Oh well, never thought I'd see the day when I'd try and post an informative post on a proposal on Valentines day, but anyways, for those of you who are ignorant of who Kathleen is, check out this site.
Sorry, couldn't resist;-)
Re:The last thing I removed from my thesis...:
on
Black Holes Disputed
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· Score: 2
My knee-jerk reaction to the article posted was that it seems like the gravastar isn't allowed to grow, and it has to grow, right?
My 0.2! That is one point against it, in fact. Also, if everything within the shell border limit of rho=p would be in the fluid state, which could be BEC. Just imagine these thingys floating around.
In fact, the way the paper considers the region in the shell is interesting. Their proof shows that r has to be a constant for the shell.
One approximation in the paper which scares me is when they say that f & h are approx. constant in the shell. It is not. The difference would mean that the gravastar _would_ grow, albeit a little by little, atleast by cosmic accounts.
BH theory does not say entropy is low. It says there is high entropy, as a consequence of Hawking radiation which implies a negative specific heat. This is also one of the arguments used by the authors in their paper against black hole, and a very valid one at that.
However, both the theories face the same problem - how do they account for the lost entropy? These guys suggest a BEC formation which sheds, and Black Hole theorists have been having equally
bizarre explanations.
Notice their explanation for the region within -
...we note that the interior de Sitter region with p = -p may be interpreted also as a cosmological spacetime, with the horizon of the ex-panding universe replaced by a quantum phase interface.
Which could be a layer of BECs? Or some undefined nature? But in a blackhole, the entropy exists within, saying we have a parallel universe interacting to preserve entropy. Big deal, both are equally bizarre.
And blackholes can work well with dark matter. Not these.
The novel assumption required for this solution to exist is that low energy gravity can undergo a vacuum rearrangement phase transition in the vicinity of r = RS, in which the energy density and eq. of state change.
Knock, knock? Very great mass/energy ratio, but a really high mass. Would it still exist? Or would it somehow disintegrate? Would the phase transition undergo reversal?
It's not just your theory, Occam's Razor, when applied to Black Holes, fails too.
From their paper -
Further, when a massless field such as that of the pho-ton is quantized in the fixed Schwarzschild background, one finds that the black hole radiates these quanta witha thermal spectrum at the asymptotic Hawking temperature TH = _h/8*kBGM [1]. The inverse dependence of TH on M implies that a black hole in thermal equilibriumwith its own Hawking radiation has negative specific heat.
In fact, that point in itself is a strong OR against BHs. But anyways, coming back....
Well, I reasoned Occam's Razor for the following reasons -
From the paper:
Energy conservation plus a thermal radiation spec-
trum imply that the black hole has an enormous entropy, S 10 77 k (M=M ) 2 [3]
Laws of thermodynamics clearly define that Entropy is on the rise. Given the amount of matter in a BH, this is acceptable (although theories on where these are a little wierd).
The novel assumption required for this solution to exist is that low energy gravity can undergo a vacuum rearrangement phase transition in the vicinity of r = RS, in which the energy density and eq. of state change.
Occam's Razor. Now just imagine a handful of dark matter in the vicinity, it no longer is _low_ gravity. I'd like to argue more technically, but I'd prefer it over e-mail than here.
Hence essentially all the mass of the
object comes from the energy density of the vacuum con-densate in the interior, even though the shell is responsi-ble for all of its entropy.
Different entropy concentrations? It's as wierd as BH causing Hawking Radiation and a high entropy of S ~10^77 k (M=M )^2:-P
Since theentropy of these objects is some 20 orders of magnitude smaller than that of a typical stellar progenitor, a violentprocess of entropy shedding, as in a supernova, is needed to produce a cold gravastar remnant.Explosive bursts in which a finite fraction of atoms are ejected have been observed in attractive BEC's in the laboratory
A laboratory is one thing, a naturally occuring phenomenon is another. I do not mean to be derisive, but I find entropy shedding a little too hard to believe.
Agreed, BECs can be formed at high density too, besides low temperatures, but just apply Occam's Razor here and you will see that this means.
These are presumably characterized by a finite density of vortices of normal phasepenetrating the condensate core. Such rotating gravitational vacuum condensate stars, dark `grava(c)stars' arecandidates for the stable remnants of stellar evolution for stars exceeding the Chandrasekhar limit.
....
The remnants are left in an excited oscillatory state afterwards.
Have these been observed outside the lab? There is evidence of what seem to be black holes. Occam's Razor.
You seem to be confusing Riemannian manifolds (ND manifolds with metric structure) with Riemann planes (2D surfaces generated from complex functions).
My mistake. I meant Cauchy-Riemann manifolds. Sorry:/
What the heck are you talking about? "Overlapping submanifolds"?? The authors aren't describing anything like that. "Frames carrying many frames?" You're babbling.
From the article: Even if they did form, how would they survive the onslaught of matter raining down on them? "What happens if a gravastar has accreting matter showered upon it? Won't it collapse to a black hole?" he says.
