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02-11-2013, 05:55 PM | #571 | |
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02-11-2013, 06:09 PM | #572 | |
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02-11-2013, 06:50 PM | #573 |
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I appreciate the accuracy. But know that I present some stuff in this thread with quite a bit of humor intended. You ruined the ****ing joke Doogie Howser. Adoption was outed in science class. That's hilarious. You have to be able to laugh at that...
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02-11-2013, 07:01 PM | #574 |
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Ohh yeah... by the way... There's a freakin 160' city-destroying asteroid whizzing toward the Earth right now. It will approach the atmosphere this weekend. But don't panic, Science is on top of it. It's calculated that there's no way it will hit us. Missing by a mere 17,000 miles.
Everything You Need to Know About This Friday’s Close Shave by Asteroid 2012 DA15 By Phil Plait | Posted Monday, Feb. 11, 2013, at 8:00 AM ET On Friday, Feb. 15, the Earth is going to get a very close shave by an asteroid*. Called 2012 DA14, this 50 meter (160 foot) rock will pass just over 27,000 kilometers (17,000 miles) from the Earth’s surface. This is closer than our geosynchronous satellites, so this really is a close pass! But, to be very clear: This asteroid poses no threat to us right now, nor in the foreseeable future. Friday’s miss is just that: a miss. And, in fact, this is a good thing, since any time an asteroid gets close (but misses), we learn a lot, including how to find them, how to track them, and even how to talk about them to the public. So let me tell you all about this little rock, and why it’s so cool. 2012 DA14 was discovered in February 2012 by astronomers at the Observatorio Astronómico de La Sagra; it passed the Earth on Feb. 16th of that year, missing us by a comfortable 2.6 million km (1.6 million miles). The asteroid has a very Earth-like orbit, talking 366 days to orbit the Sun. Its orbit is slightly more elliptical than ours and tilted by about 11° to ours as well. All that’s about to change though: After the encounter this year, the Earth’s gravity will change the orbit of DA14 quite a bit, reducing the period to about 317 days. Asteroids fall into various classes depending on their orbits; Apollo asteroids, for example, have a semi-major axis (the radius of their orbit measured across the long part of the ellipse) greater than Earth’s, and Atens have semi-major axes smaller than Earth’s. Right now, DA14 is an Apollo, but after the 15th its orbit will change shape so much it will become an Aten. The exact shape of its orbit after this weekend’s event isn’t known, but we do know it well enough to rule out any potential impact for quite some time; the next encounter won’t be until 2046, and even then it won’t get closer than about 1.6 million km (1 million miles). How Close a Miss Is This? DA14 will slip past at a distance of 27,000 kilometers from the Earth’s surface. The Earth itself is about 13,000 km across, so the asteroid will be twice our own diameter away. So, Can I See It? Even though it’s passing pretty close, DA14 is so small that it never gets bright enough to see with the unaided eye. I’ve seen predictions that it will get to about magnitude 7, which is less than half as bright as the faintest thing you can see. However, that’s well within range of binoculars or a small telescope. So It Won’t Hit. But What If It Did? Ah, you’re one of those people who enjoys scaring the crap out of yourself. OK, let’s think about what would happen if DA14’s path actually did intersect ours. We have some decent comparisons. There is a crater in Arizona called, oddly enough, Meteor Crater, that’s about 1.2 kilometers (0.75 miles) across. It was created 50,000 years ago or so by an asteroid roughly the size of DA14, which upon impact probably detonated with an explosion equivalent to a 20 megaton nuclear weapon going off. That asteroid was metallic, so it could make it through the Earth’s atmosphere and hit the ground. We now know many asteroids are much less sturdy, and probably would explode high in the atmosphere, disintegrating under the excruciating pressures of screaming through the air at Mach 20. That happened in Siberia in 1908 in the famous Tunguska event. Again, a DA14-sized rock came in, but this time blew up high over the Earth’s surface. Not that this was any blessing. Trees were knocked down and set aflame for hundreds of square kilometers, and anyone within probably 10 kilometers wouldn’t have lived to tell the tale. So we really don’t want rocks like this hitting us. They won’t cause a global extinction, but it doesn’t take something ten kilometers