313 posts • joined Thursday 19th November 2009 10:41 GMT
Re: Why not use the Knuth scheme
You do when you get to the 10,000,000,000,051st version.
Re: Again please let
Actually the errant "is" in that sentence makes me think that originally it was "Without wanting to downplay the seriousness of the trouble “Aush0k”, as Flannery is alleged to have called himself online, is in – if convicted of the attack the maximum sentence he could receive is 12 years in the slammer – news of the target means there's plenty that doesn't ring true about this csase" before being torn to bits by an incompetent sub-editor who also managed not to see "csase".
Thank you, I'm genuinely flattered. I'm not sure *all* my posts are informative or interesting, though...
We'll certainly not settle the issue one way or another without a dedicated experiment. There were discussions for one back in 2007 but then unfortunately 2008 happened and all the funding got cut - hopefully it'll come back. Actually I've spent the evening sitting in a pub with a guy who worked on MOND and we're both convinced that, one way or another, MOND is the valid description of gravity on galactic scales. Where we differ is whether this is phenomenology (which is my view; I can't accept MOND as fundamental but I very much feel that this is what we'd find if we *could* map GR from solar system scales up to galactic scales) or whether it's actually the behaviour of gravity on such large scales (which I *think* is his view but he's less prone to wild pronouncements than I am). I can't see the latter, myself, but if it were true it would certainly suggest that there should be something similar to a Pioneer anomaly...
Re: Einstein's Limit and Time Travel
You do have to find a way of seeing each end of your measuring stick though, which will be limited by the speed of light - so a measuring stick the size of the galaxy is a bit restrictive. And if you have to literally go and look at each end of the stick it'll take you billions of years to make your measurement...
The usual thought experiment in relativity is to use lasers to map everything out. It's about the only way of doing it that isn't going to quickly get bewilderingly tangled.
Of course, none of this is important if instead of a measuring stick you have a different way of measuring the size of something, and then sit and watch. So in cosmology we entertain ourselves with the wavelength of oscillations way back when the universe was hot enough that the proton+photon admixture was fully ionised; if an electron ever condensed into a proton to form hydrogen it was immediately reionised. Back then (if you believe the theory, and this one *is* a theory with a depressingly large amount of observational support unlike string theory and LQG ;) ) this coupled the protons and photons together, making them act like a single fluid. So the protons would all try and collapse into clumps under gravity but radiation pressure would push them back out again, which set up oscillations with a very predictable wavelength. That wavelength is seen on the microwave background -- it's the cause of all those little humps on this utterly staggering plot. That's from when the universe was about 300,000 years old. It's also the cause of the little ripples on this equally astonishing plot, which is from when the universe was over ten billion years old. The point of this sudden wall of text is that since we know what theory predicts that wavelength to be, we can use it as a "standard ruler". So in a manner of speaking we actually can watch things on a truly massive scale. (That wavelength there is on something like 150Mpc, off the top of my head. Something like that. That is truly enormous.)
Sorry :) I have a very bad habit of using the Register to try and write popular cosmology. It must be excruciatingly irritating...
Re: Relativity --the non existent theory.
It's why I said "almost certainly" :) I thought this paper was relatively persuasive. I'd be in favour of a mission going out there -- given budgetary constraints it would have to literally piggy-back on another mission, perhaps out to the Oort cloud or to reexamine Uranus or Neptune -- too. Personally I highly doubt that there is any new physics in it, but I would also very much love it if there was. It would be extremely neat. Solar system scales: GR works perfectly. Scales over ~200-300AU: gravity is a bit stronger than GR. Galactic scales: gravity is significantly stronger than GR (hence galactic dark matter). Cluster scales: gravity is stronger again. Then a massive fall-off -- coinciding with the homogeneity scale where the galactic distribution becomes effectively smooth -- leading to gravity being weaker than GR (hence dark energy). So basically a rise in the interaction strength up to the homogeneity scale and then a rapid fall-off.
(It's also interesting to note that the Pioneer anomaly kicks in when the acceleration drops to the MOND acceleration. Which is rather intriguing, as is the fact that that acceleration is basically the reciprocal of the horizon scale.)
"Eventually we are bound to find some parts which can not, and can never be, reconciled."
