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Okay. So, apparently, a black hole does not actually need to be super-dense. It's just, the less dense it is, the bigger its radius has to be in order for it to be a black hole.

A solar-system-sized black hole would only need to be about as dense as air. If you made a big sphere the size of the orbit of Neptune, and filled it with air -- that'd be a black hole.

Here's the weird thought. Um. Not that that previous thing ISN'T a weird thought. But here's a weirder one:

The density of the intergalactic medium is probably something like one hydrogen atom per cubic meter. Not very dense.

But nonetheless, a density.

That means that there exists a radius such that the entire universe is a black hole. And it's calculable.

Which puts an upper bound on the size of the universe. And leaves the possibility that our entire universe is, in fact, on the black hole side of an event horizon.
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I encourage all of you physics teachers to use this in your classroom.

Um, the video. Maybe not re-creating the experiment. Which was to roll a bowling ball out of a car window onto a ramp.

(In the comments, the people who did this do explain that they DID understand the physics involved -- they just figured that the guy driving would keep going, and the friction from the ramp and air resistance would cause the ball to drop behind, and next to, the car. Unfortunately, the guy took his foot off the gas, so the car decelerated every bit as much as the ball, and the ramp spun slightly when the ball hit it, imparting some lateral motion. Apparently, this video was sitting on the guy's hard drive for five years, but he finally decided to put it up on YouTube so that the whole world could share.)
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I can think of several people on my flist who might like this music video. My sister is one of them, but a lot of other people, too.
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My aunt actually emailed this link around. In it, Arthur Benjamin (a math professor at Harvey Mudd in his day job) does fifteen minutes of impressive mental arithmetic. If you enjoy numbers, you may enjoy this.

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When you ask how long a project will take, divide the answer in half, and bump up to the next significant unit of time.

If a programmer tells you that he or she can get that to you in ten minutes, that means five hours. If a contractor says it's a one-day process, that means half a week.

This rule of thumb has served me well in general.
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Now, most of you have probably seen this already -- the AP picked it up, so it's been on the broadcast news occasionally. But, for those of you who haven't see it yet -- or who want to see it again: Snowball.

Here's his YouTuibe video -- warning: Backstreet Boys music. But it's worth it.

Snowball is not, of course, the only cockatoo that dances -- put music on with a good beat, and start bobbing your head, and many cockatoos will dance along with you. But Snowball just has better moves than most birds. Okay, Snowball has better moves than 99% of the people at a nightclub.

There is apparently some argument among ornithologists about whether this is REALLY dancing or not. Cockatoos, say some ornithologists, are simply very social animals, so they're probably just using their usual display behaviors, and maybe mimicking their human if the human is bopping to the music. Or they're just using their usual display behaviors and doing them to the beat.

But, see, as far as I can tell, that's a pretty good description of "dancing". That bi
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1. Grey foxes can get hairballs. Or, at least, that's what it looked like. As a cat person, I recognize that particular hacking sound. . .

2. Snow leopards in a zoo couldn't really care less about humans nearby staring at them -- but the dog walking by on the sidewalk outside the zoo was VERY interesting. The leopard looked rather alert, and perhaps even a little jumpy, even after the dog was out of sight. The body language was more or less the same as Boopsie's when she would see another cat walk by outside the house. Boopsie didn't like other cats, and I suspect the snow leopard isn't a big fan of other carnivores of its approximate weight class.

3. A meerkat can pick a fight with a stick and lose. Twice. Same stick both times.
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Fairies can travel at Mach 49.

Data and assumptions:

In Act II, Scene 1 of Midsummer Night's Dream, when sent on a mission by Oberon, Puck says that he will "put a girdle round about the earth
In forty minutes."

Now, as a girdle goes around the widest point of a person, we can assume that Puck is saying that he can do an equatorial circumnavigation of the Earth in 40 minutes. The equatorial circumference of the earth is pretty darned close to 24900 miles, or 40075 km. (The polar circumference is 40036, by the way. They attempted to define the kilometer as 1/10000 the distance from the equator to the pole, but some error crept in, and they didn't hit it quite. Still, as an off-the-cuff number to remember, "40000 km circumference" is a fine approximation.)

