The newest MRI scanners use magnetic field strengths of up to 10 Tesla. I was told they can see down to the molecular level. You can levitate a frog with a 10-Tesla field.
Taylor Swift - what a phenomenon! I'm not particularly a fan but I am amazed by her popularity and fan loyalty. And she is insanely prolific. Apparently she was producing up to a song a week during the pandemic. And she seems to connect with young women in profound ways. It isn't all just fluff. I dated a young lady who listens to nothing but Taylor Swift music.
There is a joke in there but I won't say it. Please Register or Log in to view the hidden image! My girlfriend would go from one song to the next and give perhaps third of the songs an introduction such as: "Oh! The first time I heard this was just after I broke up with my boyfriend", or some other significant event in her life, often with tears welling up in her eyes. It was quite amazing to see the profound impact the music had on her. She was a law student with a good head on her shoulders, not just some dumb kid.
Time Mag Person of the Year. And it seems it's not because of her music. She is turning into a real international philanthropist.
Fun Fact: What's the secret ingredient in the H-Bomb ? Styrofoam, Baby !!! Please Register or Log in to view the hidden image! https://www.atomicarchive.com/science/fusion/hydrogen-bomb.html
I was watching some old Twilight Zone episodes and was reminded that the real John Boy Walton - Earl Hamner Jr. - wrote a few of my favorite episodes. And almost beyond belief, I saw an episode I had never seen before. It is titled "An Occurrence at Owl Creek". It must have been discovered recently because I have seen all the rest of the episodes more times than I can remember.
Do you know about when you first saw it? I've been watching these marathons for decades and it's the first time I've seen it. I could hardly believe it!
Wow! That really blows my mind! But then if it was discovered say ten or even twenty years ago, I guess I might have missed it. I've haven't watched them religiously for a very long time.
Yet more plastic in land fill. When these weapons have been used does any one consider what happens to all this plastic waste? No. Terrible. Plastic will be the death of us.
One mistake that I often notice in medical shows like the old series House, is that in the TV shows or movies, the magnet for MRI scanners turn on and off with the scan. That isn't true. The magnet stays on. I worked on MRI machines when they first came into use in medicine. At first they were called NMR for Nuclear Magnetic Resonance, but the word "nuclear" scared people so they were renamed MRI. This goes back to the early 80s. We had mobile units because they were too expensive for most hospitals to buy one. MRI units in hospitals normally leave the magnet active 24-7 except during maintenance. They were often charged using a pair of jumper cables. Once the required current was flowing in the magnet, the cables were disconnected. In principle the current would continue flow for as much as 10,000 years because they were superconductive. Ours used nitrogen over helium for cooling. The mobile units required that the nitrogen for the magnet be quenched when relocating to another hospital because of the power of the magnet. Once the nitrogen was purged and the supercooling was gone, the current and magnetic field disappeared almost instantly. Even the early magnets were as powerful as 1.5 Tesla. On one occasion a D8 Cat got too close to a (parked) mobile MRI unit and got sucked in through the wall. The more iron you have present, the greater the force produced. I had a close call with a chair. Everything inside the unit was supposed to be stainless steel or other non-ferrous materials. My tools were made out of beryllium. One night I had to do something to the magnet and grabbed a chair to stand on so I could reach it. But someone had accidently mixed a regular chair made with iron or steel, in with the stainless chairs. They all looked identical so I had no idea. I had my arm slung through the back of the chair so I could carry my tools and other equipment. As I approached the magnet I felt a tug on the chair. By then it was too late. The next thing I knew, I was airborne. I slammed into the magnet and hit my head pretty hard but I was okay. But I am lucky it didn't rip my arm off or crush me. Had I gotten between the chair and the magnet it could have been deadly. It took a winch and a long cable to get the chair out. I guess my favorite story came from a driver - the MRI units were on 40-foot busses. I arrived to work on the unit just after he arrived at a hospital. As I pulled in I saw him standing outside and looking bit out of sorts. I asked what was wrong; he didn't look so good. He said that as he was driving over, something felt strange, like there was a lot of odd crosswinds. Then he noticed other cars swerving a lot as they passed. It wasn't until he arrived at the hospital that he realized he had never quenched the magnet. It was active while he was driving. And that is why everyone kept swerving as they passed. Luckily no one got close enough to get completely sucked in. That could have been a disaster. Worst story: On one occasion we did a scan on a very old WWI veteran. He had a pin in his leg from the war. But back then, just after the turn of the century, even the stainless used for medical purposes was very low quality and our techs didn't know that. When they put him in the magnet, it removed the pin from his leg bone. I was in my early 20s back then and had my own fleet of million-dollar magnets to play with at night. That was so fun! I was quick to inform doctors of a major aftereffect that MRI units were having on patients. Of course they were always anxious to know more. So I explained that due to hysteresis, the iron in the blood retains a significant magnetic field after the scan. As a result, the patients have a tendency to walk North. Please Register or Log in to view the hidden image! Our company began with the first mobile CAT scanners. We pioneered the field. We were originally MCTS for Mobile Computerized Tomographic Services. We had shirts that read MCTS - We give good head and better body scans.
I operated one straight out of uni, finding out novel Chemistry structures. What the OC lab dreamt up was not always what they planned. We think we made this! No, you made that, kind of a thing. No mishaps but changing the coolant was scary, I got the hell of of the lab when they did that. A third party did it for us. One of the first questions they asked me at the interview was, "Do you have a pacemaker?" Pacemaker? I'm 22!! It made more sense when they explained! I was just a grunt but it was great experience, they had IR spectroscopy in there too, can't remember if they had mass spec.
Radio astronomers use some terms and units... that may be unfamiliar even to optical astronomers! Flux Density is specific flux explicitly in per-frequency terms and is measured in janskys. These units are named for Karl Jansky, who first detected extraterrestrial radio emission in the 1930s, and are defined as: 1 Jy = 10^-26 W m^-2 Hz^-1. http://physics.wku.edu/~gibson/radio/brightness.html