Probably, although I'd be wary of ascribing this to Goedel's theorem, which has a particular set of conditions.
"It has always seemed to me that many theoretical Physicists and String Theorists in particular forget this aspect of the language they write their theories in, and from this we get assumptions such as that the Mulitverse must be true because we can write consistent stories that require it to be true."
I don't think I'd agree with that at all, but I would certainly agree that it is often communicated to the public at large (and even the wider physics community) that way. Anyone actually working at a reasonable level in either string theory or in LQG -- or any other quantum gravity -- is well aware that others are working in entirely different approaches that use entirely different formalisms and even with different goals. String theory rapidly became an attempt to find a theory of everything, thanks chiefly to the discovery that you can have closed strings that act as massless spin-2 particles (and hence gravitons) in the same framework that you can have open strings that act as standard model particles. LQG is far less ambitious and attempts simply to find a (first-)quantised theory of gravity.
There are intriguing hints of dualities between them that could suggest that they're facets of hte same theory but it seems much more likely that actually those are little more than mathematical curiosities and that both theories cannot be true at once. Even if the dualities between the theories extend to all observables (as between Schroedinger and Heisenberg quantum mechanics) the alternative approaches to quantum gravity, such as Regge calculus, dynamical triangulations, non-commutative geometries and the rest, will almost certainly not be linkable into the same framework. That means that eventually various theories will fall. No-one working in the fields is unaware of this. This implies that basically all but one of those theories are certainly fiction, as you phrase it, and it seems most likely (including to those in the fields) that *all* of them are fiction.
Ultimately this isn't much of an issue. We're attempting to write theories that explain how gravity behaves on extremely small scales, at extremely high energies or in extremely strong gravitational fields. There are obviously different ways to do this. A natural example in this context is the relationship between GR and Newton's theory of gravity. Certainly we can demonstrate that GR reduces to Newtonian gravity in the appropriate context (slow-moving sources and weak fields), but we have to be very careful how we phrase that. The fundamental concepts of the theories are absolutely and irrevocably sundered. Newton's theory is a fiction, viewed from the point of GR, which is certainly a much more accurate theory of gravity. That doesn't invalidate Newtonian theory - it's perfectly good in the regimes in which it holds - but it does say it's nothing more than a convenient description. The same is true for GR itself and, most likely, to quantum mechanics, to quantum electrodynamics, and to practically every other theory in physics.
I would also add that ultimately all that physics is is a collection of algorithms that we apply to particular situations. You have to build those algorithms somehow, and in the absence of experimental data -- as in the cases of string theory and quantum gravity -- you use rather looser, aesthetic notions of the beauty and cleanliness of a theory, linked with plausible extensions to current theories. When experimental data comes in, you can test your algorithms, refine or reject those that don't work, and keep the ones that do. We may very well find that there *is* no theory of everything and that we merely have to be aware of the regime in which we are working and choose between the theories that operate best in those regimes.
And as far as that goes, this is no different from the rest of science, which - and I mean this with absolutely no perjorative undertones whatsoever - is phenomenological and descriptive.
Of course, where you are totally right is that unfortunately string theory in particular has been sold to the public (and to the funding agencies) as something more than it is, which is an extremely interesting, elegant solution to a particular physical problem, and one which all who research it know is not quite right, although most firmly believe they're on the right track.
(Personally speaking, I don't. I think LQG has by far the better idea, and I'm also very keen on Padmanabhan's current push towards thermodynamical descriptions of gravity. We know for sure - the only thing we know for sure - that gravity behaves on laboratory scales and upwards as if spacetime is curved by the presence of masses. We also know that the description does not work on smaller scales. We *also* know that if you model the propagation of phonons (quantised sound waves) in quantum fluids you often find that they behave as if they're propagating through a Schwarzschild spacetime -- there is an emergent geometrical structure that acts very like gravity. We further know that general relativistic black holes obey things that look startlingly similar to the first and second laws of thermodynamics. If we want to map from small scales and up, it seems to me both obvious and inevitable that we will end up considering gravity as an emergent, thermodynamical phenomenon. What the underlying microphysics is that gives rise to it is obviously a different question, and one to which I have no answer whatsoever, but that isn't necessarily a problem. Physics is replete with examples of emergent systems that are understood even if the microphysics isn't -- thermodynamics itself is a wonderful example of an emergent theory that was known decades before statistical mechanics was developed to map from the dynamics of individual molecules up to the behaviour of a roomfull of gas.)
