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The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Re:Math (168 comments)

You're trying to make stuff up. The probablity not being 0.5 stems from the fact that there will be some years in which more than one storm occurs, and this must be "balanced out" by there being no storm at all in more than 50% of the years (and thus, a probability < 0.5 of a storm occuring in a particular year). If storms don't happen independently, but come in "packs" as you suggest, and you're still holding up your scenario of one storm every two years on average, then the chance of a storm occuring in a particular year will be even lower than 0.393.


The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Re:Math (168 comments)

what? where the hell did you pull that from? why 1/e?

if a storm hit every two years, your method would give a probability of 0.393.


what sense does that make?

Imagine you're throwing a 100-sided dice 100 times in two years (i.e. 50 times a year). Then you statistically throw a particular number (say, 1) once every two years. The chance of throwing that number in one year (i.e. in 50 throws) is 1-(99/100)^50=0.395 (=the inverse of not throwing that number 50 times in a row). There you go. If you transition from discrete to continuous probabilities, the number of dice sides and throws approaches infinity, and lim_{x->infinity} (1-1/x)^x = 1/E.


The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Math (168 comments)

LeMessurier calculated that a storm powerful enough to take out the building hit New York every 16 years." In other words, for every year Citicorp Center was standing, there was about a 1-in-16 chance that it would collapse."

Umm, actually that would be p=1-(1/E)^(1/16)=0.0605869 (about 1-in-16.5052).


Heartbleed Coder: Bug In OpenSSL Was an Honest Mistake

multi io Re:Not malicious but not honest? (445 comments)

Why does the heartbeat request even contain the length of the heartbeat block?

The real question is, why even have the whole heartbeat TLS RFC in the first place, when the underlying TCP layer already checks for timeouts all by itself (you can run TLS over UDP, but hardly anybody does, and then you'd specify the heartbeat stuff only for that use case).

about two weeks ago

UN Report Reveals Odds of Being Murdered Country By Country

multi io Re:I've made a decision (386 comments)

In order to live as long as possible, I have decided to have gender reassignment surgery to become a woman, and I will move to Antarctica and start a utopian lesbian society, since there are no murders there. I haven't worked out the details yet, but it seems like a no-brainer.

You could start with killing somebody else -- the odds of *two* murders occuring would be even lower!

about two weeks ago

Stephen Colbert To Be Letterman's Successor

multi io Genuine? (193 comments)

"Simply being a guest on David Letterman’s show has been a highlight of my career"

Wait...he really meant that. It's kinda creepy when Colbert makes out-of-character statements. And now there's gonna be a whole show full of those? Ugh...

about two weeks ago

OpenSSL Bug Allows Attackers To Read Memory In 64k Chunks

multi io Re:ASLR anyone? hype? (303 comments)

Unless the mmap/malloc combo on the O/S you're using was able to purposely put guard pages after mmaped blocks so many malloced objects would end in such guard pages. Unfortunately...

Apparently OpenSSL uses its own allocator on top of the libc's (malloc). I.e. it only occasionally allocates a large chunk of memory from the C heap and then does its own allocations/reallocations in that (without anything like ASLR or guard pages of course). And apparently the particular sequence in which the OpenSSL library code allocates bits of memory using this allocator leads to a situation where the private key is always deterministically located behind the heartbeat packet space in memory. AFAICT this is why this bug is so remarkably portable and "works" reliably on all platforms.

about two weeks ago

Navy Creates Fuel From Seawater

multi io Re:Reading between the lines (256 comments)

By the time you're going to all of this trouble to turn electricity into fuel, it is unlikely that you'd want to run a car on it - you'd rather just have an electric car.

Not sure about that. Electrical energy can't be stored easily -- you need some high-tech battery with all kinds of electrolytes and complicated chemicals, and still the capacity is relatively measly. Electricity works much better if it can be consumed right after it is produced, without storing it (but if this can be achieved, electricity is otherwise very flexible -- it can be scaled up and down easily, and it can be transported quickly over long distances). HC fuels OTOH work well for storing energy -- they already store it, you just have to pour them into any airtight vessel, and they'll stay there until you burn them. So electricity and HC fuels might compliment each other quite well if the right technologies are in place. Any process that can convert electricity into fuel (and also happens to consume and thus neutralize the byproduts of burning the fuel) should be almost like a gold mine, if it can be scaled up sufficiently. So if this water-to-fuel conversion or similar processes can be made to work efficiently, chances are liquid fuels will continue to be the preferred method for large-scale mobile energy consumption needs.

about two weeks ago

Engine Data Reveals That Flight 370 Flew On For Hours After It "Disappeared"

multi io Re:Turns out, no. (382 comments)

Authorities quickly debunked this story this AM.

Denied, not debunked. Big difference.

about a month ago

Sulfur Polymers Could Enable Long-Lasting, High-Capacity Batteries

multi io 1,225 mAh (131 comments)

Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material.

