Quantum Mechanics has been known to be a time-trasnlation invariant theory. In layman's term, it means that you can run the clock backwards and everything is fine. There is no "irreversible" process. (For the jargon-empowered, QM does not have a natural "arrow of time").
However, we know the Thermodynamics 2nd law tells us that even *ideal* processes are essentially irreversible if we do work, i.e. waste heat is inevitable.
So the idea to use QM to improve this "ideal"-ness (classically speaking) is an intersting step towards understanding the *other* big issue in science : which is how the 2nd Law fits into the grand scheme of things. (Grand Unified Theories do not incorporate 2nd law since microscopically are processes are essentially reversible. The 2nd law drove many people nuts, including Roger Penrose.)
So the point of the paper is not "get more $$$" for you engine. It's an interesting gedenken-experiment (sp?) that proves a point.
Who am I suppose to believe? You, Halberstam, the US military? Whatever handwringin, conspiracies, blah you can think up off, there were hungry people out there, the hungry were fed.
IANAA, but a Malaysian. I cringed everytime I read review saying that BHD was about 18/19 americans who die in a firefight. I wonder how many Somalis died, not to mention the Malaysian soldier who was also killed in the firefight. (Contrary to many reports, the Malaysians soldiers wanted to get into the fight, but the Americans wanted US troops in the Malaysians' APCs. They compromised on Malaysian drivers with American troops.)
But it is easy to criticize from the comforts of the movie theatre. Don't fault the soldiers for doing what they are ordered to do.
actually now, it's from Peanuts. But I've seen it in code, graffiti, etc. And I think most people know where it comes from, and that's the greatest compliment one can give it.
Normally, it's a lot of fun to mock people like Alex Chiu. Then I realized that he is probably making tons of money selling his "rings" to clueless surfers. *Sigh*.
By the way, he will be coming out with your very own "One Ring" (Immortality Ring Ver 2.0) soon.
Real gravitons cannot escape a black hole any more than real photons can
Since we are in la-la land in terms of formulating theories, that's not true in general. We can have all sorts of crazy things where gravitons and photons form different causal structures, like for example dimetric theories. Then gravitons and photons will have different "event horizons" as defined by different geodesics formed by the different metric structures of both. For example.
Sorry to nitpick here, but you touched something closed to my heart:). (And yes, it's a crazy world out there.)
Re:Why can't anyone see the implications of this?
on
This is IT?
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· Score: 1
What implications? The only mildly big implication is its energy consumption c.f. to a car. But if you are planning to save the environment : why don't you just walk?
It is a feat of engineering true, but not much of a earth-shattering feat. Dynamic control systems are well-studied, so is the actuators (gyroscopes blah blah blah : btw, a bicycle keeps its balance via gyroscopic action).
It is just a scooter. Albeit a really cool, small, and expensive scooter.
Change the world? Bigger than the internet? THese are words of bezos and jobs, and both of them have lots of money invested in it. Go figure.
it's called the Penrose process. You use it on a rotating blackhole.
The idea is that in a rotating blackhole, the minimum point of the potential moves around, so you can actually "slows" the blackhole while getting a nice angular momentum kick.
Much like how you use the rotation of jupiter for slingshot. ("gravity assist" is a bad phrase, reality is that it's "angular momentum assist")
As an academic myself, I am gratified by your colleagues and your decision to publish your findings instead of claiming the $10000 prize (personally, I find the $10000 "prize" for the HackSDMI challenge measly, and even bordering on insulting.).
The fact that you are suing the RIAA for intefering into your academic activities indicates your stance on the issue of academic freedom to research. However, the RIAA has deep-pockets, and the fight has just begun. It is not inconceivable that in the future, the academia may come under the control of rich corporations manipulating research for their own selfish ends.
So, my question is, do you see a bright future for a "free academia" or do you see a academia that willi increasingly be locked down by corporate interests and their lawyers/lobbyists?
At the fundamental level, both processes are quantum electrodynamics processes, so they are essentially the same.
Your glass of water example is excellent. The phenomenon you would call it refraction. However, if you have a huge enough volume of water, shining a light on it, the light will eventually scatter so often that it will become defused and eventually loses its coherence.
