All of this aside, this will probably NOT render HST obsolete any time soon, since this is rediculously hard to do and has yet to really be done convincingly in any large-scale way, as people at my institution [yale.edu] are finding out [noao.edu].
And even beyond the difficulties in getting AO working, there are still swaths of the EM spectrum that get absorbed by the atmosphere which require going to space.
Re-read the press release. What they measured was not simply that there were 1/3 of the expected number of electron neutrinos - that's been measured many many times over the past couple decades. What's important is that they measured the total number of neutrinos (electron, mu and tau flavours) to be right.
For h=0.7 and a total neutrino mass of 0.1eV, that gives Omega_nu=0.002, which is negligible for cosmology (and probably for structure formation too, though I'm not sure exactly how much HDM you need to add to start wiping out small scale structure).
Of course, if the neutrino mass is large enough that they're cold when they decoupling, all bets are off...
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Re:The problem with all these equations...
on
Rare Earth
·
· Score: 2
Actually, the biggest problem here really struck me when I was at a colloquium that Peter Ward gave. The talk itself was interesting. During questions, one of my colleagues asked the obvious question: What are the expected correlations between these additional factors? To take one example, having a large moon and having active plate techtonics for a long time are certainly correlated. So while each of these factors may be very small, how much does finding a planet that satisfies one of them improve the chances that it will satisfy the others?
His response was essentially to shrug it off and say "we don't expect that there are any important correlations." Whereas it ought to be the most important question!
So I would say that while they bring up some interesting things that people need to be thinking about, their attitude makes me highly suspect of any number they try to assign.
That second one's pretty accurate.:-)= Though it's more than just one problem that they had in mind, the main motivator is understanding galaxy formation and evolution.
Of course, you forgot the third line...;-)
- Hmmm, the Sloan Foundation will only give us the money if we name the survey after them. Fine by me!
Wrong. The easiest way is to do a "wildcard" search. Say you have a vague idea of a song's name. Just enter the bit you do remember and most P2P programs will search based on that.
You've completely missed the point. How do you find out about music that you've never heard of before?
Trying it out right now... interesting. It's part way there. It would help if a) everyone had their profile set up so that you could see their shared files, b) you could see the user sharing a specific file, and c) you could see any user downloading a file you're sharing. But it's better than not being able to browse anyone's files.
No, none of them work like this. In fact, in every single P2P program, you must know the name of the artist you are searching for before you can search for them. Great for downloading Metallica. Terrible for downloading DistroThorque, the metal band down the street desperately trying to be heard.
The programs may not have an overt method of recommending music... but Napster at least had a pretty good subtle one.
Whenever I would log into Napster, the first thing I'd do was do a search for "Nitzer Ebb" (a good old EBM-industrial band I like). Despite the fact that I own every album and a good fraction of the singles they ever put out, and already had whatever few mp3s were floating around that I didn't already own. And then I'd browse the mp3s of each user who was sharing a Nitzer Ebb track, and download random things from them. Why? Because a track that another Nitzer Ebb fan likes is more likely to be a track I like than any random thing I hear on the radio. Learned about a lot of really cool bands that way.
I switched to gnutella, but the new version of limewire removed the option to browse a user's shared files! So as far as I'm concerned, it's almost useless. Can anyone recommend a linux-based P2P client that allows you to do this? I miss finding out about new music.
I'm still waiting for the Layla to drop down to a price I can afford. Meanwhile I've got a Roland UA-100, which periodically has sync problems (though strangely enough it's gotten better since I stuck a USB hub between it and the computer - that still makes no sense to me) but otherwise does the job. Some of the BOSS on-board effects are quite usable.
- AO works by measuring the distortions in the atmosphere and then compensating for them. But light from different parts of your field take slightly different paths through the atmosphere, and so are not perfectly corrected. As you get farther and farther away from the point where you measured the distortion, your corrections get worse and worse. The amount of sky that you can correct at once is quite small.
- In order to measure the distortions, you need a bright star that you can take as a point source. So bright that only about 1% of the sky is accessible. Artificial stars are still unreliable (but getting better).
- AO-corrected images have a really weird point spread function (PSF)... you have a fairly large halo of light around a sharp peak in the centre. Great for finding points, but hard for measuring how bright the entire thing is.
- The atmosphere blocks out a hell of a lot of the UV and IR light. No way of getting that back without going above the atmosphere.
So HST still has very unique capabilities. And just wait until we start seeing science out of the ACIS instrument!
Something occured to me while reading the answer to question 7 re: the doctrine of first sale.
What if one were to create a piece of software that was exclusively dedicated to displaying an original novel that was available in no other way? And then slapped an EULA on it that prevented resale? How would the courts treat that? Is there a way there of demonstrating that an EULA can take away rights that have been otherwise guaranteed?
I'm not sure how the impression got out there that this is about guitars.
...
