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Domain: cyberguys.com
Stories and comments across the archive that link to cyberguys.com.
Stories · 6
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How Do 'Singing Magnets' Work?
dpbsmith asks: "Singing magnets are available at all of the usual geek-toy emporia, and, for all I know, ordinary toy emporia as well. They consist of a pair of magnets made of a polished substance with the general appearance of hematite. What is surprising, pleasing, and unexpected is that when the magnets strike each other under their own power, they produce a sharp, loud buzz that rises in pitch. The sound lasts a good fraction of a second and climbs somewhere into what sounds like the 200-500 Hz range. The exact sound and its duration are somewhat unpredictable and depend on how the magnets happen to strike each other. It is a little like the sound that you get when you mash a pingpong ball against a pingpong table with a paddle. What physics are involved in the production of these sounds?" "Google searches turn up some forum postings that indicate that it is a synthetic magnetic substance similar to hematite that's available cheaply in China as an industrial byproduct. The singing magnets are a little larger than size of olives; the shape is similar to a (U. S.) football but slightly more elongated. Their major axis is about 5 cm long, their minor about 1 cm. They are fairly powerful and will jump together when placed on a desk about three inches apart. They can distort the colors on a CRT display from a distance of over 20 cm.
Contrary to expectation, the poles of the magnets are oriented along one of the minor axes of the ellipsoid, not the major axis.
Neodymium magnets in 'ordinary' shapes produce boring 'plinks' when they snap together. Something about the shape of these magnets makes the sound much longer-lasting and entertaining. It is not simply the bounding rebound of two objects made of stiff-but-elastic material. Transfers of linear to angular momentum are clearly involved.
If course, I'd love to know whether these things were 'invented' or 'discovered', and by whom, trying to do what. -
What Goofy USB Devices Have You Found?
pluckyduck asks: "What's the goofiest USB device out there? The links below are by no means an endorsement of the company, just links to goofy USB devices to illustrate my point. The first one is not really a USB device, but a wall adapter in case you want to power your USB Coffee Mug Warmer from a wall outlet (hey, there's a concept!). I believe they also have an auto adapter should you feel the need to run your USB air purifier in the car. The latest PC I bought only has 6 USB ports, I'll need to buy a hub soon!" Yes, they even have USB Massage Balls, as well. Although goofy, some of this stuff could be useful in the right situation. What off the wall USB devices have you found? How might you use some of the devices, that have been listed? -
What Goofy USB Devices Have You Found?
pluckyduck asks: "What's the goofiest USB device out there? The links below are by no means an endorsement of the company, just links to goofy USB devices to illustrate my point. The first one is not really a USB device, but a wall adapter in case you want to power your USB Coffee Mug Warmer from a wall outlet (hey, there's a concept!). I believe they also have an auto adapter should you feel the need to run your USB air purifier in the car. The latest PC I bought only has 6 USB ports, I'll need to buy a hub soon!" Yes, they even have USB Massage Balls, as well. Although goofy, some of this stuff could be useful in the right situation. What off the wall USB devices have you found? How might you use some of the devices, that have been listed? -
What Goofy USB Devices Have You Found?
pluckyduck asks: "What's the goofiest USB device out there? The links below are by no means an endorsement of the company, just links to goofy USB devices to illustrate my point. The first one is not really a USB device, but a wall adapter in case you want to power your USB Coffee Mug Warmer from a wall outlet (hey, there's a concept!). I believe they also have an auto adapter should you feel the need to run your USB air purifier in the car. The latest PC I bought only has 6 USB ports, I'll need to buy a hub soon!" Yes, they even have USB Massage Balls, as well. Although goofy, some of this stuff could be useful in the right situation. What off the wall USB devices have you found? How might you use some of the devices, that have been listed? -
What Goofy USB Devices Have You Found?
pluckyduck asks: "What's the goofiest USB device out there? The links below are by no means an endorsement of the company, just links to goofy USB devices to illustrate my point. The first one is not really a USB device, but a wall adapter in case you want to power your USB Coffee Mug Warmer from a wall outlet (hey, there's a concept!). I believe they also have an auto adapter should you feel the need to run your USB air purifier in the car. The latest PC I bought only has 6 USB ports, I'll need to buy a hub soon!" Yes, they even have USB Massage Balls, as well. Although goofy, some of this stuff could be useful in the right situation. What off the wall USB devices have you found? How might you use some of the devices, that have been listed? -
What Goofy USB Devices Have You Found?
pluckyduck asks: "What's the goofiest USB device out there? The links below are by no means an endorsement of the company, just links to goofy USB devices to illustrate my point. The first one is not really a USB device, but a wall adapter in case you want to power your USB Coffee Mug Warmer from a wall outlet (hey, there's a concept!). I believe they also have an auto adapter should you feel the need to run your USB air purifier in the car. The latest PC I bought only has 6 USB ports, I'll need to buy a hub soon!" Yes, they even have USB Massage Balls, as well. Although goofy, some of this stuff could be useful in the right situation. What off the wall USB devices have you found? How might you use some of the devices, that have been listed?