Re: Relativity --the non existent theory.
Out of interest, are you aware that the Pioneer anomaly is almost certainly due to excess dissipation rather than new physics, and that the faster-than-light neutrinos "detection" was firstly never declared as a declaration and secondly later pinned down to a systematic (that systematic being a faulty connection). Given this, I'm fairly sure that your rather incoherent write-up proving -- by splashing random numbers down onto a page connected by somewhat ungrammatical gibberish -- that neutrinos travel faster than light *to exactly the level "observed" in Italy and that the Pioneer probes are *retarded to exactly the level "observed" in data (although, interestingly, not in the Voyager data) rather invalidates your loosely-defined and loosely-formulated "theory".
An Alcubierre drive would be a wonderful weapon, and an even worse unintentional disaster. I'd rather someone didn't make one. (It couldn't work in nature, anyway, even assuming we can generate and control dark energy (which is effectively the "exotic matter" it needs, something with p<-rho/3); it relies on absolutely nothing disrupting the spacetime, and a single hydrogen atom does so, let alone the planet you're flying away from.)
Re: Any explanation of WHY we thought this might work?
"Was it reasonable to expect that relativity might have been circumvented by such a large mass?"
Not really, but we do expect GR to finally break down in strong gravitational fields, and any test of GR in increasingly strong fields is going to allow us to push it that bit further. Gravity is so damn weak it's almost impossible to probe it across a range of scales and field strengths, leaving us pretty much in the dark about how it behaves. So while within the context of GR itself there is no reason to expect anything to change close to a neutron star (hell, you don't expect anything to change when you're near to or even crossing the event horizon of a black hole), it's another regime in which to test it - and it could very well be wrong.
As it is, it doesn't look like we'll be lucky enough that GR begins to break down with such low density objects as, err, massive neutron stars, so it's back to the drawing board.
Re: Time travel
I also highly recommend Time Patrol by Poul Anderson (thankfully sold by Baen http://www.baenebooks.com/p-428-time-patrol.aspx so it's been well-made, DRM free and available in any eBook format - or indeed dead tree format - you want) for a similar kind of viewpoint.
Actually I really love this book. I only read it a year back but I might read it again, I've got a transatlantic flight coming up and it strikes me as an ideal time.
Re: I'm less convinced than I sound that all DACs are created equal
Thanks for the links, I'm going to enjoy reading my way through those :)
even ignoring questions of whether this setup is possible (it isn't) and what would actually happen (a pressure wave moving along the rod and causing it to bend quite dramatically and then snap - or, as someone commented above, actually collapse in on itself gravitationally since you're imagining a universe which is otherwise empty; actually, that's an interesting thought, you could model this setup using a spacetime which has a directionality and which can be rotated, not sure what that would be, one of the bianchi models probably), the other end of the rod wouldn't move beyond the speed of light -- time-dilation and length-contraction effects would immediately kick in. to the poor sod sitting on the far end of the rod the universe would look extremely contracted, and to everyone else he'd look both squashed flat and extremely scared.
Re: Special Theory of Relativity
"Maybe the general theory also sets the speed of light as a restriction."
Yes, and much more naturally. In GR it comes down to the type of geodesic you can follow. There are "spacelike", "null" and "timelike" and never the twain (well, three) shall meet. Spacelike geodesics involve faster than light travel, and connect us to "the present" which is unobservable. Future-directed timelike geodesics map out the "future light cone", which is everything we can ever possibly experience from where we are. Past-directed timelike geodesics map out the "past light cone" which is everything that we could ever possibly have seen or interacted with. Massless particles propagate along null geodesics.
Well, we know the flaw is more the fault of GR than QM, but no-one's going to be astonished if QM is also wrong. (I lie, a lot of people will be, but they won't be when they've stopped to think about it for more than five seconds.) The simple problem is that if you look on small enough scales GR predicts some very different behaviour to QM. For instance, going to sub-nuclear scales GR would predict that fundamental particles are black holes and shielded behind a horizon. Now that may be a hint towards how to unify the theories -- maybe all particles *are* what GR describes as black holes; they can, after all, possess classical charge and classical angular momentum (that's a Kerr-Newman hole), so perhaps a unified theory will find a way of describing an object that has a quantised charge and quantised spin and yet acts in a manner similar to a relativistic black hole. The thing is that that *still* won't be GR -- it will be a lot more like QM.
