Earlier quoted context omitted.
even when my microwave is closed, the interference it generates while running blocks my bluetooth headphones
Yep. Water molecules resonate at 2.4 GHz (so that's what microwaves emit), which is also the unlicensed radio spectrum that bluetooth and a lot of other consumer radio devices operate on. Not sure which is the chicken and which is the egg here. But the observatory had either a well-shielded microwave or break room was in an adjacent building or something (they did consider "ya know, microwaves make RF emissions, and…
Microwaves have gotten better shielding. My old one used to take out Wifi and Bluetooth standing next to it, but my current one doesn't cause problems.