senders can only be easily forged if you control the senders mail server or if they don’t use best practices for running a mail server.
See also:

• DKIM
• DMARC

there are cryptographic signatures on almost all mails sent by large mail providers these days, which makes it very hard to just forge an email that will hold up to closer examination with the help of the provider. so basically the IT techs of the company would need to be on board with whatever the perpetrator is doing, for them to get away with it.

The situation isn’t that different in Germany: emails can be used as evidence in court, though they aren’t as strong as evidence as say: a signed letter. There is also the issue with proving that an email actually arrived, but i would assume that in this case that is already covered.

https://en.wikipedia.org/wiki/Earth's_circumference#Eratosthenes

ah ok i mistunderstood what the group head is. if they are both permanently in contact with the water in the boiler then it would depend a lot on the water quality. Water with only a little conductivity (<100µS/cm) would not be a problem for pure aluminium or most alloys, since the aluminium would passivate much quicker than the corrosion could dig into it.
i would assume that a vessel made for boiling water is made of a highly corrosion resistant alloy but i can not know for sure.

but that only happens while there is water there, right? so given the limited amount of contact time i think this is not a concern. aluminum has a great capacity for self-passivation too, at least the typical alloys do.

Do you mean oldest as in invented the longest time ago or oldest as in that specific technological artefact that i use is the oldest one i have?
For the first one i guess cooking?
For the second one its definitely my microwave oven, made in 1991.

There is a limit on the spacing of the colour bands though. If you want colours then you have to hit the spots where the correct phosphors are and this limits the usable resolution.

So, i read the “Red Mars” trilogy. I also keep up with research into the Martian atmosphere, its soil and geology.

My take is that all of this is still a pipe dream as much as it was 30 years ago when we did not know many of these things.
People don’t want to see just how hostile Mars is to life. They pick a couple of the most obvious problems (e.g. radiation, no liquid water, no oxygen) and then they look for the first solution that seems viable and then declare Mars somehow liveable because look we can just implement those things.

But they are completely ignoring that: none of these proposed solutions have been implemented at scale yet, at least not outside of earth’ atmosphere, there are hundreds of other known problems that often just don’t make it to the head lines because they don’t look that interesting or threatening (example: dust is suuuuper deadly on Mars, probably even worse than moon dust) and many problems will undoubtedly only become obvious once living beings are on the surface of Mars.

I am glad that there is hard sci-fi dealing with some of these problems in very optimistic ways, because we should try to better our understanding of them and not just give up, but we also should not have any illusions about how hard this task is and that this can take centuries of work.

Most modern operating systems randomize the MAC.

[citation needed]
having the option to randomize the MAC is not the same as actually doing that. There are also a few downsides to random MACs, like captive portals not remembering you on public WiFis.

Bitwarden has a FOSS client app and FOSS server apps exist (though the default service is not FOSS).

Syncing 2FA keys brings the danger with it that you accidentally sync the key to the device that is used for the first factor thus making it not 2FA anymore.