"The gravastar is stable," counters Mottola. He says that matter falling onto the shell could make it wiggle and radiate away energy, but because the gravitational pull of the shell balances the force of the springy vacuum inside, it couldn't actually collapse. Any matter that fell onto the shell would simply become part of it, he says.
If the initial reference frame is defined by a predefined set, then the frame would forever grow. Whilst in a BH it would forever be there.
Think about it. A gravistar is forever growing. That way you will have Riemann manifolds for each previous state overlapping with the new ones.
The stability of the gstar would be defined by a very delicate balance indeed. So it kind of becomes very very recursive.
Dear Mr.photon, do you want to go inside. Fine, let me measure you and balance myself and then decide. Oh ok, now you are free to go! Get in.. Uh oh.. what about that one over there? Where does he come in? Well, he was defined by the previous state. Why? Since his distance is different, he is in a different ref frame. You mean for each of these guys my balance makes it madatory to apply different inertial frames? It appears to be a logical extension, doesn't it?
Also, consider a light cone into a gravstar. Wouldn't you have to take discrete functions for fixed intervals since a gravstar does not plainly absorb, it also grows.
What does the Bertotti-Robinson solution have to do with anything being discussed here? It's just a universe with a uniform magnetic field.
Intrapolation of br-eqn is done to determine individual gravitational patterns. When a gravistar keeps growing, it would in effect be an increasing gravitational function. If you consider a reasonable amount of gravistars distributed then you will have a universe forever varying in the mag field.
As each system has more and more matter flowing in, the force exerted would literally be really really be big.
Assuming that when two of these come together it would create a mega field. A BH does not grow beyond the event horizon. A combination of even 3 such things distributed widely is enough to cancel out the validity of BR eqn.
What is the assumption in BR eqn? The universe has a uniform field. I maybe wrong, but wouldn't a series of immense gravstars forever growing in gravity, distributed around, kind of counter this? Please clarify.
Btw, Schwarzschild Radius itself has been verified and proved by Chandrashekhar, for which he won the Nobel Prize.
He proved that the radius itself (after some modifications) could be used as a limiting factor, i.e your Event Horizon.
There has been evidence from galaxies about the existence of EHs as observed by Chandra and Hubble, independently. In fact, there is also evidence of tunneling in EHs which have been photographed.
Given so many facts, it is really really very hard to just throw the Black Hole theory out of the window. It's just not that simple.
Actually, going by entropic laws, it would seem that the Universe is better described in say, 700 constants, than say, 6 constants.
But the reason these constants _are_ of prime importance is because as a solution to certain tensor calculus equations in relativity, and these constants have been observed to be unattainable, but have been observed. Ofcourse, it is entirely possible like how we once thought that the speed of sound could not be exceeded, we may still be wrong about the speed of light and absolute zero, but that is a remote possibility because no particle in the world has been observed to have c nor have absolute zero (now don't get me started on photons.... as I read somewhere, your guess is as good as mine on what they are).
...but no one has given any reason in the last 30 years as to why we should accept the current BH theory other than it looks good on paper and the "problems" will be solved one day.
Good point. But you are forgetting one important point - there has been _some_ evidence showcasing possible black hole like behaviour, which cannot be explained by gravistar theory, atleast not yet. Example - Event horizon, dense areas which are surrounded by matter with an invisible core, and so on. In fact, Chandra has observed the existence of an Event Horizon in M82.
If you have done any amount of tensor calculus & quantum physics related mathematics (which I'm assuming you have), you'll know that Black Holes can be described with considerable ease in a Riemann plane, than gravistars.
Think of the implications these guys are suggesting --
1. You have submanifolds which would overlap as more matter gets in, and so the relativistic frame would in itself be a function carrying many frames. Assuming a standard rate of expansion for each of these frames, you can imagine the number of frames which would be in existence by now.
2. The gravitational effects caused by a tending mass are described in general relativity. These use a mere 16 coupled hyperbolic-elliptic nonlinear partial differential equations, called the Einstein field equations. Now, you have a solution for these called Bertotti-Robinson Solution, and when these are applied to a Black Hole, they work out just fine. This, despite assuming a uniform magnetic field.
However, you will realise owing to the submanifolds, you may not be able to apply the same to a gravistar. It'd be way too complex. And Bertotti-Robinson have been proved
3. Despite what the say about the Schwarzschild Black Hole, the exterior solution for such a black holes _has_ been proved, and it conforms to the field equations proposed by Einstein.
Now these are independent results to the same set of equations. I think I'd rather trust Einstein than these guys:-)
Anyways, it would be interesting to watch how this would get on. I'm not against this theory, just that there _seem to be_ far too many unanswered questions.
These problems stem from the fact that our Universe is actually very different from the one that Schwarzschild considered. If we're to produce a proper description of the Universe we live in, Einstein's classical theories need to be meshed together with what we know about the quantum laws governing the behavior of fundamental particles and fields.
Ofcourse. And that is what the Unified Field Theory is all about. In fact, if only gravitons could be proved to exist, then there is a very high probability of the existence of the UFT. In fact, there are just 6 universal constants which need to be meshed in with their corresponding DEs to get the UFT up and running. Which, I'd say, seems simpler than what these guys may have to offer. Are these guys trying imply that UFT does not exist?