Oh, wait, I actually do know how the impression got out there. Silly me, as always it involves Slashdot editors that barely read the articles they post and Slashdot readers who feel justified in commenting on them without reading them at all.
Or maybe...
It is pioneered by Gibson, a company known as a guitar manufacturer
There is an explicit quote in the article about putting ethernet jacks in guitars
Every example in the article except one (talking about a drum hit) talks about guitars
Sure, this is obviously going to be a way for moving around all sorts of audio and other synchronized information when it gets going. But it's not a stretch to think that Gibson guitars are going to be the first things that have the capability.
Do you mean that we could measure temperature in joules? That would be strange--for materials of different heat capacities, we would add different amounts of heat joules to get the same increase in temperature joules.
Yup... and the heat capacity would be a dimensionless number telling you what fraction of the input energy is wasted.:-)= It has a pretty intuitive physical meaning once you do that, rather than just seeming like a conversion factor.
The fact that it's a logarithm makes me wonder how it can have units (namely joules per kelvin, the units of heat capacity).
S = k log (Omega / C)
Omega's the phase space volume of a given macroscopic state. C is a constant with the same dimensions (whose value, and incidentally its dimensions and those of Omega, depend on how many particles are in the system). log (Omega / C) is indeed dimensionless. But Boltzmann's constant k isn't.:-)=
It would be possible to measure energy and temperature in the same units, in which case Boltzmann's constant would be unity and entropy would be dimensionless. But it's usually more convenient to use ergs (or joules or eV) for energy and Kelvin for temperature.
That goto.com (though it looks like they've changed their name to Overture) link is damn cool... over $8 per click?! Though that only hurts the companies that make the software, not the ones that use it. Still worthwhile though...
Now I wonder whether they have any limitations for hits from a given IP address? One little perl script could put some of those companies out of business otherwise....:-)=
Do you really have 250 cds filled with music you actually want to listen to?
Yeah, I do.:-)=
I've got somewhere between 500 and 600 CDs, around 400 of which I listen to regularly (meaning at least a few times a year). Plus 6 full cds worth of mp3s at an average bandwidth of 160kbps, again about 2/3 of which I listen to regularly. Nothing adds spice to life like variety.:-)=
I wonder what the price for additional hard drives are? Can you stick in a generic 76 gig IDE drive, or do you need to buy specific ones from them? 250 hours of music isn't all that much...
Slashdot Mirror
Quick summary: People are interested in science, but don't understand it.
What I want to know is what can I, as a professional scientist, do to help?
[TMB]
And even beyond the difficulties in getting AO working, there are still swaths of the EM spectrum that get absorbed by the atmosphere which require going to space.
[TMB]
Re-read the press release. What they measured was not simply that there were 1/3 of the expected number of electron neutrinos - that's been measured many many times over the past couple decades. What's important is that they measured the total number of neutrinos (electron, mu and tau flavours) to be right.
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Well, let's see... if neutrinos were relativistic at decoupling, then:
Omega_nu h^2 = (sum of neutrino masses) / 93.5eV
(Peacock 1999 p.281)
For h=0.7 and a total neutrino mass of 0.1eV, that gives Omega_nu=0.002, which is negligible for cosmology (and probably for structure formation too, though I'm not sure exactly how much HDM you need to add to start wiping out small scale structure).
Of course, if the neutrino mass is large enough that they're cold when they decoupling, all bets are off...
[TMB]
Actually, the biggest problem here really struck me when I was at a colloquium that Peter Ward gave. The talk itself was interesting. During questions, one of my colleagues asked the obvious question: What are the expected correlations between these additional factors? To take one example, having a large moon and having active plate techtonics for a long time are certainly correlated. So while each of these factors may be very small, how much does finding a planet that satisfies one of them improve the chances that it will satisfy the others?
His response was essentially to shrug it off and say "we don't expect that there are any important correlations." Whereas it ought to be the most important question!
So I would say that while they bring up some interesting things that people need to be thinking about, their attitude makes me highly suspect of any number they try to assign.
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Heheh... thanks for the laugh.
And here I thought the Super Huge Interferometric Telescope poster we posted at that same meeting was the wackiest thing there... :)
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Not only do I, but I've got a shirt of theirs. :) "Filth, Scum & Vermin". Gets lots of great looks.
Saw them live in September, and they put in a great show. Now if only I could find Six Million Ways... somewhere around here.
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I don't think that was ever the case. It was always meant to be a replacement for the Manufacturing Tax.
True. :-)=
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Yes, exactly. The proposed GST was a 9% tax, if you recall.
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That second one's pretty accurate. :-)= Though it's more than just one problem that they had in mind, the main motivator is understanding galaxy formation and evolution.
;-)
Of course, you forgot the third line...
- Hmmm, the Sloan Foundation will only give us the money if we name the survey after them. Fine by me!
[TMB]
You've completely missed the point. How do you find out about music that you've never heard of before?
