Billy. Posted November 21, 2011 Report Share Posted November 21, 2011 (edited) How can you go back in time only as an observer, surely if you go back in time you can affect the time you are then in ? Also, if history was different than we have known it to be, then there is no memory of how it was, only how it now is,even for those who lived through it, multiverse is too complex but is a useful construct. Maybe therefore Einsteins theory is much more likely as its more sensible and the neutrino did 'flip out'? I love the idea that we are living one bit of a parallel universe. In another, I'm in my mansion full of blonde nymphomaniacs. This is what you need Edited November 21, 2011 by Billy. Quote Link to comment Share on other sites More sharing options...
chockmoose Posted November 22, 2011 Report Share Posted November 22, 2011 Too true. One problem with time travel that nobody has mentioned is Heisenberg's uncertainty principal, even going back in time as an observer will alter, albeit a tiny amount, the future. By the way, particles can have energy without mass - photons for example. The Heisenberg uncertainty principle relates to accuracy of measurement at the quantum level, sweet fa to do with time travel, probably the reason why no one mentioned it. Quote Link to comment Share on other sites More sharing options...
BenBhoy Posted November 22, 2011 Report Share Posted November 22, 2011 i'll ask my soon to be brother in law - he works at CERN. Quote Link to comment Share on other sites More sharing options...
FalconFN Posted November 22, 2011 Report Share Posted November 22, 2011 The Heisenberg uncertainty principle relates to accuracy of measurement at the quantum level, sweet fa to do with time travel, probably the reason why no one mentioned it. Yes, but as every tiny interaction between atomic and subatomic particles alters their properties (position, direction and energy etc), then it stands to reason that the energy carrying photons that are intercepted by a time-traveler are not then able to transmit their energy to the atoms and molecules that they would have. From that point on, even the smallest change in the energy or position of those atoms and molecules will go on to interact and alter any surrounding molecules in a way which they did not in a previous history, and those molecules will then go on to alter even more molecules, and so on and so on. Granted, the changes would be very small, but who knows what effect these changes would produce over 50, 500 or 5,000,000 years. In short, it may have more to do with time travel than you give credit but as with all scientific ideas, nobody really knows. Quote Link to comment Share on other sites More sharing options...
Catweazle Posted November 22, 2011 Author Report Share Posted November 22, 2011 Time Machines have already been invented, but they caused so much trouble that people came back from the future and destroyed them. Possibly. Quote Link to comment Share on other sites More sharing options...
guest1957 Posted November 22, 2011 Report Share Posted November 22, 2011 I can't remember where I saw it, but it said that something with mass cannot travel faster than the speed of light, as the energy required to propel it to beyond C would require more energy than is contained within the Universe. Seeing as a Neutrino is deemed massless then I can kind of see why this is possible. (I make it all sound so easy ) I'd be pleased if it was confirmed though. Just chucks one almighty spanner in the works Standard model assumes a massless neutrino however over the past couple of years neutrinos appear to be being measured with a very tiny mass. Another spanner in the works. Quote Link to comment Share on other sites More sharing options...
margun Posted November 22, 2011 Report Share Posted November 22, 2011 (edited) By the way, particles can have energy without mass - photons for example. That's where Einstein's special law of relativity comes in - photons can obviously travel at the speed of light (having no mass and being the consituent part of light), the latest results from CERN suggest that a neutrino (with mass) has exceeded light speed. The special law of relativity states that as an object with mass approaches the speed of light, that mass of the object increases until it becomes infinite (hence the squared part of the formula). Think of an exponential curve, eventually the object with mass moving along the X plane (acceleration) will no longer be travelling along the X plane but will instead be moving along the Y plane, vertically away from the speed (X) at which it reached NEAR light speed. This is infinite mass and therefore the object cannot accelerate any further and breach the light barrier. This is the anomoly of the result from CERN - a photon with no mass is not bound by the infinite mass/light speed issue, but a neutrino is (in our current understanding). Here's a curveball though - if light is made up of photons, and photons have no mass, then how come light gets sucked into black holes? Gravity does not apply to anything with zero mass..... :yp: Edited November 22, 2011 by margun Quote Link to comment Share on other sites More sharing options...
