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A "Macroscopic Violation" of Special Relativity

According to modern physics, the speed of light is a fundamental, unbreakable limit.  Yet two physicists are now claiming they have done just that, and propelled a stream of photons faster than the speed of light. 

Günter Nimtz and Alfons Stahlhofen of the University of Koblenz, Germany, have been researching a phenomenon known as quantum tunnelling.  Two prisms are placed together. When a light is shown through the prisms, a detector picks up the light and records information about the photon.  However, when the two prisms are separated, Nimtz and Stahlhofen discovered that photons would occasionally "tunnel" between the prisms -- arriving at the detector sooner than should theoretically be possible.

The two scientists say they have now tunneled photons "instantaneously" across a distance of up to one meter.  Their conclusion, stated in a recent paper, is that the speed limit of special relativity has been violated.  Dr. Nimtz claims quantum tunneling is a little understood process that is  "the most important" aspect of quantum physics, one that may be responsible for the computational efficiency of the human brain.

Being able to violate the speed of light would undermine our current understanding of space and time, and lead to a number of bizarre effects, such as being able to travel backwards in time.

However, Dr. Aephraim Steinberg, from the University of Toronto, disagrees with the findings.  He says its all just a matter of interpretation.  The "wave packet" of the virtual photon exceeded the speed of light, but no actual information was transmitted that fast.   Therefore, according to Steinberg, Einstein's cosmic speed limit remains safe.

Nimtz and Stahlhofen may be the first scientists to create a macro-scale experiment.

In a statement published sortly after the paper was announced, Nimitz claims, "For the time being, this is the only violation [of special relativity] that I know of."

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hmm
By Gul Westfale on 8/16/2007 11:58:24 PM , Rating: 3
i guess we will have to wait for someone else to replicate these experiments, and to see whether there are any practical applications. but, any bit of research helps, and going faster than light one day is something that i want to see in my life time. hopefully...




RE: hmm
By KristopherKubicki (blog) on 8/17/2007 12:00:26 AM , Rating: 3
The interesting thing is that the experiment seems somewhat easy to do. I think we're going to have confirmation or debunking pretty quickly!


RE: hmm
By Jedi2155 on 8/17/2007 12:19:04 AM , Rating: 3
Hasn't quantum tunneling been known for a while?

From my understanding of elementary Quantum physics, and what I read in the paper, it doesn't seem like they broke any new ground.


RE: hmm
By Jedi2155 on 8/17/2007 12:21:59 AM , Rating: 3
Oh wait, nevermind my previous comment. They were dealing with photons quantum tunneling on a large scale (meters) versus electrons on the nanoscale.


RE: hmm
By GlassHouse69 on 8/19/2007 7:44:35 PM , Rating: 1
yeah, that's true.

however, the concept of a photon and the concept of any small, defined particle is similar. the article is misleading like most articles on DT.

However, nothing can travel continuously faster than the speed of light. Jumping in and out of existence does not mean you moved faster, just that you appeared. from 0mph to speed of light speed, accelerating through that, you would max out.

THis is what Einstein was saying. he found it exciting that light was the barrier for normal travel. It meant that other travel existed.


RE: hmm
By 16nm on 8/20/2007 7:42:11 PM , Rating: 2
quote:
the article is misleading like most articles on DT


Don't you mean their headings are misleading?

anyway, I'd like to use this technology to travel into the future to see who wins the Bluray/HD-DVD format war. I would also like to know when Microsoft will add support for this format in Media Center. And since I'm there I may as well take a look at the stock market and see who wins the world series, etc. How long till I can do that?


RE: hmm
By KristopherKubicki (blog) on 8/17/2007 12:22:05 AM , Rating: 4
Not on meter-sized scales ... from my understanding.


RE: hmm
By knowyourenemy on 8/17/2007 12:28:19 AM , Rating: 2
quote:
they have now tunneled photons "instantaneously" across a distance of up to one meter.


RE: hmm
By Cygni on 8/17/2007 11:25:46 AM , Rating: 2
R -> C -> P


RE: hmm
By kmmatney on 8/17/2007 3:24:37 PM , Rating: 1
I thought that was kind of funny, though, since light already does almost travel instantly across 1 meter. AT normla speed that would only take 3.33564e-9 seconds.


RE: hmm
By Oregonian2 on 8/17/2007 4:50:04 PM , Rating: 5
Three nanoseconds is a *LONG* time to me. I've worked on circuits where I was tweaking tens of picoseconds (thousandths of a nanosecond) and that amount of time is a long time to others! A modern PC would have about ten clocks in that period of time. That's *forever*. :-)

BTW - If they can make photons go at whatever speed they say, isn't the flow of photons kinda what "light" is? .. So wouldn't it still be going at the speed of light not matter what "by definition"?

:-)


RE: hmm
By GlassHouse69 on 8/19/2007 7:46:37 PM , Rating: 1
LOL!

that's an awesome thought :) made me laugh actually out loud.

Yeah, that is true, that means like um, the speed of light isnt the speed of light.

neat :)


RE: hmm
By johndenver on 8/21/2007 2:24:49 PM , Rating: 2
A state which is transmitted faster than the speed of light is nothing new, this has been accomplished in the qunatum teleportation experment using entanglement. Einstein's theory of relativity is only violated if information can be sent, this is a very subtle arguement, but it is possible for a state to not carry any information. If this kind of state is being transmitted faster than the speed of light, than this experiment does not disprove Einstein. Determining wheather information can be transferred in this way may not be a simple task, even thought the experiment seems to be fairly streight forward. For more details on quantume teleportaion see the quantum mechnaics text book by LeBellac, it has a fairly good explaination of quantum teleportaion and why it does not violate reletivity.


RE: hmm
By Christopher1 on 8/17/07, Rating: 0
RE: hmm
By otispunkmeyer on 8/17/2007 3:57:58 AM , Rating: 1
same here, i dont believe that laws like this are set in stone forever, only unitl our understanding takes on a new level or we discover something new.


