The Asus EEE really helped launch the market for cheap notebooks and costs are only going to get lower now that the idea is getting popular. Soon it will be cheaper for them to simply buy off-the-shelf netbooks and ship them to children. The OLPC really didn't have that much that made it uniquely suited for the job.
Sugar was "interesting" in the way that requires quotation marks when you say it, but it probably did more harm than good. It made a slow machine even slower and it certainly doesn't encourage practical computer skills. Children are clever. You don't need to make computers simple to make it easier for THEM to use.
That whole mesh WiFi thing was stupid idea. I'm told that it also killed the battery life.
I'd trust 128-bit WEP more than an ethernet line.
Heck, I'd trust 40-bit WEP more than a regular lane. It's trivial to tap into an ethernet line.
That's not theorestical. I've never heard of
a real system for tapping into an 802.11b link.
But the point is that you shouldn't trust any
communication link. You should learn more about
SSH or a VPN.
No, I don't understand it either.
A friend of mine sent me a link to some music
video that used it over and over as a lyric.
It's probably some anime fan thing, and now
an "in" joke.
You can make you own flouroscope. Go on eBay
and look for "x-ray film carrier" or trays.
There are green and blue sensitized trays.
These contain a sheet of plastic that is in
contact with the film. When the x-rays hit the
plastic sheet they cause it to glow which
exposes the film. The x-rays alone would expose
the film, but the florescent plastic enchances
the image allows exposure times to be cut -- thus minimizing patient exposure to radiation. At any rate, there are two type -- green and blue. The green is brighter, the blue has better contrast.
The plastic is embedded with rare-earth minerals (I think they use zink sulfide for green). You can remove the plastic from the film carriers and make your own floroscope... I'm working on making
a digital video x-ray machine. Later on I'm going to try to make my own CAT scanner. I just need help with the software.
No, no, no... don't use those silly, old mechanical vibrators. You have to go solid state. Jeeze... Check out Bill Beaty's page. http://www.amasci.com/ for some circuits.
I had good luck with a 555 switching a 2N3055 power transistor to drive 16v through an auto ignition coil. I used a VW Beetle coil. Pretty simple circuit and cheap parts.
Yes, you can find x-ray equipment on eBay
No, you cannot use a "handheld electrocution device".
X-ray generation requires DC high voltage. Those stun guns and fake TENS devices produce AC electricty. Futhermore, the current on those those devices is quite low. You need a at least 10mA to drive an x-ray tube.
Then by all mean, please do not build
an x-ray machine. I certainly wasn't advocating
that people go out and build one for party tricks.
What most people do not realize is that it's not a
trivial project. The x-ray machine described in this
article is a "cold cathode" machine. It generates weak,
soft x-rays. It's hardly very useful for weapons
or "candid" photos (exposure times are very long).
I've done a lot of research into this.
I talked with two x-ray technicians and had
a good, long conversation with a old x-ray
repairman. The old x-ray guy finally convinced me
that I would not be satisfied with a home-made
model. It would create unimpressive radiographs
and would require a lot of work.
Modern x-ray machines use a "hot cathode" x-ray tube.
They generate more penetrating, "hard" x-rays.
They are also very bulky, 200 pound devices
that require a lot of power. But if you want "real"
radiographs with nice contrast and good depth then
these are the way to go. I eventually bought two x-ray
machines from eBay (Yay!) that I use for my own Polaroid
radiographs. I won't go into the precautions I take (usually)
while operating these machines. That is a left as an
exercise for the reader.
I haven't given up on building my own machine,
but that's more for the challenge of building
a really nice, small, High Voltage DC power supply.
Maybe I will learn glass blowing and try to make
my own hot cathode tubes.
And, yes, I fully expect that my toys will take off
about 10 years of my life. Such is the price of obsession.
Now if you will excuse me, I must go apply some ointment
to these oozing sores that I have mysteriously appeared
on my face, neck, and arms.
Yours, Noah
P.S. The original article failed to note that I have my own
Polaroid x-ray samples online. I am posting an update to the
x-ray page
to make these easier to find.
http://www.noah.org/science/x-ray/index.html
Slashdot Mirror
No good deed goes unpunished...
The Asus EEE really helped launch the market for cheap notebooks and costs are only going to get lower now that the idea is getting popular. Soon it will be cheaper for them to simply buy off-the-shelf netbooks and ship them to children. The OLPC really didn't have that much that made it uniquely suited for the job.
