Thank you so much 💗💗💗

Good luck!

That's a goal of some projects, for sure. Already, there are cheapish 3D printers that can print over 90% of their components: often, you need to buy off-the-shelf electronic components to complete it.

> And wouldn’t that destroy the 3D printer industry

Already there are printers on the market where you have a choice of buying a kit and assembling it yourself, or paying more to get it already assembled - or paying less and just getting the electronics (plus a download link for the rest of the parts). Some people are happy enough to assemble their own 3D printer, but if you're just starting our with either 3D printing or electronics, that's a pretty ambitious project. 3D printers can be finicky enough even when assembled by someone who knows what they're doing, let alone by a n00b watching a YouTube video.

Thanks 👍❤️ will do

Definitely-ish, but mostly a few different printers (minus the motors, maybe the nozel, and control computer) ... Look up the rep-rap printer https://reprap.org/wiki/Build_A_RepRap designed to be able to print as many of its own parts as possible... Obviously at minimum the nozel needs to be metal, and the control board would need A specialized printer if you wanted to print that too... The motors and microchips will still probably need other manufacturing techniques to produce for the foreseeable future

The plastic parts but it would take a metal 3d printer for the metal parts and you would still need to buy or build the circuits and wires

Semi-autonomous vehicles on existing roadways is way less expensive and less complicated than building completely new rail lines everywhere.

Vacuum. Dust. Wash the dishes. Wash, dry, fold, and put away the laundry. Empty the garbage. Scrub down the bathroom. Put your dirty clothes in the hamper.

You get the idea, right?

Do all that stuff over and over forever. Share the chores.

The ancestors of mammals were nocturnal and it's difficult to see colours in dim light. This makes it less useful to produce colourful pigments since they won't be noticed.

Sure. None that currently exist, but sure.

It'd have to be an insanely high-end printer, probably using crazy-expensive feedstock, but yeah sure. It'd hardly destroy any industry, though.

3dp is usually one of the worst ways to make something. It is super convenient for making one or two, but for any product it is garbage. Anything a modern 3d printer can make in four hours with a lot of care and tweaking, an injection moulding machine can make in four seconds and repeat ten thousand times before it needs maintenance.

Hair has 3 different phases in its life cycle. First the growing stage, followed by the resting stage, and lastly the final step in which it sheds and waits to regrow.

The hair on our head has a very long growing stage (several years) and then a shorter resting stage. So the body knows that hair will grow for x amount of time before tapering off.

Body hair, however, has a very short growing stage time (days) and a longer resting stage. That's why it grows in quickly but never gets long

Earth has an atmosphere where lots of that stuff burns up.

The moon doesn't.

Also there is erosion and weathering happening on the Earth. That's not happening on the moon.

It's mainly because most features are relatively level.
We don't really have many problems making a ramp.
We build them to connect surface and elevated highways/roads all the time.

ELI5 Then how can some animals can breathe when they are underwater and on the ground? (i.e. crabs)

A melanin variant can produce an orange shade. Tigers look very bright to us, but not to their prey, which can't make out the redness.

I’m not sure exactly what you mean; curved or sloped?

Either way, keeping a bridge straight and level is simplest. It distributes loads evenly on both sides, allows the builder to use straight and square members (rather than something that’s slightly off), and things like that. They can make bridges with significant slopes and curves; freeway interchanges are a good example. But they are more complicated. And if a bridge needs a slight slope, oftentimes it’s easier to simply fill in dirt on the low side to make it level rather than have a bridge compensate for being less balanced.

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Granted our planet is much more geologically active and that definitively plays a part, but I feel like erosion is largely an atmospheric phenomenon.

It may not be. Chicxulub is absolutely massive but not visible from a normal satellite. It's been eroded by time. When you consider just how gargantuan that planet killer was, it gives erosion and plate tectonics a much stronger argument.

It wasn't even that long ago from a planetery age viewpoint, given its size.

Good answer. A comparison could be drawn with sweat. Sweat cools your body by evaporating: the energy to change it from liquid to gas has to come from somewhere. Similarly, salted ice cools the ice cream by melting: the energy to change it from solid to liquid has to come from somewhere.

Mold and bacteria thrive in moist, humid environments. It’s less that humidifiers have been engineered to need excessive cleaning and more that their intended function encourages this growth as a natural consequence.

Preventing it would require doing things to the water that you probably don’t want to do to something you’re intending to aerosolize and inhale, or else treating the device itself in ways that are likely to require cleaning and/or maintenance anyway.

So at that point it’s cheaper and safer just to tell people they need to clean their humidifiers because the thing that makes humidifiers good for you also makes it good for stuff you don’t want building up in the humidifier.

Mold is life. Life grows where there is water. Humidifiers dump tons of water in their general vicinity. It's a natural consequence of humidifiers.

As noted by the other person there are ways to get around it by making the humidifier itself out of materials that kill anything that it touches, but those materials are almost never safe.

Copper would probably be the least concerning from a health standpoint, but copper is not cheap, and it's really heavy.

It's way more practical to just ask you to scrub it every once in a while.

Anti microbial materials and coatings are rather expensive and would eventually be a hazard if they corroded or disolved into the water meant to evaporate.

Is that the same concept as a bukkter travelling through water? It causes a void then water quickly closes the space behind it causing tiny explosions. I was watching the slow-mo guys fire bullets under water. It would cause a void behind the bullet and the water pressure caused subsequent explosions.

Maybe some of the sugar substitutes compete with the sites on enzymes responsible for giving us energy which normally attach sugar. This causes an acute sense of sugar deficit and a deep sugar hunger. (?)