RE: hmm
By Gatt on 8/17/2007 4:09:42 AM , Rating: 1
I agree as well. I think our science is primarily limited only to the things that can be observed by or derived from our senses, and as such is almost absolutely flawed.

We arrogantly assume that our senses encompass all possible "Things" that can exist, be measured, or "Function". It's very likely that there are "Things" we don't know about, much like a Blind person has no understanding of sight.

Pretty much everything we know is derived from our senses, Atoms("I wonder what this is made of!"), Time("Hmm, the sun moves in regular intervals and I can't go backwards to yesterday"), Lasers("I wonder what light is"), Sonar("I wonder what sound is"), Electricity("I wonder what lightning is"), even Magnetics and Gravity.

Everything we know is sense-derived, we need to start recognizing that there's almost absolutely a vast amount of "Stuff" that exists beyond our senses or our ability to derive through pure sense-based research. We know the math doesn't work for a number of things, we need to quit making stuff up or fudging numbers and start recognizing that it's probably something we can't derive from sense.


RE: hmm
By JonnyDough on 8/17/2007 5:00:49 AM , Rating: 1
You mean like...religion?

*Gets shot at by superstitious zealots.

"The key to understanding ourselves is science. Understanding ourselves leads to solutions of our problems and ultimately unveils the truth about our reality."

~Me (Someone might have said something like this before him, I don't know)


RE: hmm
By therealnickdanger on 8/17/2007 8:11:30 AM , Rating: 4
You can't prove there's NOT a Spaghetti Monster...


RE: hmm
By logaldinho on 8/17/2007 8:20:06 AM , Rating: 3
pizza the hutt


RE: hmm
By therealnickdanger on 8/17/2007 8:23:14 AM , Rating: 3
"... or else Pizza is gonna send out for YOU!"


RE: hmm
By OrSin on 8/17/2007 7:40:09 AM , Rating: 3
Play take class college level class in science. 90% of research science is not derived from our senses. Dont even fell like going into it here, but if you actually get pass the basic understanding of the "law of nature" you will find 100's of theorys based on thing we can see or fell, but can test the nature of how it works. What you dont know, dont make it magic, it just makes it what you dont know.


RE: hmm
By HaZaRd2K6 on 8/17/2007 10:43:11 AM , Rating: 1
Have you taken any college-level classes? Because your command of the English language is absolutely horrific. Don't cut other people's comments to shreds if you're not going to do it properly.


RE: hmm
By mindless1 on 8/18/2007 12:47:27 AM , Rating: 1
Hmm. Let's see if we can spot the grammer mistakes you made. On the other hand, maybe you need to find them before calling the kettle black?

Damn grammer Nazis ought to be put in a hole and left there.


RE: hmm
By Gatt on 8/17/07, Rating: 0
RE: hmm
By InsaneGain on 8/17/2007 3:34:00 PM , Rating: 5
Did you think that maybe it's possible that the poster's first language is not English?


RE: hmm
By HVAC on 8/17/2007 4:12:33 PM , Rating: 1
I think the author should feel proud that he/she/it had others thinking they were a native English speaker with a ghetto background rather than an obvious ESL dropout.


RE: hmm
By Ringold on 8/17/2007 5:00:02 PM , Rating: 5
I believe one of the more important things I've got out of college is that the more we know the more we realize how much we don't know and, by looking at history, realizing also that what we think we absolutely do know can successfully be challenged and tweaked going forward.

Even though I haven't looked at physics since high school by listening to Lawrence Krauss and reading a bit of his work I have to agree with your general idea. All these PhD guys running around doing mind-numbing work that is, admittedly, amazing work but really they're grasping at straws, building billion-dollar colliders and praying to the gods of the universe that it answers their questions, lest they go back to being utterly confused.

Not that physics as we know it isn't "close"; it's given us Core 2 Duo's! The weatherman can tell you within minutes when it's going to rain with a high degree of accuracy in the short term though too. That doesn't mean he can even fully explain everything involved with the process, and has a harder time when the time frame becomes wider or when the focus area becomes much smaller, it just means that trial and error has made his guessing process highly complicated and accurate.

Not that it makes me religious or that we can't grasp at it all eventually, but I think we're on the same page.

Mod me down all you guys want, but when you come up with a unified field theory or an equivalent break through that can explain everything from the start of the present universe to the present then let me know. ;)


RE: hmm
By Ringold on 8/17/2007 5:16:30 PM , Rating: 2
To follow up, 2 points
1) There is no 'god' but Google.

2) It has delivered me the transcript that I based my above view on, an interview with Krauss from several years ago.

http://www.sciam.com/article.cfm?chanID=sa006&colI...

I like Krauss because he states things in such a way that an economist can understand. :P Or anybody else, for that matter.


RE: hmm
By Kuroyama on 8/17/2007 11:31:37 AM , Rating: 4
Shouldn't waste my time responding to this troll, but oh well, here goes.

A blind person does not need to understand sight in order to figure out where objects are and where they are moving, as this can be deduced by their other senses. In a universe of blind people we would eventually be able to deduce the existence of light through its effects, such as warming up our skin, giving energy to plants, etc.

For instance, stars appear to be in a different location when they're on the opposite side of our sun then when (say 6 months later) they're on the same side as us. Well, once general relativity came along it explained how gravity bends light, and the calculations were fairly consistent with what we observed. Time dilation was even discovered through special relativity before it had ever been observed (I'm not a physicist so perhaps there was some observation I don't know of).

Sure, if "things" exist which in no way impact our environment then perhaps we cannot deduce them. But then, do said things actually matter? Since you presumably refer to supernatural powers, the very observance of ghosts or ESP means that they are detectable by our senses, whereas if god(s) created the universe and then sat back to watch then presumably we will keep running into walls when trying to discover the origins of the universe and/or life.


RE: hmm
By Gatt on 8/17/2007 2:37:18 PM , Rating: 2
Oddly, I was thinking the very same thing after reading your first sentence.

Perhaps a blind person would be able to deduce the presence of light through the warming of objects, but aside from that, there's no way for them to deduce anything else. They aren't going to deduce "Giving energy to plants", they can't see light, they cannot tell that the difference between a plant indoors and a plant outdoors is light, they'll have no idea why it dies.

