I am heading off to give a talk in Florida Friday morning (I leave at 6:15 my time, YIKES!), so I won’t be writing anything until Sunday, most likely. And I plan on being busy then as well, so I’m leaving you with a few linkies with which to have fun.
- First, The 37th Skeptics Circle is up!
- As promised, IAU approves the names of Pluto’s two small moons.
- The House of Representatives has a budget for NASA, and it’s not quite as bleak as I expected, though it’s still not enough. It’ll be at least two months before the Senate looks at it as well.
- Speaking of which, here’s an article about NASA science cuts as well.
- What happens when you dump a bowl full of liquid nitrogen into a pool? This happens.
- Has the oldest astronomy computer been found?
- And finally, an optical illusion that’s pretty cool.
June 23rd, 2006 at 12:25 am
I must admit the I never had considered what would happen when you dump a bowl full of liquid nitrogen. But now that I have seen it, I will try the same at home. Except I don’t have a pool so the bathtub will have to do, I don’t have any liquid nitrogen either so a handful of ice cubes will have to do…
I’m really excited about this…
June 23rd, 2006 at 1:03 am
[...] I’m a fan of optical illusions so I’ll quite happily stare at all sorts of things. This page (found via Bad Astronomy) has an interesting twist on how colour is interpreted by the eyes and brain which I hadn’t seen before. It also instructions on how to make a similar image of your own. [...]
June 23rd, 2006 at 4:39 am
I’m wondering now what happens if you dump a truckload of liquid oxygen and two truckloads of liquid hydrogen into an empty pool?
June 23rd, 2006 at 4:55 am
Mark, I imagine the results would be roughly “KABOOM” if anyone has a case of static electricity.
June 23rd, 2006 at 6:35 am
Great stuff! Thanks!
June 23rd, 2006 at 7:11 am
I’m disappointed. I was hoping to see the pool frozen solid in an instant and the pool walls crack, as I am told will happen if you dump a thermos of liquid nitrogen into a toilet.
June 23rd, 2006 at 7:56 am
Awesome stuff! I loved the optical illusion! As for the liquid nitrogen…. Hee! I always wanted to have some of that stuff to do stupid ideas.
June 23rd, 2006 at 8:12 am
So do we think the results of the “nitrogen in the pool” is strictly thermal, or is there a chemical interaction going on?
June 23rd, 2006 at 8:15 am
A good friend of mine was firing liquid-nitrogen bottle rockets one drunken evening. It’s a simple design: you pour beer into yourself, then pour water and liquid nitrogen into an empty 2-liter soda bottle. Then you jam your thumb down the bottle neck, point the thing upwards and let the heat from the water boil the LN2 — voom!
The drunken part may, on second thought, have been a bad idea. I only say this because he tore open his thumb and got nitrogen-chilled blood everywhere.
Ah, those warm summer nights at MIT. I get nostalgic just thinking about all the dumb things that were possible. Like filling an air-pressure cannon with Coffeemate powder and firing blasts of it over an open flame. Boom! goes the three-meter fireball. Or devising a way to make building a Tesla coil into a community project: build the capacitors out of beer bottles. (It’s the modern day version of the Leyden jar.) When we fired the thing up, we got a beautiful blue glow inside the bottles, like someone had caught and tamed the aurora. You know what I called it?
“Corona discharge.”
Don’t mention stupid ideas to me: I’ve got oodles of them.
June 23rd, 2006 at 8:35 am
I had a professor once in my freshman year that brought a thermos full of liquid nitrogen to class.He was teaching us about somthing or the other, can’t remember what. After class some of us went up to him to ask some questions and to answer one of them he dumped some of the stuff on our shoes. We all had a heart-attack right there.I mean, he ad just said that if he poured it over his hand he would lose it and then he goes and pours the stuff on our shoes! Of course it evaporated in an instant and he laughed if butt off but we almost wet our pants. Looking back on it, it was a great experiment, but boy was I scared back then
June 23rd, 2006 at 8:45 am
The “Antikythera Mechanism” was found to have the words “Archimedes was here” scratched on the side of the device during the extensive removal of crustations from the many years it spent on the sea floor.
Just kidding! Really though, there is evidence to show that this was most likely a model of an Archimedes device, or a copy of one of his devices.
June 23rd, 2006 at 9:18 pm
It seems to me that liquid nitrogen in the pool trick could have been deadly for the person that jumped in. Having recently taken the industrial safety course called, “Confined Space Entry”, I learned to be extremely careful about places where the mixture of your breathing air has been or may have been altered.
