Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

×

Comment: Re:WIMPs (Score 1) 165

by Rei (#49360117) Attached to: Dark Matter Is Even More of a Mystery Than Expected

One thing that dark energy can't be is *all* fundamental constants, plus position, velocity, etc scaling up evenly. Because if such was the case then there would be no perceptible change.

If youe saying that for example what is ground state would change too then it seems like you're arguing that things at the quantum level *aren't* moving into higher energy states. But things at the macroscopic level absolutely are moving into a higher energy state. So are you arguing that dark energy doesn't act on the quantum scale? I find that difficult to accept if so.

Comment: Re:WIMPs (Score 4, Interesting) 165

by Rei (#49358535) Attached to: Dark Matter Is Even More of a Mystery Than Expected

That the thing about dark matter... it has a perfectly reasonable explanation (WIMPs). It's not that weird of a "thing".

Dark energy on the other hand, that's just WEIRD ;) It doesn't act like any "energy" as we know it, even though everything is clearly moving into a higher energy state. A question I've had for a while... if space itself is being inflated (or any sort of mathematically equivalent scenario) - everything inflating in all directions at all scales - wouldn't there be some sort of weak radiation signal from electrons expanding into a higher energy state due to dark energy and then collapsing back down? But I have trouble picturing how to reconcile an absolute, varying distance at the atomic scale with quantization of energy states, positions, etc...

Comment: Re:Ummmm ... duh? (Score 1) 341

by Rei (#49358149) Attached to: Modern Cockpits: Harder To Invade But Easier To Lock Up

Sure there is: add this to the CPDLC standard and make all of the hardware modifications needed to support it:

----
Message type: Revert flight plan and lock
Message arguments: TIME: the time of the flight plan to use
Message description: Revert to the flight plan that was active at TIME that had been approved by both ground control and the pilot; engage autopilot; and disable all pilot / copilot access to all systems. If there is no approved flight plan then the flight plan is to return to the nearest suitable airport in the most direct route possible.
----

Additional modifications: Make sure that the pilot can never disable datalink communications with ground by any means that ground wouldn't have time to respond to.

Result: Nobody is ever "remote controlling" the plane from the ground. A murderous / terrorist ground controller can't crash the plane, only make it autopilot itself on a previously approved or otherwise reasonable flight plan. A pilot behaving suspiciously can't crash the plane, as ground control will just engage the autopilot and lock them out. To abuse the system both ground and the pilot would have to agree on a suicidal flight plan.

Comment: Re:Memorizing site-unique passwords isn't possible (Score 2) 253

by Rei (#49350175) Attached to: Generate Memorizable Passphrases That Even the NSA Can't Guess

Yeah, the suggested method for generating passwords generates needlessly long passwords. The total entropy is good, but the entropy per character is pretty poor. You get much better entropy per character with abbreviation passwords, where you have a sentence or group of random words and you use the first letter from each, or second, or last, or alternating, or whatever suits you. It's still not as much entropy per character as a random pattern, but it's much better than writing out full words - and pops into your head just as fast (because it is, in essence, the same).

Comment: Re:what will be more interesting (Score 5, Insightful) 631

by Rei (#49345311) Attached to: Jeremy Clarkson Dismissed From Top Gear

Are people really going to miss yet another totally fake show pretending to be reality? Is it just because this one combined cars and Daily Mail-style politics?

Sorry, but I have no sympathy for a primadonna for whom curses at an employee for 20 minutes and then physically assaults him up for half a minute (without any resistance from his victim) before someone pulled him off, all because the Clarkson's food wasn't warm. And this is hardly the first time Clarkson has behaved like this, he was already on "final warning" after a string of other incidents. What befalls him is his own bloody fault. And all of the abuse that the victim got over this whole thing... my favorite tweet on the subject was:

"Man assaults another man and victim receives abuse because people can’t watch a TV show about cars. Bravo society. "

Comment: Most of Japan is very beautiful... (Score 4, Interesting) 194

by Rei (#49342927) Attached to: Japan To Build 250-Mile-Long, Four Storey-High Wall To Stop Tsunamis

.... but their beaches, usually not so much. So hopefully this won't be too much of an eyesore. Japan is usually pretty good about trying to fit human-made structures into the landscape; my friends and I had a running joke when we were there: "They have the prettiest drainage ditches here!" ;) That said, a 250-mile long, 4-story "anything", that's going to be hard to make look nice.

I'm rather curious about what kind of concrete they're going to use. Japan has been a pioneer in the use of fiber-reinforced concrete, I wonder if they'll use that in lieu of steel that may need cathodic protection in such a high salt environment?

Comment: Re:Keyword "apparently" (Score 1) 110

by Rei (#49342817) Attached to: The One Thousand Genes You Could Live Without

Well, not exactly. The answer to the question of how the immune system can defeat a foe that is mutating and evolving so quickly is "it also is mutating and evolving quickly". Immunoglobulin genes in B cells mutate very rapidly. Those whose antigen binds best with an invader are stimulated to reproduce (and evolve more), ultimately differentiating into plasma B cells (whose job it is to mass produce antibodies) and memory B cells (which stay alive for long periods of time, allowing the body to "remember" how to fight off an invader that it fought off in the past).

That said, this only applies to genes responsible for antibody production, and only in B cells.

Comment: Re:floppy disk (Score 2) 110

by Rei (#49342779) Attached to: The One Thousand Genes You Could Live Without

Where do you get that? Wikipedia says that the human genome is 3,23473 billion base pairs. I mean, you could compress that to fit on a CD, but it won't fit at one byte per BP. Won't even fit at 2 bits per BP.

And if we want to think of a BP like a letter in a piece of code, with an average programming code line length of say 15 non-whitespace characters, that corresponds to a program 216 million lines long. That'd be no little program...

Of course, only a tiny fraction of our DNA codes for what we would consider to be the "interesting stuff".

All the simple programs have been written.

Working...