As far as stars go...

"Stars appear in different location..."- Sight.
"Gravity bends light"- Sight, observing the action of an object in motion.
"The calculations were [i]fairly[/i] consistent with what we observed"- Sight, apparently the math didn't add up so we fudged it a bit?

I have located your biggest problem though, assuming I'm talking supernatural or religion. I wasn't, nor can you find a single word in my post that alludes to either. In the future, might want to avoid that whole assumption thing.


RE: hmm
By Kuroyama on 8/17/2007 3:13:31 PM , Rating: 2
Regarding a blind person and light, they would eventually deduce that plants grow, and that plants placed in an enclosed structure do not grow (since at least on earth any non-synthetic would likely be opaque), so there must be something "up there" that is causing them to grow. If we continue this train of thought the blind society would eventually discover magnetism (from magnetic compounds orienting themselves), etc. and some day come to electromagnetism. Would likely be a very slow process, but I have no doubt these discoveries would eventually be made.

If we have some other "things" that are not observable by our senses, and in fact nothing they influence can in any way influence something observable by us (by even 100 degrees of separation), then it is irrelevant to our existence. If there are 100 degrees of separation then we will eventually deduce the existence of this "thing" by working our way back up the chain. May take a damn long time, but I have no doubt it would be done. If you don't believe that, then just look at the amazing discoveries we make at a subatomic level which were deduced by working our way back many many levels from what is "observable" by our senses.


RE: hmm
By chrismrulz on 8/18/2007 11:19:56 AM , Rating: 2
quote:
A blind person does not need to understand sight in order to figure out where objects are and where they are moving, as this can be deduced by their other senses. In a universe of blind people we would eventually be able to deduce the existence of light through its effects, such as warming up our skin, giving energy to plants, etc.


umm.. you basically just proved his point.
you still went back to using senses to make up for not having sight.
and as you can imagine, you wouldn't be able to have as good a perception of light as people who have vision.
it's the same reason we don't have an accurate understanding of other things.
if we had a sense that allowed us to sense the location of planets and the solar system, we'd have a better understanding of it. but we weren't given that sense.
sure senses allow us to have a relatively better understanding of things,
but it's clear that they some things have been left out (by the same person that gave us all these senses that coincidentally enable us to discover all these things - God) that we weren't meant to understand.

maybe the OP's post wasn't the best example,
lets say, you have NO senses at all.
no sight, sound, touch etc.. you would know nothing about the world by using your brain at all..
then try to figure out the effects of light.
you wouldn't be able to survive without senses, let alone have the ability to use your brain to discover things based on 'science'.

so what he said is true; every 'fact' and theory discovered through science is only possible due to our limited senses.
and thus, we will never know everything about anything.


RE: hmm
By Kuroyama on 8/18/2007 12:23:56 PM , Rating: 3
My response to the blind person example was meant to show that even in the absence of a sense like sight, we can generally use our other senses to deduce the existence of things we would have otherwise used our eyes for. Perhaps my second response (right above yours) shows such a deductive process a bit more clearly. And if something doesn't effect any of our senses, nor effect anything we can sense even through many degrees of separation, then arguably it is irrelevant to our existence. Belief in god is predicated on the assumption that god is in some way involved in our lives, whether through having created us, occasionally working "miracles", or making you feel tingly all over when you pray, i.e. all things which impact our senses (creation being something we would deduce by "looking" at fossil records or whatever).

But I am not in the business of philosophizing so pardon me if I haven't made my case very well.


RE: hmm
By Hawkido on 8/21/2007 2:49:36 PM , Rating: 2
The OP you are replying to mis quoted the blind person saying... It should have been color not light. While a blind person can make a connection of warming and such to what they are told of light, they have no chance of knowing one color from another (assuming blind from birth of course!).

If no one told a blind person about light they would not be able to tell the difference between the visable light spectrum, and the invisible spectrum, as it would all be invisible. Light would be just convected heat, like that from a fire or a coal or a hot skillet just removed from the stove, or the Sun above.


RE: hmm
By stromgald on 8/17/2007 12:20:54 PM , Rating: 4
quote:
I agree as well. I think our science is primarily limited only to the things that can be observed by or derived from our senses, and as such is almost absolutely flawed.

You do realize that nobody has seen, heard, felt, smelled, or tasted an atom right? We've had some electron microscopes generate 'images' of little balls that are atoms, that's about much we've detected an atom via our senses. Also nobody's 'sensed' a proton, electron, or photon in any way shape or form(we don't actually see a photon, we register large amounts of them hitting our retina). Gluons, quarks, and gravitons are even one step smaller.

You should realize that the cutting edge of physics has already gone way past what our senses can tell for quite a long time. It took us decades to develop experiments that could truly test relativity. Dark matter, super string theory, and grand unification theory aren't derived from our senses, but mathetmatical models that hope to explain things that are so small, invisible, or far back in time, we can't 'sense' it in any way right now.

quote:
We know the math doesn't work for a number of things, we need to quit making stuff up or fudging numbers and start recognizing that it's probably something we can't derive from sense.

And the statement that math doesn't work for everything is ridiculous. Math is a human construct that can be molded to EVERYTHING. It works for everything, but falls short at times because our brains and our computers can't always handle the data throughput required.


RE: hmm
By Gatt on 8/17/2007 2:46:55 PM , Rating: 2
You do realize that Atomic Theory is derivating of sense right? What's that table made out of? Wood. What's wood made out of? Atoms. All of atomic theory is derivative of sense based questions which are being followed to conclusions. "I see this, what is it made of?".

You should realize that cutting edge physics often finds itself with math that doesn't return valid results, and physicists consistently "Create" something to explain it that generally falls within the realm of sense, such as "Dark Matter and Dark Energy" when their math models fail. While Dark Matter is likely very valid, Dark Energy? Never considering the possibility that there's likely a great deal of "Stuff" that exists beyond our senses.

