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Possible neutrinos travel faster than light


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#21 dysphoric   Members   -  Reputation: 148

Posted 26 September 2011 - 11:02 AM

One way to visualise how light is affected by gravity, imagine space time is like a flow of a tide or a medium and you are trying to go against it. At some point the tide is going to so fast that you can not counter it at your maximum speed, therefore you are swept with it... into a black hole.



Black holes are not the only things to effect the speed of light. Explain this.

http://abcnews.go.com/Technology/story?id=99111&page=1

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#22 ligh   Members   -  Reputation: 477

Posted 26 September 2011 - 11:10 AM

I'm putting my money on a fluctuation on the space-time plane and for that specific moment, the emitter and the detector were 60 feet closer to each other. No laws broken.

#23 ligh   Members   -  Reputation: 477

Posted 26 September 2011 - 11:12 AM


One way to visualise how light is affected by gravity, imagine space time is like a flow of a tide or a medium and you are trying to go against it. At some point the tide is going to so fast that you can not counter it at your maximum speed, therefore you are swept with it... into a black hole.



Black holes are not the only things to effect the speed of light. Explain this.

http://abcnews.go.co...id=99111&page=1


The speed of light changes depending on medium. It travels fastest in a vacuum. Its nothing new. Its like trying to get to the front of the mosh pit, to many particles to interact with




#24 Eelco   Members   -  Reputation: 301

Posted 26 September 2011 - 01:01 PM


snip


What are you talking about the theory of relatively does talk about time and therefore time travel. According to the theory of relatively the faster something travels the slower time passes for that object. Also the higher the gravity around an object the slower time passes for it. Therefore if you travel faster than the speed of light, according to the equation, you would go backwards in time. The notion of time travel was originally proposed by scientist studying relatively, not science fiction writers.


O RLLY?

Indeed, more velocity means slower passing of time; but clearly the geometry of the equation doesnt allow for the extrapolation you posit here, since time dilation as a function of v isnt even differentiable at v==c; it has an infinite slope. The correct extrapolation of ever more velocity isnt into negative time; the correct extrapolation is that the function doesnt extend into the v>c domain at all cause it completely curves away from that domain and doesnt point toward it at all.

Try and plug v > c into the formula for time dilation; you dont get a negative number as your naive extrapolation would have, but an imaginary one. An imaginary flow of time... indeed a concept more apt for science fiction writers than scientists. (or perhaps scientists looking to pry funding loose from people who never looked at the math themselves)

#25 Discount_Flunky   Members   -  Reputation: 102

Posted 26 September 2011 - 04:28 PM



snip


What are you talking about the theory of relatively does talk about time and therefore time travel. According to the theory of relatively the faster something travels the slower time passes for that object. Also the higher the gravity around an object the slower time passes for it. Therefore if you travel faster than the speed of light, according to the equation, you would go backwards in time. The notion of time travel was originally proposed by scientist studying relatively, not science fiction writers.


O RLLY?

Indeed, more velocity means slower passing of time; but clearly the geometry of the equation doesnt allow for the extrapolation you posit here, since time dilation as a function of v isnt even differentiable at v==c; it has an infinite slope. The correct extrapolation of ever more velocity isnt into negative time; the correct extrapolation is that the function doesnt extend into the v>c domain at all cause it completely curves away from that domain and doesnt point toward it at all.

Try and plug v > c into the formula for time dilation; you dont get a negative number as your naive extrapolation would have, but an imaginary one. An imaginary flow of time... indeed a concept more apt for science fiction writers than scientists. (or perhaps scientists looking to pry funding loose from people who never looked at the math themselves)


When you put v = c you get 0 which means times stops for the object. The thing is though that getting anything to go the speed of light that has mass takes infinite energy, because things also get more massive the faster they go. According to the equation mass is infinite at the speed of light therefore the energy needed to go faster then the speed of light is impossible to reach. That is way the possibility of Neutrioes going faster then light is so freaky, because that implies that there is a loop hole in relativity.