SHine light into a body of water/mass that is stellar in size...you get the idea.
The thing I pick on in your OP is that you claim that the delay in photons getting to us is due to defraction. That's not quite true. The slowness is due to random walk of photon through a large enough body of mass.
But, of course, you can always say that they are both QED scattering effects.......
The "sort-off" time-dilation effects of a photon zapping through glass is not a random process. Zap a photon towards a piece of glass, you can compute when and where you will receive it at the end (ok, ignoring quantum stuff here, but you get the idea). This has something to with the fact that a glass is a lattice of ordered potentials.
But the random-walking of photon through matter
is. Zap a photon through a bunch of matter, it will random-scatter through the stuff, but you have no idea where or when it will end up in. That's because stuff is not ordered and not a lattice.
This is the same reason that a photon generated in the center of the sun takes about a million years to random walk from the center to the surface. (I.e. the light you see from the sun is a million yeards old).
A better analogy would be Brownian motion, not light zapping through glass.
The neutrinos produced by the core of the collapsing star escape easily through the stellar atmosphere since they interact weakly with matter, whereas the light took significantly longer to escape - think of how light travels more slowly in a block of glass. So the neutrinos reached us first.)
Good try, but not quite right either.
Neutrinos have very low crossectional area, so interact weakly with other stuff. Photons, however, interact strongly with electrons and protons and what have you. So during a SN collapse neutrinos escape first, while the other stuff begins to fall into the core of the dying star. Photons are generated during the collapse, but their escape from the SN is blocked by the collapsing matter. So photons have to "work" themselves via random scattering, which takes a lot more time, i.e. a few hours.
I think you missed the point. Their paper has been submitted for peer-review. You can even get it at the XXX place (postscript required) and read it if you want to. The paper is not published yet, but big results like this do not come out of your nostril on a whim. People in the physics community knows about what you are doing and wait for your results. Getting it to the public (and the rest of the world) as early as you can is part of your job else NSF will ask you what they hell are you doing with our money.
So, yeah, you can come up with your nostril theory. And yeah, if you want to get it published, submit it to a journal. Better, you can put it up on the LANL XXX archive site.In fact, you will see once in a while a crazy theory like this appearing there. But don't cry mommy if people laugh at you.
Well, it is part of the job of the scientists to try to get them interested. That's called public outreach. And lots of money from grants goes into PO programs. Believe it or not.
That's fine. If you areconfident in y our results and your results are sufficiently groudbreaking that itdeserves to be told to Joe Public who funds it in the first plac.
You can get the articles (not-reviewed) from the XXX server and decide for yourself how good they are.
I will add here some notes in addition to the other response to the your post (the oscillating universe has been around for a while, but observations have ruled out the so-called "idling" universe : if you believe in General Relativity which most people do.)
There are recent revival of the idea of the "big crunch before big bang universe". People have thought about these some time ago, but it ran into a problem called the "weak-energy condition". Basically, the equations of general relativity which describes the "motion" of the universe, says that once the universe goes into the "big crunch mode", it will hit a singularity which is an infinity. But this means that we do not know how to "connect" the big bang to the big crunch "continuously" (discontinuous things are non-causal and unphysical). Recent attempts by some prominent theorists try to by-pass the WEC by finding some loop-hole so that the big crunch never hits infinity. The results are kinda mixed (I don't know the exact details.)
Of course, people are working within the confines of current known physics. There may be some unknown undiscovered processes that allows us a way out. The verdictis still open.
True. That's always implicit in any scientific discourse that it will be extremely cumbersome to add the words "until proven wrong experimentally" at the end of every sentence.
Slashdot Mirror
I think all that jargon is what I called "do work". :P
yes. you are right of course. I was talking about plain vanilla QM. In QFT, CFT is the symmetry that we should care about.
Quantum Mechanics has been known to be a time-trasnlation invariant theory. In layman's term, it means that you can run the clock backwards and everything is fine. There is no "irreversible" process. (For the jargon-empowered, QM does not have a natural "arrow of time").