24900 in 40 min is 37350 mph, which is just about Mach 49. Therefore, fairies can travel at Mach 49 sustained for forty minutes.
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Look, I suppose that if you are an XKCD reader (RSS feed at [livejournal.com profile] xkcd_rss), there's a chance that you'd understand this, too.

But, see, as I was walking home from the store, I started wondering: if you spin Magneto around reasonably fast, does he turn into Static from Static Shock?

(Because, see, Static has control over electricity, and Magneto has control over magnetism, and magnetic fields and electrical fields are the same thing transformed through rotation. . . oh, forget it, it wasn't important anyway.)


Apr. 13th, 2007 01:46 pm
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From [livejournal.com profile] trcabbage.

Wow. If you like horses, you may already have seen this. If you aren't horsey, then you'll STILL be totally amazed by this.

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I often don't leave the house for days at a time, but I just walked outside to get something from the car.

It's autumn. I walked outside and it smelled like autumn.

The first day of the year that smells like autumn doesn't just smell like autumn, it smells like every autumn. You smell that, and you don't just smell now, you smell the autumn of every year of your life, past and future. And possibly every autumn before you were born, and after you die, too.

Whenever the seasons change, you get that. Four times a year, you can smell time.
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. . . 'cause the SMART1 probe smashing into the Moon with enough force to be visible from Earth really deserves a Casey and Andy Mad Science Award.

"Because any experiment that leaves a crater is a success!"
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If the TSA was going to ban an entire phase of matter from the cabins of their planes, couldn't they have started with plasmas? I mean, not allowing passengers to bring plasmas onto a plane would be a reasonable security measure in my opinion.
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Having recently read a book on edible plants in the New England area, I've started just popping things into my mouth while I'm walking around the neighborhood. I know, this is generally stupid -- they may have pesticides, I live in an urban area, so they certainly have car exhaust, and there are dogs around. . . but still.

Grass seeds are pretty darned tasty. And clover tastes AMAZINGLY good.
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So, the Competitive Enterprise Institute has come out with a 60-second television spot about how greenhouse gas emissions aren't important. It's called "CO2 -- We Call It Life", and is all about how you need carbon dioxide to live, and therefore it can't possibly be dangerous.

I'm looking forward to the other spots they will be producing soon, "You'll Die Without Water, So Shut The Fuck Up Already, New Orleans," and "Plants Grow Buried In Dirt: Why Mine Safety Standards Are Bad."
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So, a lot of you outside of New England are seeing pretty scary-looking photos of the floods around here.

And we've had a lot of rain -- ten inches, twelve, in one area, eighteen -- in an area of the country that tends to get forty-six inches PER YEAR. In the past week, we've had a quarter of the rain we'd get in a year.

But the damage, while expensive and FUCKING annoying, isn't catastrophic.
Read more... )
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Right down the hill, the parking lot of the supermarket has eight inches of water in it. In the parking lot of the condominiums next to it, there are cars in water over their tires. Apartment buildings nearby are being evacuated, and there have been sporadic reports of plumbing backing up in disgusting ways.

None of this has, however, directly affected our home, baruch Hashem, and knock on wood. We're at the top of the hill where all this is happening at the bottom. We may be the only people in Massachusetts on my friends list who don't need a sump pump. If anyone is flooded out, bring over a sleeping bag -- we can probably give you a dry spot to sleep in.
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The Stone Zoo in Stoneham is an okay zoo as zoos go. If you come to Boston, the Boston zoos aren't a major attraction. I mean, I've been to really, really good zoos, and the Zoo New England zoos aren't them. The animals look healthy and happy, but there aren't particularly many exotic ones.

So it's a small zoo. But I liked it. There were jaguars, and a Canadian lynx, and cougars, and snow leopards. There were spider monkeys and a capybara, and flying foxes -- bats with six foot wingspans. There was an adorable gray fox, and a small pack of Mexican wolves. And here a llama, there a llama, and another little llama. A fuzzy llama, a funny llama, llama, llama, and a duck. And a pheasant. And teeny little sixteen-inch-tall deer.