Billy. Posted November 22, 2011 Report Share Posted November 22, 2011 Here's a curveball though - if light is made up of photons, and photons have no mass, then how come light gets sucked into black holes? Gravity does not apply to anything with zero mass..... :yp: Black holes scare me. Not because of what damage then can do, but because of all this 'event horizon' and how someone would view another person falling into the black hole, whereas the person falling into it would see nothing happen and would just be suspended there... Obviously there's loads more, but it's an interesting one. What's really is cool is that all these things are calculated before they were ever discovered. Quote Link to comment Share on other sites More sharing options...
margun Posted November 22, 2011 Report Share Posted November 22, 2011 Black holes scare me. Not because of what damage then can do, but because of all this 'event horizon' and how someone would view another person falling into the black hole, whereas the person falling into it would see nothing happen and would just be suspended there... Obviously there's loads more, but it's an interesting one. What's really is cool is that all these things are calculated before they were ever discovered. Have just spoken with a boff at work with a doctorate in physics (optics) - he said the black holes gravity does not directly suck the photons in, rather it distorts space time which changes the path of the photons. So they get caught up in the distorted area of space time and basically roll round and round. He also suggested it is possible to alter the path of a light beam using electromagnetism, seeing as light is an electromagnetic ray. So there you go....I wish I'd tried harder in my Physics A level..... Quote Link to comment Share on other sites More sharing options...
Billy. Posted November 22, 2011 Report Share Posted November 22, 2011 Take a laser pointer and point it at one side of the moon. Flick it across the moon and the dot (I say dot quite loosely) will travel across the moon faster than the speed of light. Mind you, it's only one photon hitting the moon, followed by another, x distance away, and again and again. It's still faster than the speed of light though Quote Link to comment Share on other sites More sharing options...
Gully Posted November 22, 2011 Report Share Posted November 22, 2011 I think this thread should be closed now before someone hurts themselves. I've got a degree in physics and am lucky if I know what day of the week it is nowadays. Quote Link to comment Share on other sites More sharing options...
margun Posted November 22, 2011 Report Share Posted November 22, 2011 I've got a degree in physics and am lucky if I know what day of the week it is nowadays. most people I work with who did physics are like that. They claim to have reached a point where the brain is saturated and can take no more. Funnily enough, they all seem to be full of useless facts, so maybe they just lack a 'stuff that comes out ya bum' filter Quote Link to comment Share on other sites More sharing options...
Billy. Posted November 22, 2011 Report Share Posted November 22, 2011 so maybe they just lack a 'stuff that comes out ya bum' filter Please stop derailing the thread. This is Physics, not Biology Quote Link to comment Share on other sites More sharing options...
Gully Posted November 22, 2011 Report Share Posted November 22, 2011 most people I work with who did physics are like that. They claim to have reached a point where the brain is saturated and can take no more. Funnily enough, they all seem to be full of useless facts, so maybe they just lack a 'stuff that comes out ya bum' filter Maybe you're right on the first bit, probably not the second. I did get interested by the neutrino thing and dug out a few books on special relativity to try and get my head round it again. There have been so many experiments done that seem to lead to Einsteins theories (Michelson-Morley springs to mind) that I think they're onto another 'cold fusion' type mistake. My money's on the error being due to the GPS clocks they use. Each GPS satellite has a caesium clock on board but they have to compensate for the time shift due to their motion relative to the earth below. A tiny error there would account for the errors in this experiment. Quote Link to comment Share on other sites More sharing options...
petethegeek Posted November 22, 2011 Report Share Posted November 22, 2011 I think this thread should be closed now before someone hurts themselves. I've got a degree in physics and am lucky if I know what day of the week it is nowadays. most people I work with who did physics are like that. They claim to have reached a point where the brain is saturated and can take no more. Funnily enough, they all seem to be full of useless facts, so maybe they just lack a 'stuff that comes out ya bum' filter "No man should escape our universities without knowing how little he knows." - J. Robert Oppenheimer Quote Link to comment Share on other sites More sharing options...
