# Is this really true or it's just science fiction?

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• 04-04-2002
f0ul
The world is flat
Having just read 4 pages of formula and confidence inspiring theory - what if we don't know enough yet to be correct?

Imagine that we were discussing manned flight about a 2000 years ago.

most theories would say that you would have to act just like a bird .. be light and flap wings in proportion to the weight being carried - and it would make sense.

now we know that its all to do with air pressure differences - something nobody knew about even 300 years ago.

My point being that although we have a number of theories that either say yes, warp speed is possible, or no it isn't - it is really only guessing.

Looking back at the time of the romans and putting todays knowledge into practice - they could have easily built an aeroplane with their technology.
• 04-04-2002
Clyde
"My point being that although we have a number of theories that either say yes, warp speed is possible, or no it isn't - it is really only guessing"

Hardly guessing, relativety has been "proved" umpteen times.

No-one will ever travel faster than C in linear space. Never gonna happen.

However, theoretically there are other possibilities:

Wormholes, could possibly provide a way to travel great distances in small lengths of time.

"Warping" ala Star Trek offered a possible way round the speed of light limitation................... unfortunately it turns out that in order to "warp" space you need 10x more energy than there is in the universe..... bummer.

"The first law of thermodynamics is actually just a clarification of the law of the conservation of energy and really only applies to heat"

Since when? It applies to ALL forms of energy, not just heat: potential, kinetic, etc.
• 04-04-2002
shtarker
>>Since when? It applies to ALL forms of energy, not just heat: potential, kinetic, etc

That is the law of conservation of energy. It simply states that energy can neither be created or destroyed. The first law of thermodynamics is similar but says that when something changes state it will usually do so as a response to external energy flows. Energy may be supplyed as such:
1: Heat energy (joules) flowing into the system.
2: Work done on the system (such as compression from an external force).

Hence the law of thermodynamics is a clarification of the law of conservation of energy.
• 04-05-2002
>>> what if we don't know enough yet to be correct?

This is, of course, correct. However, to get to a more advanced state, one has to begin somewhere, and where we are now, is where we are. The flight analogy is not a good one to use though, sure planes do not work entirely like birds, but birds are heavier than air, (you can weigh one if you like), and they do fly - fact, heavier than air flight is possible. Back then, they knew this, they simply did not know how too.

We do not have an observation of faster than light travel, so at this point, we do not know that it is possible.

>>> Hardly guessing, relativety has been "proved" umpteen times.

A little devils advocating here, but, nothing yet has conclusively proved relativity to be wrong, not quite the same thing. There have been some counter claims, but at the moment, the big money is in the standard model, so to protect budgets, departments and careers, people like to stay in there. I'm afraid things will be like that while research grants are allocated in the way they are today.

>>> Never gonna happen.

Horribly long time, never!
• 04-05-2002
xds4lx
Hmm, i cant find a link to the article now but if its true you can look at www.space.com . NASA had contracted some company to construct a device that can successfuly reduce the effects of gravity. Well if this is true and it can be refined to eliminate gravity's effects than light speed travel would be feasable since with out gravity you dont have no mass!
• 04-05-2002
>>>
NASA had contracted some company to construct a device that can successfuly reduce the effects of gravity.
<<<

Actually, NASA have contracted out an investigation into the claims that the device can reduce the gravitational force.

>>> with out gravity you dont have no mass!

All matter has mass. Without gravity it may not have weight, but that is not the same.
• 04-05-2002
shtarker
>>NASA had contracted some company to construct a device that can successfuly reduce the effects of gravity.

Yes on the basis of a single set of results for an expirment that has never been sucessfuly repeated.
Nasa also wants to put a huge rotating cable in space to help accelerate the space probes that they launch. Not all of what they do is really that fesiable.
• 04-05-2002
Unregistered
Quote:

Originally posted by Sean
Well saying they'll be really old isn't accurate. It slows down time as you experience it. It's all in Einsteins theory of relativity. Just a relativity question: It is theoretically impossible to move faster than light. RElative to what? If two rays of light pass eachother, relative too the other one, the first will be travelling at 332,000 miles per second (600,000 km / second) - twice the speed of light. Is that a relativity loophole?
Actually if the one beam of light is your reference frame you are not looking from and inertial frame. Because you are not in an inernertial frame you would be unable to tell the speed that the other beem is traveling at. So it is not realy a loophole
• 04-05-2002
Clyde
"The first law of thermodynamics is similar but says that when something changes state it will usually do so as a response to external energy flows"

The first law is:

dU = dw + dq

It does not specifically address changes of state (they are merely another example of energy changing forms), and is merely a mathematical expression for the conservation of energy.

