Yes, Dirac. Besides being a great introduction to classical quantum theory, imho the extremely crisp exposition was a pure pleasure to read. (Warning: my 20-years-past recollection may be coloured by rosy-tinted undergrad glasses.)
For bonus flavour, find a used copy with the elegant old 1930's typography.
Many posters have made many negative comments. Fine, be like that. Off the top of my head, plus 10 minutes' research:
Emacs does all the same stuff and much more
Okay, granted. It's good to have choice, isn't it? Hydra looks easier to use for many people.
MS NetMeeting
...looks more whiteboard/desktop-oriented than document-oriented. Good feature list; royalty-free is unexpectedly nice.
At microsoft it appears NetMeeting is frozen back at Win98 / NT4, which is less good. I code for web in a Windows shop (Mac at home); I'll look into NetMeeting more.
Other people will mess up my code
...so collaborate only with people you trust. No-one? I guess you don't need collaboration tools.
Slashdot posts too much piddly Apple news
I must be more in the editors' target audience than you are: I think Hydra looks very cool.
It's already cool as a 1.0 product, it's FREE, and it may help inspire a more collaborative workflow. (For some kinds of work, for some people, some of the time.)
Not into it? Scroll down instead of taking the time to complain. Jeez.
G-d knows I'm pro-Mac, but having been The Mac Tech Guy for numerous coworkers and friends, I find people using Macs have problems about as often as Winfolken.
I will say, I solve Mac problems more easily in general, esp. OS X -- but that might be because I've been trouble shooting Macs for 15 years and NT4/2000 for only 3 years.
I agree with WD's theme, but his defense of Open Source has a weak/irrelevant point.
But all this does not mean that there is no group responsible for the car. At a level different from the mechanic, the manufacturer follows the repair history of each car model, then issues repair advisories and occasionally recalls a model for maintenance if a serious fault is found.
I think auto-manufacturer responsibility is anchored in legal liability. If the wheels come off, the builder is sued, no matter whether the engineering diagrams are freely available to the car's owner.
Moreover, just because a program is open-source software does not mean that no one is responsible for it.
Yes, but it doesn't mean someone is. He's arguing in favour of a (legally liable) vendor.
As noted by other posters, the basic arguments have been written in more detail by people like Bruce Schneier -- see his Cryptogram newsletters for some well-thought-out writing.
A nice little article, suitable for sharing with less-technical coworkers.
The size issue: the companion star's orbit tells us the maximum possible size of the central object. If the orbit is 17 light hours across, the primary is at most that large. It can be smaller, just as our Sun's diameter is smaller than the orbit of Mercury.
The proof the central object is a black hole is that nothing else can fit millions of solar masses into a sphere 17 light-hours across. The black hole need not fill that volume. More precisely, the event horizon need not fill that volume.
Singularities, point masses, event horizons: the size of a black hole depends what you mean. The singularity is the postulated point of infinite density: outside observers can't see it because it's inside the event horizon. The event horizon is the point of no return; in classical terms, the escape velocity equals the speed of light at the event horizon. The gravitational force is finite at the event horizon, and need not be extreme if the black hole is very, very large. If the universe is closed, we are all inside a black hole now, and will experience singularity at the Big Crunch.
But it isn't useful to think about the inside of a black hole. Different physics might apply -- lots of smart people think so. From the outside, as another poster wrote, all you get to observe is the black hole's total mass, total charge and total angular momentum -- that's plenty to work with in astronomical observations.
As to matter 'spiralling in', or the entire galaxy being sucked in by 'infinite gravity': Earth isn't being sucked into our Sun, is it? Unless you're quite close to one, the gravitational field of a black hole essentially (asymptotically) follows an inverse square law, like the gravity from any object. (When you get close, in units of the Schwarzchild radius, you do indeed 'spiral in' because the field strength increases faster than inverse square. The precession of Mercury's orbit is used to measure the deviation from inverse-square near our Sun, and is one of the 'proofs' of Einstein's General Relativity.)
The other mechanism for 'spiralling in' is loss of orbital energy due to friction, as in the accretion disk around neutron stars, for example.
That is all. Return to your homes and families.:-)
In the old comic strip, Dick Tracy's 2-way communicator predated reality -- if not already available, surely wristwatch-sized 2-way video will be soon.
related: Saturday slashdot article:
http://slashdot.org/article.pl?sid=01/11/24/034624 0&mode=thread
Like his stuff or not (I like about half), his fiction is strongly set in contemporary culture and for this alone will probably be read 50 years from now -- both for "this is what people were reading c.2000" and "this portrays N.American society c.2000"
Slashdot Mirror
Yes, Dirac. Besides being a great introduction to classical quantum theory, imho the extremely crisp exposition was a pure pleasure to read. (Warning: my 20-years-past recollection may be coloured by rosy-tinted undergrad glasses.)