Billy. Posted November 22, 2011 Report Share Posted November 22, 2011 Maybe you're right on the first bit, probably not the second. I did get interested by the neutrino thing and dug out a few books on special relativity to try and get my head round it again. There have been so many experiments done that seem to lead to Einsteins theories (Michelson-Morley springs to mind) that I think they're onto another 'cold fusion' type mistake. My money's on the error being due to the GPS clocks they use. Each GPS satellite has a caesium clock on board but they have to compensate for the time shift due to their motion relative to the earth below. A tiny error there would account for the errors in this experiment. They accounted for the fact that the two locations may have shifted due to the earth's plates moving around. I'm sure that they ruled out the GPS pretty early. When I was watching something on this, they were showing what bits they were accounting for and when added up, it only meant that the neutrinos arrived a % slower, which was still a significant amount away from being slower than C. Obviously there's going to be a margin of error, but when it's still way outside of the MoE, even after extra bits are taken into account it becomes interesting Quote Link to comment Share on other sites More sharing options...
timps Posted November 22, 2011 Report Share Posted November 22, 2011 Take a laser pointer and point it at one side of the moon. Flick it across the moon and the dot (I say dot quite loosely) will travel across the moon faster than the speed of light. Mind you, it's only one photon hitting the moon, followed by another, x distance away, and again and again. It's still faster than the speed of light though Only in the perception of the person observing the ‘spot of light’ who supposes they are the same spot. In reality nothing has actually travelled faster than c. Quote Link to comment Share on other sites More sharing options...
Gully Posted November 22, 2011 Report Share Posted November 22, 2011 They accounted for the fact that the two locations may have shifted due to the earth's plates moving around. I'm sure that they ruled out the GPS pretty early. When I was watching something on this, they were showing what bits they were accounting for and when added up, it only meant that the neutrinos arrived a % slower, which was still a significant amount away from being slower than C. Obviously there's going to be a margin of error, but when it's still way outside of the MoE, even after extra bits are taken into account it becomes interesting Billy, I'm not going to pretend to know much more than the average layman about physics. I made the error of thinking that doing a degree in it would be all about mechanics, nuclear bombs and dropping things off tall buildings etc whereas in fact after the first year it was all particles and quantum mechanics, basically philosophy with stupidly complex maths used to test ideas. I wish I'd done engineering instead. My thoughts about the GPS clocks being to blame are the fact that up until this time it has not been possible to find one single set of laws that explain both the motion of large objects (planets, satellites etc) and small objects (sub-atomic particles). They are currently using a measure of time defined using calculations and more importantly corrections based on the General Theory of Relativity to explain movements of particles which can normally only be explained using the Special Theory of Relativity. I think its here that the problem lies. Maybe this discovery will lead to a theory that can unify the two. We live in interesting times. Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted November 22, 2011 Report Share Posted November 22, 2011 Billy, I'm not going to pretend to know much more than the average layman about physics. I made the error of thinking that doing a degree in it would be all about mechanics, nuclear bombs and dropping things off tall buildings etc whereas in fact after the first year it was all particles and quantum mechanics, basically philosophy with stupidly complex maths used to test ideas. I wish I'd done engineering instead. My thoughts about the GPS clocks being to blame are the fact that up until this time it has not been possible to find one single set of laws that explain both the motion of large objects (planets, satellites etc) and small objects (sub-atomic particles). They are currently using a measure of time defined using calculations and more importantly corrections based on the General Theory of Relativity to explain movements of particles which can normally only be explained using the Special Theory of Relativity. I think its here that the problem lies. Maybe this discovery will lead to a theory that can unify the two. We live in interesting times. Gully - you are talking GUTh! (Grand Unified Theory)! Sorry couldn't resist that one. BTW - what makes you think Engineering Degrees are much different? I thought I'd seen it all with descriptions of oscillations, dampers, partial differential equations etc. and then did a higher degree in another subject and had to learn discrete mathematics and formal methods I've been thinking about all this a bit more and reckon all the "fudge factors" and caveats point to some well dodgy errors and concluded that I am better off, for now, not trying to think about it any more. I do recall that my questions on the very large and extremely small used to do my old man's head in and these were pretty much the only subjects he did not have a readily coherent answer to. That adage about "the more I learn the less I know" has never been truer Interesting times indeed. Good discussion with healthy banter this one! Quote Link to comment Share on other sites More sharing options...