However, we know the Thermodynamics 2nd law tells us that even *ideal* processes are essentially irreversible if we do work, i.e. waste heat is inevitable.
So the idea to use QM to improve this "ideal"-ness (classically speaking) is an intersting step towards understanding the *other* big issue in science : which is how the 2nd Law fits into the grand scheme of things. (Grand Unified Theories do not incorporate 2nd law since microscopically are processes are essentially reversible. The 2nd law drove many people nuts, including Roger Penrose.)
So the point of the paper is not "get more $$$" for you engine. It's an interesting gedenken-experiment (sp?) that proves a point.
Who am I suppose to believe? You, Halberstam, the US military? Whatever handwringin, conspiracies, blah you can think up off, there were hungry people out there, the hungry were fed.
IANAA, but a Malaysian. I cringed everytime I read review saying that BHD was about 18/19 americans who die in a firefight. I wonder how many Somalis died, not to mention the Malaysian soldier who was also killed in the firefight. (Contrary to many reports, the Malaysians soldiers wanted to get into the fight, but the Americans wanted US troops in the Malaysians' APCs. They compromised on Malaysian drivers with American troops.)
But it is easy to criticize from the comforts of the movie theatre. Don't fault the soldiers for doing what they are ordered to do.
actually now, it's from Peanuts. But I've seen it in code, graffiti, etc. And I think most people know where it comes from, and that's the greatest compliment one can give it.
5 dollars, that makes it about 20 Ringgit Malaysia. Which means she's been scammed! You can buy Adobe Macromedia Vol. II for 7 Ringgit!
Ha! Those western foreigners, so easily scammed!
Normally, it's a lot of fun to mock people like Alex Chiu. Then I realized that he is probably making tons of money selling his "rings" to clueless surfers. *Sigh*.
By the way, he will be coming out with your very own "One Ring" (Immortality Ring Ver 2.0) soon.
Real gravitons cannot escape a black hole any more than real photons can
:). (And yes, it's a crazy world out there.)
Since we are in la-la land in terms of formulating theories, that's not true in general. We can have all sorts of crazy things where gravitons and photons form different causal structures, like for example dimetric theories. Then gravitons and photons will have different "event horizons" as defined by different geodesics formed by the different metric structures of both. For example.
Sorry to nitpick here, but you touched something closed to my heart
That's funny. Because I begged my mom to get me a computer after watching TRON like, say, 20 times. And then she got me an ORIC-1.
:).
The first thing I typed went something like :
REQUEST : Run Program
Of course, I was like 10 or something too
Zhang is actually the reserve member of the Pine-Laughlin tag team!
Gross's partner should have been....
Dr. Joe "The Big Book " Polchisnki!
What implications? The only mildly big implication is its energy consumption c.f. to a car. But if you are planning to save the environment : why don't you just walk?
It is a feat of engineering true, but not much of a earth-shattering feat. Dynamic control systems are well-studied, so is the actuators (gyroscopes blah blah blah : btw, a bicycle keeps its balance via gyroscopic action).
It is just a scooter. Albeit a really cool, small, and expensive scooter.
Change the world? Bigger than the internet? THese are words of bezos and jobs, and both of them have lots of money invested in it. Go figure.
yes. which is why I added my errata on the error of my ways.
thinking a bit more, Penrose Process is nothing like the gravity assist. Sorry!
it's called the Penrose process. You use it on a rotating blackhole.
The idea is that in a rotating blackhole, the minimum point of the potential moves around, so you can actually "slows" the blackhole while getting a nice angular momentum kick.
Much like how you use the rotation of jupiter for slingshot. ("gravity assist" is a bad phrase, reality is that it's "angular momentum assist")
Hi Prof Felten,
As an academic myself, I am gratified by your colleagues and your decision to publish your findings instead of claiming the $10000 prize (personally, I find the $10000 "prize" for the HackSDMI challenge measly, and even bordering on insulting.).
The fact that you are suing the RIAA for intefering into your academic activities indicates your stance on the issue of academic freedom to research. However, the RIAA has deep-pockets, and the fight has just begun. It is not inconceivable that in the future, the academia may come under the control of rich corporations manipulating research for their own selfish ends.
