A superconductor does not let magnetism penetrate it. Stand a superconductor in a magnetic field and electric currents will flow through its surface. These currents create a magnetic field that cancels the original field trying to get inside the superconductor and repelling the magnetic field outside. When the metal is no longer superconductive, the electric currents face resistance again and so the magnetic field that cancels out the original field cannot do so anymore.
The transition elements are atomic numbers 21-30, 39-48, 57, 72-80, 89, and 104-106. Yes, they are all metals.
Well if you're talking Halo 4 for the 360 rather than the MCC, that is a possibility. You see, if you didn't go back in and manually select the default Ravine map it had a nasty habit of saving your previous work in it's place.
On the MCC though, it could simply be a UI glitch. Try loading a non-forged map from Halo 4 (one of the default maps besides Ravine), play on it for a minute, and then try to load Snipe. If the map is still Griffball Ramps, then the save for Snipes has been overwritten.
Lol the song is actually named "Take Me Out to the Ball Game" and it was created by Jack Norworth and Albert Von Tilzer, neither of which had actually been to a baseball game. They didn't actually go to one for another 30 years or so either. The song is actually about a woman who is named Katie Casey who is obsessed with baseball, and is speaking to her 'boyfriend' when she sings the chorus.
The reason for it's popularity is that radio was that day's internet/television. Songs were a lot easier to hear than they are today (I know right?) and so catchy tunes had a tendency to stick with people. Not to mention that this was in the United States, where baseball was huge. The easy to remember melody and chorus was then sang at a few games and was referred to by several other popular programs just a few years later, pretty much cementing it's popularity.
"Buy us some peanuts and crackerjacks" is actually a bastardization of the original song sang at 'home games' and is actually a line that doesn't appear in the original song as well. lol