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Re: Steven Hawking's - Time Travel - 2010
Posted:
May 7, 2010, 11:43 PM
Ps.
if you liked the movie, feel free to post a reply. i have posted many videos of science stuff in the past and rarely does any one reply, which brings me to wonder if there is no point in me posting videos like this.
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Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 8, 2010, 5:15 AM
ah well, so Stephen Hawking's email has sent me a reply, it reads as follows, didnt hurt to try hehe ,
Thank you for your email to Professor Hawking.
As you can imagine, Prof. Hawking receives many such every day. He very much regrets that due to the severe limitations he works under, and the enormous number of requests he receives, he is unable to compose a reply to every message, and we do not have the resources to deal with many of the specific scientific enquiries and theories we receive.
Please see the website http://www.hawking.org.uk for more information about Professor Hawking, his life and his work.
Yours faithfully
Sam Blackburn
Technical Assistant to Professor S W Hawking CH CBE FRS
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA. United Kingdom.
Re: Steven Hawking's - Time Travel - 2010
Posted:
May 9, 2010, 12:55 AM
I can only speak for myself, but I've appreciated the scientific entertainment you've provided. I plan to watch this as soon as I get a chance. My wife gets bored with this kind of stuff, so I have to watch bits and pieces when I get a few minutes here and there.
Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 10, 2010, 11:36 PM
There is a book called "How to build a time machine" by Professor Paul Davies. This deals mostly with the idea of enlarging and controlling wormholes so that you could go through them into the future etc. This is an interesting book, that deals carefully with all of the problems associated with attempting to do this, and is well written for the layperson.
There are other issues not addressed in the video relating to thermodynamics. There is a problem with conservation of energy when you send a mass from one time to another time through a wormhole. The total mass-energy of the universe at the point of departure is lowered, and it is increased at the point of arrival. This presents a problem for which there is no clear solution, particularly if the wormhole time-traveller affects the universe while she is there (moves objects, destroys things, makes noise, flashes a torchlight), and then returns to the present. The impact of these affects, if they were allowed in physics, are difficult to assess since as they are violations of the laws of physics we have no means to calculate them. Some have speculated that the wormhole itself deals with these problems in a general-relativistic way as you pass through it. Others have said that the energy required to expand and control a wormhole would be infinite. There is not a great deal of published work on this either due to the fear, as Hawking said, of being labelled a crackpot.
Also, you need to consider the way that other violations of the law of conservation of energy could be carried out. If you had a wormhole with one end in earth's orbit and the other at sea level, then you could step in and go straight up to orbit, then fall back down to earth, and go straight back into the wormhole and back to orbit over and over. As the earth attracts you each time, accelerating you to the ground, a little tiny piece of the earth's mass energy is consumed, but where does this mass energy go? Equally you could create a hydroelectric station where water falls down under gravity driving a turbine and creating electricity. The water would then fall into a wormhole and arrive back up to the top of the system (tank, reservoir) and fall through again. This system is extracting energy from the universe for free, and hence is impossible.
Hawking's point about feedback is important but in practice one could conceivably regulate input and output at each end of the wormhole 'controller' device just as you do with the volume or gain control on a PA system. Adjusting the PA once feedback commences does not cancel the sound that has already gone through the system. However the point here is that, for example, sunlight moving into the wormhole could be beamed back into the sun, heating it up further. If this process were to continue it would lead to serious problems, such as all of us frying here on earth. So any of you working on a wormhole controller in your garage, just be careful where you point that thing!
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Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 11, 2010, 3:55 AM
ahh ok u addressed the feed back issue at the end, i was going to ask if you didn't, but u did. interesting
i find it interesting that light travels into the future. and that mass bends time. and the micro worm hole thing.
have they considered combining all 3 of these ideas?
using light to send data into the future could be interesting.
the law of free self perpetuating energy being impossible i find interesting too, thanks.
and the universe has a built in security system preventing objects from exceeding 99.9% the speed of light is interesting,.. it actually knew about the problem of the girl running forward on the train ahead of time and pre-compensated? i realize they base this off of the particle excellerator of course,.. all these preset laws preventing creative paradox's is interesting, the universe is very smart?
if a worm hole shuts down from feed back, then why doesnt a black hole do this too?
