Later this or next month NASA is planning to launch a one ton rover to land in Gale Crater, Mars next August. How do you softly land a one ton robot on a rocky, frozen, thin atmosphered, desert planet? NASA put up a video and it is fun to watch all the steps that have to work in the landing. I hope nothing goes wrong.
Saturday, November 5, 2011
Speaker success
I mentioned earlier that we tried to make a speaker for a weekend project (and also as a part of the kids education). It didn't work at all and I figured we needed more power. We were using ceramic magnets, so I ordered some more powerful neodymium magnets to play with. We also used more wraps (250) with thinner (32 gauge) wire to get a more powerful electromagnet coil to push and pull the magnet. These were glued to two plastic plates and one plate is supported over the other by springs. When it is hooked up to a battery you can see the top plate being pushed or pulled by the magnetic field interactions. We stripped a 1/8" audio cable and hooked it to our speaker then plugged it into the computer and played a song. It worked! Sort of. The sound was very faint, but if you listened closely you could hear the audio coming from the top plate. If you touch the plate you can clearly feel the vibrations.
We also plugged it into the microphone port and tried recording. It makes a very bad microphone but it does work to an extent. You have to lean close and speak loudly. There is a lot of hissing and so on but you can recognize a voice in the background. Here is a picture of the raw recording using Audacity.
Below I've amplified the signal and labeled places where T said "testing one two three."
We also plugged it into the microphone port and tried recording. It makes a very bad microphone but it does work to an extent. You have to lean close and speak loudly. There is a lot of hissing and so on but you can recognize a voice in the background. Here is a picture of the raw recording using Audacity.
Below I've amplified the signal and labeled places where T said "testing one two three."
Wednesday, November 2, 2011
Happy Halloween
The kids all dressed up for Halloween. Then F crawled toward me to see what the camera was all about.
We carved pumpkins and the kids went out and brought back a huge amount of candy.
We carved pumpkins and the kids went out and brought back a huge amount of candy.
Saturday, October 15, 2011
Simple Motor
I have been trying to start doing projects with the kids each weekend. Last weekend we tried to make a simple speaker from scratch, no success on that one so far. So this weekend I went for something easier and we made a simple motor out of wire, paperclips, magnets, tape, an AA bettery and two alligator clips. All taped to a plastic plate base. Above is a picture of it unhooked (I used small ceramic magnets to hold the wires to the battery). The coil is about 35 wraps of 26 AWG enamel coated wire. The connections to the clips have the enamel scraped off one side, so each revolution the electromagnet turns on and off repelling it from the magnets below and it spins. Below is a picture in action.
T made a motor like this from a kit a few years ago, but this one is completely from common off the shelf parts.
Wednesday, October 5, 2011
Palestine
Why shouldn't Palestine be able to participate internationally at the UN (i.e. receive UN recognition). Israel is a UN member. Palestinians are not Israeli citizens. Palestine is a separate nation. Palestinians and Israelis are both human beings. Is there any reasonable argument that Palestinians should not have any self determination. Is there any reasonable argument that Palestinians should not have the same level of recognition as everyone else?
"When in the Course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn that mankind are more disposed to suffer, while evils are sufferable than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security."
"When in the Course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn that mankind are more disposed to suffer, while evils are sufferable than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security."
Monday, October 3, 2011
The family is here!
I have moved yet again, to a rental house. Also, V, T, M and the baby F arrived and I picked them up from the airport. We also just got internet access hooked up at home yesterday.
Saturday, September 17, 2011
Brown Anole
There are brown anoles (Anolis sagrei) all around the house I am temporarily subleting. They bob their heads up and down and sometimes puff out their throat to display.
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