What's worse are two simple things:
1) We cannot properly formulate quantum field theories on a curved spacetime. You run into all manner of problems in defining a vacuum. (Technically what I've said isn't entirely true. We can do it, in principle, both in string theories and in loop quantum gravity, and probably other approaches to quantum gravity that I'm unaware of. But in practically every situation one defines a *classical* background - almost always Minkowski or Schwarzschild - and then propagates both quantum fields and gravitons on that background. This is not a complete theory.)
2) We still cannot, despite the best efforts of some staggeringly intelligent string theorists and equally intelligent (though less appreciated) loop quantum theorists and some even less appreciated people working on non-commutative geometries, dynamical triangulations etc. etc., find a quantised theory of gravity. That means we cannot yet describe gravity even with the language of Schroedinger/Heisenberg ("first-quantised") QM, even in the absence of particles. We *can* write down loop quantum gravity, which is a first-quantised vacuum theory, but mapping from LQG up to GR is to my knowledge still an unsolved problem... and what the hell is a vacuum gravity meant to mean in a quantum context anyway? We can also write down various string theories, which are technically "second-quantised" (meaning they're described by interactions between virtual particles; the terminology is horrible), but they are both practically useless in that it is still impossible to get anything close to a testable prediction from them, and somewhat unhelpful since you can boil them down to about 10^10^120 different universes anyway. Which doesn't strike me as particularly helpful.
The big problems are that GR itself is "non-renormalisable", which means if you attempt to second-quantise it you run straight into numerous unhelpful infinities, and that if you attempt to first-quantise GR you have to deal with the fact it doesn't actually have a Hamiltonian (which you can interpret as a kind of mind-breaking spacetime energy, if you want) so you're attempting to solve the equation 0 * | psi > = E * | psi > which obviously gives you nothing of any worth...
Anyway, TL;DR, we know it's more the fault of GR because QM is extremely well tested in the laboratory and quantum electrodynamics in particular is still by far our most accurate theory, whereas GR is absolutely untested on scales below about 0.1mm and above roughly the distance to the Oort cloud (which raises entertaining questions about whether we should believe conclusions about galactic dynamics based on GR, let alone cosmology - and obvious we shouldn't, which includes all speculation about dark matter and dark energy, except that we still don't have a good alternative, alas) and entirely fails to predict the behaviour of matter on smaller scales.
And on crappy Apple ear-buds, which are the litmus test of a good mix. If it still sounds reasonable coming through those pieces of turd then you know you've done a good job.
I wouldn't label them audiophiles. To me that's derogatory, whereas wanting to enjoy music in as high quality as possible is perfectly justified. It's the pseudoscience and smug, ill-informed willy-waving that marks out an audiophile to me.
(Though saying that I'm less convinced than I sound that all DACs are created equal, which makes me as ill-informed as the worst audiophile...)
While I won't argue your point because I agree, DACs are dirt cheap these days and are practically all the same. What's going to destroy their enjoyment is the shitty encoding done by whoever they torrented the tracks from, and the shitty headphones they're using.
Re: Beats vs. BeyerDynamic
You also need to make sure that when you do master on headphones you're doing it with monitor headphones with as flat a frequency response as possible. (You then also master on some tinny little piece of shit, reasonable consumer-grade speakers and back up to the full studio kit.) Not that I'm much of a mastering engineer - I'm terrible at it, truth be told, and have a bad habit of drenching music in reverb - but at least I'm vaguely aware of how people better than me go about it.
or you could, you know, install kde or cinnamon or mate or xfce or lxde or..... i don't use ubuntu myself (fedora + cinnamon on my linux partitions) but i do tend to feel that not using it just because of unity is silly. i hate gnome 3, and yet i use fedora which has positioned itself as very much a gnome 3 distribution.
@Eadon. To be pedantic
What that six sigma meant is that they were six sigma away from the predictions of a basic "massless neutrinos traveling at light speed" model. Turns out the model that best fitted the observation was the "loose optical cable" model, but the important thing to note is that the deviation only tells you how far deflected your observations are from a prediction.
