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Klystron
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Rene Descartes's little known little brother, Bob, suffered from lifelong body order necessitating daily immersion in the Zuider Zee. Said Bob:
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attention @chemisttreedavenn said:
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So, what’s most funny about it? The tree (I spell it ttree) or the warning to me not to touch it?gmax137 said:
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An infinite number of mathematicians walk into a bar. The first asks for a pint of beer. The second asks for half a pint. The third asks for a quarter-pint. The fourth asks for an eighth of a pint.
The bartender interrupts to say, "I'll serve the whole group two pints, and that's your limit!"
The bartender interrupts to say, "I'll serve the whole group two pints, and that's your limit!"
DaveC426913
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Q: How long does it take an infinite number of mathematicians to drink 2 pints?DrGreg said:
A: 34 days.
https://www.physicsforums.com/threads/collection-of-science-jokes-p2.847743/post-6416910
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Oops. It appears that 34 days is how long it takes for one ex-mathematician to forget that they've seen a joke before.DaveC426913 said:Q: How long does it take an infinite number of mathematicians to drink 2 pints?
A: 34 days.
https://www.physicsforums.com/threads/collection-of-science-jokes-p2.847743/post-6416910
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If you have an MRI done and then float on your back in a pool immediately afterwards, you will act like a human compass.
Tell your friends on Reddit. LOL!
With that in mind, true story: I used to work on mobile MRI units mounted on buses. They would travel to a hospital, power up the magnet, do some number of studies, power down, and then drive to the next hospital. On one occasion I had arrived at the hospital just as the MRI arrived. The operator came up to me looking a little faint. He was in a bit of a panic. He had forgotten to purge the 0.75 Tesla or so magnet before driving. He said he kept noticing cars swerving at him as they drove by.
The magnet was kept superconductive so it didn't need power to operate once charged.
I always wanted to park one up against a hardware store wall.
Tell your friends on Reddit. LOL!
With that in mind, true story: I used to work on mobile MRI units mounted on buses. They would travel to a hospital, power up the magnet, do some number of studies, power down, and then drive to the next hospital. On one occasion I had arrived at the hospital just as the MRI arrived. The operator came up to me looking a little faint. He was in a bit of a panic. He had forgotten to purge the 0.75 Tesla or so magnet before driving. He said he kept noticing cars swerving at him as they drove by.
The magnet was kept superconductive so it didn't need power to operate once charged.
I always wanted to park one up against a hardware store wall.
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Borg said:
Driving down the road? I don't know if it could have wiped cards in passing cars or not. I know that one time a D8 Cat got too close to one at a hospital site. That was bad. I don't know who won the tug of war but they ended up crunching together. Those magnets are insanely powerful.
One night I was working alone and needed to get to something on top of the magnet which was charged. We had Beryllium tools. And the chairs and other hardware were supposed to be stainless. So I grabbed a chair, slung my arm through the back so I could carry my tools, and walked into the magnet room. By the time I felt the tug on the chair indicating that it was NOT stainless but instead a regular chair, I was airborne. I probably flew a few feet through the air as the chair sought the center of the field and crashed into the magnet. It about yanked my arm off. And I hit my head when I crashed into the magnet but I was okay. I had to use a manual winch with about a 20 foot cable extended to get the chair out.
Back when I first started, we had a [very old] WWI vet at one hospital. The pin in his leg from the war was made of very low quality stainless and the magnet pulled the pin out before they could get him out of the field.
This was a fun demo we did from time to time.
Also
And
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In the middle video they are lucky the cable didn't snap!Ivan Seeking said:
DaveC426913
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Tell me you're not serious!Ivan Seeking said:He said he kept noticing cars swerving at him as they drove by.
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DaveC426913 said:
I'm dead serious. The more the mass of ferrous metal, the greater the force. It probably did. One pulled into a D8 Cat. But I don't know if the MRI or the Cat is what slid.
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However you will not act like a human compass if floating in a pool after getting an MRI. That WAS a joke. :)
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What happens if it warms up while driving around?Ivan Seeking said:
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Keith_McClary said:
Eventually it would and then lose the field. I don't remember the max temp but we had to use liquid nitrogen over liquid helium for cooling. Once the nitrogen boiled off it would be dead.
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I thought that would be catastrophic, but I didn't know about the "alternate circuit":Ivan Seeking said:
The magnet is designed with an alternate circuit that can protect it and keep it from burning up. This is where it gets dramatic: The alternate circuit is essentially a heater that dissipates the magnet's stored energy by boiling all the liquid helium in magnet's storage tank. A white cloud of helium comes billowing out of multiple pressure relief ports.
TIL
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Keith_McClary said:
IIRC we just purged the nitrogen, not the helium. But that was a very long time ago. And I wasn't responsible for that system. So I may not remember all of the details correctly.
Purging the cooling system was a normal part of the procedure for transport. And in the early days, they might hit 2 to 4 hospitals in a day.
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My favorite new quote comes from Young Sheldon: I don't believe in a God but I sure like acting like one!
That's good.
That's good.
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Ivan Seeking said:
A bit of personal trivia: For anyone who remembers the movie Volcano, the D8 Cat-MRI incident was at Cedars Sinai Medical Center right where the movie scenes took place - right across from the Beverly Center. That same pad was where we put the MRI [not a driven unit but more like a mobile home]. My old MRI was gone. I guess it got wiped out by the volcano. :(
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What an egocentric guy/gal - no regard for what those bewildered drivers were thinking when their own cars started acting weird pulling to one side.Ivan Seeking said:
I wonder how many went to garages complaining about loose steering the next day.
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It may have mostly been cloudy but festive Earth didn't miss it! ...
Merry Christmas!
Merry Christmas!
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An infinite number of mathematicians walk into a bar. The first asks for 1 beer. The second asks for 2 beers. The third asks for 3 beers. The fourth asks for 4 beers. The bartender interrupts to say: "Sorry, but I can't take your order. One beer is one dollar and I don't have a twelfth dollar coin to pay you."DrGreg said:
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