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### Easily-Captured Asteroids Identified

Re:58 Second Burn? (160 comments)

Well, let's consider the damage from the impact of a rocky asteroid, 60m in diameter. Plug this into the excellent Earth Impact Effects program at http://impact.ese.ic.ac.uk/ImpactEffects/. Assume a velocity of 17 km/s, which they say is "typical for asteroids," and an impact angle of 45 degrees.

The calculator says:

The projectile begins to breakup at an altitude of 54000 meters = 177000 ft
The projectile bursts into a cloud of fragments at an altitude of 4700 meters = 15400 ft
The residual velocity of the projectile fragments after the burst is 4.77 km/s = 2.96 miles/s
The energy of the airburst is 4.52 x 1016 Joules = 1.08 MegaTons.
No crater is formed, although large fragments may strike the surface.

Clearly you wouldn't want to be right underneath it, but even as close as 20 km, the air blast effects seem rather anticlimactic:

Peak Overpressure: 18900 Pa = 0.189 bars = 2.69 psi
Max wind velocity: 41.4 m/s = 92.6 mph
Sound Intensity: 86 dB (Loud as heavy traffic)
Damage Description:
Glass windows will shatter.
About 30 percent of trees blown down; remainder have some branches and leaves blown off.

So it'd be like BOOM! But not like KA-FOOOM!

For comparison, the Chelyabinsk meteor was estimated at 17-20m, with an airburst energy of 0.4 MegaTons.

about a year ago
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### NASA Considers Putting an Asteroid Into Orbit Around the Moon

Re:What could possibly go wrong? (171 comments)

No, they defintely mean 7 meters. 500,000 kg. Which seems like a lot, if it's hitting your house at several miles per second.

But that's only 90,000 kg more than the ISS (http://www.nasa.gov/mission_pages/station/structure/isstodate.html).

On the other hand, I bet the ISS would burn up a lot better on its way towards your house.

about 2 years ago
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### Ask Slashdot: 2nd Spoken/Written Language For Software Developer?

Spanish is a good idea, but won't help in the Philippines, where they speak Tagalog (a.k.a. Filipino) and English.

Spanish will help you learn Tagalog, since there are some cognates. But none of my Pinoy friends speak any Spanish.

about 2 years ago
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### Secret Security Questions Are a Joke

My favorite make-up-your-own pair, which a CSR at a bank was once forced to read to me over the phone:

Q: "You're not going out dressed like that are you?"

A: "You can't tell me what to do! You're not my real father!"

more than 2 years ago
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### Build Your Own Camera, Launch It Like a Grenade

Re:Launcher barrels rifled! (117 comments)

Mr. Elm:

That's a good point about the rifling. It appears that the Defcon fellows are using flare launchers, which, anecdotally, are described as smoothbore.

I dunno why flare launchers aren't rifled. Maybe the need for accuracy in shooting a flare is low: if it goes UP, instead of sideways, it's probably considered a success. The energy expended on making it spin could arguably be better spent on making it fly.

more than 3 years ago
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### Samsung Keylogger Stories a False Alarm

Good for Slashdot for following up (183 comments)

At least Slashdot has the journalistic ethics to post the follow-up. Good for them. I note that Network World is doing the same.

Yes, I said "journalistic" in the same sentence as "Slashdot." It's important.

more than 3 years ago
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### Revenge of the Cable Customer

They will simply drop you as a client if you take them to court.

more than 4 years ago
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Re:I don't care about "most dictionaries"... (180 comments)

That's really interesting, thanks. The main dictionary (oed.com) is \$295/year. I didn't know they had a concise one for free.

And it really is concise. One (really good) definition. Not 37 links, like the Google dictionary.

Not that there's anything wrong with 37 links. But sometimes I just want to want to know the definition of the word.

about 5 years ago
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### Brain of Patient H.M. Being Sliced, Streamed Live

Re:sectioned while alive? (199 comments)

I thought the same thing. Nowhere in the summary does it say that the patient is deceased.

May I suggest a clarification?

The slicing the brain of the famous amnesic patient H.M. WHO IS FRICKIN' DEAD into giant histological sections...

about 5 years ago
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### Simple, Free Web Remote PC Control?

Who rated this a troll? It's funny.

about 5 years ago
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### Chicago Court Throwing Out LIDAR Speeding Tickets

The link doesn't work. On the other hand, there's a very nice 404 page. It's funny, friendly, and attempts to be informative.

