4 that `Shadows` can under certain circumstances be `superluminal`.

I also believe that Tachyons of some description (God knows what that description might eventually be) will be proven to exist as they crop up in too many theories, probably one hundred and fifty years away from that one though.

In the strictest terms relativity doesn't forbid speeds in the excess of light it just suggests weird effects might happpen from achieving that kind of velocity like your mass increasing by ridiculous factors but there are ways that could be circumvented as we dont fully understand what `mass` is and why material objects have `mass` thats why we are building the latest accelerator in switzerland to find the Higgs boson. The particle we think is responsible for matter exhibiting mass.

If we could find a way in the distant future to control mass, reduce it or even get rid of it altogether the possibilities for superluminal spacecraft could be endless not likely for at least five to ten thousand years away from that though I think.