"A little devils advocating here, but, nothing yet has conclusively proved relativity to be wrong, not quite the same thing. "

The predictions Einstein made about the time dilation effect have been experimentally reproduced many times, as has the increase in mass observed when a body is close to the speed of light. They have also showed experimentally the validity of just about every equation he derived.

Never might be a long time, but you can't change the laws of physics.

You see, as long as something is technically possible, there is hope that we will some day achieve it. Travelling faster than light through linear space is not technically possible, so my statement is safe.
• 04-05-2002
Shiro
A theory is true as long as an experiment or other theory proves that the theory is false. History shows that physics theories are continuus being corrected or completed.

It was quite safe to say that current physics is incorrect at some points and not completed at other points. Relativity completed classical mechanics, but relativity isn't also complete.

>Never might be a long time, but you can't change the laws of physics.

If someone proves that a certain law of physics is incorrect, then that law must be changed. Also one can doubt about the speed of light being the fastest speed. Some say that the Einstein-Podolsky-Rosenparadox (EPR-paradox) proves that it is possible for particles to communicate faster than light.
• 04-05-2002
>>> Never might be a long time, but you can't change the laws of physics.

Newtonian physics were the laws of physics once.
• 04-05-2002
Clyde
"If someone proves that a certain law of physics is incorrect, then that law must be changed. Also one can doubt about the speed of light being the fastest speed. Some say that the Einstein-Podolsky-Rosenparadox (EPR-paradox) proves that it is possible for particles to communicate faster than light."

Well indeed, if the relativity were proved wrong then travelling faster than light would be possible........ but it ain't gonna happen.

Relativety is cetainly NOT the whole picture, and could well be refined by the same amount that newtonian mechanics were refined. BUT thats the thing its refinement not total disproval in favour of another theory. Relativity did not "disprove" Newtonian mechanics, it added to it.

Relativity was believed BEFORE it was experimentally proved, and for good reason. It is derived from Maxwell's wave equations, which have been proved umpteen times over.

The EPR-parradox was cited BY Einstein in order to refute quantum mechanics (Einstein hated quantum mechanics), what comes into question is whether or not QM is a complete theory or whether there are hidden variables describing the state of electrons that are currently hidden. It is of note that DESPITE the HUGE amount of evidence for QM, it is QM that is called into question by the EPR-parradox rather than special relativity.

Anyhow, I wasn't really reffering to information, i was reffering to objects that have a rest-mass. The tachion (who's existance is highly doubted i might add) supposedly is a massless particle/wave that some have theorised could travel faster than light.

BUT the key point is it's massless.

"Newtonian physics were the laws of physics once."

And they still are; we sent man to the moon with newtonian physics, your cars/planes/boats, buildings, foot-balls, all work according to Newtonian mechanics. Refinement of a theory is not the same as annihilation of a theory.

With every refinement we get closer to a complete discription of the truth. Whatsmore many physists think that a GUT (grand-unified theory) is within this generations grasp.. (personally, i'm dubious :))
• 04-05-2002
Shiro
>Newtonian physics were the laws of physics once.

They still are, but they are not complete. So these laws have not changed, but new laws have been added.

>Well indeed, if the relativity were proved wrong then travelling
>faster than light would be possible........ but it ain't gonna
>happen.

Why are you so sure about that? I know that from the point of relativity it's impossible. But experiments in quantummechanics have showed that very close related particles can communicate with eachother in almost zero time, whatever their distance is.

>BUT thats the thing its refinement not total disproval in favour of
>another theory. Relativity did not "disprove" Newtonian
>mechanics, it added to it.

