Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror

Comment Re:Sigh (Score 1) 206

I agree that ultimately what is the oldest living thing comes down to a question of semantics. A distinction that's often made is clonal versus non-clonal organisms. I've seen Methuselah called the oldest non-clonal organism. The creosote bush that you mention is a clonal organism, as is Pando, a clonal colony of aspen thought to be something like 80,000 years old.

Comment Re:600 light years... (Score 1) 257

Remember, though, that the mass itself is not really the important part. The question is what is the surface gravity. Using your assumption of identical density (maybe not likely, but I don't know offhand what density is likely), the mass of this new planet in terms of the density rho will be M = rho*4/3*pi*R^3. The gravitational acceleration at the surface will be
a = (G M) / R^2
Combining that with the expression for the mass gives
a = G*rho*4/3*pi*R^3 / R^2 = (G*rho*4/3*pi) R.

All the stuff inside the parenthesis is assumed to be the same for both planets, so if we want to write it in terms of the surface gravity of Earth, g, and radius of Earth, r, then we'd have
a = g*(R/r). Thus, the surface gravity (under the assumption of identical density) is only 2.4 times greater.

Of course, if you're going to visit this place and plan to leave again (maybe not so useful without warp drive, given) then you might also be concerned with the energetic depth of the gravity well. For an object of mass m to escape to interstellar space from the surface will require an amount of energy
E = G*M*m/R
and in terms of the earth value E_earth this would be
E = (E_earth)*(R/r)^2
meaning it will take about 6 times as much energy as getting off Earth.

I was actually just thinking about this issue the other day while playing Mass Effect, because I was wondering if they'd done their numbers right on the planet properties (they had).

AI

Submission + - John McCarthy, AI Pioneer, Dead at 84 (wired.com)

mpearrow writes: Wired has an article about the death of John McCarthy, the inventor of the LISP programming language and possibly the single most important contributor to the field of AI.

Submission + - Lisp Creator John McCarth dead at 84 (techcrunch.com)

johnjaydk writes: The creator of Lisp and arguably the father of modern artificial intelligence, John McCarthy, died last night.

Lisp was (and to some extend still is) a radical leap forward and have had a strong influence on a lot of other languages although many still refuse to see beauty between parens.

AI

Submission + - John McCarthy, creator of Lisp, has died (i-programmer.info)

mikejuk writes: John McCarthy, the man who, among other things, first coined the term "Artificial Intelligence" and who invented the Lisp programming language died, aged 84, on October 23, 2011. The first use of the term "Artificial Intelligence" came in John McCarthy's proposal for a two-month, ten-man workshop to be carried out at Dartmouth College in 1956. This event went ahead, with Marvin Minsky, Claude Shannon, Nathaniel Rochester, Arthur Samuel, Allen Newell, Herbert Simon, Trenchard More, Ray Solomonoff and Oliver Selfridge, and is considered as "the birth" of AI.
McCarthy went on to create LISP. motivated by his
"desire for an algebraic list processing language for artificial intelligence work",
Best known as a way to torment students with brackets it is still considered to be the language of AI and it has influenced languages as different as JavaScript and Clojure.

Comment Re:Not the same thing (Score 1) 771

My girlfriend and I both read and liked the comic, and we were both pretty happy with the movie. We went with a couple of friends who had not read the comic but actually were the ones who suggested seeing the movie. They really did not like it. From talking to them, the problem seemed to basically be one of unfulfilled expectations. They knew it was a movie about superheroes and were expecting a typical superhero movie, which is to say an action-packed movie with pretty light themes. What they got was something that was dark and more dialog and ennui than action, so they were not happy.

Maybe if they'd been expecting something different going in they would have liked it better or perhaps not. Maybe there were other people who it would have suited better, but they decided not to see it assuming it was just another dumb superhero movie. I don't know, but I wouldn't discount the effect of mistaken expectations.

Comment Re:Which is more realistic (Score 1) 945

No ISP has ever done that. Mostly because if they did so they would cease to be a common carrier and be liable for every torrent. Do you see how the system is self-regulating to prevent this issue?

Broadband ISPs are not common carriers. In fact, for the reason you point out, if they were common carriers then I believe we would effectively have net neutrality enforced (just as with phone service), and some have suggested this as a solution.

Security

Submission + - 70% TSA Failure Rate at Some Airports (go.com)

An anonymous reader writes: Nearing the height of last year's Christmas travel season, TSA screeners at Bush Intercontinental Airport somehow missed a loaded pistol, one that was tucked away inside a carry-on computer bag.

"I mean, this is not a small gun," Seif said. "It's a .40 caliber gun."

Seif says it was an accident which he didn't realize until he arrived at his destination. He says he carries the glock for protection but forgot to remove it from his bag. He reported the incident as soon as he landed, shocked at the security lapse.

"There's nothing else in there. How can you miss it? You cannot miss it," Seif said.

Authorities tell ABC News the incident is not uncommon, but how often it occurs is a closely guarded government secret. Experts say every year since the September 11 attacks, federal agencies have conducted random, covert tests of airport security.

A person briefed on the latest tests tells ABC News the failure rate approaches 70 percent at some major airports. Two weeks ago, TSA's new director said every test gun, bomb part or knife got past screeners at some airports.

Comment Re:No kidding (Score 1) 1065

The correct decision depends on the numbers. If enough accidents are caused by cell phone use while driving, and you can effectively stop that cell phone use, then you may save more lives than are lost by people in accidents not being able to use their cell phones. I don't know what the numbers are, and in fact I wouldn't be surprised if there aren't really reliable numbers on cell phones as a cause of accidents (seems like that could he hard to determine accurately).

That being said, the decision between those two choices may be a false dichotomy; there might be a 3rd way that's better than both. And even if a cell phone blocking measure did net good, good luck to the politician trying to explain that when some mother of 3 dies trapped in her crashed car because she couldn't call 911. Of course, it shouldn't be so hard to make any jamming device turn off when, say, the airbags deploy.

I generally find the idea of not being able to use my phone, mobile broadband device, etc. when I'm a passenger pretty annoying. It seems like a overly broad approach to the problem. I also wonder what about all the other devices that distract drivers, like navigation systems. Will this really change the level of distraction or just change which things people are distracted by. Still, if the numbers tell us that enough lives will be saved, it's hard to argue against that (given that this is not really a fundamental issue of liberty or something).

Slashdot Top Deals

As the trials of life continue to take their toll, remember that there is always a future in Computer Maintenance. -- National Lampoon, "Deteriorata"

Working...