When most scientist speak of time travel mostly they speak of using something like a black hole's gravity field to make yourself live way longer then you normally would so that you can see the future. The only way to got to the past would be a worm hole, and those haven't been proven yet. Also you could only go back to the time that the worm hole was created.

Edit: Also just because something sounds far fetched it doesn't mean it's form or should only be mentioned in science fiction. There's a lot crazy science out there. For instance many scientists are starting to find proof that humans have a sixth sense.

#26 phantom   Moderators   -  Reputation: 6785

Posted 26 September 2011 - 05:07 PM

it might be an interesting dabble into science fiction to open another topic and try and fantasize what the arrow of time actually is and why we perceive it the way we do. Because I don't believe anyone really has an idea.


I was under the impression that the 'arrow of time' was simply entropic decay, leading the universe to move from one state to another (order to disorder if memory serves). So given two space-time reference points one in the past (A) and one in the future (B) to go from B to A would require that you could get back to the state the universe was in at point A, which I'm pretty sure is covered as a 'no go' in at least one 'law' (Thermodynamics springs to mind, but dont' quote me, I'm going on half remembered stuff). Or to put it another way; at 4:08pm I break an egg, any attempts at time travel to 4:07pm would require going back to a point where the egg was no longer broken.

IF this is proven correct and IF we can make use of it the only real use I can see is FTL communication. Now, with respect to light speed this is a form of time travel, in that information could make it from one location to another before light (to use the sci-fi example you'll be able to see the enemy fire his laser slightly before it starts trying to remove your hull) but it only remains 'time travel' in that sense.

To give a poor example;
Two space ships are 5 light seconds apart with clocks which are syncronised; at 10seconds past the minute space ship one fires a laser beam at spaceship two, 15 second past the minute space ship two is hit, 20 seconds past the minute spaceship one sees the hit.

With FTL vision when spaceship one fires spaceship two might see the beam coming at 13 seconds past the minute but he still didn't see the event before it happened. Spaceship one would see the 'hit' at 18 seconds past the minute as the event didn't happen until 15seconds past the minute.

The only way this could result in time travel is if Spaceship two saw the laser coming BEFORE 10 seconds past the minute, in other words before the event happened.

So, in short; while I'm no top physicist I'm pretty sure that we are safe from time traveling robots from the future bent on trying to kill people named Connor for a while yet ;)

#27 phantom   Moderators   -  Reputation: 6785

Posted 26 September 2011 - 05:09 PM

For instance many scientists are starting to find proof that humans have a sixth sense.


Can has links?

#28 Discount_Flunky   Members   -  Reputation: 102

Posted 26 September 2011 - 05:52 PM


For instance many scientists are starting to find proof that humans have a sixth sense.


Can has links?


http://noosphere.princeton.edu/

http://en.wikipedia.org/wiki/Rupert_Sheldrake

These are some I could find. It's really hard to get links about scientific developments when you don't know the name of the experiment or the names of the scientist evolved

#29 Prefect   Members   -  Reputation: 373

Posted 26 September 2011 - 11:38 PM

I don't think this has been pointed out before: the observation of the 1987a supernova suggests very strongly that neutrinos travel at exactly the speed of light to very large precision. So this new observation should be taken with a lot of salt.
http://scienceblogs....claim_requi.php
Widelands - laid back, free software strategy

#30 irreversible   Crossbones+   -  Reputation: 1196

Posted 27 September 2011 - 12:25 AM


it might be an interesting dabble into science fiction to open another topic and try and fantasize what the arrow of time actually is and why we perceive it the way we do. Because I don't believe anyone really has an idea.