Kind of like Ultraviolet and Infrared light, until we investigated "What light is" and discovered it's wavelength form, it did not exist nor did the entire realm of possibilities that it holds exist, because it did not exist within our senses. We lucked into those two, only because it derived from something within our senses.

I also hate to tell you, the Math doesn't "Mold to everything", the math quite often fails. Go do some research on the Universe Expanding, find that the math consistently fails. It's the one reason we know we don't know everything. Obviously, there's more out there than we can recognize with our senses.


RE: hmm
By rcc on 8/17/2007 5:46:10 PM , Rating: 1
quote:
Kind of like Ultraviolet and Infrared light, until we investigated "What light is" and discovered it's wavelength form, it did not exist nor did the entire realm of possibilities that it holds exist, because it did not exist within our senses. We lucked into those two, only because it derived from something within our senses.


If you consider someone/thing without sight as someone who can't "see" any wavelength higher than Infrared, (touch, heat), they could still infer and create instruments to measure and evaluate light. Much as we can measure, use and work with radio waves. But man what an incredible pain in the butt that would be from our perspective. Now, consider, if some race could directly sense radio frequencies, how limited and slow would they consider "blind" people like us?


RE: hmm
By modestninja on 8/18/2007 2:05:53 AM , Rating: 4
The mathematical model may fail, but it's not because of any deficiency in math, it's because of the deficiencies in our understanding of the subject being studied (aka: the theory behind the math).


RE: hmm
By stromgald on 8/23/2007 3:54:10 PM , Rating: 2
quote:
Atoms. All of atomic theory is derivative of sense based questions which are being followed to conclusions. "I see this, what is it made of?".


If you're going to say that all the questions we ask are derived from our senses, that's probably true. But whatever we can't "sense" in your definition of "sense" doesn't affect us. If it did affect us, we would "sense" it, right?

Dark matter is an easy example. We "sense" dark matter because we see it's effects on matter we can see. We "sense" it's presence and make assumptions about it. The only reason earlier mathematical models failed was because they assumed that all the matter was what we could directly detect/see. Now that the mathematical model has failed, scientists have adapted their assumptions to include matter we can't see (a.k.a. dark matter). The math didn't fail. The assumptions that the mathematical model was based on was wrong.

Look into the evolution of math and you will see how it is purely a human construct that adapts constantly. Basic geometry, which was started in pre-historic times, failed to find the volume of a goatskin jug or the area of a leaf, but these items still had volumes and areas, right? Eventually we developed something called 'calculus' and we could determine the volumes of complex-shaped objects.

The same is happening here. Mathematical models fail because our assumptions are incorrect. Eventually someone will figure out how to adapt numbers and create a model to describe dark matter and other currently obscure aspects of the universe. Math in itself can never actually 'fail'. It evolves. Math is our struggle to quantify everything we see/sense, and so far nothing has stopped us for very long.


RE: hmm
By KiDDGuY on 8/17/2007 6:05:15 AM , Rating: 2
actually thats what we believe ...,

Laws of nature as we so call them are nothing less than fragments of our own imagination.
Actually, all the so called laws are MAN MADE. So, everything that is man made is irreversible, destructible, perishable etc

Summary: Man has (or *might* have) broken a SELF CREATED barrier. Kapeesh !


RE: hmm
By therealnickdanger on 8/17/2007 8:22:13 AM , Rating: 2
I always try to keep a perspective similar to this when dealing with any and all science, philosophy, or religion. As others above have noted, our inability to understand something doesn't make it magic, we just don't understand it yet . Further, everything that we do know in this world is based upon standards and rules that we invented based upon what our tools allow us to proove. To me, the question isn't "Is it possible?", it's " When will it be possible?".


RE: hmm
By stromgald on 8/17/2007 12:30:40 PM , Rating: 2
I don't think of it so much as 'breaking' a law or barrier. One example I can think of are the kinematic equations and special relativity. Relativity supposedly broke the traditional Newtonian mechanics, but then why do we still teach the old kinematic equations? Because they still hold for most cases.

As we learn more about our environment, we develop better and better mathematical models/equations to represent our environment. Kinematics works fine for bridges, airplanes, etc., but when applied to light and high speeds, we found that something else became the dominant influence. Hence, a revision of the Newtonian-based kinematic equations to ones that support relativity.

There are never any 'barriers' or 'breaking'. It's all just knowledge and updates to that knowledge/understanding.


RE: hmm
By oTAL (blog) on 8/17/2007 2:23:38 PM , Rating: 2
Kapeesh!???

Wha-?
Is that neo-Italian l33t slang?

Nice comment by the way, although I do agree with Dr. Steinberg ;)

In order to violate relativity and affect our understanding of the universe information has to be transmitted. Stuff similar to this this was previously achieved through entanglement and the answer was the same... nice discovery, but relativity holds its ground.

Show me a simple ASCII message transmitted faster than light and I'll bow at your superior wisdom.


RE: hmm
By Cygni on 8/17/2007 11:42:24 AM , Rating: 2
This comment is highly depressing. you cant 'sneak' around a true law of nature. a law of nature is UN breakable. UN breakable. if it was breakable, it wasnt a law!

If ANY natural phenomenon functions in a way that is against a 'law', it is simply due to our incomplete understanding of the system as a whole. If we as people had fully mapped out all of physics, those laws would be completely and utterly unbreakable. Our current 'laws' are only breakable because they arent laws. The limitation of our ability to fully predict the natural world is a consqeunce of our own ignorance, NOT because the true laws are breakable in and of themselves.

Which is PRECISELY the reason no modern scientist will attach the word 'Law' to any theory. ;)


RE: hmm
By TwistyKat on 8/17/2007 6:59:10 AM , Rating: 3
I'm not worried about anything going faster than the speed of light right now. I want ROBOTS!

I want affordable, fully-functional robots who can mow the lawn, cook supper, clean the house and drive me around drunk.


RE: hmm
By xsilver on 8/17/2007 8:15:39 AM , Rating: 2
If we had robots that could do those things - something as complex as cooking supper... an assuming that they're affordable for someone middleclass to have one.

half the world would be unemployed overnight.
cant buy a robot with a IOU
sounds grand no?


