My girlfriend and I are the top two students in EE at a small but prominent school in Texas in 1989. She is deciding between UC Berkeley and MIT for grad school, and I am choosing between the equivalent med schools...
A letter (remember paper?) from a Prof at Berkley has an email address on it (joe@ucb.edu, or something like that) I go "hey, their computer's email uses the "@" sign just like our VAX." Leave it to my girlfriend, the smart one, to say "maybe the computers are connected!"
Re:A warning to experimenters
on
Build Your Own ECG
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· Score: 4, Interesting
We cannot emphasize this enough. By applying electrodes or gel to yourself, you are opening yourself up to "microshock" Current at the correct frequency can STOP YOUR HEART (technical term = ventricular fibrillation) This can happen at shocks as low as 300 mA if applied at exactly the wrong time and place.
The risk depends on the frequency of the AC current. And guess what the worst frequency is? 60 Hz... exactly what is coursing through your household current and appliances... including the computer that you're looking at right now.
Building an EKG was a simple homework problem in my Biomed Engineering course. My final exam was an EEG (brain electrical activity, not heart electrical activity). We paid a lot of attention to ground isolation and electrical safety. The key was to use a battery and not be hooked up to AC wall current at all.
Unfortunately, the strength of an EEG signal is much less than EKG, and my final exam instrument wasn't working well enough to pick the signal out of the background noise. I got it to work by rubbing the skin off my temples so that the gell pads were on raw flesh (cutting down the resistance). Now that is what I call a "bloody hard" final exam.
1.8 GHz/sec. Let's see now... heat production is a function of frequency... assuming the power supply is designed to keep up with a machine uptime of at least a few days (very conservative design)... then THE WORLD IS GOING TO EXPLODE INTO A CLOUD OF GAS FROM THE HEAT!!!!
Anyone know enough physics to calculate how long it would take a 1.8 GHz/sec. chip to destroy the world?
-- Holy Heat-sinking Hellfire, Batman!!
MP3's actually INCREASE music sales, you just can't tell because the economy started to tank right when file sharing took off. I'll bet if you look at Apple iTunes customers, their purchase of CD's actually INCREASED when the iTunes store opened (mine did). Problem is, there aren't enough of us to make a blip on the CD sales charts.
When iTunes for Windows comes out, I'll bet that you will be able to see a music CD sales increase.
As an analogy, interest in photography will (has?) increase as digital cameras become common. Unfortunately, Eastman Kodak is still screwed until they do a better job selling digicams and printers.
RIAA will make MORE money when they let the iTunes Music Store blossem (it still needs more songs).
Slashdot Mirror
Thank god for Slashdot! For some reason, I had thought that the law's name was "U-CAN-SPAM"
My girlfriend and I are the top two students in EE at a small but prominent school in Texas in 1989. She is deciding between UC Berkeley and MIT for grad school, and I am choosing between the equivalent med schools... A letter (remember paper?) from a Prof at Berkley has an email address on it (joe@ucb.edu, or something like that) I go "hey, their computer's email uses the "@" sign just like our VAX." Leave it to my girlfriend, the smart one, to say "maybe the computers are connected!"
We cannot emphasize this enough. By applying electrodes or gel to yourself, you are opening yourself up to "microshock" Current at the correct frequency can STOP YOUR HEART (technical term = ventricular fibrillation) This can happen at shocks as low as 300 mA if applied at exactly the wrong time and place. The risk depends on the frequency of the AC current. And guess what the worst frequency is? 60 Hz ... exactly what is coursing through your household current and appliances ... including the computer that you're looking at right now.
Building an EKG was a simple homework problem in my Biomed Engineering course. My final exam was an EEG (brain electrical activity, not heart electrical activity). We paid a lot of attention to ground isolation and electrical safety. The key was to use a battery and not be hooked up to AC wall current at all.
Unfortunately, the strength of an EEG signal is much less than EKG, and my final exam instrument wasn't working well enough to pick the signal out of the background noise. I got it to work by rubbing the skin off my temples so that the gell pads were on raw flesh (cutting down the resistance). Now that is what I call a "bloody hard" final exam.
1.8 GHz/sec. Let's see now ... heat production is a function of frequency ... assuming the power supply is designed to keep up with a machine uptime of at least a few days (very conservative design) ... then THE WORLD IS GOING TO EXPLODE INTO A CLOUD OF GAS FROM THE HEAT!!!!
Anyone know enough physics to calculate how long it would take a 1.8 GHz/sec. chip to destroy the world?
-- Holy Heat-sinking Hellfire, Batman!!
MP3's actually INCREASE music sales, you just can't tell because the economy started to tank right when file sharing took off. I'll bet if you look at Apple iTunes customers, their purchase of CD's actually INCREASED when the iTunes store opened (mine did). Problem is, there aren't enough of us to make a blip on the CD sales charts. When iTunes for Windows comes out, I'll bet that you will be able to see a music CD sales increase. As an analogy, interest in photography will (has?) increase as digital cameras become common. Unfortunately, Eastman Kodak is still screwed until they do a better job selling digicams and printers. RIAA will make MORE money when they let the iTunes Music Store blossem (it still needs more songs).