When I'm about to leave my lab, after turning out the lights I sometimes turn around and look at the hundreds of LEDs and indicators dimly lighting up cryostats and vaccum bellows. It looks like it could be inside the Nostromo, much different from when it's fully lit and you see the clutter of tools and cable.
posted to MetaFilter by springload at 8:47 AM on July 26, 2008

Bletch: But how do you scale that up to a kilogram?

In analogy, there's ongoing work to redifine the ampere in terms of the electron charge, and utilize as the standard a little machine that pumps a known number of electrons between two leads every second.

There are such electron pumps that provide the required accuracy of 10^-8, but it's a real problem that they can't produce more than a picoampere or so. A nanoamp at the very least would be... [more]
posted to MetaFilter by springload at 1:53 PM on June 16, 2007

Another interesting thing: There is a rivaling scheme called the Watt balance. It essentially determines how much power you need to send through an electromagnet in order to keep the kilogram afloat. From what I heard, they compared the silicon sphere with the watt ballance, and the discrepancy was so large that they had to reevaluate Avogadro's number.

And Bletch: I think the answer to the question I asked you is here, under "Ion accumulation approach".... [more]
posted to MetaFilter by springload at 3:01 PM on June 16, 2007

insomnus: That's not a Lada, it's a Volvo 242. My granddad had one of those, and it's exactly what I imagine Homer would drive.
posted to MetaFilter by springload at 7:07 PM on March 4, 2006

Oh sorry, that is Marge's car.
posted to MetaFilter by springload at 7:10 PM on March 4, 2006

driveler: These are areas of production forest, and harvesting lumber is what they're used for. They often don't contain that much interesting wildlife - the grounds were drained before that was forbidden due to its adverse environmental impact. As mentioned, the lumber has to be taken away, lest bugs invade and spread to the trees still standing.

It's not left there just to keep prices up - the lumber mills and paper mass factories can't keep up, and it's too expensive... [more]
posted to MetaFilter by springload at 12:40 AM on February 1, 2006

My job is quite liquid N2-intense. I like to toy with it in my hands, but never gargled and don't intend to. We use it to precool cryostats and provide a heat shield to a bath filled with liquid helium. Into the bath goes the real refrigerator, which cools things to 0.03K. When the fridge is pulled out of the helium, you can sometimes see chunks of frozen air attached to it.

StickyCarpet's swallow link is quite creepy. The poor student wouldn't just freeze, but also get... [more]
posted to MetaFilter by springload at 2:41 PM on November 19, 2005

Very, very nice!
posted to MetaFilter by springload at 12:51 PM on November 14, 2005

Colors are not accurate

(disclaimer on Bohr's atomic model)
posted to MetaFilter by springload at 12:06 PM on November 11, 2005

I hope they get a stern reprimand from the pope.
posted to MetaFilter by springload at 3:22 AM on November 9, 2005

I don't think it can be reduced to Maxwell's demon, though there are similarities in the design. But the ball wouldn't pop out in the water. You would either expend all the energy you get from the buoyancy getting it into the water, or let water into the tube.

The idea is tempting because it could work for the first couple of balls, before the tube fills up. The energy you get that way is the energy you spent by forcing the air-filled tube into the water in the first... [more]
posted to MetaFilter by springload at 5:02 PM on November 5, 2005

dsword: The problem is getting the water out of the capillaries. You could have atmospheric pressure in the chamber, through the ball-feeding tube. It's just that the capillaries will fill with water, which you can't get it out again without expending the energy you gained. It won't squirt out at the surface. So you may get a couple of balls through at first, but then you are stuck. What you got out by floating those first balls is energy that you put in when you installed the machine. Using... [more]
posted to MetaFilter by springload at 7:14 AM on November 6, 2005

dsword: Regarding the pressure differential, it pushes water up in the tube exactly to the level of the outside surface. If you just put one end of an open pipe in a lake, the level of water is the same inside the pipe as on the outside.