[TMB]
Trying it out right now... interesting. It's part way there. It would help if a) everyone had their profile set up so that you could see their shared files, b) you could see the user sharing a specific file, and c) you could see any user downloading a file you're sharing. But it's better than not being able to browse anyone's files.
[TMB]
The programs may not have an overt method of recommending music... but Napster at least had a pretty good subtle one.
Whenever I would log into Napster, the first thing I'd do was do a search for "Nitzer Ebb" (a good old EBM-industrial band I like). Despite the fact that I own every album and a good fraction of the singles they ever put out, and already had whatever few mp3s were floating around that I didn't already own. And then I'd browse the mp3s of each user who was sharing a Nitzer Ebb track, and download random things from them. Why? Because a track that another Nitzer Ebb fan likes is more likely to be a track I like than any random thing I hear on the radio. Learned about a lot of really cool bands that way.
I switched to gnutella, but the new version of limewire removed the option to browse a user's shared files! So as far as I'm concerned, it's almost useless. Can anyone recommend a linux-based P2P client that allows you to do this? I miss finding out about new music.
[TMB]
The definitive list can be found on crank.net. If you ever want a good laugh, try reading through the sites listed as "illucid". ;-)
Why do cranks always pick on either cosmology or the moon? I want to see a crank theory of horizontal branch morphology or AGB stars! :-)=
[TMB]
I'm still waiting for the Layla to drop down to a price I can afford. Meanwhile I've got a Roland UA-100, which periodically has sync problems (though strangely enough it's gotten better since I stuck a USB hub between it and the computer - that still makes no sense to me) but otherwise does the job. Some of the BOSS on-board effects are quite usable.
[TMB]
There are a few advantages that HST still has...
- AO works by measuring the distortions in the atmosphere and then compensating for them. But light from different parts of your field take slightly different paths through the atmosphere, and so are not perfectly corrected. As you get farther and farther away from the point where you measured the distortion, your corrections get worse and worse. The amount of sky that you can correct at once is quite small.
- In order to measure the distortions, you need a bright star that you can take as a point source. So bright that only about 1% of the sky is accessible. Artificial stars are still unreliable (but getting better).
- AO-corrected images have a really weird point spread function (PSF)... you have a fairly large halo of light around a sharp peak in the centre. Great for finding points, but hard for measuring how bright the entire thing is.
- The atmosphere blocks out a hell of a lot of the UV and IR light. No way of getting that back without going above the atmosphere.
So HST still has very unique capabilities. And just wait until we start seeing science out of the ACIS instrument!
[TMB]
You mean Gliese 229B... Gliese 229 is the parent star. :-)=
And yes, that was the first direct image of a sub-stellar object outside the Solar System. CNN's science writers could use a clue.
[TMB]
Something occured to me while reading the answer to question 7 re: the doctrine of first sale.
What if one were to create a piece of software that was exclusively dedicated to displaying an original novel that was available in no other way? And then slapped an EULA on it that prevented resale? How would the courts treat that? Is there a way there of demonstrating that an EULA can take away rights that have been otherwise guaranteed?
[TMB]
Or maybe...
Sure, this is obviously going to be a way for moving around all sorts of audio and other synchronized information when it gets going. But it's not a stretch to think that Gibson guitars are going to be the first things that have the capability.
[TMB]
Yup... and the heat capacity would be a dimensionless number telling you what fraction of the input energy is wasted. :-)= It has a pretty intuitive physical meaning once you do that, rather than just seeming like a conversion factor.
[TMB]
IAAP (I Am A Physicist)
S = k log (Omega / C)
Omega's the phase space volume of a given macroscopic state. C is a constant with the same dimensions (whose value, and incidentally its dimensions and those of Omega, depend on how many particles are in the system). log (Omega / C) is indeed dimensionless. But Boltzmann's constant k isn't. :-)=
It would be possible to measure energy and temperature in the same units, in which case Boltzmann's constant would be unity and entropy would be dimensionless. But it's usually more convenient to use ergs (or joules or eV) for energy and Kelvin for temperature.
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That goto.com (though it looks like they've changed their name to Overture) link is damn cool... over $8 per click?! Though that only hurts the companies that make the software, not the ones that use it. Still worthwhile though...
:-)=
Now I wonder whether they have any limitations for hits from a given IP address? One little perl script could put some of those companies out of business otherwise....
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Yeah, I do. :-)=
I've got somewhere between 500 and 600 CDs, around 400 of which I listen to regularly (meaning at least a few times a year). Plus 6 full cds worth of mp3s at an average bandwidth of 160kbps, again about 2/3 of which I listen to regularly. Nothing adds spice to life like variety. :-)=
Now playing: Kraftwerk's Autobahn.
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I wonder what the price for additional hard drives are? Can you stick in a generic 76 gig IDE drive, or do you need to buy specific ones from them? 250 hours of music isn't all that much...
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I can't speak for the poster, but I'm more or less in the same situation as an astrophysicist.
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