So in this case, they've got a three sigma deflection away from "no WIMPs in this region". Whether that means they've seen dark matter (which I doubt, it's far too light), it's simply the usual kind of fluctuation that particle physics sees the whole time, or if it's actually an uncontrolled systematic is a different matter.
And like you say, three sigma is not treated in particle physics as an observation. It's not a "joke", but it is treated as something interesting that should be followed up on because it may well not be reliable. That's not to say that particle physicists don't sometimes mock us in cosmology for treating one sigma as interesting and three sigma as "practically" proven...
Re: 32 reports and they are Troubling...
"other areas exhibited periodic changes in emission levels of up to +3,-3 degrees"
That would be extraordinarily troubling were it true; the CMB being at about 2.76K to one part in 1000 (even before subtracting off a dipole which is probably almost pure Doppler), so -3 would take it to below absolute zero... Ignoring that pednatry, such large deviations would also have shown up in COBE as a horrible distortion of the blackbody spectrum. They would also be very clearly evident in WMAP. (And depending on the scale they occur on, would also have shown up at the South Pole Telescope, in Boomerang, and various other smaller-scale CMB experiments. The scale on the angular power spectrum is in microKelvin; the dipole anisotropy is one part in 1000, whlie the first acoustic peak, which is the maximum anisotropy otherwise seen on the CMB, is one part in 10,000. The typical anisotropy is one part in 100,000.) Where did you read that part?
The SH initials were basically WMAP facetiously claiming that none of the anomalies are significant. There is a gross difference between hunting for SH in the dataset (which is a posterior statistic) and finding anomalies like the dipolar signal seen in both WMAP and Planck, and WMAP rather disingenuously conflated the two, which is unfortunate since otherwise WMAP was an exemplary piece of science and contributed enormously to cosmology. I started my PhD in the September before the first WMAP data release, so my undergraduate cosmology classes showed angular power spectra compiled from the likes of COBE and the first Boomerang release, and we basically had a few blocks that showed hints that there may or may not be an acoustic peak. Then WMAP came along and cosmology changed overnight - it was an amazing time to start a PhD. Planck is a similar step ahead of WMAP, and the angular power spectrum they've derived is astonishing, and moving to astonishingly small scales. Vast datasets are suddenly almost obsolete and to be used more as consistency checks than raw data (although the importance of such checks should not be understated, as a control on systematics even if nothing else).
Next year will be good; Planck will finally be able to release polarisation data. WMAP similarly had to delay it from the first year to the third year (cancelling a second-year data release in the process), and the sheer precision of Planck makes their job cleaning foregrounds out of the polarisation maps all the more ludicrously difficult. I'm looking forward to it. Hope number 1: detection of a B mode spectrum. Hope 2: E mode spectrum cosmic-variance limited up to say l=500 or so. Hope 3: T/E cross-correlation cosmic-variance limited up to l=1000 or greater. It will be fantastic.
Re: Bubble is beginning to burst
An FTL drive (taking it in the simplest idea; what I'm saying certainly won't apply to something like the Aclubierre drive) is intrinsically a time machine. Faster than light travel means you go on spacelike geodesics. Granted, I can never actually go to our past light cone so I can't actually go to that spot, but I can go to a time when the proper age of the universe is about 380,000 years and take a look around.
Re: Bubble is beginning to burst
The picture of the cold spot is from when the universe was less than 400,000 years old. Unless you're going faster than light you'll get to where it was and find nothing but destruction. (An alternative is that it's actually an enormous void, a gigaparsec or so across. But that in itself is probably from when the universe was, I dunno, 7 billion years old. So when you get there it'll still be destruction and nothing else.) It was nice knowing you (or your descendents, at least.)
aha, the blogger is rich easther. he's well worth listening to. i still disagree with him slightly on that point, the fact that two different datasets show the same anomalies is significant. the dipolar anomaly in itself is extremely interesting. he's right that i think they're being played as headline fodder, but i don't think it's fair to say it's not significant.
one other thing of interest is the surprisingly low hubble rate, which is in tension with astrophysical observations, although in agreement with estimates from large-scale galaxy surveys. resolving that tension is going to take some interesting astrophysics.