I was under the impression that the 'arrow of time' was simply entropic decay, leading the universe to move from one state to another (order to disorder if memory serves). So given two space-time reference points one in the past (A) and one in the future (B) to go from B to A would require that you could get back to the state the universe was in at point A, which I'm pretty sure is covered as a 'no go' in at least one 'law' (Thermodynamics springs to mind, but dont' quote me, I'm going on half remembered stuff). Or to put it another way; at 4:08pm I break an egg, any attempts at time travel to 4:07pm would require going back to a point where the egg was no longer broken.


This really is an interesting topic and my post will quickly spiral out of control, but that's only because there's no real answer to this question.

First off, allow me to make a small correction to the terminology you used: since entropy is a measure of disorder and the universe started out in a state of almost perfect order, then entropy is necessarily growing, not decaying :). But that's that.


Strangely enough entropic growth cannot be proven to be the cause of the arrow of time as it would actually create a causal loop: entropy cannot grow without time. Unless your example regarding the broken egg is a coincidence, it seems you're familiar with Brian Greene's The Fabric Of Cosmos (if you're not, then he discusses the arrow of time very thoroughly - it's quite an exhilarating read). While his argumentation largely explains that since pretty much all of physics (with the exception of some negligible effects from the weak force) is time-invariant (in other words the laws of physics do not forbid time to run in reverse, causing the egg to unshatter), there is no apparent reason for entropy to grow.

It might seem logical that a uniform mist of particles that contains impurities has the potential for entropic growth, but that doesn't quite explain why a) the universe couldn't be experiencing decreasing entropy instead (actually the answer to this would be negative gravity and the reversal of all other forces in nature) and b) why the two would be linked (at this time the cyclic universe is no longer considered a viable option due to its rate of expansion, but a cyclic universe would actually have required the reversal of time to achieve the big crunch). A better answer could be to interpret time as a potential of entropic growth, but again there's no proof of this anywhere other than the fact that the properties of forces cause it to go down this route.

Consider another example that stems from the bubble multiverse theory: "infinite time on the outside equals infinite space on the inside" (this is why a bubble universe might seem infinite on the inside, but is finite on the outside). This in turn brings up two problems to which there are currently no solutions: a) (our) mathematics doesn't have a branch that can reliably handle infinities meaning that we cannot explain how something that has no beginning and no end can flow from one to the and b) and logically, if an increase in entropy is a causal property (not a side effect) of time and there's a finite amount of matter/energy (either in the universe or the multiverse), then at one point you'll still reach the Russian doll situation where you need to explain the starting state of the universe/multiverse and will eventually run out of time as entropy reaches a maximum.

This is all bollocks, though as the ugly truth behind it is that time is a quality/dimension/phenomenon/river we simply do not understand.

As a small thinking exercise consider a simulated universe (khm, a computer game) where, at each iteration, you increase all values by a certain (fixed) amount. This amount doesn't even need to be based on time in our universe - it just happens at every iteration. This means that to the characters in the game time would seem to be flowing at a constant rate. The questions to answer are:

1) why are you increasing (not decreasing or randomizing) all the values at each iteration?
2) would your game character ever hope to understand your nature or your motives?
3) this one is also from Brian Greene: can you yourself imagine a universe without space and time?

#31 Eelco   Members   -  Reputation: 301

Posted 27 September 2011 - 12:34 AM




snip


What are you talking about the theory of relatively does talk about time and therefore time travel. According to the theory of relatively the faster something travels the slower time passes for that object. Also the higher the gravity around an object the slower time passes for it. Therefore if you travel faster than the speed of light, according to the equation, you would go backwards in time. The notion of time travel was originally proposed by scientist studying relatively, not science fiction writers.


O RLLY?

Indeed, more velocity means slower passing of time; but clearly the geometry of the equation doesnt allow for the extrapolation you posit here, since time dilation as a function of v isnt even differentiable at v==c; it has an infinite slope. The correct extrapolation of ever more velocity isnt into negative time; the correct extrapolation is that the function doesnt extend into the v>c domain at all cause it completely curves away from that domain and doesnt point toward it at all.

