https://en.wikipedia.org/wiki/Nick_Piantanida

This guy was in a remote controlled, parachute equipped gondola at 17km altitude wearing a pressurized suite. His suit broke and even though the emergency descent of the gondola was immediately activated to descend safely, he later died from embolism (bubbles forming in the blood because of rapidly decreasing pressure). Passenger jets cruise at about 11km so i gather it would be similar.

OpenWRT does not use liblzma or systemd so i think that one is pretty safe. I would also be surprised if Android included OpenSSH server binaries in that way.

Maybe those were illegal smoke and honey melons 🤔

Other commenters have pointed out the problems with overloading of connectors and reduced efficiency because of the added resistance but there is another really important reason not to chain power strips: circuit breakers work best against short circuits when the resistance between the breaker and the short is fairly low (for instance less than 0.5Ω) so that the current will quickly go over the rated current of the breaker. If the resistance is a lot higher because you have too many extensions between the breaker and the fault, the time the breaker needs to react will go up. Counterintuitively this usually means more energy will be turned to heat by the fault.

In extreme cases this can mean the difference between a broken power strip that you can just throw out and a burned down house.

If you want to be super exact about it it would be roughly 4 times the mass of limescale + mass of already dissolved CaCO₃ in your tap water (you can look that up if you know the hardness index of your water).

But really just don’t be stingy with citric acid and it will be fine is what i am saying.

Here is the math:

Note that citric acid works a bit more nuanced than many other descalers: it acts as a chelating agent at high concentrations (2x the Ca2+ concentration) and is more effective at removing scale because of this effect, but at lower concentrations the effect might actually be reversed because it can form solid calcium citrate, which has a very low solubility in water.

If you are using citric acid based descaler you should make sure that you are always using enough of it to avoid the formation of calcium citrate.

that sounds almost exactly like the Reichsbürger in Germany. They also claim the current German state is actually just a corporation and the laws of the German empire are somehow still applicable. They also create their own passports. And of course they are deeply interconnected with Neo-nazis.

oh i must have missed a few orders of magnitude there. 6Mt of helium is a ridiculous amount though … what is all that used for? according to WA that is about the water volume of the three gorges dam at STP

Edit: just read the report, wow, more than a quarter of all the helium is used just for “breathing mixes” which i assume means its for scuba diving.

from the wiki article on Helium:

an estimated 3000 metric tons of helium are generated per year throughout the lithosphere.

I think the main issue here is not that we are loosing helium on a planetary scale but that the easy to reach helium from gas wells is wasted. We will never run out of helium at our current rate of consumption before the sun goes nova, if we consider all sources on earth, but it will get a lot more expensive and the supply will get less steady.

skipped reading the silkscreen … it says Q1 on the lowermost package but the other three are diodes. so could also be a forward converter or something similar.

indeed it looks like a Royer oscillator in there (because there are transistors before AND after the transformer).

click on the link pls

“ἰχθύς” is the ancient greek word for “fish” https://en.wiktionary.org/wiki/ΙΧΘΥΣ

yes indeed. i keep being confused how email can still suck so much sometimes when it had decades to mature.

yeah this is a real pet peeve of mine.

In German many people, web mailers and also sometimes even email software use “AW:” (short for AntWort) instead of “Re:” and then some of them don’t even recognize the existence of a previous “AW:” or “Re:” giving you such wondrous email subjects as: “AW: Re: AW: Re: AW: AW: Re: AW: Re: really important subject” 🤦

you h2e it?

Acording to the datasheet the TDA7294 uses -V_s and +V_s in the block diagram so i would assume it is intended to be used with DC power. If the module is specced for use with AC as well as DC, then this just means what you already suspected: it has an integrated bridge rectifier and most likely some sort of low pass for the rectified power (read: a bunch of big capacitors).

You could just go with a big transformer core that powers them all at the same time; many commercial amps do that and it works fine in general, provided you have enough margin for power spikes and the modules will not influence each other when connected in parallel to power.

In my opinion using separate transformers would be paranoid but it would work of course.

Edit: dont forget that this thing will produce heat. If you really go with an 800W transformer then you have to be able to cool about 400W in the worst case (going by the data sheet power dissipation of the chip and assumed transformer + rectifier efficiency of 90%).

woah this is awesome!

maglevs need classical wheel systems anyway because there might be a power outage, so simply having wheels that are compatible with the local rail system is a brilliant idea.

add in a tiny propulsion system so they can use the normal tracks at low speed without the help of the maglev tracks and you can sort of blend the two systems together in critical locations like switches and train stations.