So, my question is, do you see a bright future for a "free academia" or do you see a academia that willi increasingly be locked down by corporate interests and their lawyers/lobbyists?
I am an astrophysicist, and damned, I am excited!
*duck*
the www.foreignpolicy.com website at the moment.
At the fundamental level, both processes are quantum electrodynamics processes, so they are essentially the same.
Your glass of water example is excellent. The phenomenon you would call it refraction. However, if you have a huge enough volume of water, shining a light on it, the light will eventually scatter so often that it will become defused and eventually loses its coherence.
SHine light into a body of water/mass that is stellar in size...you get the idea.
The thing I pick on in your OP is that you claim that the delay in photons getting to us is due to defraction. That's not quite true. The slowness is due to random walk of photon through a large enough body of mass.
But, of course, you can always say that they are both QED scattering effects.......
The "sort-off" time-dilation effects of a photon zapping through glass is not a random process. Zap a photon towards a piece of glass, you can compute when and where you will receive it at the end (ok, ignoring quantum stuff here, but you get the idea). This has something to with the fact that a glass is a lattice of ordered potentials.
But the random-walking of photon through matter
is. Zap a photon through a bunch of matter, it will random-scatter through the stuff, but you have no idea where or when it will end up in. That's because stuff is not ordered and not a lattice.
This is the same reason that a photon generated in the center of the sun takes about a million years to random walk from the center to the surface. (I.e. the light you see from the sun is a million yeards old).
A better analogy would be Brownian motion, not light zapping through glass.
The neutrinos produced by the core of the collapsing star escape easily through the stellar atmosphere since they interact weakly with matter, whereas the light took significantly longer to escape - think of how light travels more slowly in a block of glass. So the neutrinos reached us first.)
Good try, but not quite right either.
Neutrinos have very low crossectional area, so interact weakly with other stuff. Photons, however, interact strongly with electrons and protons and what have you. So during a SN collapse neutrinos escape first, while the other stuff begins to fall into the core of the dying star. Photons are generated during the collapse, but their escape from the SN is blocked by the collapsing matter. So photons have to "work" themselves via random scattering, which takes a lot more time, i.e. a few hours.
I think you missed the point. Their paper has been submitted for peer-review. You can even get it at the XXX place (postscript required) and read it if you want to. The paper is not published yet, but big results like this do not come out of your nostril on a whim. People in the physics community knows about what you are doing and wait for your results. Getting it to the public (and the rest of the world) as early as you can is part of your job else NSF will ask you what they hell are you doing with our money.
.In fact, you will see once in a while a crazy theory like this appearing there. But don't cry mommy if people laugh at you.
So, yeah, you can come up with your nostril theory. And yeah, if you want to get it published, submit it to a journal. Better, you can put it up on the LANL XXX archive site
Well, it is part of the job of the scientists to try to get them interested. That's called public outreach. And lots of money from grants goes into PO programs. Believe it or not.
That's fine. If you areconfident in y our results and your results are sufficiently groudbreaking that itdeserves to be told to Joe Public who funds it in the first plac.
You can get the articles (not-reviewed) from the XXX server and decide for yourself how good they are.
I will add here some notes in addition to the other response to the your post (the oscillating universe has been around for a while, but observations have ruled out the so-called "idling" universe : if you believe in General Relativity which most people do.)
There are recent revival of the idea of the "big crunch before big bang universe". People have thought about these some time ago, but it ran into a problem called the "weak-energy condition". Basically, the equations of general relativity which describes the "motion" of the universe, says that once the universe goes into the "big crunch mode", it will hit a singularity which is an infinity. But this means that we do not know how to "connect" the big bang to the big crunch "continuously" (discontinuous things are non-causal and unphysical). Recent attempts by some prominent theorists try to by-pass the WEC by finding some loop-hole so that the big crunch never hits infinity. The results are kinda mixed (I don't know the exact details.)
Of course, people are working within the confines of current known physics. There may be some unknown undiscovered processes that allows us a way out. The verdictis still open.
True. That's always implicit in any scientific discourse that it will be extremely cumbersome to add the words "until proven wrong experimentally" at the end of every sentence.