RE: hmm
By therealnickdanger on 8/17/2007 8:30:16 AM , Rating: 3
quote:
half the world would be unemployed overnight

In which case unemployment would be a good thing. Robots doing all the work is the only condition in which I feel socialism would work. Everyone would get paid based upon the work of robots and we could all focus on science, art, and other skills... and recreation. People could literally afford to stay at home playing WoW all day.


RE: hmm
By artemicion on 8/17/2007 9:30:00 AM , Rating: 4
But then the third generation of robots would be so advanced that they would rebel against us, and then we would have to depend on the second generation of robots (whose more rudimentary coding would maintain the directive to protect all humans). And then in a scene of cinematic irony, a human who hates robots (but has a robotic arm) will save humanity by destroying the robot leader.

But then later, the robots will rebuild a leader called SkyNet and manufacture an army of robots except then a leader will be born from the humans that will lead a revolt against the robots. Then the robots will send a robot back in time to kill the leader's mother before he's born but will be thwarted three times.

But then later the robots will eventually win and enslave humanity by hooking us all up to virtual reality machines and harvest the energy produced by our bodies until a group of rebels escape from the machine and finds The One who has magical robot controlling powers and saves the world.

The end.


RE: hmm
By GoatMonkey on 8/17/2007 7:51:16 AM , Rating: 6
Too late. I already repeated these experiments 10 years from now.


RE: hmm
By masher2 (blog) on 8/17/2007 8:51:30 AM , Rating: 2
Well that was funny to me if no one else :)


RE: hmm
By 1078feba on 8/17/2007 9:12:58 AM , Rating: 2
No masher, it was funny, and very, very Doug Adams....


RE: hmm
By B166ER on 8/17/2007 9:41:48 AM , Rating: 2
It was truly beyond funny. I just love it when we geeks get out of our "I know more than you, so go home and take a course and pay attention this time" mode, and get into funny.


RE: hmm
By Polynikes on 8/17/2007 1:13:34 PM , Rating: 2
Seriously. It's like a big game of one-upmanship.

My joystick is bigger than yours!


RE: hmm
By P4blo on 8/20/2007 6:16:26 AM , Rating: 2
This made me grin as well but on a more serious note, doesn't it actually illustrate a very important point? Scientists say that if true faster than light travel were possible then *in theory* time travel should also be...

Surely here lies the problem. If anyone could really travel back in time we would all be in a pretty deep paradoxical doo-doo before very long. Surely this is the reason why it cant be done? We would effectively become Gods to ourselves and I suspect we'd make a right hash of it !!

You dont have to watch Back To The Future to realise this. So if someone said 'oh you can travel faster than light but it doesn't mean you can time travel' I would be more likely to believe this.

Sorry, no science in my argument, just human logic!


RE: hmm
By metalqga on 8/20/2007 9:47:56 AM , Rating: 2
"we would all be in a pretty deep paradoxical doo-doo before very long"

Theoretically if it was possible it should have already happened (although a long time after this moment). A questions comes up my mind?
If one can travel and change history, let's say save the US president Kennedy how would we know he actually died? We will take the fact that he still lives for granted; a part of a new history as good as ours now.
How do you sense that somebody had been tampering with history? It is impossible.
Maybe if one finds a way to travel back in time but is smart enough not to make big changes so he does small things like:
travel back in time and file patents on behalf oh his grandparents.

The travelling back in time is so difficult to comprehend that I hope it is not possible.


RE: hmm
By BitJunkie on 8/25/2007 6:54:54 PM , Rating: 2
I think the argument used is that "You can't travel back in time to a point BEFORE time travel was invented, or you'd be stuck there and be unable to return". It would be some kind of time-travel-suicide.

If time travel is invented in the future all the fun will be going on after that point....not before.


RE: hmm
By derwin on 8/17/2007 12:47:47 PM , Rating: 1
The more interesting aspect of this issue was touched on at the very end of the article. Scientists don't really disbelieve that this happened, but according to morden day physics dogma (if you will) that doesn't actually mean that the speed of light was broken. I believe that physicist's quote seemed to not comprehend the situation entierly, as he seems to be refering more to the fact that in a photon, parts of it do go faster than the speed of light (phase velosity) but the whole thing (group velocity) is limited by c = 3*10^8 m/s. This is not what the experiment did at all.


RE: hmm
By Scorpion on 8/17/2007 1:38:02 PM , Rating: 2
Yep. I read Ars Technica's rebuttle to this paper yesterday before seeing it posted here. It appears that this paper could not be the claim that people think it is. I in fact was surprised that the paper was only 2 pages long and somewhat lacking in detailed explanations of equations and experiments.


RE: hmm
By KristopherKubicki (blog) on 8/17/2007 1:39:58 PM , Rating: 2
Nimtz has been making this claim since the 80s -- this is the first time though he's attempted to prove it on the macro scale though.


RE: hmm
By GreyMittens on 8/17/2007 4:21:42 PM , Rating: 2
Yes me too, because in my day to day life the speed of light just isn't fast enough sometimes :p


Why would this not work...
By timmiser on 8/17/2007 4:42:26 AM , Rating: 2
OK, I've always wondered this and need some of you really smart people to explain to me why it wouldn't work.

If we humans manufactured a really long rod or pipe that was 1 light year long and attached it to the surface of the earth. (Stay with me now...only talking theory here!)

Since the pipe would mostly be in the weightless environment of space, there would be no drag or resistence on it...other than earth's gravity but for the sake of my argument, lets just ignore that or say that the pipe is strong enough to withstand those forces.

So this pipe that is 1 light year long has one end attached to the earth and the other end a distance of 1 light year out in space away from the earth. 12 hours later as the earth has rotated 180 degrees, the far end of the pipe is now pointing 1 light year in the opposite direction so didn't the end of that pipe just travel the distance of 2 light years in 12 hours time??




