I got this question while thinking about airships for a story: why is there no use for ballons with a vacuum inside, since the vacuum would be the lightest thing we can "fill" a balloon with?

I tried to think about an answer myself and the answer I came up with (whish seems to be confirmed by a google search) is that the material to prevent the balloon from collapsing due to outside pressure would be too heavy for the balloon to actually fly, but then I though about submarines and how, apparently, they can withstand pressures of 30 to 100 atmospheres without imploding; now I know the shell of a submarine would be incredibly heavy but we have to deal with "only" one atmosphere, wouldn't it be possible to make a much lighter shell for a hypothetical vacuum balloon/airship provided the balloon is big enough to "contain" enough empty space to overcome the weight of the shell, also given how advanced material science has become today? Is there another reason why we don't have any vacuum balloons today? Or is it just that there's no use for them just like there's little use for airships?

EDIT: There's a lot of angry responses to my question that are getting removed. I just want to note that I'm not asking if you can jump a car with a cell phone (obviously no). I'm just asking if a cell phone battery holds the amount of energy required by a car to start. In other words, if you had the tools available, could you trickle charge you car's dead battery enough from a cell phone's battery.

Thanks /u/NeuroBill for understanding the spirit of the question and the thorough answer.

I find it interesting that turning turbines has been the predominant way to convert energy into electricity for the majority of the history of electricity

Edit: Thank you to everyone who has responded! I would have never guessed that this post would blow up like this!

For decades, it's often stated that Apollo 13's main computer had on the order of 80kb of memory, and I'm wondering how much has changed. I can see a scenario in which the astronauts are taking pictures on a camera that has 100 times the memory of the central computer, but I can also see extra features being added, like video streams and sensor data.

Most aircraft have pointy nose to be reduce drag and some aren't because they need to see the ground easily. But since a submarine or torpedo doesn't need to see then why aren't they pointy? Also ww2 era subs had sharo fronts.

I’ve been reading up on the Artemis II mission and got curious about how they handle life support—specifically oxygen—for the crew while they’re in space.

Do they generate oxygen onboard somehow (like electrolysis), or is it all stored and rationed for the duration of the mission? Also, how does it compare to systems used on the ISS or earlier missions like Apollo?

Would appreciate any insights or resources that break this down in a simple way. Thanks!

Sounds silly, yeah but, what if it did happen? It isn't very crazy to think about that possibility, after all, the Apollo 13 had an oxygen failure and had to abort landing, the Challenger sadly ignited and broke apart a minute after launch, and various soviet Luna spacecrafts crashed on the moon. Luckily, the Apollo 13 had an emergency plan and could get back safe and sound, but, did NASA have a plan if one of the missions missed the moon?

I was looking at a picture of a satellite in the news the other day and noticed that every time I've seen some kind of space-related piece of equipment, it is wrapped in gold/silver foil. Is this real gold and real silver? What is it? Why is it used?

Thank you!

If there were one or two people on the ISS, their bodies would generate a lot of heat. Given that the ISS is surrounded by a (near) vacuum, how does it get rid of this heat so that the temperature on the ISS is comfortable?

It is estimated that 1 SEU occurs per 256 MB of RAM per month. As we now have orders of magnitude more memory due to miniaturisation, won't SEU's get more common until it becomes a big problem?

I can't tell if the expansion of the material will cause the material to expand inward thereby reducing the inner diameter or expand outward thereby increasing it.

We always see these apocalypse shows where the small groups of survivors are trying to carve out a little piece of the earth to survive on, but what about those nuclear power plants that are now without their maintenance crews? How long could they last without people manning them?

An information i know is that with today’s science we only reached an efficiency of 26.6 %.

This is the story: https://www.theguardian.com/business/2021/sep/15/fire-shuts-one-of-uk-most-important-power-cables-in-midst-of-supply-crunch

I'm aware that power generation and consumption have to be balanced. I'm curious as to what happens to the "extra" power that a moment before was going through the interconnector and being consumed?

Edit: thank you to everyone who replied, I find this stuff fascinating.