So I guess it's a pretty good zoo, after all. We spent two hours there walking around and looking at animals and quite enjoyed ourselves.

Oh, and they try to sort of group animals by ecosystem, so the snow leopard was next to the Himalayan Mountain Goats, and stuff like that.

But my POINT is, was it really wise to put the coyote enclosure right next to the roadrunner?
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First, if relatively friendly questioning about her husband claiming to be a member of a bigoted organization is going to be so hard on Mrs. Alito that it causes her emotional distress, it behooves Sam Alito to remove his name from consideration for the Supreme Court. Because what he's going through now is NOTHING compared to how people talk about people who already ARE on the Supreme Court. If she can't deal with THIS, she won't be able to deal with what is going to be said about her husband constantly for the rest of their lives. That's just part of being a very public judge.

Lis, if, G-d forbid, I ever end up in public hearings for some position like Supreme Court justice, and it gets difficult to hear people savage me, please fake checking your watch or something, and leave BEFORE you lose your composure. You don't have to listen to it, but don't ever let 'em see ya sweat.

Second, you know what would be my ideal way to deal with Daylight Saving Time, time zones, and all that malarkey?

It would be if everybody who needed a standard time to work with just used GMT, universally, across the globe. As 24 hour military time.

So Lis would start work at like 0330 and get off at about 1200, House would be on at something like 1600 or something like that (I'm probably off by an hour or two one way or the other). Television schedules, work schedules, train schedules, and the like would all use 24-hour GMT.

Everything else would use local noon. So, for instance, right now, for me, would be 0643, but would also be, um, (lesse, right now, our local noon is about seven minutes before EST noon, so we're about seven minutes later in general), "ten minutes of 12 o'clock".

I could call that 11:50 to distinguish it from 1150, for instance. Or just use "o'clock", "half past", and all those other terms like that.

Digital clocks would generally use 24 hour GMT, and not have colons in them. Analogue clocks would generally be set such that 12 o'clock was local noon, and would use AM and PM.

I think that would allow both the universal time that you need for worldwide commerce, and yet still have a sense that "time" was in some sense tied to the real, physical world.

Plus, it'd be cool.
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We're at my parents' house; my niece and nephew and their parents were over for the weekend for New Year's, and they just left, and Lis is asleep, and I was telling my parents about how Intelligent Design actually all holds together, if you assume that HUMANS aren't the creature that was designed. As I said, "So, all you need is to think of a creature without joints, without teeth, and whose eyes don't grow from their optic nerves, but are intelligent and have the ability to use tools. . . "

And Dad said, "Oh! Octopuses!"

I explained about Cthulhu and the Flying Spaghetti monster are probably therefore just visions of the Great Octopus.

And I explained my further theory about how, according to this theory, the purpose of humans was to be controlled by the Intelligent Designer to create global warming to make large shallow seas over the coastal areas that humans have built up, so that the octopuses could have the benefit of our structures while they created their own society.

And Mom said, "So, the Bush Dynasty is being controlled by Cthulhu in order to destroy humanity?"

And Dad said, "It explains a lot about Cheney -- he always did have that kind of fishy, Innsmouth look to him."

I said, "Yeah. This has actually been keeping me up at nights. . . it all hangs together all too well. If you can come up with ANYTHING that would be an argument against this, anything that will make me feel better about this, I'd love to hear it."

Mom and Dad were quiet and thinking for a while. And Mom said, "Well, they'll probably need a small slave population of humans to work the dry-land areas for a while. . . ."

(Other comments: "Well, if the Greenland ice caps go, the sea levels will go up about fifty feet. Once the octopuses get MIT, it's all over. On the other hand, they'll also get Logan Airport, which should slow them down some. . . 'I dunno, man, I went to this place near the shore, and I was stuck there for six freakin' hours. . . '")

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