swansont

What is the purpose of the Bi? Magnetic shielding? Magnetic fields have zero divergence. What this means is that in any region of space, there will be as many flux lines entering as leaving. The lines always loop around and close in on themselves, so you can't shield one pole they way I think you want. You will concentrate the flux lines in a high-permeability material, but they leave the material, too. Also: Magnetic forces do no work.

If it's from a battery-powered toy you might have to worry about whether there is any DC-AC conversion going on before the motor that's built-in to the box. And you don't have to spin it backwards, per se. It's just whether you are providing a voltage to get motion, or motion to gat a voltage.

This is being discussed in QM.

Not to diminish the accomplishment, which is significant, but note that what happened what a teleportation of the atom's state, and not the atom itself. The atom wasn't moved across the room (or whatever) - the information contained in it, by virtue of being in a particular state - was.

No, as I stated and YT confirmed, even Th-232 radioactive, but since the half-life is long compared to the age of the earth, there is still a significant bit of it about (and anything in its decay chain should be present in some quantity as well. To be radioactive and naturally occurring it either has to have a half life longer than ~ 109 years or be continually produced somehow, either in a decay chain or an induced reaction like the one that prduces C-14) Th was (and perhaps still is) used in gas mantles because it fluoresces nicely. It's also used in high quality lenses because it makes very high index glass when added to the mix. Since the half-life is so long, you aren't going to lose that many atoms to decay.

Why is Thorium an exception? It has no stable isotopes. Th-232 is long-lived, but it still decays.

It's a bias field (aka "C field") coil for an atomic fountain clock.

No, it wouldn't. Relative to any inertial observer, it goes as the speed of light. If one is asked the question, you can stop after "it's impossible to travel at the speed of light, see the Lorentz-Einstein formulas."

Your first question makes no sense to me. Your second - no. The observer in an inertial frame can always consider himself to be at rest. There is no difference, however, if you assume the object to be at rest. You get the same answer. If you don't, then you have made an error.

DARK IN HERE A woman takes a lover during the day while her husband is at work. Her 9 year old son comes home unexpectedly, sees them and hides in the bedroom closet to watch. The woman's husband also comes home. She puts her lover in the closet, not realizing that the little boy is in there already. The little boy says, "Dark in here." The man says, "Yes, it is." Boy - "I have a baseball." Man - "That's nice." Boy - "Want to buy it?" Man - "No, thanks." Boy - "My dad's outside." Man - "OK, how much?" Boy - "$250" In the next few weeks, it happens again that the boy and the lover are in the closet together. Boy - "Dark in here." Man - "Yes, it is." Boy - "I have a baseball glove." The lover remembering the last time, asks the boy, "How much?" Boy - "$750" Man - "Fine." A few days later, the father says to the boy, "Grab your glove, let's go outside and have a game of catch." The boy says, "I can't, I sold my baseball and my glove." The father asks, "How much did you sell them for?" Boy -"$1,000" The father says, "That's terrible to overcharge your friends like that...that is way more than those two things cost. I'm going to take you to church and make you confess." They go to the church and the father makes the little boy sit in the confession booth and he closes the door. The boy says, "Dark in here." The priest says, "Don't start that $%*& again".

Speaking of coils, I wound one recently and am getting set to measure the field uniformity.

What I believe is that any post that long that contains no math is philosophy, not science. I believe that quoting the entire post to make a one sentence comment is a rude waste of bandwidth (not that bandwidth matters like it once did) I think that saying that we are orbiting binary stars is demonstrably wrong. Any conclusion drawn from an invalid premise is itself invalid. Not that any of that matters - tell me how you can say for sure we are moving and something else is at rest, or vice-versa. Relativity works. It makes testable predictions that have held true. It is falsifiable. "Grounded doesn't like it" is insufficient reason for me to discard it. Go show where it's actually wrong.

I do have a basic idea of 'jokes that will get me slapped' or 'jokes that will eliminate the chance of another date.' It's not foolproof. Women claim to like guys with a sense of humor, but they are, shall we say, 'highly nonlinear.'

Well, yes. But posting a joke isn't necessarily an endorsement of that point of view.

A fresh-faced lad on the eve of his wedding night goes to his mother with a question that had been puzzling him for most of the day "Mom" he asks "why are wedding dresses white?" The mother looks at her son and replies, "Son, the color is symbolic of the bride's purity of spirit and devotion." The son thanks his mom and goes off to double-check this with his father. "Dad why are wedding dresses white?" The father looks at his son in surprise and says, "Son, all household appliances come in white."

A young bloke has started work on at a large ranch, and the boss sends him up the back paddocks to do some fencing work, come evening hasn't returned. The boss gets on the CB radio to check if he's all right. "I've got a problem, Boss. I'm stuck 'ere. I hit a pig!" "Ah well, these things happen sometimes," the boss says. "Just drag the carcass off the road so nobody else hits it in the dark." "But he's not dead, boss. He's gotten tangled up on the bull bar, and I've tried to untangle him, but he's kicking and squealing, and he's real big boss. I'm afraid he's gonna hurt me!" "Never mind," says the boss. "There's a .38 under the tarp in the back. Get that out and shoot him. Then drag the carcass off the road and come on home." "Okay, boss." Another half an hour goes by, but there's still not a peep from the young fella. The boss gets back on the CB. "What's the problem, son?" "Well, I did what you said boss, but I'm still stuck." "What's up? Did you drag the pig off the road like I said?" "Yeah boss, but his motorcycle is still jammed under the truck."