do you know about the twin particals? i forget their name, but they are twins where if one is effected the other is too, even if far far apart. and that while black holes take away data, white holes theoretically bring in data. perhaps twins? maybe worm holes have twins too, and that they dont actually shut down from feed back. perhaps they are like black holes, stable from feed back, but shut down from a different reason we didnt consider yet. if that was found as true, then worm holes might be more stable than we realize given the right solution to the right problem. maybe worm holes simply need to feed on data to grow into a black hole. like all living things, if not fed, they die.
and as far as what u said about the water power impossible effect. what if the worm hole simply required more energy to maintain than power it could supply? problem solved there i think. perhaps the more power you harvested from it the more it would demand in energy feed to maintain stable in order the not break the law.
or perhaps a worm hole will simply refuse to be aimed at its own self...
perhaps a wormhole is a seed to make a black and white hole (twins), and either the worm hole needs to be divided into 2 parts (male and female/ black and white holes),..twins,.... or perhaps the wormhole already has a twin, and one of them just needs to be fed to trigger the birthing stages of becoming the 2 giants.
perhaps one of the reasons they haven't yet found any white holes is because they are not only polar opposites in function, but polar opposites in size? and the center point of size between them was the size of their birthing seed? and that white holes convert mass and energy to a infinitely small sizes, after all,.. every thing is filled with 99.9999% empty space, so consolidation is possible?
and what about VSL? variable light speed. theorized that at one time light exceeded its own speed limit. if that was true, just imagine what else could be true as a result....
Message was edited by: zoeyk at May 10, 2010 10:08 PM
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Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 11, 2010, 12:34 PM
alison; you could create a hydroelectric station where water falls down under gravity driving a turbine and creating electricity. The water would then fall into a wormhole and arrive back up to the top of the system (tank, reservoir) and fall through again. This system is extracting energy from the universe for free, and hence is impossible.
zoeyk; ok i will try to create a theory to counter this proposed problem. i think rules can be bent or even broken when new counter rules are found. kind of like your supposed to block a 3 in pente but there are counter rules to bend and break this basic rule. probably a bad example, but was the first thing that came to mind.
you know,.. modern day theory says we have i think its 11 universes,.. or something, and that its theorized that we trade energy back n forth between universes via black and white holes. like valves in a complex plumbing system connecting several tanks of fluid perhaps.what if one of these valves opened or closed a bit to compensate for energy gain?
or the same idea but, what if we were connected to a negative mirror of our universe, and they had the same thing happening but instead of producing energy it was losing energy perpetually and the black and white holes allowed the balance of positive and negative to occur?
but if that were true, after about a infinite amount of time both universes would have equal parts of positive and negative and thus would be identical,...if the perpetual free energy machine kept going after that we start to sling shot into becoming the negative universe? and the other the positive? the universes would then perpetually sling shot back and forth, forever? or perhaps in that situation a new variable comes into play.
hehe being a crack pot is rather entertaining to ones self
Message was edited by: zoeyk at May 11, 2010 6:43 AM
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Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 11, 2010, 1:13 PM
hmmm,.. thinking about those illusive white holes again. we cant see a black hole,... but we can see its surroundings so that's how we detect it. light cannot escape it so its black. ok,.. and the assumption has been that the opposite is white, because light went in, so when light and energy comes out there should be a ton of light shooting out like fireworks,.. they assume,.. but,.. what if a black hole and a white hole are both in fact,.. black. and that they are only opposite in function. but not just the function of directional flow, but what if when energy comes out,.. the energy is now reversed as well. meaning light is now dark,.. energy is now negative, mass is invisible,.. this would explain why you can never see a white hole any where, but we have found hundreds of black holes. and this would further explain dark matter, which supposedly makes up 90% of our universe to maintain gravity yet we can never seem to locate the stuff even tho we are surrounded by it every where. or perhaps white holes really are bright and hard to miss,.. but they are in a alt universe instead of our own,.. and the matter just gets sucked over to there,.. but if that's so,.. then our universe would just eventually shrink from lack of energy matter and light until the universe stopped existing. hmm
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Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 12, 2010, 7:47 AM
Zoey, I like your creative thinking. You should be a physicist.
