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Cake day: February 1st, 2024

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  • Aluminum foil is very common in physics labs. And a main use for it is “baking”! To get ultra high vacuum (UHV)* you generally need to “bake out” your chamber while you pump down. Foil is used same as with baking food — keep the heat in and evenly distributed on the chamber.

    Sadly, it’s usually not food grade aluminum foil, as that can contain oils, and oils and vacuum are generally a big no-no.

    *Just how good is UHV? Roughly: I live in San Francisco, which is ~7 miles by ~7 miles (~11km). Imagine you raise that by another 7 miles to make a cube. Now, evacuate every last molecule of gas out of it. Now take a family sedan’s trunk, fill it with 1 atmosphere of gas, and release that into the 7 mile cube. That’s roughly UHV pressure.















  • It’s a pretty standard bandwidth/latency tradeoff in my view: email is high bandwidth (it’s in writing, you can re-read, etc.), whereas phone is low latency (several back-and-forth explanations can happen in seconds). Each has its place.

    If social anxiety is a factor, that’s a perfectly valid, but separate, issue.