Try and plug v > c into the formula for time dilation; you dont get a negative number as your naive extrapolation would have, but an imaginary one. An imaginary flow of time... indeed a concept more apt for science fiction writers than scientists. (or perhaps scientists looking to pry funding loose from people who never looked at the math themselves)


When you put v = c you get 0 which means times stops for the object. The thing is though that getting anything to go the speed of light that has mass takes infinite energy, because things also get more massive the faster they go. According to the equation mass is infinite at the speed of light therefore the energy needed to go faster then the speed of light is impossible to reach. That is way the possibility of Neutrioes going faster then light is so freaky, because that implies that there is a loop hole in relativity.

Light doesnt have a special role in relativity per se. If the neutrinos would go faster than the 'maximum' speed posited by relativity, yes, that would be freaky. Going faster than light should more likely be taken as light not reaching that maximum.

When most scientist speak of time travel mostly they speak of using something like a black hole's gravity field to make yourself live way longer then you normally would so that you can see the future.

Sure, thats perfectly valid, but im not sure id call it time travel.

The only way to got to the past would be a worm hole, and those haven't been proven yet. Also you could only go back to the time that the worm hole was created.

Not only have they 'not been proven yet', 'they' are complete theoretical speculation; and not even theoretically sound. Nontrivial space topologies are entirely logically sound notions, but have never been observed; and to extrapolate from that to nontrivial spacetime topologies is just to assume time travel could exist using fancy words; without doing anything to solve the logical contradictions inherent in the notion, by the way.


Edit: Also just because something sounds far fetched it doesn't mean it's form or should only be mentioned in science fiction. There's a lot crazy science out there. For instance many scientists are starting to find proof that humans have a sixth sense.

Yes, absence of proof is not proof of absence; but thats truely the only thing time travel has going for it. There are no hints or clues it could be possible in our current understanding at all; all people have done is tried to explore what would happen if you forced it into existing theoretical frameworks; and invariably ran into complete nonsense rather than an interesting new experiment to perform.

#32 Eelco   Members   -  Reputation: 301

Posted 27 September 2011 - 12:43 AM

I don't think this has been pointed out before: the observation of the 1987a supernova suggests very strongly that neutrinos travel at exactly the speed of light to very large precision. So this new observation should be taken with a lot of salt.
http://scienceblogs....claim_requi.php


Well; the neutrinos did in fact come three hours earlier; a fact that we managed to rationalize by our model of how light escapes from the core; but then again, how much do we really know about that? Three hours is still very small relative to the OPERA findings, but to use the word 'exactly' seems unwarranted; I think there is a large margin of error here.

Besides, the neutrinos from OPERA are far higher energy, and the particles from the supernova have been moving through a medium which is rather different from our terrestial one, which might matter in some yet to be determined way.

That said, this is the main reason that makes me suspect that what we are to get from all this is a more accurate GPS system, not new physics.

#33 Discount_Flunky   Members   -  Reputation: 102

Posted 27 September 2011 - 02:37 AM

@Eelco

You talk to me like I'm a third grade boy vainly hoping that time travels exists so I can go back and see Charlemagne or something. Many high profile scientist have put there entire careers into the theory of time travel. It IS A POSSIBILITY using today concepts of science. It's it partially feasible? I really doubt it, but it is theoretically possible. If you aren't read up on the latest theories of time travel then you can't really call yourself a science fan. The truth is stranger then fiction, that's a fact that has been proven time and time again. There are scientist who state that you can create a new universe using giant lasers for crying out loud. Science fiction has nothing on real science.

#34 Lauris Kaplinski   Members   -  Reputation: 841

Posted 27 September 2011 - 03:51 AM

IF this is proven correct and IF we can make use of it the only real use I can see is FTL communication. Now, with respect to light speed this is a form of time travel, in that information could make it from one location to another before light (to use the sci-fi example you'll be able to see the enemy fire his laser slightly before it starts trying to remove your hull) but it only remains 'time travel' in that sense.

