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Comment: Re:Hard to detect (Score 1) 264

by JanneM (#46838411) Attached to: Are Habitable Exoplanets Bad News For Humanity?

I did some research, and in order to pick up a TV level signal 100 light years away, we could built an antenna the size of Rhode Island in space.

You make my point :) 100 light years is still really in the neighbourhood. The vast majority of detected planets lie outside that range - that new possibly earth-like planet if five times longer away.

It assumes that you actually have an island-sized structure in space, and it assumes that any civilization is currently blasting radio signals in the same wasteful way as terrestrial TV. We don't have anything approaching your detector, so even at 100 light years we'd miss it, and, as I argue, civilizations are unlikely to beam out strong radio waves in that manner.

I would like to see what kind of detector we'd need for a more realistic scenario. Say, detect things within 1000 light years, and when radio use looks more like our digital low-power and directed radio devices.

Comment: Simple Solution: everyone goes (Score 1) 387

Instead of a lottery or affirmative action -- why don't we let everyone have higher education who wants it.

This country progressed with the GI bill and letting a lot of people who wouldn't otherwise afford college go. And we could do the same for trade schools. You only have to pay for education if you leave the country.

It's the reverse of the "H1-B Visa" where businesses don't pay for education in the USA and import people who got educations paid for by their countries.

Comment: Re:Weird decision (Score 1) 449

by Vitriol+Angst (#46838335) Attached to: Supreme Court OKs Stop and Search Based On Anonymous 911 Tips

Scalia dissented from an opinion where a right to innocence is removed? That's a surprise.

I can only assume that Thomas and Scalia take turns being "the bad guy" so it doesn't always look like a slam dunk that they'll vote with fascism each and every time.

What would shock me is real thought and concern for citizens from the likes of Scalia and Thomas.

Comment: Re:Uh... (Score 1) 449

by Vitriol+Angst (#46838329) Attached to: Supreme Court OKs Stop and Search Based On Anonymous 911 Tips

Many police officers are quite certain of their ability to determine guilt or innocence; usually in direct relation to how much the person in front of them is pissing them off.

If it takes an "anonymous call" to make sure they get the bad guy they are 100% certain is bad -- then it's going to happen. There's already a drop bag and a drop gun for mistakes. Now there's going to be the burner phone.

Is America falling apart because we don't have enough poor people in prison or enough bankers in prison?

Comment: Re:Uh... (Score 1) 449

by Vitriol+Angst (#46838313) Attached to: Supreme Court OKs Stop and Search Based On Anonymous 911 Tips

No a lawyer, but I thought "probable cause" was that the original CAUSE for the police stop and search has to be legit. If you can't arrest the driver for "forcing someone off the road" then anything found after that wasn't supported by the search.

Or maybe I'm living in a fantasy world. I'm just not too enthused to live in a country where the "right to imprison" supersedes the right to liberty. Pot shouldn't be against the law -- but it is, because of stupidity and it means we have to buy a lot of anti depressants to compensate.

But really, society isn't breaking down because we don't have enough people in prison. A person should be a real menace to society in order to justify the government taking away their liberty. Prison is a sick, sad place. And I don't want to make this an easy process for the state.

Comment: Re:We can survive sustainably with energy input (Score 1) 264

by Animats (#46838305) Attached to: Are Habitable Exoplanets Bad News For Humanity?

On the contrary, if we flatline our population at a low enough level, we can maintain a high tech society indefinitely on this planet.

Possibly, but estimates of that number tend to be below 1 billion. The world population is expected to peak around 2050 at 8.7 billion, and decline to 8 billion by 2100. Remember, most of the developed world is already below replacement rate.

The future may involve a lot more biotechnology, which isn't that resource intensive, and a lot less mining, refining, smelting, heavy manufacturing, and long distance transport. That means less of the resources required for space travel.

Comment: Re:"Science" == "Argumentum ab auctoritate" ?!?!?! (Score 1) 132

by Yaztromo (#46838105) Attached to: Ask Slashdot: Books for a Comp Sci Graduate Student?

Cite Knuth... This is, of course, good science.

Well at least Professor Knuth is still alive, and I don't [YET!] need to refer to the poor man as spinning in his grave.

AC posted an excellent response here.. In the event you're filtering AC's, take the time to read it, as it's completely on point.

I would add is this: if you've never completed a Masters thesis or Doctoral dissertation, just try submitting one to your committee without adequate citations. If you write somewhere "I used well-known algorithm ABC because of XYZ" and you don't have a citation for that algorithm, you'll be sent back for rewrites pretty quickly to add appropriate citations.

By way of example, in my Masters thesis several years ago, I mentioned Unix diff , without a citation. Why would this need a citation? It was mostly mentioned in passing, and every computer scientist under the sun knows what diff is, right?

