343 karma · joined September 23, 2011
x,Hx->Mx
->
Hs->Ms
which returns "The statement is necessarily true."That site doesn't mention the spot size, but its likely much larger than the page thickness, so the iron signal from a tilted page probably wouldn't differ in a measurable way from having the page perpendicular to the beam. Keep in mind that they require ~24 hours to get even the images shown. Instead it sounds like they rely on compositional differences in the ink from the two sides and look at fluorescence from an element that is only present on one side.
It might be possible to get the other side by taking a difference between the Fe and Ca signals (after scaling appropriately).
The guy writing the tweet (not necessarily the interviewer).
Note: I don't use Facebook's app often, and have no context for what the actual issues are.
I wonder what was actually "compromised" about the 76 million accounts if not account information.
Alternatively, you have a short period (60s) before the migration occurs during which you can lame a service: https://cloud.google.com/compute/docs/metadata#maintenanceev...
However, I'll grant that both of these lack the "in your own convenient time" portion of your desire.