You need to keep in mind that it is possible to conceive of any number of possibilities for a physics framework that makes it possible to have controllable wormholes without feedback, paradoxes, instability or thermodynamics violations, or to invoke multiple universes linked by networks of energy balancing black and white holes. It is also possible to simply sweep aside today's physics with the catch cry "this is what we know today, but tomorrow we could discover what we know today is all wrong". You need to be careful here because while we know our physics is incomplete, and that there are fundamental conflicts between relativity and quantum mechanics, we also have immense amounts of evidence that confirm these theories. So if we are to speculate, then we should keep to trying to avoid violating what we do know to be true, in situations where we know it is true. Yes this constrains us in our imaginings, but it also guides us toward more feasible possibilities and away from error.
Also you should bear in mind that these videos are targeted at the layperson and leave out significant parts of the picture. The spaceship accelerating to light speed for instance will increase in mass as it gets close to C, as will the little girl running. The energy cost of further acceleration as you approach C gets incrementally larger for smaller and smaller gains in velocity. Thus the mass-energy ratio to velocity is exponential with respect to C and prevents C being achieved. The video does not explain this and implies that the universe cleverly contrived a situation that prevents the girl reaching C merely to protect itself. This implication is pretty silly actually. The mass-energy increase is the real reason C cannot be reached via acceleration of mass, and this is covered mathematically by Einstein's theory.
Your proposal that the energy cost of controlling a worm hole would offset the gain in the hydro scheme fails because if there is an energy cost of controlling a worm hole, then that cost will be there anyway even if you don't use it to generate electricity. If you argue that it only costs you if you generate electricity then the wormhole would have to "know" in advance how much electricity you will generate and make sure it demands exactly that amount from you. Now stranger things than that occur daily in the quantum world, so I can't rule it out, but I would say that you are proposing something that has even more problems to solve than the original problem, and this goes against Occam's Razor. My guess is that the violation of conservation of energy that would result from mass/energy transfer through wormholes, or using them to create energy from nothing, means that they are not possible.
As for white holes. There is some general support for the possibility of white holes in the theory, but there is nothing concrete. Hawking himself is under attack from many quarters for his rather bizarre theories and assertions about the goings on in inside black and white holes. This is an area where research is almost entirely speculative and very little data exist to support many of the ideas put forward. Inside black holes the laws of physics as we know them may indeed break down, but the effects of the presence of these bodies in our spacetime will be measurable using physics that does work at our scale and under our conditions. In other words we ought to be able to detect the presence of these bodies. It may be that a white hole is out there to discover, but my hunch is that if such a body existed, given its higher visibility, it would probably have been seen by now.
Anyway, don't let me discourage your creative approach. You have some interesting thoughts, and yes being a crackpot can be fun...
Re: Stephen Hawking's - Time Travel - 2010
Posted:
May 12, 2010, 3:48 PM
Zoey: what if a black hole and a white hole are both in fact,.. black. and that they are only opposite in function. but not just the function of directional flow, but what if when energy comes out,.. the energy is now reversed as well. meaning light is now dark,.. energy is now negative, mass is invisible,.. this would explain why you can never see a white hole any where, but we have found hundreds of black holes. and this would further explain dark matter, which supposedly makes up 90% of our universe to maintain gravity yet we can never seem to locate the stuff even tho we are surrounded by it every where. or perhaps white holes really are bright and hard to miss,.. but they are in a alt universe instead of our own,.. and the matter just gets sucked over to there,.. but if that's so,.. then our universe would just eventually shrink from lack of energy matter and light until the universe stopped existing. hmm
Alison: You will need to explain your negative energy, what it is and also what process converts it from positive energy. In my experience the most effective method of converting positive energy to negative energy is a forum flame thread.
These holes are called black and white because that describes their visibility which in turn is a result of their function as extrapolated from theory (however tenuous it may be). If you simply declare by fiat that white holes are black then you are saying that the theory is wrong. Which kind of destroys the premise upon which our whole discussion rests, since if the theory is wrong to that degree then we would not have black holes. So, to be a little bit scientific about this you would need to posit an explanation for this, an alternative physical theory, one which in your case also accounts for your negative energy proposition. Don't worry I can help you with the math...
If you are looking for a black/white hole pathway that is a useable shortcut through spacetime, then you could focus your attention on an anti-spagettification device so that you can travel through it. Let's see, you want something that will prevent you from becoming long and thin... hmmm...didn't Morgan Spurlock do some work in that field..?
Message was edited by: alisontate at May 15, 2010 5:15 PM