In a capillary, the water may be forced up a bit above the lake surface, but this capillary force works both ways. It doesn't specifically suck water up the capillary, it sucks water into the... [more]
posted to MetaFilter by springload at 10:05 AM on November 6, 2005

The capillary force works both ways in the following sense:

If the capillary pulls water up through the lower orfice, it would also pull water down from the upper orfice, so there is a force preventing water from being pulled out through the top of the capillary.

The capillary action results entirely from intermolecular attractions: it has nothing to do with gravity or pressure.

I didn't bring up... [more]
posted to MetaFilter by springload at 12:22 PM on November 6, 2005

I get 15 repeatably by making a horizontal figure 8 in the center of the pie with little overlap. I can then eat my way around the edge, clockwise from about 1 o'clock. The third piece is the tricky one.
posted to MetaFilter by springload at 7:04 AM on November 3, 2005

Being Scandinavian, this made me cringe. The intro text says "The fags have done it again". They sing about how they are kings of the street, drink some beer and run from the cops. I was never that fond of hiphop in Swedish, and this clip did nothing to change my opinion.
posted to MetaFilter by springload at 8:54 AM on October 23, 2005

It's very good, but it's been here before.
posted to MetaFilter by springload at 11:30 AM on October 21, 2005

Kickstart70: The combination of high initial cost (in money and energy), low efficiency, high maintenance and desert-specific logistical problems make Stirling engines unusable. Solar cells would probably do better, and they are in turn not used for just these reasons. Such a plant would take forever to pay for itself.
posted to MetaFilter by springload at 2:59 PM on October 14, 2005

Western Infidels: It's because they're pushing towards a hard limit. When steam engines and car engines emerged, they did so from a strong position, since anything was better than some moody old horse.

The Stirling engine has a maximum theoretical efficiency of 1-Tc/Th, where Th and Tc are the temperatures of the hot and cold end, respectively. As an example, the temperature difference between ice and boiling water can be utilized to a mere 27%, in... [more]
posted to MetaFilter by springload at 4:23 AM on October 16, 2005

Western Infidels: Yes, my scepticism is not limited to Stirlings, but applies equally to all heat engines. The California project looks interesting though, and has better prospects than the Sahara plant I had in mind, but a brief look at the page leaves some questions unanswered:

Is 25kW peak power, averaged over 24h, or over a year or an expected device lifetime? Does it include downtime, cloudtime, and times when the mirror is out of optimum position? From the previous... [more]
posted to MetaFilter by springload at 6:17 AM on October 17, 2005

We're just about to start an experiment where we bury nuclear waste in a mountain. Then will see whether someone gets curious and digs it up again. The experiment will go on for 100 000 years.
posted to MetaFilter by springload at 8:31 AM on October 15, 2005

Plenty of things there could have been in a SkyMall catalog.
posted to MetaFilter by springload at 5:31 AM on October 11, 2005

daksya: Yes, it's officially sort-of-peer, but unofficially not really. There is plenty of people - even within the Nobel Committee - who think it was a mistake to let the economists in on the prize.
posted to MetaFilter by springload at 8:59 AM on October 10, 2005

Goedel: Economic theory often lacks clear support from experiments and quantitative observations. It also has some problematic political tainting. So do the peace prize and the literature prize, but those fields make no claims of being part of science. The scientific merits of economics come from it being a subdivision of applied mathematics. It would be much better to have a general maths prize, which economists would be welcome to compete for.

By introducing the new... [more]
posted to MetaFilter by springload at 2:38 AM on October 11, 2005

Plutor: Relax. I don't mean he's The Next Starwars Kid. He just does some moves in that style, and he does them with a shovel, and he's very serious about it. I think it looks funny.
posted to MetaFilter by springload at 10:01 AM on October 7, 2005

I like Asparagirl's foxy shovel ad a lot!

urbanwhaleshark: Yes, it never seems to die out. I get a hint of bad conscience for bringing him up. That kid really deserves to be left alone.