Committee came back asking for further citations on a few things, including diff (which, for the record, is "Hunt, J. W., and McIlroy, M. D. An algorithm for differential file comparison. CSTR, 41 (1976).")

Using citations isn't an appeal to authority. It's akin to using an existing library call in programming. Just as you wouldn't roll-your-own quick sort algorithm when coding, someone writing a scientific paper doesn't re-invent every algorithm ever derived. You find someone who has already done that, and you cite them. The AOCP is useful in this regard due to the sheerly massive number of algorithms Knuth describes. It's hard to go through a Computer Science program and not use one of these algorithms. Knuth himself likewise cites all of the algorithms in the AOCP, so it's not an appeal to his authority, as he delegates that out to others appropriately. It's simply useful because instead of having to track down papers written in the 1960's on your own, you can cite Knuth who cites those papers for you. This is why the AOCP is useful for a graduate student.

FWIW, I cited Knuth. I needs an algorithm to calculate variance, and another on the Box-Meuller transformation. Art of Computer Programming had one for each, which I adapted for my needs, and cited appropriately.

Yaz

Comment: Re:How does an elevator accelerate? (Score 1) 107

by plover (#46838001) Attached to: "Going Up" At 45 Mph: Hitachi To Deliver World's Fastest Elevator

I was thinking that, too. They could install a second cable, tying the bottom of the elevator to the bottom of the counterweights and looping it through a pulley at the bottom of the shaft. That way they could fully control acceleration unbounded by gravity. They could accelerate the elevator slightly faster than the speed of gravity for the first fraction of a second, leaving the occupants floating about the cabin in mid-air, and then match the acceleration of gravity until it's at the end of the free-fall period. It would truly be the fastest elevator possible.

Apart from the spilled coffee, dropped laptops, tumbled wheelchairs, shrieking, cursing, rushed prayers, and the several heart attacks induced each day, I can see no downside to this elevator!

Comment: Re:Apples and oranges (Score 1) 113

by plover (#46837905) Attached to: OpenSSL: the New Face of Technology Monoculture

The problem isn't specific to OpenSSL or libssl or libcrypto, it's the overall idea in info security that "This is the One True Solution, thou shalt not Roll Thine Own crypto, lest thou livest in a state of Sin."

It's important to keep in mind this paranoia is completely justified. I've seen some really poor home-grown crypto implementations, written by well intentioned but completely inept developers. And I know most older libraries never defended against side channel attacks. OpenSSL is a product people trust to keep current defending against the latest cryptanalytic attacks. And after this little gaffe, I suspect people will keep a much closer eye on it.

The reason heartbleed made the news was that of scale. All this paranoia led to a monoculture. And the monoculture enabled B.O.R.E. - Break Once, Rob Everyone.

Comment: Theory and practice (Score 1) 132

by HalfFlat (#46837861) Attached to: Ask Slashdot: Books for a Comp Sci Graduate Student?

Graduate-level CS encompasses a lot of ground!

Knuth is of course a valuable addition to the book-shelf — as others have pointed out, it's a superb source for chasing up information, details and citations for algorithms and data structures one needs to justify or investigate, if nothing else.

Okasaki's Purely Functional Data Structures has also already been mentioned, and I'd add my endorsement!

I would recommend two other texts to add to a collection:

  • Computational Geometry by de Berg et al.: computational geometry techniques have a habit of turning up all over the place in CS and computing more generally, and this is probably the best overview text, providing motivating examples, a good high level theoretical discussion, and pseudo-code.
  • Category Theory for Computing Science by Barr and Wells is an excellent introduction to both type theory and category theory, each informing the other.

I would recommend a book on convex optimisation and probabilistic graphical models, but frankly I don't know of a single text on either topic that I could whole-heartedly recommend. Any suggestions?

Comment: Re: Maybe not extinction... (Score 3, Informative) 264

by Kjella (#46837347) Attached to: Are Habitable Exoplanets Bad News For Humanity?

In fact we learned today that the FCC is going to allow capitalists to fuck the internet up at least in the US.

Considering all the nice things I've heard about American ISPs, you already seem more buttfucked than the goatse guy. But I guess from now on you'll pay extra for lube.

Comment: Re:knuth's art of computer programming (Score 3, Informative) 132

by Yaztromo (#46837301) Attached to: Ask Slashdot: Books for a Comp Sci Graduate Student?

They're kind of dated, because few people do sorts and list manipulation at that level any more. I have both an original edition and a current edition of vols. 1-3, but haven't looked at them in years.

Sure, for the average programmer these days who relies on existing libraries, these probably aren't all that useful.

As a grad student working on a thesis and other papers however, Knuth's books are invaluable for citations. Need to defend the use of a specific algorithm? Cite Knuth. His books were invaluable citation material for when I wrote and defended my thesis a few years back.

This is, of course, good science. You may not need to use Knuth to program your own B* tree, but you have a pretty much universally accepted reference for citation if you use one in your research.

Yaz

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