I think it is quite well established, that there is no actual difference between "communication" and "effect". Thus if any information can be transmitted FTL, true time travel is also (theoretically) possible.

This also would make type 2 perpetum mobile possible, as you could use the information abut future state to influence current state, thus always choosing the state, that will result in minimal future enthropy.
Lauris Kaplinski

First technology demo of my game Shinya is out: http://lauris.kaplinski.com/shinya
Khayyam 3D - a freeware poser and scene builder application: http://khayyam.kaplinski.com/

#35 Hodgman   Moderators   -  Reputation: 27466

Posted 27 September 2011 - 03:55 AM

Science fiction has nothing on real science.

Seeing that the purpose of science fiction is to explore via literature the consequence of invention, it shouldn't.


#36 Lauris Kaplinski   Members   -  Reputation: 841

Posted 27 September 2011 - 03:58 AM



snip


What are you talking about the theory of relatively does talk about time and therefore time travel. According to the theory of relatively the faster something travels the slower time passes for that object. Also the higher the gravity around an object the slower time passes for it. Therefore if you travel faster than the speed of light, according to the equation, you would go backwards in time. The notion of time travel was originally proposed by scientist studying relatively, not science fiction writers.

O RLLY?

Indeed, more velocity means slower passing of time; but clearly the geometry of the equation doesnt allow for the extrapolation you posit here, since time dilation as a function of v isnt even differentiable at v==c; it has an infinite slope. The correct extrapolation of ever more velocity isnt into negative time; the correct extrapolation is that the function doesnt extend into the v>c domain at all cause it completely curves away from that domain and doesnt point toward it at all.

FTL travel indeed would make traveling backwards in time possible, but not because of some naive interpolation of equations.


According to the theory of relativity, if two space-time points A & B are separated by space-like distance (i.e. light cannot travel from A to B before B takes place and vice versa), the time-order of those events is not definable. I.e. there are always some reference frames, where A happens before B and some where B happens before A.

Now, if somehow something travels from A to B FTL and reaches the spatial location of B "at or before" B takes place, then in those reference frames where B takes place BEFORE A, it has traveled backwards in time.


Lauris Kaplinski

First technology demo of my game Shinya is out: http://lauris.kaplinski.com/shinya
Khayyam 3D - a freeware poser and scene builder application: http://khayyam.kaplinski.com/

#37 Eelco   Members   -  Reputation: 301

Posted 27 September 2011 - 07:23 AM




snip


What are you talking about the theory of relatively does talk about time and therefore time travel. According to the theory of relatively the faster something travels the slower time passes for that object. Also the higher the gravity around an object the slower time passes for it. Therefore if you travel faster than the speed of light, according to the equation, you would go backwards in time. The notion of time travel was originally proposed by scientist studying relatively, not science fiction writers.

O RLLY?

Indeed, more velocity means slower passing of time; but clearly the geometry of the equation doesnt allow for the extrapolation you posit here, since time dilation as a function of v isnt even differentiable at v==c; it has an infinite slope. The correct extrapolation of ever more velocity isnt into negative time; the correct extrapolation is that the function doesnt extend into the v>c domain at all cause it completely curves away from that domain and doesnt point toward it at all.

FTL travel indeed would make traveling backwards in time possible, but not because of some naive interpolation of equations.


According to the theory of relativity, if two space-time points A & B are separated by space-like distance (i.e. light cannot travel from A to B before B takes place and vice versa), the time-order of those events is not definable. I.e. there are always some reference frames, where A happens before B and some where B happens before A.

Now, if somehow something travels from A to B FTL and reaches the spatial location of B "at or before" B takes place, then in those reference frames where B takes place BEFORE A, it has traveled backwards in time.

What do you mean, 'has travelled backwards in time'? Indeed, faster than light travel would play funny tricks with our perceptions of causality, but not with causality itself. Yes, if you go faster than light, people get to see your present state before ever getting to see your past states. You can do essentially the same thing with a good old mirror.