For bonus flavour, find a used copy with the elegant old 1930's typography.
Amazon link here to go with parent B&N link.
heh heh... that's funny.
That's Michael Richards, of course.
woops -- re: MS NetMeeting being frozen at NT4: it's available in Win2000 after all.
Okay, granted. It's good to have choice, isn't it? Hydra looks easier to use for many people.
At microsoft it appears NetMeeting is frozen back at Win98 / NT4, which is less good. I code for web in a Windows shop (Mac at home); I'll look into NetMeeting more.
It's already cool as a 1.0 product, it's FREE, and it may help inspire a more collaborative workflow. (For some kinds of work, for some people, some of the time.)
Not into it? Scroll down instead of taking the time to complain. Jeez.
G-d knows I'm pro-Mac, but having been The Mac Tech Guy for numerous coworkers and friends, I find people using Macs have problems about as often as Winfolken.
I will say, I solve Mac problems more easily in general, esp. OS X -- but that might be because I've been trouble shooting Macs for 15 years and NT4/2000 for only 3 years.
My 2cents...
I agree with WD's theme, but his defense of Open Source has a weak/irrelevant point.
I think auto-manufacturer responsibility is anchored in legal liability. If the wheels come off, the builder is sued, no matter whether the engineering diagrams are freely available to the car's owner.
Yes, but it doesn't mean someone is. He's arguing in favour of a (legally liable) vendor.
As noted by other posters, the basic arguments have been written in more detail by people like Bruce Schneier -- see his Cryptogram newsletters for some well-thought-out writing.
A nice little article, suitable for sharing with less-technical coworkers.
Picky note: Dude better not be looking for a Nobel prize. There is no Nobel prize in Mathematics.
The size issue: the companion star's orbit tells us the maximum possible size of the central object. If the orbit is 17 light hours across, the primary is at most that large. It can be smaller, just as our Sun's diameter is smaller than the orbit of Mercury.
The proof the central object is a black hole is that nothing else can fit millions of solar masses into a sphere 17 light-hours across. The black hole need not fill that volume. More precisely, the event horizon need not fill that volume.
Singularities, point masses, event horizons: the size of a black hole depends what you mean. The singularity is the postulated point of infinite density: outside observers can't see it because it's inside the event horizon. The event horizon is the point of no return; in classical terms, the escape velocity equals the speed of light at the event horizon. The gravitational force is finite at the event horizon, and need not be extreme if the black hole is very, very large. If the universe is closed, we are all inside a black hole now, and will experience singularity at the Big Crunch.
But it isn't useful to think about the inside of a black hole. Different physics might apply -- lots of smart people think so. From the outside, as another poster wrote, all you get to observe is the black hole's total mass, total charge and total angular momentum -- that's plenty to work with in astronomical observations.
As to matter 'spiralling in', or the entire galaxy being sucked in by 'infinite gravity': Earth isn't being sucked into our Sun, is it? Unless you're quite close to one, the gravitational field of a black hole essentially (asymptotically) follows an inverse square law, like the gravity from any object. (When you get close, in units of the Schwarzchild radius, you do indeed 'spiral in' because the field strength increases faster than inverse square. The precession of Mercury's orbit is used to measure the deviation from inverse-square near our Sun, and is one of the 'proofs' of Einstein's General Relativity.)
The other mechanism for 'spiralling in' is loss of orbital energy due to friction, as in the accretion disk around neutron stars, for example.
That is all. Return to your homes and families. :-)
How many people were at the Toronto event, and where was it held? I never heard of slashmeets until too late yesterday to get out...
On close reading, the referenced article doesn't claim the mass loss is due to radiation of energy.
I expect the dominant mechanism would be mass lost via solar wind, eruptions, etc.; not E = mc^^2.
-- lars
In the old comic strip, Dick Tracy's 2-way communicator predated reality -- if not already available, surely wristwatch-sized 2-way video will be soon. related: Saturday slashdot article: http://slashdot.org/article.pl?sid=01/11/24/034624 0&mode=thread
Like his stuff or not (I like about half), his fiction is strongly set in contemporary culture and for this alone will probably be read 50 years from now -- both for "this is what people were reading c.2000" and "this portrays N.American society c.2000"