Good error handling is something many of us don't always do well.

more than 5 years ago
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### Vermont City Almost Encased In a 1-Mile Dome

Re:Rain? Insects? Birds? (456 comments)

Water needs? A river runs through downtown.

Plus, as the owner of a house with a leaky roof and a lawn that needs mowing, I say FUCK the plants.

more than 5 years ago
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### Vermont City Almost Encased In a 1-Mile Dome

I dunno, man. Snow is heavy (456 comments)

A couple of years ago Burlington, VT received 25.7 inches (0.65 m) of snow in 24 hours. I don't know what the density of snow is (I imagine it varies wildly), but that seems like a lot of weight.

OK, maybe the warm air can support that... but if that were the case, then on days when there wasn't 89 grillion kg of snow on top, there would be some pretty huge upward forces on the tent-pegs.

OK, well, then, there are vents, to let our some of the hot air. But then you waste all that energy heating air that you're venting.

But maybe it all works out somehow.

more than 5 years ago
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### Trojan Kill Switches In Military Technology

Re:Thatcher and Argentina (392 comments)

Wait! I retract my earlier assertion.

According to this article (cited elsewhere in this thread by acb) about French President Mitterand, PM Thatcher successfully pressured the French to reveal the "codes to make the Exocets deaf and blind" after the Sheffield was sunk.

Very interesting.

more than 5 years ago
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### Trojan Kill Switches In Military Technology

Re:Thatcher and Argentina (392 comments)

Perhaps you're referring to the French-made Exocet missiles, launched from the Argentine Super Etendard planes? The 20 dead sailors on HMS Sheffield, sunk by an Exocet, would disagree.

more than 5 years ago
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### Is City-Wide Wi-Fi a Dead Idea?

Downtown Charlottesville, VA begs to differ (259 comments)

I dunno about other places. But a pretty good chunk of downtown Charlottesville, Virginia is covered by free municipal wifi, and it works OK. Not everywhere, and no, you can't "seamlessly roam from one hotspot to another," as they say.

But so what? The signal is reasonably reliable where I've tried it, on and near the downtown pedestrian mall, and the throughput is significantly better than that provided by the coffee shop or the library, even with the trees in full radiation-absorptive leafy-mode.

Maybe "municipal wireless" means something more ambitious, like everybody who lives downtown gets a big honking signal even in their basement, and I don't think that's what they're trying to do here. But it sure is useful to be able to assume that, no matter where you get your latte, or slice, or dumpling, you'll be able to get some work done.

That doesn't sound "dead" to me.

more than 5 years ago
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### Comcast the Latest ISP To Try DNS Hijacking

Re:Comcast's version is orders of magitude better. (352 comments)

I got the same results. That is: asking for asdrfkjgshklghrfgserg.com got me the stupid Comcast "Maybe you're looking for douchebags in Singapore" page.

more than 5 years ago
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### Comcast the Latest ISP To Try DNS Hijacking

That's a nice thought, and I agree. But after you get through the 18 layers of phone menus... who are you going to talk to? The billing clerk? The tech support person? I guarantee you that their response will be: "Please unplug your cable modem and wait sixty seconds..."

"Caller is ranting about broken DNS functionality" is NOT on their script.

And anyway it's (888) COMCAST (not 800-). I have it memorized from all the service outages we get around here.

more than 5 years ago
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### Software Glitch Leads To \$23,148,855,308,184,500 Visa Charges

Re:triggered an overlimit fee, as I recall (544 comments)

Correct, Mr. Deviant. Perhaps that was my screencap that you saw. They removed the \$23,148,855,308,184,500.00 within a few hours, but I had to speak to a supervisor to get them to remove the \$20 "Negative Balance Fee."

more than 5 years ago
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### Software Glitch Leads To \$23,148,855,308,184,500 Visa Charges

I'm afraid you're wrong, sir (544 comments)

I'm afraid you're wrong, sir or madam.

I am one of the victims of this programming error, and I can tell you that several thousand VISA debit transactions were miscoded with the same amount: \$23,148,855,308,184,500.00.

I was not smart enough to look at my card number before I sent it off to Consumerist so that VISA could be made fun of. Happily, the string does not contain my (or apparently anybody's) credit (or debit) card number.

more than 5 years ago

# Slashdot: News for Nerds

The moon is a planet just like the Earth, only it is even deader.

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