RE: Why would this not work...
By Connoisseur on 8/17/2007 5:21:52 AM , Rating: 3
No. The issue is of transmission of information. How would you KNOW that the end of the pipe shifted 1 light year in 12 hours? You'd have to LOOK at it. Looking at it implies reading the photons that reflect off the end of the pipe. So if you were looking from the earth, the light from the other end of the pipe would not reach you for a year. Thus, the end of the pipe would appear to have taken 1 year to shift 1 light year which is perfectly fine. Same from the other end of the pipe. Either way, it's transmission of information and frame of reference. There's no way you can PROVE that the pipe shifted 1 light year in any less than a year.


RE: Why would this not work...
By Connoisseur on 8/17/2007 5:40:36 AM , Rating: 3
also, I don't think a 180 degree rotation would imply a shift of 1 light year considering the pole itself was 1 light year. I believe it would have covered a perimeter of pi*r. While i'm no expert physicist, I believe the calculation of distance gets a tad more tricky due to relativistic effects of the end of the pole travelling because of relativistic effects (take into account the fact that the pole is travelling perpendicular from the earth's viewpoint), but the bottom line is that the knowledge that the pole shifted a distance of x will always travel at less than or equal to light speed.


RE: Why would this not work...
By nrb on 8/17/2007 5:40:49 AM , Rating: 2
quote:
OK, I've always wondered this and need some of you really smart people to explain to me why it wouldn't work.
I'll try and make this as non-technical as I can.

In order for something to move in a circular path it has to be constantly accelerating towards the centre of the circle. It therefore requires a force pulling it towards the centre of the circle.

For those who did not do secondary school Physics: acceleration means a change in velocity , not a change in speed, i.e. the direction of travel is significant. If you change from travelling in a car at 30mph forwards to travelling at 30mph backwards, this represents a sizeable change in velocity, even though there is no overall change in speed. And it requires a lot of force to suddenly make a car go from 30mph forwards to 30mph backwards. Newton's laws tell us that any given change in velocity - or, more precisely a change in momentum, which is velocity multiplied by mass - requires a correspondingly powerful force to achieve it.

So, as I said before, something moving in a circular is constantly being accelerated towards the centre of the orbit. Think about a stone tied to the end of a string being swung around your head. If the string breaks, the stone does not remain orbiting you in a circular path, it goes off in a straight line. To keep it in a circular path the string has to keep pulling on the stone.

Now, suppose the stone is travelling all the way around you once per second. What happens if you increase the length of the string, but keep the stone travelling all the way round you once per second? As the string gets longer, the amount of pull needed to keep the stone in a circular path at one revolution per second increases. Eventually you get to the point where the string isn't strong enough to handle that much pull and it breaks.

The same thing would happen with your rod - long before you got anywhere near the speeds and lengths you are talking about, the force necessary to keep any given section of the rod travelling in its circular path would reach the point where the rod was no longer strong enough to take the strain, and the whole rod would tear itself to pieces.

In addition, you have to think about where the energy and momentum come from to make something revolve that fast. Think about an ice-skater who is spinning quickly with his arms by his sides and then stretches out his arms: he spins more slowly. In order to make him spin just as quickly with his arms stretched out something has to actively speed up his rate of spin - something has to put more energy into the system. Even if you had an infinitely strong rod, as you extended it out from the Earth, if there were no additional means of propulsion, the rotation of the Earth would simply get slower and slower, just like the skater.


RE: Why would this not work...
By FITCamaro on 8/17/2007 8:09:26 AM , Rating: 2
quote:
If the string breaks, the stone does not remain orbiting you in a circular path, it goes off in a straight line.


Unless you're really fat and have your own gravitational pull. :)


RE: Why would this not work...
By BeastieBoy on 8/24/2007 6:20:12 AM , Rating: 2
That made me laugh.
Come on mods, surely this is worth a 6.


RE: Why would this not work...
By timmiser on 8/20/2007 1:17:30 AM , Rating: 2
Thanks for the explanation however your examples seem to be based on the reasons for not breaking the speed of light is because of the power required to rotate the rod and the strength of the rod. The way I interpret your explanation is that we don't have the power to turn the rod fast enough AND we don't have a rod strong enough to exceed the speed of light but for the sake of the theory, let's say we have the power AND we have the techology in rod strength to do it.


RE: Why would this not work...
By masher2 (blog) on 8/17/2007 8:00:59 AM , Rating: 4
> "...so didn't the end of that pipe just travel the distance of 2 light years in 12 hours time?? "

The past explanations why this wouldn't work are incorrect. NRB was close...but you did specify that the pipe "be strong enough" to withstand the force of the rotation. So lets assume it is.

But even in this case, it doesn't work. Why? Because a pipe is just a string of atoms. To turn the pipe, you apply a force at one end. That force has to travel to the other end via a mechanical wave. The speed of that wave is limited by the speed of light. So even if your pipe *was* strong enough to withstand the force without breaking, it would have to 'bend' as it rotated.

12 hours later, the near end of the pipe would be on the other side of the earth...but the force rotating the pipe wouldn't have even reached the far end yet. The pipe would now be twisted like a corkscrew....and twisted worse, the longer the rotation went on, as it could never catch up.


RE: Why would this not work...
By Ringold on 8/17/2007 5:34:23 PM , Rating: 2
So, looking up in the sky, you'd see within a day a pole wrapping around the Earth, yes?

Additionally, a situation could exist where two stars, for example, are heading towards each other at a speed faster than light as it would appear to a third party observer, but observers at those two stars would just never know it themselves? (Ex: seeing two stars converging on the third observer from opposite directions at, say, .6c)

At least, of course, until they collided.


RE: Why would this not work...
By Jedi2155 on 8/17/2007 7:20:47 PM , Rating: 2
quote:
So, looking up in the sky, you'd see within a day a pole wrapping around the Earth, yes?


Actually, if I understand it correctly, no.

What you would actually see is the straight rod, but since the information of location of the rod travels to you at the speed light of light, it would always appear straight as the farthest you could see would be the point at which the rod is being moved.

However, say you were from another perspective at least a light year away, you could see the effect of the bending rod as the forces are applied to the rest of the rod.