They believe that in the extreme conditions of a collapsing star, space-time undergoes a quantum version of a phase transition. The phenomenon is nothing new. The Nobel Prize for Physics in 2001 was awarded for the observation of just such an event in the lab: the transformation of a cloud of atoms into one huge "super-atom," a Bose-Einstein Condensate (BEC). This clump of atoms, which all share the same quantum state, forms at temperatures within a whisker of absolute zero.
In this context, are these people trying to say that the gravistar behaves as a BEC? That makes it a hell lot more complex because you will need really low temperatures, and adding more particles rushing to you at the speed of light increases the temperature and the entropy, both of which their theory goes against. Also Bosons (which are carrier particles, having an integer spin measured in the units of h-bar) would all possess exactly the same quantum state. So considering the existence of identical entities elsewhere, we could jump to any of these thingys just like that. Or any matter trapped in even one of these, could be spread across multiple copies of these entities.
The implications are really wierd, I somehow feel that Black Hole theories were a lot more plausible.
Occam's Razor -- These guys say that there are a lot of discrepancies in the Black Hole theory that are unanswered, and provide alternate explanations. There are some problems with their own theory --
...whether an exploding star could really lose enough entropy to form a gravastar, given that the second law of thermodynamics says that the entropy of an isolated object will always tend to increase.
That point in itself would be against the gravistar theory. Because, they themselves have admitted that there have been mathematical shortcomings. The implication of this is that quantum behaviour _can_ stabilise, in which case, we would have had BEC occuring naturally, which is not the case.
"The gravastar is stable," counters Mottola. He says that matter falling onto the shell could make it wiggle and radiate away energy, but because the gravitational pull of the shell balances the force of the springy vacuum inside, it couldn't actually collapse. Any matter that fell onto the shell would simply become part of it, he says.
It is easier to accept the Black Hole theory. Just consider the Chandrashekar limit for example - if you are withing range, you are absorbed, else you are pulled closer. And since photons themselves have been proved to be absorbed by these, there is evidence of even horizon. But in this, we would be having an evergrowing event horizon. Given the age of the universe, if the horizon _does_ grow, just imagine for a moment what this means. Heck, there would absolutely no chance of survival for giant stars, which is not the case. Agreed, could be anamolies, but nevertheless worth a thought, right?
IMHO, as someone with experience in particle physics (I've worked on SQUIDS), I feel that this theory has a lot of points which need to be ironed out.
For those of you interested in messing around with SMS from Linux (and Windows), check out this project. Damn cool, but generally getting it running is a pain (although the site does not state any dependencies, there are a few).
In fact, me and my friends were trying to get SMS working so that a centralised Linux box could be used to play simple games. This way, we got about 5 people on SMS at the same time:-) playing simple word games. But again, for all these thingys to be working, your provider must support messaging from the net (which most do).
Although we did not go any further, it was fun doing it. If someone is interested, I'd be happy to help them start some SMS based centralised gaming (yes, OSS). Nothing great, but even simple ones could be great fun!
Oops! Sorry, my mistake. I thought that mc was in some way related to nc, hence the err.
Btw, one question. If I'm right, mc supports an mc-vfs virtual file system, correct? Is this a feature of nc, or is it only in mc? Or is it impossible to have a vfs in windows?
I ask this since there are unerase utils in windows, could they be using a vfs? If they are, wouldn't they have to stay resident forever monitoring all content?
Why go that far? Even good old Norton Midnight Commander can do an undelete of the files on Linux.
It had troubles with the 2.0.x series, where only the first few blocks could be recovered, but as of 2.1.x & upwards, it works like a charm on ext2.
I'm sure there would be other utilities capable of this for other platforms. There was also this old program for Solaris (whose name I've forgotten) that'd do just what you'd said to restore deleted files.
I'm sorry, but I'll have to disagree with you. There is one important point which you miss out -- India already has an existing user/customer base of Linux which is ever growing, except that it is not very well known.
For example, some people from our own local LUG (http://www.chennailug.org) convinced the electricity board of some states here to use Linux.
(Incidentally, the other developer besides Miguel working on Mono, Ravi Pratap, is from our LUG)
The LUGs also take it upon themselves to spread Linux to colleges and schools. Lots of LUGs around the country have convinced schools, colleges and offices by conducting local Linux expos to showcase the prowess of Linux. The problem is, India being a relatively big country, you do not hear about these things. And offlate, we are really getting commercial queries to the LUG, and people are beginning to use it as a hiring ground for hunting good talent. Which I'd say, is a very good thing!
Another point is that, there are a lot of LUGs in India which have convinced their respective state/local bodies to switch to Linux. Since it is a bunch of freelancers doing it, it is not known.
But the truth is, India is beginning to see an evergrowing stream of companies switching to Linux. But because of the fact that other things are also going on, these are just not noticed. As an example, the number of people attending our LUG meets has literally tripled in the past couple of months!
My point is this - just because some companies do not do it, and there is no monetary benifit involved does not mean it's not happening. Just that world domination is happening subtly but surely:-)
As a lot of readers pointed out, one of the main advantages we have here in India is that our entire education is in English.