across (like the one that did in the dinosaurs) to have a catastrophic effect. Anything the size of DA14 would be able to take out a city. And it doesn’t even have to hit over populated land; just having one come in over the United States could trigger a global economic collapse. Remember, it only took a handful of people flying a couple of planes into buildings to do that. An asteroid impact, especially one that comes in without warning, could be a lot worse. This threat is no joke. It’s quite real, and we need to take it seriously. We need more observatories watching the sky, and a plan in place in case we do see one with our number on it. Some new observatories will soon be coming online that will help. Also, both NASA and the privately-funded B612 Foundation have plans to launch space missions that can better look for near-Earth asteroids. B612 even has ideas on how to stop a potential impactor from ruining our day, too. I gave a TEDx talk on this very topic. By the way, the asteroid Apophis made a lot of headlines when it was thought to have a non-zero chance of whacking us. That has now been downgraded to zero, so we’re safe from that one, too. OK, Fine. But Can It Hit a Satellite? Since DA14 is passing closer than some satellites, it makes sense to ask if it will hit any. The answer is that it almost certainly won't. There's a tiny chance, but the rock is small, and satellites smaller. Space, however, is big. That's why we call it space. There are billions of cubic kilometers of emptiness out there, only very slightly occupied by solid bits of matter. Put it this way: Hits to satellites by tiny grains of cosmic debris are incredibly rare, and there is a lot of that stuff floating around out there. The odds of one lone chunk of rock hitting a satellite are far, far smaller. I'd bet a lot of money nothing will get hit by DA14—and of course, satellite manufacturers actually are betting that money. NASA has consulted with satellite comapnies and given them updated coordinates of DA14 as a precautionary measure, but I don't think anyone seriously thinks there's any real danger to our birds out there. What, Me Worry? For most people, this pass of 2012 DA14 is a non-event; if you hadn’t hard about it you would never have known it would happen. It will pass us in the night, silent and dim. But this is in fact a big deal. For one thing, it allows us to check our models of asteroid behavior; how accurate were predictions last year based on observations of the time, how well can we improve them, how quickly and accurately are new observations included? These can all be checked. Plus, this sucker will be moving across the sky fast. At closest approach it will appear to move in the sky quickly enough to cross the face of the Moon in about 40 seconds. Getting most telescopes to track that fast is not all that easy. It’ll be a nice test of engineering. Also, we’ll have a lot of observations of it, and those will have to be processed and compiled into a set of orbital parameters used to make predictions in the future. I imagine that will keep some astronomers busy for a while. And let’s face it, people will have heard of this, one way or another. It’s not hard to find breathless headlines (one I saw said the asteroid will pass “perilously close” to Earth, a phrase that has no meaning except to scare people; a miss is a miss) and ridiculous conspiracy theories that the asteroid will actually hit or affect us in some way. We’ve seen those before—and they’ve always been wrong—and we’ll see them again. So for me, this asteroid is interesting scientifically, but it’s also yet another exercise in informing the public, who are curious about scientific matters in general and in asteroids specifically. I’m actually pretty happy with what I’m seeing out here right now; lots of facts and not as much nonsense and scare-mongering as usual. Maybe we’re doing better. And plus, let’s face it: This near miss of an asteroid is simply cool. It’s a big Universe out there, and the Earth is a teeny tiny target. We don’t get an opportunity like this very often, and I think it’s wonderful it’s getting the attention it is. Everything happening with DA14 is a net positive, including the public awareness. I hope that as these passes continue to happen people become even more excited by them, and it leads to us being able to fund more work on understanding asteroids, from observing them to actually visiting them some day.
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02-11-2013, 07:12 PM | #575 | |
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My bad. Last edited by Cephalic Trauma; 02-11-2013 at 07:18 PM.. |
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02-11-2013, 07:19 PM | #576 |
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^^That **** is amazing. Wow.