RE: Why would this not work...
By jamesmk on 8/17/2007 8:04:50 PM , Rating: 2
I was gratified to read that my assumption appeared to be basically correct:

Assuming that:
1) The rod was strong enough to not break.
2) The rod was also rigid enough to not bend.
3) The rod was connected to the earth in a manner that would not bend or break, or cause the earth to break up or slosh around or anything.

As the far end of the pole approached the speed of light that the energy required to move it would approach infinity.

In other words, given my 3 above assumptions: The rotation of the earth would stop, regardless of the amount of energy applied, as the end of the rod approached c . Correct?

But this raises a couple of other questions in my mind: Doesn't "strong enough" in reality translate into "infinite strength"? Also, "rigid enough" seems it would translate into "infinitely rigid".

Now maybe it's just because I never did take physics, but every explanation I've ever heard has stopped at "as speed approaches c, mass approaches infinity, and so energy requirements approach infinity".

I've never heard any discussion or supposition about what happens when infinite energy is applied. I've always assumed that this was because infinite energy is something that cannot be achieved, thus has no (real) meaning. But if other imaginary traits can tell us something about reality, why not infinite energy?

Hmmm...

I started to write something about the 'wave' effect having to reach the far end of the pole before it could start rotating, but in the case of an infinitely rigid pole, what would be the 'wave'? Normally it would be a slight physical flexing, but in the case of an infinitely rigid object, how is the energy carried to the far end? It doesn’t seem right to say that it cannot rotate.


RE: Why would this not work...
By 3kliksphilip on 8/17/2007 8:05:31 AM , Rating: 2
I'll try and explain it as simply as possible. From what I've learned from interrogating my Physics teacher is that although the pipe may have rotated at the Earth's end, the other end wouldn't have moved because there's a 'wave' effect at the speed of light. Think of it as a group of people in a long line, prodding the next person when the person behind them prods them. Or as a line of dominoes.

I still want to know how E = mc² proves that the speed of light equates to infinite mass! Please someone, help me- why aren't light waves crushing me?


RE: Why would this not work...
By masher2 (blog) on 8/17/2007 8:29:19 AM , Rating: 2
> "I still want to know how E = mc² proves that the speed of light equates to infinite mass! Please someone, help me- why aren't light waves crushing me"

It's pretty simple really. Precisely, the speed of light equates to an "infinite multiplier" to the moving object's rest mass.

Photons have no rest mass, thus zero * infinity still equals zero.


RE: Why would this not work...
By Zirconium on 8/17/2007 9:28:51 AM , Rating: 2
Maybe I'm misunderstanding you, but what you are saying doesn't sound right. You are correct in saying that photons have no mass. However, the rest of what you say is false.

The speed of light isn't an "infinite multiplier." E = mc² doesn't show that the speed of light equates to infinite mass. There are other equations that you can derive (along the same lines as E = mc²) that show that as you approach the speed of light (to an observer), your mass increases (to that observer).

Secondly, the "zero * infinity still equals zero" comment. Mass * speed is momentum. Photons have momentum, but no mass (hence the viability of solar sails). And photons can carry energy, also in the absence of mass.

Finally, what E = mc² shows is that mass and energy are the same thing, and that you can convert between the different forms (i.e. if I were to take 1 kilogram of anything, and convert it to energy without losing any to entropy, I'd have about 9*10^16 Joules of energy). In reality though, what it is saying is that 1 kilogram is 9*10^16 Joules of energy.


By theapparition on 8/17/2007 10:15:01 AM , Rating: 2
quote:
Finally, what E = mc² shows is that mass and energy are the same thing

Exactly correct. Most people see E = mc² and think that's relativity. That's the formulae for bodies at rest.

The real relativistic equation is E=mc²/sqrt(1-v²/c²)

As your velocity increases sqrt(1-v²/c²) approaches 0, so mass and energy must appoach infinity.


RE: Why would this not work...
By masher2 (blog) on 8/17/2007 11:12:46 AM , Rating: 2
> "The speed of light isn't an "infinite multiplier"

More precisely, a velocity of the speed of light equates to an infinite multiplier (the Lorentz factor).

> "In reality though, what it is saying is that 1 kilogram is 9*10^16 Joules of energy"

Not really. If this were true, we wouldn't need fusion reactors and atomic bombs to convert mass into energy. What E = mc² really means has to be said in equations, not words, but more precisely, it implies the conservation of the "mass-energy" of a system. In a closed system, if the energy content increases, the mass must decrease, and vice versa...and the "exchange rate" between the two is given by E = mc².

> "the "zero * infinity still equals zero" comment. Mass * speed is momentum. Photons have momentum, but no mass..."

For a photon, its momentum is defined by its wavelength, or equivalently, by its total energy. This is true for objects with rest mass also. Motion at the speed of light equates to infinite energy (rest energy (mass) plus kinetic energy). Infinite energy corresponds to infinite mass.


RE: Why would this not work...
By Durrr on 8/17/2007 11:36:18 AM , Rating: 2
if you want to learn more about this effect, you can read about "mass defect" with regards to nuclear fission.


RE: Why would this not work...
By stromgald on 8/17/2007 12:41:10 PM , Rating: 2
Good explanations throughout. If I could up your post ratings, I would, but I've already replied earlier. It's good to know someone here has a good grasp of the whole quantum and relativistic phsyics stuff.

I had a pretty good grasp about 6 years ago when I was still in school, but now it would probably take me an hour to think through and create responses similar to yours.


RE: Why would this not work...
By maroon1 on 8/18/2007 8:10:00 AM , Rating: 2
quote:
Photons have momentum, but no mass (hence the viability of solar sails). And photons can carry energy, also in the absence of mass.


If photons don't have mass then how can a strong gravity like black hole pull photons ?

So, I think photons have a mass but it is negligible


RE: Why would this not work...
By 3kliksphilip on 8/19/2007 10:48:05 AM , Rating: 2
I heard that things with out mass don't exist. I think it was something to do with looking for ghosts and stuff. Never mind, I'm happy with my B in A-level Physics.


RE: Why would this not work...
By masher2 (blog) on 8/21/2007 9:05:16 AM , Rating: 2
quote:
"If photons don't have mass then how can a strong gravity like black hole pull photons ?