It may not sound all that great to a non-Indian, but then think of it, we usually know our mothertongue, our national language (Hindi) and based on the state you reside in, the language of that state, besides English (thanks to India being a former British colony).
So in a way, English acts as a binding factor, and in fact, most of us know better English than our own mothertongues. This has given us a small edge over several other Asian countries, where English is not compulsory.
An offshoot of this is the Support Industry from India. Decent technical skills, coupled with good knowledge of English and cheaper manpower, I'm beginning to see a lot of US/European companies outsourcing their support to third party Indian companies.
This works out great for both parties, since the Indian gets paid really well (well atleast relative to Indian standards) and the company need only pay very less. A poster above had said that Indians get paid $5 an hour -- although this seems to be a slight exaggeration, $5 is still fairly high for an Indian, where a fairly good programmer gets about $6000 a year, which is more than enough to lead a luxurious life here!
Another advantage is the cost of hardware & other structural costs. Hardware and other communications equipment here are *very* cheap. For example, you can get about 128 MB RAM for about $10-12. An ethernet card is about $8. So, the setting up of the support organization takes less time, and is cheaper.
Really, it is a win-win situation. And given market inertia, it may not prove to be easy to swerve the customers away that easily.
True. In fact, I'm surprised that lesser known languages like Lambda, Curl & Proto were given more importance than Ruby.
But on a different note, Curl is a pretty interesting language, and has a lot of features not seen in some of the design specific high level languages (like OO).
Not only is it a wierd mix of content and design, it has some wierder still means of accessing databases -- makes a HTTP/HTTPS request to an PHP/ASP/JSP/Perl file which performs the operation.
Although the interfaces generated are pretty nifty, these mostly look pretty only on IE.
And these guys have a business model that tracks the clients to see which servers using curl were accessed by those. Some privacy policy these ppl must have...
I want to be a Revolutionary like RMS and stick it to Microsoft. Hey, great. I now pronounce you a Revolutionary. Now: how are you going to stick it to Microsoft? Any schmuck can write free softwarwe. Not every schmuck can write something world-shaking.
Absolutely! M + X + World; C + X + Shake...
Sheesh, that was easy!;-)
As one reader in an earlier post, people who write bad and insecure code have an equal hand in security compromises.
Most of the worms and virii are being coded by teenagers or kids who just do not have an idea as to what they are doing.
Think of this, why are people allowing their systems to be compromised again and again? A hack is a different thing, a worm/virus is a different thing. When there are so many different worms/virii, it cannot all be squarely blamed on the creators. The makers of the softwares should own up responsibility for writing bad code.
Why aren't other operating systems as vulnerable as the Win* platform? It is not like there are not enough people willing to write worms in Linux or FreeBSD. It is just that it is not that easy to.
Most of these people are kids, for God's sake!
Writing a computer worm to show off to your friends is akin to showing off your driving skills. It is just a means of getting recognized by the peers. These people should just be taught that writing bad code is harmful. To compare it to heinous crimes and huge losses is just plain stupid.
If it also causes harm, that is largely because of the immaturity of the technologies. If sysadmins regularly patched up their softwares, and if programmers wrote secure code, the effect of these worms will steadily decline.
But how many admins bother to administer the latest patch? And how many software companies bother to get out good code? It is plain stupidity to blame it all one some poor nerd out there.
I work in a company that provides technical support. Hence, despite Christmas, we are working. The bad news is that most of our support engineers are here in India, and so it is only 24th in US when it is 25th here. So, most of these guys have to work on 25th (Indian time), and usually they don't have much of a choice.
And no, not everyone is India is a Hindu, there is a significant amount of Christian, Moslem and Jewish population here.
Re:Priorities: India, Kashmir and the Internet
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Carnivore Comes To India
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· Score: 3, Interesting
I believe you are correct that most Indians will not even know about these measures and that they can do something about them (even if they aren't affected at this point in time) due to more basic issues such as survival.
Dude, we don't exactly live in caves here.:-)
It is not like we are going to let our privacy be taken overnight. There are LUGs around the country which are also active in privacy issues.
But, at this moment, it is more important that we preserve our sovereignity and our integrity.
Benjamin Franklin's quote of those who compromise freedom for safety deserve neither sounds great, but when terrorists are out there waiting to wreck havoc, it isn't exactly that simple.
Democratic nations will preserve the interests of their people. There may be instances when it may seem otherwise, but ultimately the people will win. History has proved this to us, and Argentina is the latest example of this.
You said that a country pre-occupied with a war has little time for concern with such things as Internet privacy. True, but people are not going to keep quiet either. The amount of people involved in IT is *too* high in India to just ignore such troubles.
But anyways, they are not taking our rights just like that, not for now atleast;-)
Slashdot Mirror
If it's pot, it definitely is vapour! ;-)
Oh well, never thought I'd see the day when I'd try and post an informative post on a proposal on Valentines day, but anyways, for those of you who are ignorant of who Kathleen is, check out this site.