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02-14-2013, 10:03 AM | #577 |
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Cool shit that happened last year.
27 SCIENCE FICTIONS THAT BECAME SCIENCE FACTS IN 2012 http://myscienceacademy.org/2013/01/...facts-in-2012/ |
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02-14-2013, 10:21 AM | #578 | |
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02-14-2013, 01:01 PM | #579 |
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Want some peace and quiet? Think twice about that quiet part.....
World’s Quietest Place Lets You Hear Your Internal Organs The mad and hectic pace of life, sometimes makes us all crave some peace and quiet. But then, as they say, too much of a good thing can actually be bad for you. That applies to silence, as it turns out people can’t stand to be in the world’s quietest place for too long. The longest a person has lasted in there is 45 minutes. The place I’m talking about is a room at Orfield Laboratories in South Minneapolis. The room, also known as the ‘anechoic chamber’, is 99.99% sound absorbent. The double-insulated walls are made of steel and foot-thick concrete. Along the walls are also 3.3-foot thick fiberglass acoustic wedges that contribute to the ultra-quietness. The room holds the current Guinness World Record for being the quietest place on Earth. While it does seem like a dream come true, especially for those who live with kids or have stressful jobs, it’s actually not all that great. The room gets so silent that you can actually hear your internal organs at work. And after a while, the hallucinations begin. The founder and president of Orfield Labs, Steven Orfield says that people are challenged to sit in the chamber with all the lights out. There was this one reporter who managed to stay in there for 45 minutes. Mr. Orfield himself can do it for 30 minutes, in spite of his mechanical heart valve that becomes very loud inside the room. “When it’s quiet, ears will adapt,” he says. “The quieter the room, the more things you hear. You’ll hear your heart beating; sometimes you can hear your lungs, hear your stomach gurgling loudly. In the anechoic chamber, you become the sound.” The experience is so disorienting that it could drive a person mad. In fact, it is imperative that people sit down. Standing up and walking around is simply impossible. Because we orient ourselves through the sounds we hear when we walk, there are no cues to go by inside the chamber. “You take away the perceptual cues that allow you to balance and maneuver. If you’re in there for half an hour, you have to be in a chair,” Mr. Orfield says. As bizarre as it seems, the anechoic chamber has plenty of uses. Several manufacturers test their products for noise, and see how they could be made quieter. For instance, the room was used to make Harley Davidson motorbikes much quieter, while retaining their trademark sound. Nasa uses it to put their astronauts through various tests. They are made to float in there in a water-filled container, to see how long it takes before hallucinations begin and whether they could work through it. Because believe it or not, outer space is just one big anechoic chamber – the silence out there is just too loud.
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02-14-2013, 01:41 PM | #580 |
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For single nerds out there... here's a scientific formula for calculating compatible mates...
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02-18-2013, 03:37 PM | #581 |
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This shot is making it's way through Google+ today. It's to show how small the moon actually is.
Which reminded me of this photo that show just how large Africa is. |
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02-18-2013, 03:49 PM | #582 |
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[QUOTE=Fish;9402854]
I spent time doing some acoustical work for a product we were developing. I can say for certain that being in rooms with the ability to efficiently absorb sound are annoying. It's hard to explain, and it may be different for everyone, but it was as if there was pressure on the eardrum. I suspect this sensation was due to the fact that the eardrum wasn't vibrating at all. Weird stuff. Last edited by Stewie; 02-18-2013 at 03:56 PM.. |
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02-18-2013, 04:14 PM | #583 | |
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[QUOTE=Stewie;9412997]
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02-18-2013, 04:59 PM | #584 |
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There was no pressure change. I was trying to explain the sensation and it's difficult because so few people experience this type of room. Even a normal conversation in the room is odd because we are so used to sounds bouncing off of objects (that our brain ignores) that when they aren't there you go... hmmm...
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02-18-2013, 05:36 PM | #585 |
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