spiny Posted November 27, 2011 Report Share Posted November 27, 2011 (edited) You can't accelerate anything past the speed of light , but quantum theory allows something already travelling at the speed of light to be accelerated faster. Many scientists believe that time doesn't actually exist , it's just something we've invented to make our physics easier. Many believe time is just the position of something in an expanding universe. Because the framework of the universe is expanding at the speed of light it is this that stops anything travelling faster than light as it would reach and pass the edge of the universe eventually and nothing exists or can outside the universe. Edited November 27, 2011 by spiny Quote Link to comment Share on other sites More sharing options...
henry d Posted November 27, 2011 Report Share Posted November 27, 2011 ........ Many believe time is just the position of something in an expanding universe. Because the framework of the universe is expanding at the speed of light it is this that stops anything travelling faster than light as it would reach and pass the edge of the universe eventually and nothing exists or can outside the universe. Soooo at "time" zero, there was no space or time or light, how can something come from nothing, when there can be nothing exists out-with it? Quote Link to comment Share on other sites More sharing options...
petethegeek Posted November 27, 2011 Report Share Posted November 27, 2011 "Time is nature's way of keeping everything from happening at once." Woody Allen - well known physician physicist. Quote Link to comment Share on other sites More sharing options...
Diceman Posted November 27, 2011 Report Share Posted November 27, 2011 Soooo at "time" zero, there was no space or time or light, how can something come from nothing, when there can be nothing exists out-with it? Nobody knows, that's what they are trying to find out at CERN and other places. There are some theories that suggest we are in one big loop and an infinite number of universes have been and will continue expanding and contracting for ever. One thing is certain, and I guess this is what you are getting at, the answer to this question isn't just that "a higher being" did it, because that just raises the question about where the higher being came from... Quote Link to comment Share on other sites More sharing options...
Catweazle Posted November 27, 2011 Author Report Share Posted November 27, 2011 Soooo at "time" zero, there was no space or time or light, how can something come from nothing, when there can be nothing exists out-with it? Well that's a question we may never know the answer to. I'll admit to not being the sharpest tool in the box, but I seriously wonder whether any version of the rather limited human mind is actually capable of understanding the mechanics involved. Quote Link to comment Share on other sites More sharing options...
henry d Posted November 27, 2011 Report Share Posted November 27, 2011 Nobody knows, that's what they are trying to find out at CERN and other places. There are some theories that suggest we are in one big loop and an infinite number of universes have been and will continue expanding and contracting for ever. One thing is certain, and I guess this is what you are getting at, the answer to this question isn't just that "a higher being" did it, because that just raises the question about where the higher being came from... Second part first Yep, it is one thing I am getting at, however by asking where the higher being/creator came from is a never ending circular argument and is illogical. I was not, am and will not be, however I cannot create a universe, a creator of everything, is and always shall be. I have a problem with "loops" again it is to do with how can they? Surely with what is known of entropy and the heat death of the universe, these do not hold water? As for infinite universes, where does all the energy come from? If it is infinite then how are they simultaneous, yet unknown to each other? Well that's a question we may never know the answer to. I'll admit to not being the sharpest tool in the box, but I seriously wonder whether any version of the rather limited human mind is actually capable of understanding the mechanics involved. I agree totally Quote Link to comment Share on other sites More sharing options...
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