So, I think photons have a mass but it is negligible
A black hole doesn't attract photons through gravity. Its gravity distorts space itself, and that warp causes photons to change their path.


RE: Why would this not work...
By Kuroyama on 8/20/2007 12:41:01 AM , Rating: 2
quote:
zero * infinity still equals zero

Eh? For y=0 and fixed constant C not equal to zero,

0*infinity = y*(C/y) = (y/y)*C = C

and so 0*infinity = C for whatever constant you like.

Of course, I am secretly taking a limit here, and in physics the terms in the limit usually do evaluate to 0*infinity=0.


RE: Why would this not work...
By NilkanthP on 8/17/2007 9:19:25 AM , Rating: 3
why can't it happen?
By Kode on 8/17/2007 6:24:33 AM , Rating: 2
I never understood why people always say that when going faster then the speed of light, you go back in time. It makes no sense to me. The only thing that could possibly be, is that you can see in the past. I know it has to do with a theory(relativity?).

I understand that the speed of light is seen as the maximum speed an atom can have, but I fail to understand something. Perhaps somebody can enlighten me?:

Aren't there fluctuations in the speed light can have? And, isn't there a difference in speed of light from different stars or light sources?

I know that light should be under influence from gravity(Einstein's law E = mc2), but does it have any effect on speed? (couldn't find anything decent on google)




RE: why can't it happen?
By FITCamaro on 8/17/2007 8:12:19 AM , Rating: 2
Gravity does affect light. Hence a black hole. Its "black" because its gravitational pull is so strong that nothing escapes, even light. Thats why they're still largely a mystery. We can't see them.


RE: why can't it happen?
By NullSubroutine on 8/20/2007 3:12:28 PM , Rating: 2
The speed of light is constant in reference of space-time. Black holes do not effect light via gravity as gravity only effects mass (in the sense you understand). Black holes such immense mass that the gravitational pull effects the space-time around the black hole.

Think of it as light is equal to someone running. They can only go say, 20MPH. However, this 20MPH is based on a stationary surface aka, the ground. Now, if you place a person on a treadmill they can run 20MPH in reference to moving treadmill belt but in reference to anyone observing this would see that he is going 0MPH in reference to the ground.

The black hole does not pull light, as I said above, it has no mass. It pulls and bends space-time around the black hole, in the above example it is though the black hole is pulling the entire ground as if it were the belt on the treadmill.


RE: why can't it happen?
By masher2 (blog) on 8/17/2007 8:24:46 AM , Rating: 2
> "The only thing that could possibly be, is that you can see in the past."

If you can travel faster than light, then not only can you "see" into the past, but you can send information there as well. Sending a note to your mother to request she not conceive you is not only unwise, it violates causuality-- the principle that "cause" always precedes "effect". And that is the real reason for the speed-of-light limitation.

As to exactly why FTL travel equates to time travel, its a bit confusing to explain without drawing s a light cone diagram. But the simple explanation is that, under relativity, two observers separated in space can never agree on the order of events. Say you see a bright pulse from a star 5 light-years way, and simultaneously make a pulse of your own. To you, both pulses happened at the same time. To the observer on the other star, his pulse occurred several 10 years before yours. If you can send information faster than light, then its possible to setup a case by which you can see his pulse, then send him a message about it that he receives, in his reference frame, before he sent it.

In this case, the effect (the msg about the pulse) precedes the cause (the pulse itself). Thats equivalent to time travel.


RE: why can't it happen?
By FITCamaro on 8/17/2007 9:52:24 AM , Rating: 2
I'd like to set up the case where I send my parents a message and tell them not to sell my dads 71 Chevelle he had.


RE: why can't it happen?
By theapparition on 8/17/2007 10:03:55 AM , Rating: 2
quote:
In this case, the effect (the msg about the pulse) precedes the cause (the pulse itself). Thats equivalent to time travel.

Not entirely true. Say it was possible to travel at the speed of light (hypothetical spaceship). As you start accelerating to your desination, you notice that it takes time to get there. As you approach lightspeed, that time diminishes. At lightspeed, there is no time anymore and you can reach any destination in the universe instantly (From your point of view on the lightspeed craft). However, from an observers point of view, its still taking a finite time to transverse that distance (d/c). This also gives rise to the theory that if you travel FTL, you go back in time. Care must be made to consider POV, though. Even at FTL travel, it still takes finite time to span distances.

So in your example, a response message sent at 5 times the speed of light would still take 1 year to transverse that distance, so the response pulse would be received 6years after the original. Not before the original was sent. But if you were a light creature on that response message, your POV would be to arrive at your destination before you were even sent.

Can go nuts thinking about this, and there are many paradoxes (exactly why everything is theory). But the distance limitatation is exactly why thought experiments like "tachyeon duels" are flawed.


RE: why can't it happen?
By masher2 (blog) on 8/17/2007 11:17:15 AM , Rating: 2
> "so the response pulse would be received 6years after the original. Not before the original was sent"

No. Superluminal travel implies causality violation for all observers. It's not just a phenomenom of your point of view.

As I said earlier, its extremely difficult to visualize it without drawing light cones. If you google one of the many references online and examine the diagrams, you'll see why this is so.


RE: why can't it happen?
By jamesmk on 8/17/2007 8:28:50 PM , Rating: 2
quote:
Superluminal travel implies causality violation for all observers. It's not just a phenomenom of your point of view.

So, as an intergalactic trader, I couldn't find out that nuts had suddenly dropped at a nearby star, jump into my FTL ship and fly there, buy the stuff, and fly back to sell them for a profit, because:

I'd arrive at the star before the prices fell.

The good news is that I got home, I could tell myself about the paradox before I left.

But if I didn't ever pay attention to myself, wouldn't I destroy my planet with an infinate number of myself comming back from the star?

Nice.

So basicly you couldn't hold an FTL conversation with anyone because each responce would arrive before the 'last'?


RE: why can't it happen?
By NaughtyGeek on 8/17/2007 11:50:35 AM