;-)
Sorry, couldn't resist
My knee-jerk reaction to the article posted was that it seems like the gravastar isn't allowed to grow, and it has to grow, right?
My 0.2! That is one point against it, in fact. Also, if everything within the shell border limit of rho=p would be in the fluid state, which could be BEC. Just imagine these thingys floating around.
In fact, the way the paper considers the region in the shell is interesting. Their proof shows that r has to be a constant for the shell.
One approximation in the paper which scares me is when they say that f & h are approx. constant in the shell. It is not. The difference would mean that the gravastar _would_ grow, albeit a little by little, atleast by cosmic accounts.
BH theory does not say entropy is low. It says there is high entropy, as a consequence of Hawking radiation which implies a negative specific heat. This is also one of the arguments used by the authors in their paper against black hole, and a very valid one at that.
...we note that the interior de Sitter region with p = -p may be interpreted also as a cosmological spacetime, with the horizon of the ex-panding universe replaced by a quantum phase interface.
:-)
However, both the theories face the same problem - how do they account for the lost entropy? These guys suggest a BEC formation which sheds, and Black Hole theorists have been having equally
bizarre explanations.
Notice their explanation for the region within -
Which could be a layer of BECs? Or some undefined nature? But in a blackhole, the entropy exists within, saying we have a parallel universe interacting to preserve entropy. Big deal, both are equally bizarre.
And blackholes can work well with dark matter. Not these.
The novel assumption required for this solution to exist is that low energy gravity can undergo a vacuum rearrangement phase transition in the vicinity of r = RS, in which the energy density and eq. of state change.
Knock, knock? Very great mass/energy ratio, but a really high mass. Would it still exist? Or would it somehow disintegrate? Would the phase transition undergo reversal?
It'd be interesting to work on that one
It's not just your theory, Occam's Razor, when applied to Black Holes, fails too.
:-P
From their paper -
Further, when a massless field such as that of the pho-ton is quantized in the fixed Schwarzschild background, one finds that the black hole radiates these quanta witha thermal spectrum at the asymptotic Hawking temperature TH = _h/8*kBGM [1]. The inverse dependence of TH on M implies that a black hole in thermal equilibriumwith its own Hawking radiation has negative specific heat.
In fact, that point in itself is a strong OR against BHs. But anyways, coming back....
Well, I reasoned Occam's Razor for the following reasons -
From the paper:
Energy conservation plus a thermal radiation spec-
trum imply that the black hole has an enormous entropy, S 10 77 k (M=M ) 2 [3]
Laws of thermodynamics clearly define that Entropy is on the rise. Given the amount of matter in a BH, this is acceptable (although theories on where these are a little wierd).
The novel assumption required for this solution to exist is that low energy gravity can undergo a vacuum rearrangement phase transition in the vicinity of r = RS, in which the energy density and eq. of state change.
Occam's Razor. Now just imagine a handful of dark matter in the vicinity, it no longer is _low_ gravity. I'd like to argue more technically, but I'd prefer it over e-mail than here.
Hence essentially all the mass of the
object comes from the energy density of the vacuum con-densate in the interior, even though the shell is responsi-ble for all of its entropy.
Different entropy concentrations? It's as wierd as BH causing Hawking Radiation and a high entropy of S ~10^77 k (M=M )^2
Since theentropy of these objects is some 20 orders of magnitude smaller than that of a typical stellar progenitor, a violentprocess of entropy shedding, as in a supernova, is needed to produce a cold gravastar remnant.Explosive bursts in which a finite fraction of atoms are ejected have been observed in attractive BEC's in the laboratory
A laboratory is one thing, a naturally occuring phenomenon is another. I do not mean to be derisive, but I find entropy shedding a little too hard to believe.
Agreed, BECs can be formed at high density too, besides low temperatures, but just apply Occam's Razor here and you will see that this means.
These are presumably characterized by a finite density of vortices of normal phasepenetrating the condensate core. Such rotating gravitational vacuum condensate stars, dark `grava(c)stars' arecandidates for the stable remnants of stellar evolution for stars exceeding the Chandrasekhar limit.
....
The remnants are left in an excited oscillatory state afterwards.
Have these been observed outside the lab? There is evidence of what seem to be black holes. Occam's Razor.
You seem to be confusing Riemannian manifolds (ND manifolds with metric structure) with Riemann planes (2D surfaces generated from complex functions).
:/
My mistake. I meant Cauchy-Riemann manifolds. Sorry
What the heck are you talking about? "Overlapping submanifolds"?? The authors aren't describing anything like that. "Frames carrying many frames?" You're babbling.
From the article:
Even if they did form, how would they survive the onslaught of matter raining down on them? "What happens if a gravastar has accreting matter showered upon it? Won't it collapse to a black hole?" he says.
"The gravastar is stable," counters Mottola. He says that matter falling onto the shell could make it wiggle and radiate away energy, but because the gravitational pull of the shell balances the force of the springy vacuum inside, it couldn't actually collapse. Any matter that fell onto the shell would simply become part of it, he says.
If the initial reference frame is defined by a predefined set, then the frame would forever grow. Whilst in a BH it would forever be there.
