These include the large middle-class suburbs of Peoria, Mesa, Chandler, and Glendale; upscale Scottsdale; and the college area of Tempe which serves as home to Arizona State University. All areas are modern and generally lacking in historic interest, but keep in mind that Phoenix only had 100,000 residents in 1950.
do {} until ($false) is an infinite loop; it'll only exit if you use something like break, return or throw from inside the loop body. do { } until ($true) would execute the loop body exactly once (which would make the loop rather pointless.) It looks like what you intended to do was wait for a file to exist.
Be sure to completely cover the egg with vinegar so that the entire shell dissolves. If there are any pieces of shell left, the eggs won't bounce. If you put eggs in their shells into vinegar, however, the vinegar will do the work of removing the shell for you. That's right. The vinegar will dissolve the eggshell. This happens because vinegar contains an acid called acetic acid, which reacts with the high calcium content of the eggshell. It takes three or four days for the shell to dissolve completely, and you must wait until all the shell is gone before trying to bounce the egg.