Re: Uneven expansion?
to be pedantic, actually a bit of both. the expansion rate itself picks up some corrections from perturbations; it would be strange if it didn't. but by far the dominant effect is, yes, of course, these were pre-existing perturbations. (and the influence of the stretched expansion rate is itself automatically taken into account, since the linear theory is closed.)
The reason they're so significant now is that they *have* been seen in both WMAP and Planck. What that tells us is that it isn't instrumental systematics in WMAP; the two probes are set up very differently and with totally different scanning strategies. So now we know there is something there, that if we sent another probe out to L2 it would see the same. Whether it is another cause of systematics -- local environment (L2 does after all attract quite a bit of crap), something galactic, whatever -- or whether it is cosmological is another matter. The good thing is that we now know it's real.
But the blogger is right, they were there before. Just now we have to take them seriously, unlike Bennett who released this snide paper a few years ago sneering at anyone who thought they were real anomalies. Well, Bennett, they are, and what's more they've been shown to be by a project you're an important member of. I doubt he'll withdraw his shitty attitude though.
Re: Lost interest after ATV 2nd gen
(Plus the WDTV Live is a hell of a lot better. Same price but handles AVI, MKV, FLV and whatever else you throw at it, up to 1080p though I imagine it would start burning with a 1080p MKV. Icon because this isn't quite a troll since I've used friends' Apple TVs and I certainly wouldn't trade my WDTV Live with them, I love it despite its crappy remote. It is however anticipating a flaming.)
Re: the answer
It's going slightly off-topic but recently I watched through "In Search of the Trojan War" by Michael Wood again. Despite the shoddy quality of the camerawork, the weirdly over-dramatic synth music, and the habit of showing him with his shirt half-unbuttoned, it was a lengthy, in-depth, erudite examination of archaelogical and historical aspects of Troy and its position balanced between Greek, Egyptian and Hittite worlds. This covered six hours. I then watched a more recent BBC documentary on the same topic, which covered a single hour and consequently the experience felt a bit like lying in a puddle after bathing in the Mediterranean, despite the 20 years of additional data they had to work with, and the vastly improved production values.
I then went to try and find "In Search of the Dark Ages". The only thing I can track down is a YouTube posting where some doofus has split the damned thing into 2:54 chunks followed by a few 12:00 chunks, for no readily-apparent reason other than to piss me off stitching the damned things back together. The BBC seem to have lost their videos, given it's not out on DVD (or I'd have been happy to buy it). I'd love it if they would start collecting what programs they possibly can, and put them all up for streaming online. I'd pay for that service, very happily. Alas, no, and I'm stuck with video rips on YouTube cut into absurdly small chunks.
Re: UK adverts on TV catchup sites
I live in Norway, where the cost of a TV license would horrify the "ripped-off" Brits, and which is payable on ownership of a TV, not on the reception of broadcast media (though I imagine the use of that little loophole is nigh-on impossible in the modern world). In return for my extortionate license fee of roughly double that I paid in Britain in 2006, I get a couple of channels of utter unmitigated drivel, the ability to say "I helped pay for Eurovision and that forced the World Cup off the telly because NRK couldn't afford both! Go me!", and then a range of private channels that rebroadcast British and American TV with semi-illiterate subtitles in Norwegian. As a result, I haven't watched a single bit of Norwegian telly in years.
Not that I'm saying the British aren't actually ripped off (I've been out of the country so long I don't know if you are or not), but I think we're worse done by here. You get the BBC which for all its many faults - and there are very many - remains amongst the best news organisations, and better content producers, that I'm aware of. We get NRK, which is shit and grotesquely expensive. And shit.
Re: Guess that includes me then
Mandriva went pay-only? I never knew that! Shows how long it is since I looked at it, I guess... At the minute I've got Fedora+Cinnamon on my Linux box and it works fine for me. A few niggles about Mint drove me back to Fedora which I know and understand a bit better, but I'm very much liking where Cinnamon is going and it plays happily with Fedora. That's not to say I don't have the usual problems - at the minute my wireless connection, which has been a wearying, tedious fight for the last five years with that machine...
