Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:He's missing the point. (Score 4, Insightful) 130

It would be nice if people could learn to think in terms of threats that fell somewhere between "safe to ignore" and "extinction level event". Or could distinguish between "extreme and expensive" responses and "effective" ones.

9/11 could have been prevented by simple, conservative and inexpensive countermeasures. After 9/11 politicians droned on about how "9/11 changed everything," but the cold sober fact was that it in fact changed nothing. It just showed that some of the things sensible people had already been telling us to do (like reinforcing cockpit doors or getting agencies to work together despite institutional rivalries) really did need to be done. Instead "9/11 changed everything" became the rallying cry for every pet scheme that had heretofore been correctly dismissed as too expensive, hare-brained, or just plain dumb.

Which doesn't change the fact that something needed to be done. Here's the lesson I think we should take into this infrastructure debate: we should take sensible and conservative steps to secure infrastructure against terrorism now, before events put foolish ones on the table.

Comment Re:Good but... (Score 1) 110

Or... what if anytime anyone called a residential number, a nickel was transferred from the caller's account to the callee's account.

That wouldn't stop anyone from making a call where an actual person is likely to be involved; the labor costs for a three minute conversation would swamp that. But it would discourage people from robocalling a hundred thousand people in order to turn up a handful of suckers.

And the public wouldn't have to pay a regulator to try to track down these boiler room operations.

Comment Re:Agrument in favor of modularity (Score 1) 86

I don't have to do anything. Even stored under ideal circumstances li-ion batteries lose capacity.

What matter is capacity relative to demand. In a phone like the Droid Maxx from a few years ago with plenty of surplus battery the phone will still be usable four years later. But something like a Samsung Galaxy S6 barely has enough battery to make it through the day when brand new and is pretty much unusable two years later even under ideal conditions.

Comment Re:There's a lot more iron much closer... (Score 4, Informative) 287

And there's some twenty million tons of gold dissolved in the Earth's oceans. Jules Verne made it the source of Captain Nemo's incredible wealth.

To put twenty million tons of gold in perspective, all the gold that has ever been mined by humans totals up to about 180 thousand tons. To put in another perspective: sure, it's gold, but at a concentration of thirteen billionths of a gram per liter of seawater it's worthless unless you have unlimited time and energy to extract it.

That's the problem with asteroid mining in general. Until the cost of changing an object's momentum goes down drastically it's not worth doing. If Pysche were a 1000 kg block of pure, refined platinum (market price: $34 million) you'd be hard-pressed to retrieve it and return it to Earth at a profit. Which is not to say asteroid mining is a bad idea; but first things first: you've got to reduce the price of interplanetary propulsion by a couple orders of magnitudes. One thing that never happens in a sci-fi asteroid mining scenario is the hero worrying about running out of gas. Propulsion in stories is always practically limitless and free of charge. Real propulsion will never be that good, but it could get good enough.

Comment Re:"developed an artificial intelligence(AI) progr (Score 1) 153

The only thing the 1950s needed to obtain recent results in convolutional neural networks, was the planar process of 1959 and a suitably accelerated coefficient of Moore's law. We can get there by applying the inverse Hackermann function.

When planning a project, increase the amount of time that you estimate it will take by doubling the number and going up to the next time unit.

Dividing 18 by 2 and shifting to a lower unit gives us a doubling time of nine weeks. Probably we're recognizing cats by 1967. Before the modern API was half fleshed out.

Seriously, have you looked at the sophistication of mathematics in the 1950s?

Ramanujan surprises again

The discovery came when Ono and fellow mathematician Andrew Granville were leafing through Ramanujan's manuscripts, kept at the Wren Library at Trinity College, Cambridge. "We were sitting right next to the librarian's desk, flipping page by page through the Ramanujan box," recalls Ono. "We came across this one page which had on it the two representations of 1729 [as the sum of cubes]. We started laughing immediately." ...

What the equation in Ramanujan's manuscript illustrates is that Ramanujan had found a whole family (in fact an infinite family) of positive whole number triples x, y and z that very nearly, but not quite, satisfy Fermat's famous equation for n=3.
...

Ono and Trebat-Leder found that Ramanujan had also delved into the theory of elliptic curves. He did not anticipate the path taken by Wiles, but instead discovered an object that is more complicated than elliptic curves. When objects of this kind were rediscovered around forty years later they were adorned with the name of K3 surfaces — in honour of the mathematicians Ernst Kummer, Erich Kahler and Kunihiko Kodaira, and the mountain K2, which is as difficult to climb as K3 surfaces are difficult to handle mathematically.
...

His work amounts to one box, kept at Trinity College, and three notebooks, kept at the University of Madras. That's not a lot. It's crazy that we are still figuring out what he had in mind. When is it going to end?"

The book is not even closed yet on the mathematics of the 1920s.

Comment Re:most of those reasons have in common (Score 1) 252

Restated as 32% of Americans admit they disagree with American copyright law. Passing laws that most people don't agree with causes the people to stop respecting all laws, leading to them not respecting the government. This is a road that eventually ends with the ruling class dying in a violent revolution.

I ask you this: was less leadership ever required? Has a smaller, easier, less bitterly swallowed step ever been contemplated in the annals of the human condition?

On the "eventually" question, do you think before or after the Second Coming? (Name your sect if you wish, bearing in mind that a diligent and exhaustive land-title-search on "eventually" will set you back a king's ransom.)

In the 18th century, mathematicians such as Euler succeeded in summing some divergent series by stopping at the right moment; they did not much care whether a limit existed, as long as it could be calculated.

Likewise, we are less concerned here with whether history repeats itself in practice, than whether we can by facile bloviation declaim it so.

Comment Re:Agrument in favor of modularity (Score 5, Interesting) 86

How much thickness do you think the extra outer layer of plastic adds to the phone? If it has to be more than a millimeter I would be surprised.

Personally, I think it has more to do with the fact the lithium ion batteries have a finite shelf-life than it does with thickness. That means in two years you need a new phone even if you never added any software to it and managed the battery recharging perfectly. Even if the phone had been sitting in a box all that time it'd have significantly less battery life.

Comment From TFA: (Score 1) 165

The patterns were a mishmash of unrelated structures that were as misleading as they were illuminating.

This pretty much describes the state of every branch of science after a major influx of new data. Just look at the maps of the world produced after Europe became aware of North America. Early maps sometimes show California as an island; and it's not because the cartographer is stupid; he just put the data at his disposal together into what was at the time a plausible conjecture. And in fact the problem might not even have been that he was ignorant. He may have misinterpreted some of the (at that stage) imprecise data he had to work with.

New information confounds. The detection and resolution of conflicts in data is arguably what science is.

Slashdot Top Deals

A mathematician is a device for turning coffee into theorems. -- P. Erdos

Working...