Divine_Wino: Glad you like it. Regarding accurate shovel throwing, I found some guys over at martialtalk.com drooling over this picture.
posted to MetaFilter by springload at 2:42 PM on October 7, 2005

It's funny that it happens in Jönköping, since that is sort of the Bible Capital of Sweden. One would perhaps guess that they prefer more orthodox methods of disposal.
posted to MetaFilter by springload at 6:05 AM on October 1, 2005

It clearly accumulates some position error at low speeds. If you tweak the speedometer down to a square, you can make it bounce on a flat surface some 20 degrees off the proper direction.
posted to MetaFilter by springload at 6:51 AM on September 21, 2005

Balisong wrote: On that note, since biodiesel is picking up steam, Will there ever be a device that is part of your vehicle that you can load with any sort of carbon based expendables to power you around?

These devices were used during World War 2, at least in northern Europe. They are fuelled with wood, but maybe you can mod them to accept general rubbish as well.
posted to MetaFilter by springload at 3:22 AM on September 15, 2005

I used to think it was a precision job to make a skyscraper collapse vertically, but the WTC attacks didn't make it seem so. At least on TV, the towers seemed to fall just as if they'd been imploded on purpose. Anyone knows if they plan for that when constructing a new building, or if it just comes naturally with the high moment of inertia?
posted to MetaFilter by springload at 3:20 AM on September 13, 2005

Yes, it's difficult to see with all the dust, but maybe there isn't as much loose stuff flying sideways when they do it properly.
posted to MetaFilter by springload at 4:34 AM on September 13, 2005

I wrote this in a different thread, but after we'd moved on to a new one. I paste it here where it fits better:

---

From here, comments by George Bush, visiting the Red Cross headquarters:

"I just passed the place where volunteers and staffers are taking calls from around the country, and the response has been good, but there's more that needs to be done." he said. "Remember, it's the Red Cross that... [more]
posted to MetaFilter by springload at 3:58 PM on September 6, 2005

From here, comments by George Bush, visiting the Red Cross headquarters:

"I just passed the place where volunteers and staffers are taking calls from around the country, and the response has been good, but there's more that needs to be done." he said. "Remember, it's the Red Cross that provides much of the first compassion that a person finds…it's the Red Cross that helps feed. And so the Red Cross needs money."

Of course when... [more]
posted to MetaFilter by springload at 12:19 AM on September 6, 2005

First time on Opera in a long time. I really like the mouse gestures! Is there any Windows software that can give me this in other applications as well? Just certain gestures corresponding to keyboard shortcuts. Logitech should include that in their drivers.
posted to MetaFilter by springload at 2:06 AM on August 31, 2005

Sorry, I didn't Google first. StrokeIt seems to do exactly this.
posted to MetaFilter by springload at 2:09 AM on August 31, 2005

In the northern European countries, 20 miles is not a long distance. It's also cold in the winters, so a lot of oil goes to heating houses. The price of gas is high compared to the US, and of course there is some complaining from people in the rural areas. Still, people are used to it and do what they can to keep petrol costs down. Houses are typically well isolated. You get three-glass windows if you don't already have them to reduce the heating costs. It's getting quite common to install... [more]
posted to MetaFilter by springload at 5:42 PM on August 28, 2005

wah: But for different reasons. Planets and stars are spherical due to gravitational force, while the lack of external gravity allows the surface tension of the drop to shape it. Very nice link!
posted to MetaFilter by springload at 5:03 AM on July 16, 2005

Brilliant! "Does the Earth Rotate? NO!" is a book I would like to own.
posted to MetaFilter by springload at 3:05 PM on July 15, 2005

weston: If you alternate directions when folding, you only need P/(2^21) folds per side. You'd end up with a stack 0.1 micrometers square and 1000000km high if P was originally 25cm.
posted to MetaFilter by springload at 9:40 AM on June 23, 2005

Mayor Curley: He dodged some that was floating around. Seems like he's swimming through the rinsing water.
posted to MetaFilter by springload at 6:16 AM on June 17, 2005

Tell us you're ok!
posted to MetaFilter by springload at 1:26 PM on June 16, 2005