The best way to reheat pizza

Easiest method that is still very good:

Get a cookie sheet. Put baking paper on it so the pizza won’t stick to it. Put cold slices on tray. Completely cover the cookie sheet in alfoil (tin foil, whatever you call it). Put in cold oven. Turn oven on to about full, 220°C or 430°F. Leave for about 20 minutes (depends how many slices you’re putting in and how quickly your oven heats up, check at 15 minutes or earlier.)

Complicated method for optimisers:

I haven’t tried this because if I’m eating re-heated pizza, I’m not in an “optimise cooking” mode. But it’s r/pizza’s official recommended method, and reddit is usually good for finding the optimal method for something. It’s where I get all my skincare advice from.

Fastest method:

Chlorine trifluoride seems pretty effective?*

This piece was originally published in The Whippet #119 – subscribe to get the next issue in your inbox!

* That was a reference to a piece earlier in that issue of The Whippet, which I include here

The sheer terror of working with chlorine trifluoride

Chlorine trifluoride, or CTF, is an almost perfect fuel for rockets, with a very big almost:

It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel [hypergolic with = spontaneously catches fire upon contact], and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively.

It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.

In one recorded spillage, CTF set fire to the concrete floor, burning through a foot of solid concrete and then three more feet of gravel underneath it before it flamed out.

But let’s assume you manage to actually handle it safely and get it into a rocket:

Ignition was beautiful—so smooth that it was like turning on a hose. Performance was high—very close to theoretical. And the reaction was so fast that you could burn it in a surprisingly small chamber. But. If your hardware was dirty, and there was a smear of oil or grease somewhere inside a feed line, said feed line would ignite and cleverly reduce itself to ashes.

Gaskets and O-rings generally had to be of metal; no organic material could be restrained from ignition. Teflon would stand up under static conditions, but if the CTF flowed over it with any speed at all, it would erode away like so much sugar in hot water, even if it didn't ignite.

(Both quotes from John Drury Clark’s 1972 book, Ignition! An Informal History of Liquid Rocket Propellants [PDF] via @klezmerstyle on twitter.)

The many-step, arduous process of how to get it safely into the feed lines is similarly delightful, I cut it out of respect for your time, but it’s a fun read. After explaining the arduous, multistep process of safely getting it into the feed lines, the next paragraph begins: “It was when the stuff got into the motor that the real difficulties began…”