brainwagon

I was a little bit disappointed when I found out the total was a bit short of what the header proclaimed, but you should still check out 1001 things to do with liquid nitrogen

LN2 also works great for sweeping and cleaning hard floors such as concrete or wood.
Get a couple liters in a container, and dump it on the floor in the direction
you want the debris to travel. It picks up everything in it’s wave and if it hits a wall,
the wave will boil off and deposit the junk there. Now all you have to do is go
around the perimeter and sweep up the clutter.

Gravity is a very, very weak force.  Back in 1798, Cavendish used a torsion balance to try to estimate the value of G, the gravitational constant.   What’s cool is that you can reproduce this experiment yourself.   Check out Bending Spacetime in the Basement, which includes some nifty videos of the torsion balance in action.

[tags]Science,Gravitation,Science Fair[/tags]

Courtesy of the Make blog, here are some instructions on building a very simple refracting telescope. I’ve done something like this before by scavenging lenses from broken binoculars I find a flea markets and mounting them into lengths of PVC pipe. Of course real telescope makers grind their own mirrors.

Today’s bizarre science link of the day comes from the opticsforkids.com website, and is entitled Optics Fun With Gelatin.

Edible optics? What optical phenomena have you noticed in a bowl of Jell-O? Find a small laser, buy a box of unflavored gelatin, and have some fun in your kitchen.

I couldn’t agree more.

Hamster-Powered Night Light is a really nice school project that the people at otherpower.com helped an eight grader realize. They modified a hamster wheel to be a custom generator, and also rigged an ordinary bicycle computer to give them “telemetry”. Neat stuff, and definitely helps student learn about motors, generators, and magnetism.

Slashdot is running an article about a Cornell group who built an unmanned model aircraft using rather conventional hardware and Microsoft Windows XP embedded. What intrigued me most about the story was that the group tested their algorithms for flight control by using them to control a simulated aircraft in Microsoft Flight Simulator. A brief dig turned up other projects. Of course, other groups have been working on autonomous helicopter control, such as CMU and SourceForge’s autopilot project. A cool hobby, if you have the green stuff.

Tom Van Baak has a fascinating obsession with timekeeping. His website, www.leapsecond.com, has a great deal of information regarding timekeeping and his vast collection of odd and accurate timekeeping devices. He even wrote a nice paper which details the state of the art in amateur timekeeping. The short of it: amateurs can achieve ridiculous accuracy for fairly cheap amounts of money.

Oh, and he took some photos of the Venus transit too.

Today’s useful link of the day is to Mini-FAQ Macro Photography, Frugal, mostly Digital. This page has lots of good ideas for getting images from digital cameras, microscopes and flatbed scanners. I’ll have to try this sometime. My Zeiss-Jena microscope I bought at a flea market for $15 isn’t getting enough use.

While doing one of my usual bored browses of the web looking for odd science projects, I ran across a page detailing a homemade 3d laser scanner. This is another of a long series of projects that I thought would be fun to do, but never have gotten around to working on. I’ve also seen a similar cheap setup done without a laser, but instead just using a simple light source and shadows. You can also look at another implementation of this idea here or
here.

A Panoramic Camera is a terrific webpage by Giorgio Carboni. The rest of his website is awsome too, and includes many nifty science projects. His panoramic camera though is awesome, and the construction description is detailed and interesting. But most important, images that he takes with it are awesome, and include some beautiful Italian cityscapes.

My friend Phil sent me these pictures he took using a Canon D60 through a small wide angle telescope. He sent me these pictures to ask what the streaks are. My best guess is a geosynchronous satellite. To verify this, I was thinking of first of all plotting the direction of the trail. Assuming they are in order, the satellite should track almost exactly east west. A little head scratching math should indicate its orbital velocity (assuming a circular orbit).

Anyway, from his letter to me…

I was shooting some wide-field photos of Orion’s belt
about 7:45 tonight and four or five of them show this
strange streak. It seems like it’s moving awfully slow
for a satellite but I can’t imagine what else it could
be.

Please see the two attached full rez crops from the
(much larger) original jpegs taken with a Canon D60,
through my Celestron Rich Field 80 piggy-backed on my C8.
These are totally unenhanced at the full pixel rez of
the full frames. As I said, the duration of the streaks
is 30 sec.

Satellite? Asteroid? Whaddaya think?

Last year I carted my wife and son out to view the Leonic meteor shower, and we were blessed with
a pretty spectacular show. I went out sometime after dark (my house is actually a pretty dark
location, at least for a suburb of Oakland) and didn’t see any in the first five minutes when I viewed
at 7:00. At 8:00, similar results. At 9:00, I saw my first one, and decided to load up some chairs and
go to the Chabot Science Center. We weren’t alone: several thousand people showed up, and were
treated to a very nice meteor shower: the best of my memory. We returned home slightly after
midnight, and I watched more meteors streak accross the sky from my backyard.

It’s that time again, so I’ll probably be out doing the same thing this year. Check out the information
on space.com for more information.

In an earlier story I mentioned the project to fly a model airplane across the Atlantic Ocean. So far they have managed to lose two of their four planes in rather disappointingly short periods of flight. Check here for updates. I’m keeping my fingers crossed for them.

I’ve been interested in CCD imaging for quite some time, but haven’t had the scope + budget to really get involved. Nonetheless, I monitor a couple of CCD imaging mailing lists, and there are occasionally excellent pictures, pictures every bit as detailed as classic Sky Survey images such as those done at Palomar.
(more…)

Often I donate my Friday evenings to teach telescope making at the Chabot Science Center. Gert Gottschalk often shows up to participate, and he reminded me that he has a
very nice webpage of his own, which has many nice astrophotos, done with film, digital cameras and CCD imaging. Take a browse, they are quite nice.
(more…)