Think about it. A gravistar is forever growing. That way you will have Riemann manifolds for each previous state overlapping with the new ones.
The stability of the gstar would be defined by a very delicate balance indeed. So it kind of becomes very very recursive.
Dear Mr.photon, do you want to go inside. Fine, let me measure you and balance myself and then decide. Oh ok, now you are free to go! Get in.. Uh oh.. what about that one over there? Where does he come in? Well, he was defined by the previous state. Why? Since his distance is different, he is in a different ref frame. You mean for each of these guys my balance makes it madatory to apply different inertial frames? It appears to be a logical extension, doesn't it?
Also, consider a light cone into a gravstar. Wouldn't you have to take discrete functions for fixed intervals since a gravstar does not plainly absorb, it also grows.
What does the Bertotti-Robinson solution have to do with anything being discussed here? It's just a universe with a uniform magnetic field.
Intrapolation of br-eqn is done to determine individual gravitational patterns. When a gravistar keeps growing, it would in effect be an increasing gravitational function. If you consider a reasonable amount of gravistars distributed then you will have a universe forever varying in the mag field.
As each system has more and more matter flowing in, the force exerted would literally be really really be big.
Assuming that when two of these come together it would create a mega field. A BH does not grow beyond the event horizon. A combination of even 3 such things distributed widely is enough to cancel out the validity of BR eqn.
What is the assumption in BR eqn? The universe has a uniform field. I maybe wrong, but wouldn't a series of immense gravstars forever growing in gravity, distributed around, kind of counter this? Please clarify.
Thanks.
Btw, Schwarzschild Radius itself has been verified and proved by Chandrashekhar, for which he won the Nobel Prize.
He proved that the radius itself (after some modifications) could be used as a limiting factor, i.e your Event Horizon.
There has been evidence from galaxies about the existence of EHs as observed by Chandra and Hubble, independently. In fact, there is also evidence of tunneling in EHs which have been photographed.
Given so many facts, it is really really very hard to just throw the Black Hole theory out of the window. It's just not that simple.
Actually, going by entropic laws, it would seem that the Universe is better described in say, 700 constants, than say, 6 constants.
...but no one has given any reason in the last 30 years as to why we should accept the current BH theory other than it looks good on paper and the "problems" will be solved one day.
:-)
But the reason these constants _are_ of prime importance is because as a solution to certain tensor calculus equations in relativity, and these constants have been observed to be unattainable, but have been observed. Ofcourse, it is entirely possible like how we once thought that the speed of sound could not be exceeded, we may still be wrong about the speed of light and absolute zero, but that is a remote possibility because no particle in the world has been observed to have c nor have absolute zero (now don't get me started on photons.... as I read somewhere, your guess is as good as mine on what they are).
Good point. But you are forgetting one important point - there has been _some_ evidence showcasing possible black hole like behaviour, which cannot be explained by gravistar theory, atleast not yet. Example - Event horizon, dense areas which are surrounded by matter with an invisible core, and so on. In fact, Chandra has observed the existence of an Event Horizon in M82.
If you have done any amount of tensor calculus & quantum physics related mathematics (which I'm assuming you have), you'll know that Black Holes can be described with considerable ease in a Riemann plane, than gravistars.
Think of the implications these guys are suggesting --
1. You have submanifolds which would overlap as more matter gets in, and so the relativistic frame would in itself be a function carrying many frames. Assuming a standard rate of expansion for each of these frames, you can imagine the number of frames which would be in existence by now.
2. The gravitational effects caused by a tending mass are described in general relativity. These use a mere 16 coupled hyperbolic-elliptic nonlinear partial differential equations, called the Einstein field equations. Now, you have a solution for these called Bertotti-Robinson Solution, and when these are applied to a Black Hole, they work out just fine. This, despite assuming a uniform magnetic field.
However, you will realise owing to the submanifolds, you may not be able to apply the same to a gravistar. It'd be way too complex. And Bertotti-Robinson have been proved
3. Despite what the say about the Schwarzschild Black Hole, the exterior solution for such a black holes _has_ been proved, and it conforms to the field equations proposed by Einstein.
Now these are independent results to the same set of equations. I think I'd rather trust Einstein than these guys
Anyways, it would be interesting to watch how this would get on. I'm not against this theory, just that there _seem to be_ far too many unanswered questions.
These problems stem from the fact that our Universe is actually very different from the one that Schwarzschild considered. If we're to produce a proper description of the Universe we live in, Einstein's classical theories need to be meshed together with what we know about the quantum laws governing the behavior of fundamental particles and fields.
Ofcourse. And that is what the Unified Field Theory is all about. In fact, if only gravitons could be proved to exist, then there is a very high probability of the existence of the UFT. In fact, there are just 6 universal constants which need to be meshed in with their corresponding DEs to get the UFT up and running. Which, I'd say, seems simpler than what these guys may have to offer. Are these guys trying imply that UFT does not exist?