Yep, that's what I meant. I didn't say relativity is false, but I think it is not complete. I also think that quantummechanics isn't complete. Both theories seem quite correct but they contradict at certain points.

Recently I followed a lecture on string theory, it seems it is quite able to unite quantummechanics and relativity. A string is pure energy and massless(?).

I also wonder if the tachion exists. Relativity can't be used with the tachion. One of the basics of relativity is that the speed of light is the limit. So if the tachion travels faster than light, you can't apply relativity to it.
• 04-05-2002
>>> but it ain't gonna happen.

I accept that given the current understanding, that is true.

However, you must accept that to a stone age man, if you throw a stone up in the air, it will fall back to the ground. He has absolutely no concept of escape velocity - it is totally meaningless to him, his frame of reference is simply not broad enough to comprehend the possibility of being wrong.

Blindly accepting that what is, is what there is, and nothing else is possible is narrow sighted, anti-scientific I would suggest. (I would, however, reiterate something I said earlier - that kind of thinking is likely to get your research budget renewed, anything else, hmmmm)

>>> Refinement of a theory is not the same as annihilation of a theory.

Who said anything about that? You refuse to accept the possibility that at a time in the future a refinement, (your words), to the current model may change this?
• 04-05-2002
Clyde
"Why are you so sure about that? I know that from the point of relativity it's impossible. But experiments in quantummechanics have showed that very close related particles can communicate with eachother in almost zero time, whatever their distance is."

I'm sure about it, because i've seen the derivations (albeit reasonably brefily). And the equations themselves have been experimentally proved.

There are some theories/statements, that you can see being disproved there are others (barring loopholes) that really aren't going to be.

Gravity will NEVER be disproved, ie. there is a force between two masses. Now i can't say that we will "never" make an anti-grav devide (but i'm dubious) but i can say that in a "normal" environment two masses will ALWAYS exert a force on each other. And i can state that with as much certainty as is possible (see Decarte).

Now people don't question gravity because they have personal experience with it, + they're "used" to it as an idea, they don't question it. But if you give them a theory they're not "used to", and thats not intuitive then they express doubt EVEN if there is as much evidence supporting it as there is the theory they're used to. -> Human nature.

"But experiments in quantummechanics have showed that very close related particles can communicate with eachother in almost zero time, whatever their distance is."

And what is moving faster than light there? Information.. and whats that? We have no idea, i'll tell you what its not: Something with mass. Besides which there are several possibilties that resolve the EPR-parradox with special relativity, though the debates are still raging over their validitiy.

"I didn't say relativity is false, but I think it is not complete. I also think that quantummechanics isn't complete. Both theories seem quite correct but they contradict at certain points."

That is very true, neither theory is believed to be complete, however for objects with mass to travel faster than the speed of light through linear space, relativty would have to be COMPLETELY wrong. Since the speed of light being an absolute is a central tenant of relativity.

Whats more, you have to consider the ramifications of what has been observed; when a guy is driving towards me at 10km/h and he shouts a message to me that travels away from him at 25km/h (yea slow sound :)) then the sound travels towards me at 35 km/h. Now if instead of throwing a wave of sound at me fromhis car they throw a photon of light, common sense collapses:

The light travels away from them at 3*10^8 ms-1 AND towards me at 3*10^8 ms-1 NOT at (3*10^8 ms-1 + 10hm/h). EVEN if he is driving at 2.8*10^8 ms-1 (me thinks he'd be speeding) the light still travels towards me at c!

It does so because the speed of light is a property of SPACE.

This is the reason c is absolute: its a property of space itself, to change that you have to change the nature of the universe.

"Recently I followed a lecture on string theory, it seems it is quite able to unite quantummechanics and relativity. A string is pure energy and massless(?). "

String theory was thought (and still is to an extent) as the great hope for the grand unified theory, unfortuneately it hit quite a few previously unforseen problems. My knowledge of what "strings" actually are is very limited, but my udnerstanding is they are the fundamental "particle" that everything is built on IE. that quarks are made of strings as are the force particles and everything else etc. Hence one would assume they have mass.. but i'd have to check it out.

If tachions don't have mass then relativity doesn't really apply to them so yes they could travel faster than light.
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