About 3 weeks ago there was a news report about 4 people who died after crawling inside a partially deflated helium ballon. The remaining helium displaced the oxygen and asphixiated them.
Normal atmoshpere is about 80% nitrogen, 18% oxygen and 2% other gases. By pouring liquid nitrogen in the pool, there must have been an unusually high concentration of nitrogen just above the water’s surface. It would probably remain there for an indefinate period before heating up sufficiently to mix with the ambient air. It’s not inconceivable the nitrogen content could have been 95% or greater over the pool.
And if that person had passed out due to lack of oxygen, guess what would happen to any rescuers that jumped in to save her?
June 24th, 2006 at 1:37 am
I was just working on a post for my blog the other day concerning the use of liquid nitrogen for cooling astronomical CCDs and happened across this video.
That’s the second time you’ve read my mind Phil.
June 24th, 2006 at 8:39 am
Good idea Mark! I wonder the pool will be overflowed.
June 24th, 2006 at 10:07 am
Phil, where in Florida are you?
BAMom
June 24th, 2006 at 11:09 am
Quote
I’m disappointed. I was hoping to see the pool frozen solid in an instant and the pool walls crack, as I am told will happen if you dump a thermos of liquid nitrogen into a toilet.
/Quote
A thermos is roughly 1 liter, and a toilet bowl is roughly 5 liters. So you have a 1/5 ratio in volume, and high walls that trap the nitrogen inside and magnify the cooling.
A Pool is roughly 500 000 liters and the bowl is roughly 10 liters. So you have a 1/5000 ratio, and a very high surface area and low walls which permit a quick dissipation of the Nitrogen, so you have two very different problems. Add to that the whole pool area is at a much higher temperature (around 26°C) than the toilet (around 19°C) and that the air over the pool is saturated with humidity, which immediatly condenses as fog, giving up a lot of heat.
June 24th, 2006 at 9:44 pm
I just saw a note on CNN’s web site that the primary camera is out of commission, at least temporarily, on the Hubble. Apparently it stopped working on Monday. They’re evaluating the situation to see if it can be fixed. Meanwhile, the other instruments are still working.
Click here for the CNN page
jbs
June 24th, 2006 at 11:51 pm
Liquid nitrogen in the pool is neat…but not as neat as one I saw a couple of days ago about using liquid oxygen as charcoal starter!!! Used a cheap, stamped metal grill. Nothing left of the grill, just a pile of briquette ashes on the ground!
June 25th, 2006 at 8:12 am
Evelyn Plait:
Phil was with all of us in Cape Canaveral Florida at a Planetarium meeting.
He behaved himself and gave a good talk.
You woulda been proud (again).
Spacewriter
June 25th, 2006 at 2:28 pm
Hmm, that’s odd. The Antikythera device has been known for at least 4 or 5 years to track a particular form of the epicylic motion of planetary bodies (http://www.economist.com/displaystory.cfm?story_id=1337165),
and it has been studied since the 1960s as a very interesting geared ancient Greek mechanism, so I wonder what it is that is new.
June 25th, 2006 at 8:32 pm
Re Amara,
What is new, is that they were finally able to read the enscription that was actually on the device itself that described what the device is for.
Since it has being found, people mostly reverse engineered its mechanism from its physical construction to figure its usage.
Finally we are now able to see if it match what the device says it is for. It is like discovering the original manual for the device. And from what I read it mostly confirms the results from the physical reconstructions.
It is quite amazing that they used an eight ton CAT scanner to accomplish this feat.
I wonder if this thing could have being accurate enough and tough enough to be taken out to the seas to measure longitude with?
June 26th, 2006 at 2:52 am
Every time I read stuff like this I think of the Darwin awards site. Sometimes its amazing to think more people don’t kill themselves doing stupid things. At my work we have a cleaning crew that uses about a million gallons of water each night to clean the facility, we make stoffers foods. One night I observed a member of that crew hosing down an open 120 volt outlet. Why is he not dead? I asked him if he thought that seemed like a good idea and he said everything is waterproof here. I doubt anyone here would think of dragging your garden hose in your house and hosing down one of your outlets but to this guys it seemed like the thing to do. I do love a good experiment too. I had a chemistry teacher blow up a beaker in class, I think she then went to change her underwear. Anyway, cool stuff, I still check out that optical illusion daily, its awesome