This is an excellent example of super cooled liquids. If pure water is not disturbed and is truly pure, it can be chilled well beyond its normal freezing point (0 degrees C). If there is nothing for the water to crystallize around all is fine, it stays a liquid. The water can stay liquid down to -42 C, past that the water will crystallize on it’s own. If something is introduced like a mote of dust or tiny bubbles caused by moving the water, a chain reaction occurs and the body of water freezes.
More super cooling examples are here:
Supercooling Experiment 1
Supercooling Experiment 2
Supercooling Experiment 3
BTW, the guys on Digg are saying that it’s a hoax. I doubt it, I’ve had this happen to be before. Its happen with bottles of water or water in an ice tray in the freezer, and even a can of Coke. The Coke froze into a can of slush as soon as it was opened, I think the vending machine was set a little too cold that day. Conditions need to be just right for this to happen in your home freezer. The circulating fan will more than likely cause your supercooling experiments to fail. If you unplug the refrigerator just remember to plug it back in. Looks like fun, I have some water in the freezer in hopes I too can make instant ice.
[inspired by digg]
Wikipedia entry on supercooling
Category: Science
New Breed of Stereoscopic Video Camera
This is a lovely video clip demonstrating the latest and greatest in 3D video technology from the mind of James Cameron. The system uses two high def cameras and a nice little parallax adjustment to create two images that are fused in the user’s head via polarizing glasses.
This should make this a wonderful camera if it ever become a standard production camera. The mass adoption of LCD screens in the home may make this rather tricky however. It’s common to use an alternating left right frame display coupled with LCD shutter glasses worn by the viewer. This is fine with old CRT tube TVs and monitors because of the way the images are ‘painted’ on the screen but it won’t work on LCD displays. I have no idea if it would work on a plasma or a DLP screen. Anyone know the answer to this?
I look forward to seeing the movie when it comes out, in an IMAX theater near you I should think. One extra note, it’s nice to see that I was on the right track with my own 3D video camera. I would ‘toe in’ the cameras when the subject would get near to mimic the way the human eyes deals with moving targets. Nice to see I’m on the right track.
[via uberreview]
Scientists Spark Super Nova On Cue
Ever want to see exactly how a white dwarf star goes nova? Well now you can, or at least you can see a simulation of what it would be like. I doubt you would want to be next to one if it did go nova. Sunburn would be the least of your worries.
Micro Wind Turbines
In urban settings many times it just isn’t practical to install wind turbines in order to harness the energy of the wind. The buildings may not be able to support a large generator or it might be that there just isn’t enough wind. Strange as that sounds, wind turbines won’t work if the wind is too slow. The blades won’t turn. Simple as that. They need at least 20mph winds to be any good. What is an eco conscious urban dweller to do?
The Motorwind might be an answer to some of your power needs. It’s a bank of turbine blades (apx 10" in dia) that are geared together that will generate power in winds of only 7mph (4m/s). That’s a light breeze, just a 3 on the Beaufort scale, and is pretty common. You should be able to get that from just the convection currents coming off from all the cement in the car park next to your office. With one of these Motorwind turbine setups you can charge batteries and power devices directly or with an AC inverter. All in all a good way to get some work out of a nice spring breeze.
The picture below is of the first micro-turbine array set up in Hong Kong. It includes 40 turbines, which has daily production capacity of 960W/h with average wind speeds of 5.5 m/s. This installation was made in November, 2006, and is large enough to power all of the lights in the apartment below.
[via neat-o-rama]
MotorWave
GFS-UAV N-02 ‘UFO’ Takes to the Sky
At first glance this flying craft looks like a simple ducted fan with a weird skirt under it. Fancy hovercraft? Kind of. In reality the skirt has no air flowing through it only over it. Something called the ‘Coanda effect‘(wiki) causes the air to ‘stick’ to the outside of the craft and in effect creates an inside out hovercraft. The high efficiency electric motor in the top housing forces air to flow over the outside of the main body to create lift. The torque of the motor and the spin created by the prop wash are countered by the fins that ring the mid section and the direction is controlled by the four lower flaps. The platform is quite stable and looks to be a very good platform for just about any UAV application.
Solar Storm Warning, Head For The Basement!
Very cool. I’ll have to load the camera up with some nice film so I can take photos of the Northern lights. Too bad I have to wait until 2010 or 2012.
This week researchers announced that a storm is coming–the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). "The next sunspot cycle will be 30% to 50% stronger than the previous one," she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
I wonder if that in the next few years as the solar activity peaks the weather will be effected. Anyone remember the news about the coming ice age back in the 70’s? I do know that the ham radio guys will be enjoying it. Solar Max makes for good DX’ing.