Of course these mere perceptions tell us nothing about the interesting question, as to how such a superluminal actor would experience time; how fast or in what manner his elementary particles would jiggle relative to eachother. He isnt going to kill his great gandfather, thats for sure, and as for what would happen to himself, our theory is entirely silent on the matter, unless you can give an interpretation to the passing of imaginary time.

#38 Lauris Kaplinski   Members   -  Reputation: 841

Posted 27 September 2011 - 07:42 AM


FTL travel indeed would make traveling backwards in time possible, but not because of some naive interpolation of equations.

According to the theory of relativity, if two space-time points A & B are separated by space-like distance (i.e. light cannot travel from A to B before B takes place and vice versa), the time-order of those events is not definable. I.e. there are always some reference frames, where A happens before B and some where B happens before A.

Now, if somehow something travels from A to B FTL and reaches the spatial location of B "at or before" B takes place, then in those reference frames where B takes place BEFORE A, it has traveled backwards in time.

What do you mean, 'has travelled backwards in time'? Indeed, faster than light travel would play funny tricks with our perceptions of causality, but not with causality itself. Yes, if you go faster than light, people get to see your present state before ever getting to see your past states. You can do essentially the same thing with a good old mirror.

According to the theory of relativity there is NO preferred reference frame - thus the descriptions of reality from all inertial reference frames are equally true.
As I gave in above example - for space-like events in space-time there are no fixed (true) order of precedence. If events A and B are separated by space-like distance, then always for some inertial reference frame (let's call it frameX) event A happens before event B, for some other frame (let's call it frameY) event B happens before event A (and, of course for some frames they are synchronous). And all these descriptions are equally true descriptions of the Universe.

Now, if signal reaches from A to the spatial location of B before ot at the time B takes place, then viewing the situation from reference frame Y:

  • Signal reached from A to (the spatial location of) B before B took place
  • B happened BEFORE A
Thus signal travelled backwards in time.
Lauris Kaplinski

First technology demo of my game Shinya is out: http://lauris.kaplinski.com/shinya
Khayyam 3D - a freeware poser and scene builder application: http://khayyam.kaplinski.com/

#39 Antheus   Members   -  Reputation: 2393

Posted 27 September 2011 - 08:15 AM

For instance many scientists are starting to find proof that humans have a sixth sense.


Humans are painfully predictable and creatures of habit. Google and Facebook are mining all this data to run their own "sixth sense". Gather enough data and you can tell, with 95% confidence what the person will do. "Enough" in this case means web activity. Visa has been able to predict many decisions people make solely from purchasing history for many years now.

Human brain works through pattern matching, much of it is subconscious. While called sixth sense, it's nothing more than learned experience.

In the end, there is nothing mystical about it. Like weather. Gather enough inputs, fit them through some statistical model and you end up with a good enough prediction for next few days. Biggest change in recent years is the availability of computing power and number of sensors. Both have advanced sufficiently to the point where individuals' actions can be predicted in same way as weather.

And over long term, it does mean pre-crime becomes viable. Not through paranormal activity, but through simple math operating on vast amounts of data. Retail will also change. So will jobs. Linkedin has been promising this for a while, but we aren't there yet. Generations born today however will be providing sufficient records through entire life through which the models will be built, and eventually used for their successors. All big companies are using such models already and have been for a while. Not with breakthrough success, but sofficient to notice various trends.

#40 Eelco   Members   -  Reputation: 301

Posted 27 September 2011 - 09:10 AM

According to the theory of relativity there is NO preferred reference frame

You mean that theory you intend to throw out of the window by positing a faster-than-fastest object?


...And all these descriptions are equally true descriptions of the Universe.

Assuming the axioms of relativity hold, yes. Little surprise one can derive a contradiction from inconsistenly applying ones axioms.





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