They believe that in the extreme conditions of a collapsing star, space-time undergoes a quantum version of a phase transition. The phenomenon is nothing new. The Nobel Prize for Physics in 2001 was awarded for the observation of just such an event in the lab: the transformation of a cloud of atoms into one huge "super-atom," a Bose-Einstein Condensate (BEC). This clump of atoms, which all share the same quantum state, forms at temperatures within a whisker of absolute zero.
In this context, are these people trying to say that the gravistar behaves as a BEC? That makes it a hell lot more complex because you will need really low temperatures, and adding more particles rushing to you at the speed of light increases the temperature and the entropy, both of which their theory goes against. Also Bosons (which are carrier particles, having an integer spin measured in the units of h-bar) would all possess exactly the same quantum state. So considering the existence of identical entities elsewhere, we could jump to any of these thingys just like that. Or any matter trapped in even one of these, could be spread across multiple copies of these entities.
The implications are really wierd, I somehow feel that Black Hole theories were a lot more plausible.
Occam's Razor -- These guys say that there are a lot of discrepancies in the Black Hole theory that are unanswered, and provide alternate explanations. There are some problems with their own theory --
...whether an exploding star could really lose enough entropy to form a gravastar, given that the second law of thermodynamics says that the entropy of an isolated object will always tend to increase.
That point in itself would be against the gravistar theory. Because, they themselves have admitted that there have been mathematical shortcomings. The implication of this is that quantum behaviour _can_ stabilise, in which case, we would have had BEC occuring naturally, which is not the case.
"The gravastar is stable," counters Mottola. He says that matter falling onto the shell could make it wiggle and radiate away energy, but because the gravitational pull of the shell balances the force of the springy vacuum inside, it couldn't actually collapse. Any matter that fell onto the shell would simply become part of it, he says.
It is easier to accept the Black Hole theory. Just consider the Chandrashekar limit for example - if you are withing range, you are absorbed, else you are pulled closer. And since photons themselves have been proved to be absorbed by these, there is evidence of even horizon. But in this, we would be having an evergrowing event horizon. Given the age of the universe, if the horizon _does_ grow, just imagine for a moment what this means. Heck, there would absolutely no chance of survival for giant stars, which is not the case. Agreed, could be anamolies, but nevertheless worth a thought, right?
IMHO, as someone with experience in particle physics (I've worked on SQUIDS), I feel that this theory has a lot of points which need to be ironed out.
For those of you interested in messing around with SMS from Linux (and Windows), check out this project.
:-) playing simple word games. But again, for all these thingys to be working, your provider must support messaging from the net (which most do).
Damn cool, but generally getting it running is a pain (although the site does not state any dependencies, there are a few).
In fact, me and my friends were trying to get SMS working so that a centralised Linux box could be used to play simple games. This way, we got about 5 people on SMS at the same time
Although we did not go any further, it was fun doing it. If someone is interested, I'd be happy to help them start some SMS based centralised gaming (yes, OSS). Nothing great, but even simple ones could be great fun!
The Bustpatents site is worth spending some eye-rubbing time on.
:-)
Whew! For a second I thought that was Bust patents. Almost had me...
Oops! Sorry, my mistake. I thought that mc was in some way related to nc, hence the err.
Btw, one question. If I'm right, mc supports an mc-vfs virtual file system, correct? Is this a feature of nc, or is it only in mc? Or is it impossible to have a vfs in windows?
I ask this since there are unerase utils in windows, could they be using a vfs? If they are, wouldn't they have to stay resident forever monitoring all content?
Why go that far? Even good old Norton Midnight Commander can do an undelete of the files on Linux.
It had troubles with the 2.0.x series, where only the first few blocks could be recovered, but as of 2.1.x & upwards, it works like a charm on ext2.
I'm sure there would be other utilities capable of this for other platforms. There was also this old program for Solaris (whose name I've forgotten) that'd do just what you'd said to restore deleted files.
I'm sorry, but I'll have to disagree with you. There is one important point which you miss out -- India already has an existing user/customer base of Linux which is ever growing, except that it is not very well known.
:-)
For example, some people from our own local LUG (http://www.chennailug.org) convinced the electricity board of some states here to use Linux.
(Incidentally, the other developer besides Miguel working on Mono, Ravi Pratap, is from our LUG)
The LUGs also take it upon themselves to spread Linux to colleges and schools. Lots of LUGs around the country have convinced schools, colleges and offices by conducting local Linux expos to showcase the prowess of Linux. The problem is, India being a relatively big country, you do not hear about these things. And offlate, we are really getting commercial queries to the LUG, and people are beginning to use it as a hiring ground for hunting good talent. Which I'd say, is a very good thing!
Another point is that, there are a lot of LUGs in India which have convinced their respective state/local bodies to switch to Linux. Since it is a bunch of freelancers doing it, it is not known.
But the truth is, India is beginning to see an evergrowing stream of companies switching to Linux. But because of the fact that other things are also going on, these are just not noticed. As an example, the number of people attending our LUG meets has literally tripled in the past couple of months!
My point is this - just because some companies do not do it, and there is no monetary benifit involved does not mean it's not happening. Just that world domination is happening subtly but surely
As a lot of readers pointed out, one of the main advantages we have here in India is that our entire education is in English.