Anyway, this is slightly off-topic. On-topic, Mint is a very good choice for people wanting to get away from Ubuntu; and for those disillusioned with Unity and Gnome 3 and who, like me, aren't really that big fans of KDE, both Cinnamon and MATE are in decent shape and moving along nicely.
Re: Guess that includes me then
If you really want to ditch Ubuntu and stay on something similar then either Mint or straight Debian are far the easiest options; mainstream Mint even still hangs off Ubuntu rather than direct from Debian. Or you can go for kubuntu, xubuntu or whatever else floats your boat (though I always preferred Mandrake/Mandriva as a KDE distribution). Or install Fedora and join the wild ride of constant kernel updates to add some adrenalin to your days.
Re: Of the things I'd like to see in the next...
You speak like one previously burned :) I used to do some sysadmin on a Solaris system and I learned to loathe it because it never did quite what I thought it would... :)
I was meant to be writing large chunks of a program I've been meaning to build for years this afternoon. Instead I found myself starting up DOSBox and a new city -- childishly dubbed "Pisshole on the Prairie" -- and turning it into the most depressingly ugly place to live that a man could dream of. I think I'll be building code on Sunday instead since my ambition is by then to have filled the city with dangerous, depressing Arcos and millions of policemen.
It's far too useful for it not to be a common tactic, surely? I do like the only justifcation I can come up with, that the water is flowing downhill through my turbines, and then I'm pumping it back uphill again. No-one ever announced a perpetual motion engine in the newspapers that flash up but evidently that's because it was invented just before 1900...
I found that if you put down strips of ornamental water and surrounded them with pumps you could have an enormous water supply. That wasn't meant to work, I don't think, but it did... Same as getting effectively free electricity by putting ornamental water on a slope and then putting hydroelectric dams on it. So I had little hillocks dotted around my cities with water tiles surrounding them, coated in hydro dams, and with a park on top that no-one could realistically get to because there were hydro dams in the way.
This was all nice and green but about the only nice and green thing about the smog-ridden industrial behemoths with police stations on every corner that I tended to build. I would have hated to live in those cities. No bus stations, no train stations, no subway, precious few parks except hidden behind hydroelectric dams, police stations everywhere and a military base that the mayor has a track record of calling on whenever people protest in the streets. Making cities *nice* always seemed a bit too much effort :) (Except the patch in the middle of woods and marinas over on the far side of the map where the mayor had his mansion and his statue and some luxury residences around.)
Re: Well hello there...
You wouldn't need direct thought interfaces -- just eye-tracking glasses would be fine. Forward and rear-facing cameras would mean it could tell where on screen you were looking.
Granted, an issue there is that every time you glanced down to see your health you'd start shooting your feet off, but there are drawbacks with every control method.
Re: @AC 02:46
"Death-throes". Things that are dying rarely have the strength to throw things all that far. Hell, even Arthur had to get Bedivere to throw Excalibur into the lake.
Re: Vacuum state of the universe
No problem, I just like people listening to me and asking sensible questions I can answer (or saying something that totally stumps me) :)
Re: Vacuum state of the universe
The number simply comes from saying "Well, the energy in momentum space is sqrt(p^2+m^2), right? Right? Well, then, we get the vacuum energy by integrating across that, right? Right? But we need a cut-off because it will go to infinity, right? Right? So what cut-off do we use to get the most idiotic answer? The Planck energy, right? Right? Right!" And then you find a number something like 123 orders of magnitude greater than the observed vacuum energy. Silliness, you can't assume there's no running towards higher energies, and you can't even apply that formula to something near the Planck energy, and you can't pretend you know what happens in the Planck regime. And if you get an infinite answer it just says that something needs renormalising, which happens throughout field theory anyway, and what we're seeing is a screened vacuum energy which quite possibly is composed of different parts anyway. (A cosmological constant is not necessarily hte same thing; if for instance gravity was well described by, I don't know, alpha * exp(R/R0), then in weak fields you'd get alpha + alpha*R/R0 in your action, and alpha would act as a vacuum energy. It would not necessarily have the sign of the vacuum energy from the matter fields so we would have cancellation of the screened constant with the gravitational constant, etc. etc.
120 orders of magnitude is absurd. Taken at face value though it doesn't half make us look like a bunch of duffers. Hell, the 40 orders of magnitude makes us look like a bunch of duffers....