Sugar was "interesting" in the way that requires quotation marks when you say it, but it probably did more harm than good. It made a slow machine even slower and it certainly doesn't encourage practical computer skills. Children are clever. You don't need to make computers simple to make it easier for THEM to use.
That whole mesh WiFi thing was stupid idea. I'm told that it also killed the battery life.
I liked the clamshell-to-tablet design.
Except that Perl is more like a highly addictive, carcinogenic drug than a cup of tea. Friends don't let friends write Perl...
Although I'm open minded enough to look forward to seeing what comes out of Perl 6.
Ruby is nice, but it's not pretty enough.
I'm a happy indenter with Python.
The TAB key is your friend.
Don't fear the whitespace.
I'd trust 128-bit WEP more than an ethernet line. Heck, I'd trust 40-bit WEP more than a regular lane. It's trivial to tap into an ethernet line. That's not theorestical. I've never heard of a real system for tapping into an 802.11b link. But the point is that you shouldn't trust any communication link. You should learn more about SSH or a VPN.
No, I don't understand it either. A friend of mine sent me a link to some music video that used it over and over as a lyric. It's probably some anime fan thing, and now an "in" joke.
You can make you own flouroscope. Go on eBay and look for "x-ray film carrier" or trays. There are green and blue sensitized trays. These contain a sheet of plastic that is in contact with the film. When the x-rays hit the plastic sheet they cause it to glow which exposes the film. The x-rays alone would expose the film, but the florescent plastic enchances the image allows exposure times to be cut -- thus minimizing patient exposure to radiation. At any rate, there are two type -- green and blue. The green is brighter, the blue has better contrast. The plastic is embedded with rare-earth minerals (I think they use zink sulfide for green). You can remove the plastic from the film carriers and make your own floroscope... I'm working on making a digital video x-ray machine. Later on I'm going to try to make my own CAT scanner. I just need help with the software.
No, no, no... don't use those silly, old mechanical vibrators. You have to go solid state. Jeeze... Check out Bill Beaty's page. http://www.amasci.com/ for some circuits. I had good luck with a 555 switching a 2N3055 power transistor to drive 16v through an auto ignition coil. I used a VW Beetle coil. Pretty simple circuit and cheap parts.
I find that iZone Polaroid film works well. You can buy it all Wallgreens and K-Mart. All film is sensitive to x-rays.
Yes, you can find x-ray equipment on eBay
No, you cannot use a "handheld electrocution device".
X-ray generation requires DC high voltage. Those stun guns and fake TENS devices produce AC electricty. Futhermore, the current on those those devices is quite low. You need a at least 10mA to drive an x-ray tube.
Then by all mean, please do not build an x-ray machine. I certainly wasn't advocating that people go out and build one for party tricks. What most people do not realize is that it's not a trivial project. The x-ray machine described in this article is a "cold cathode" machine. It generates weak, soft x-rays. It's hardly very useful for weapons or "candid" photos (exposure times are very long).
I've done a lot of research into this. I talked with two x-ray technicians and had a good, long conversation with a old x-ray repairman. The old x-ray guy finally convinced me that I would not be satisfied with a home-made model. It would create unimpressive radiographs and would require a lot of work.
Modern x-ray machines use a "hot cathode" x-ray tube. They generate more penetrating, "hard" x-rays. They are also very bulky, 200 pound devices that require a lot of power. But if you want "real" radiographs with nice contrast and good depth then these are the way to go. I eventually bought two x-ray machines from eBay (Yay!) that I use for my own Polaroid radiographs. I won't go into the precautions I take (usually) while operating these machines. That is a left as an exercise for the reader.
I haven't given up on building my own machine, but that's more for the challenge of building a really nice, small, High Voltage DC power supply. Maybe I will learn glass blowing and try to make my own hot cathode tubes.
And, yes, I fully expect that my toys will take off about 10 years of my life. Such is the price of obsession. Now if you will excuse me, I must go apply some ointment to these oozing sores that I have mysteriously appeared on my face, neck, and arms.
Yours, Noah
P.S. The original article failed to note that I have my own Polaroid x-ray samples online. I am posting an update to the x-ray page to make these easier to find.
http://www.noah.org/science/x-ray/index.html