At what voltage? mA*h isn't a unit of energy. V*mA*h is.

about a month and a half ago

Apple SSL Bug In iOS Also Affects OS X

multi io Re:Considering Apple admitted.... (140 comments)

No, it was a stupid coding standards error

Which is just what you would do to have plausible deniability. :-P

about 2 months ago

Megatons To Megawatts Program Comes To a Close

multi io Which reactors? (125 comments)

Can existing commercial reactors run on weapons-grade Uranium or Plutonium?

about 3 months ago

23-Year-Old Chess Grandmaster Whips Bill Gates In 71 Seconds

multi io Re:How many Libraries of Congress is that? (449 comments)

Regardless, it took 23-year-old Magnus Carlsen, a "grandmaster" Chess player since the age of 13 and new world Chess champion, just 71 seconds to defeat Gates in a friendly game of Chess on a Norwegian television show. It takes longer to heat up a cup of water in the microwave.

Thanks for that helpful comparison---without it, I would have had no clue how long 71 seconds actually is.

Can't you convert it into football fields first?

about 3 months ago

New England Burns Jet Fuel To Keep Lights On

multi io [OT] mmBtu? (230 comments)

Due to high demand for heating, natural gas supplies dropped and prices skyrocketed to $140/mmBtu

Off-topic question: Do these people actually invent new units of energy for each application?


A BTU is the amount of heat required to raise the temperature of 1 pound (0.454 kg) of liquid water by 1 F (0.56 C) at a constant pressure of one atmosphere.[1] As with calorie, several BTU definitions exist, which are based on different water temperatures and therefore vary by up to 0.5%.

The unit MBtu or mBtu was defined as one thousand BTU, presumably from the Roman numeral system where "M" or "m" stands for one thousand (1,000). This is easily confused with the SI mega (M) prefix, which multiplies by a factor of one million (1,000,000). To avoid confusion many companies and engineers use MMBtu or mmBtu to represent one million BTU.

Somebody must have thought really long and hard to come up with that stuff.

about 3 months ago

200 Dolphins Await Slaughter In Japan's Taiji Cove

multi io Re:Is this a cuteness thing? (628 comments)

Yes, dolphins are cuter than cows and pigs ... is harvesting one worse than the other?

How many million cows are slaughtered every year? How many pigs? How many chickens?

This sounds like one set of animals has better PR than another.

If we had dolphin farms with millions of animals, then maybe your argument would me more valid. But I guess the point is that dolphin farms just wouldn't work. There are some animals like pigs and cows that can be herded and bred easily -- they hardly try to escape, and they reproduce in captivity easily and in large numbers. You can basically just catch a few of them in the wild and build a fence around them, and provide food and water, and they'll be content until the day you kill them. So we use them as livestock. The same wouldn't work with other animals, for example because they show strong territorial behavior or just mature or reproduce too slowly or not at all in captivity. Which is why most of us eat cows or pigs but not mountain goats, antelopes or dolphins. If you nevertheless try to use one of those "wild", undomesticated types of animals for food in large quantities, you'll end up endangering the species.

about 3 months ago

Wikimedia Community Debates H.264 Support On Wikipedia Sites.

multi io Re:Why? (247 comments)

It's an encyclopedia

Exactly, it should just support formats that users have and not play politics.

Wrong. I think it should "play politics" in this case. Wikipedia is one of the very few sites which, because of its popularity, uniqueness, and non-commercial nature, has some leverage over browser vendors, and has more freedom than others to make use of it.

Almost everywhere else on the web it's the other way round: The browser vendors can force the site owners into compliance. If you have a smallish website and you want to provide video content on it, you often have no choice than to use an encoding like H.264 that all browsers support -- thereby furthering the agenda of consortiums like MPEG LA to steer the market towards a universal adoption of a patent-encumbered "hands off" format, and also lessening the incentive for browser vendors to support open royalty-free encoding formats. But if you run the like 4th most popular site in the world, the only one of its kind, AND you're not commercially bound to maximize your number of visitors no matter what, then you have some power to drive the web (and the whole industry) in the direction of truly open, royalty-free, "free to tinker with" video encoding formats, which would help lower costs and market entry barriers for new companies and individuals. Wikipedia shouldn't throw this leverage away.

about 3 months ago

4K Is For Programmers

multi io Re:39" display for workstations? (520 comments)

Bingo. My first thought when I read TFS was "my neck hurts already."

4K is for sprendthrifts.

Most developers these days run dual- or triple-screen setups with at least 22" monitors; the edge-to-edge width of that would be larger than that of one single 40" 4K screen -- albeit with much less vertical resolution.

about 3 months ago

Japan To Create a Nuclear Meltdown

multi io Re:Great (222 comments)

Fukushima's containment vessel could (and did) contain the molten core...

I didn't claim otherwise. I said existing reactors aren't designed to contain a nuclear accident as a whole, so that the environment would be unaffected. Your language implied that existing reactors had that capability, because you reduced what's a whole array of potential safety problems to just the capability of the containment vessel to contain a molten core.

about 3 months ago

Japan To Create a Nuclear Meltdown

multi io Re:Great (222 comments)

We don't understand the mechanics involved, and we didn't really need to in order to build safe containment vessel floors that can hold an ugly puddle of radioactive sludge.

So we did build such containment vessels? Then why did the Fukushima accident happen at all? The tsunami didn't breach the containment. It only shut down all the generators. Your language implies that nuclear powerplants are "run-away safe", i.e. if anything really bad happens, there's always the "safe" containment to contain it all, because "we" built it so it can contain the molten reactor core. But no existing plants really have that capability.

about 3 months ago


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