It may not sound all that great to a non-Indian, but then think of it, we usually know our mothertongue, our national language (Hindi) and based on the state you reside in, the language of that state, besides English (thanks to India being a former British colony).
So in a way, English acts as a binding factor, and in fact, most of us know better English than our own mothertongues. This has given us a small edge over several other Asian countries, where English is not compulsory.
An offshoot of this is the Support Industry from India. Decent technical skills, coupled with good knowledge of English and cheaper manpower, I'm beginning to see a lot of US/European companies outsourcing their support to third party Indian companies.
This works out great for both parties, since the Indian gets paid really well (well atleast relative to Indian standards) and the company need only pay very less. A poster above had said that Indians get paid $5 an hour -- although this seems to be a slight exaggeration, $5 is still fairly high for an Indian, where a fairly good programmer gets about $6000 a year, which is more than enough to lead a luxurious life here!
Another advantage is the cost of hardware & other structural costs. Hardware and other communications equipment here are *very* cheap. For example, you can get about 128 MB RAM for about $10-12. An ethernet card is about $8. So, the setting up of the support organization takes less time, and is cheaper.
Really, it is a win-win situation. And given market inertia, it may not prove to be easy to swerve the customers away that easily.
Seems to be a very eye-ventful day, isn't it? :-)
Note: Who you like and dislike is not private; it can and will be used against you.
Sheesh! It's amazing what too much of IANAL stuff can do to you
True. In fact, I'm surprised that lesser known languages like Lambda, Curl & Proto were given more importance than Ruby.
But on a different note, Curl is a pretty interesting language, and has a lot of features not seen in some of the design specific high level languages (like OO).
Not only is it a wierd mix of content and design, it has some wierder still means of accessing databases -- makes a HTTP/HTTPS request to an PHP/ASP/JSP/Perl file which performs the operation.
Although the interfaces generated are pretty nifty, these mostly look pretty only on IE.
And these guys have a business model that tracks the clients to see which servers using curl were accessed by those. Some privacy policy these ppl must have...
Top 10 Sports Queries
;-)
2001
1. anna kournikova
Ofcourse. I'm very sure those searches were for the sporting capabilities of Anna Kournikova. The question is, which sport?
I want to be a Revolutionary like RMS and stick it to Microsoft. Hey, great. I now pronounce you a Revolutionary. Now: how are you going to stick it to Microsoft? Any schmuck can write free softwarwe. Not every schmuck can write something world-shaking.
;-)
Absolutely! M + X + World; C + X + Shake...
Sheesh, that was easy!
Well said. Just my thoughts...
As one reader in an earlier post, people who write bad and insecure code have an equal hand in security compromises.
Most of the worms and virii are being coded by teenagers or kids who just do not have an idea as to what they are doing.
Think of this, why are people allowing their systems to be compromised again and again? A hack is a different thing, a worm/virus is a different thing. When there are so many different worms/virii, it cannot all be squarely blamed on the creators. The makers of the softwares should own up responsibility for writing bad code.
Why aren't other operating systems as vulnerable as the Win* platform? It is not like there are not enough people willing to write worms in Linux or FreeBSD. It is just that it is not that easy to.
Most of these people are kids, for God's sake!
Writing a computer worm to show off to your friends is akin to showing off your driving skills. It is just a means of getting recognized by the peers. These people should just be taught that writing bad code is harmful. To compare it to heinous crimes and huge losses is just plain stupid.
If it also causes harm, that is largely because of the immaturity of the technologies. If sysadmins regularly patched up their softwares, and if programmers wrote secure code, the effect of these worms will steadily decline.
But how many admins bother to administer the latest patch? And how many software companies bother to get out good code? It is plain stupidity to blame it all one some poor nerd out there.
I work in a company that provides technical support. Hence, despite Christmas, we are working. The bad news is that most of our support engineers are here in India, and so it is only 24th in US when it is 25th here. So, most of these guys have to work on 25th (Indian time), and usually they don't have much of a choice.
And no, not everyone is India is a Hindu, there is a significant amount of Christian, Moslem and Jewish population here.
I believe you are correct that most Indians will not even know about these measures and that they can do something about them (even if they aren't affected at this point in time) due to more basic issues such as survival.
:-)
;-)
Dude, we don't exactly live in caves here.
It is not like we are going to let our privacy be taken overnight. There are LUGs around the country which are also active in privacy issues.
But, at this moment, it is more important that we preserve our sovereignity and our integrity.
Benjamin Franklin's quote of those who compromise freedom for safety deserve neither sounds great, but when terrorists are out there waiting to wreck havoc, it isn't exactly that simple.
Democratic nations will preserve the interests of their people. There may be instances when it may seem otherwise, but ultimately the people will win. History has proved this to us, and Argentina is the latest example of this.
You said that a country pre-occupied with a war has little time for concern with such things as Internet privacy. True, but people are not going to keep quiet either. The amount of people involved in IT is *too* high in India to just ignore such troubles.
But anyways, they are not taking our rights just like that, not for now atleast
There was a mention of this in the ACM magazine, Communications of the ACM.
An online version of the article can be found here.