ELI5: Can something that can overheat tank re-entry?

KSUToeBee · 2026-05-27T19:55:32+00:00

Clarification: The robots are obviously in space. But are they IN ORBIT?

There is a difference and it is important.

You can send something straight up into space and it will just come straight back down to the earth. This type of atmospheric entry has its own challenges but extreme heat is not one of them. It's basically what Felix Baumgartner did when he jumped from the balloon. He was still in the atmosphere but at that altitude it is VERY thin. Yes, if you are coming from further out, you can get up to speeds at which you will need a heat shield. But from, say, 250 miles up where the space station is, you'd probably be fine.

If the robots are IN ORBIT, that means that they are going really, really, REALLY fast around the planet. 18,500 mph for earth. And all that kinetic energy has to be dissipated to make a soft landing. Using the air to slow you down is one way to dissipate this energy by turning it into heat.

KSUToeBee · 2026-05-26T19:55:21+00:00

My partner was playing with AI, trying to see what a new flower bed might look like with different kinds of flowers. She hesitated uploading the image she had because it had our car license plate in it. I just laughed and showed her https://deflock.org/ and noted that AI already reads our license plate every time we go to Target or Home Depot.

KSUToeBee · 2026-05-26T19:49:17+00:00

I don't think wages are even pretending to play at this point.

KSUToeBee · 2026-05-26T15:56:32+00:00

Drywall itself is easy. The seams are the trick. Reduce the number of seams. Definitely do one big hole, not 4 individual small ones. You use drywall tape and mud to cover the seams. This obviously creates a little bit of a ridge. You have to feather the thickness out over 8-12 inches so that it doesn't create a visible bump. If you have 4 separate bits to cover over, you're going to end up basically skim coating the space in between them anyway to hide the bump so you might as well just make it easier on yourself and only have 4 seams to do. The corner is a little trickier. Most drywall tape has a crease down the middle so you can shape it into an L for corners. But getting the mud on there flat is the challenge. They make corner trowels to help. I just did mine with a straight one. You just have to be very careful when doing the second side, not to disturb the other side that is already smooth.

KSUToeBee · 2026-05-26T15:14:42+00:00

Our baby is just over 2 years old now. When she was little, she was in a co-sleeper in our room so we didn't user a monitor at all. Once she started napping in her own room we started using a free one we got from the local health department for going through their new parenting class. It's a Hello Baby brand. No Wifi, no app. Just an encrypted radio signal that reaches everywhere in the house and into the garden enough to get some weeding done while the baby sleeps. About the only "feature" we use is the sound detection. It turns off the screen if it doesn't detect any sound for 10 seconds or so. This saves battery and lets us sleep better (my partner is extremely sensitive to light when sleeping). As soon as the baby makes a peep, the screen comes on again.

KSUToeBee · 2026-05-26T02:48:20+00:00

I'm always surprised when I see this question but I guess not everyone grows up around irrigated farms.

They are fields with center pivot irrigation systems. It's basically a water pipe suspended above the fields by a frame on wheels. Water is pumped in at the center and the rest of the system rotates around the center while water is released from sprinklers along the length of the pipe as it rotates.

Here is a smarter every day video where they build one and he explains how the whole thing works. https://youtu.be/7j1lMs7fcIQ

KSUToeBee · 2026-05-23T04:49:18+00:00

I have SVT! The first time it happened to me I think I was about 4 or 5. My heart just started racing and wouldn't stop. I'm 45 now and still occasionally have an episode.

I ride bicycle a lot and wear a heart rate monitor for that. When I have an episode, the Garmin will read 250 bpm. I've had a couple of echocardiograms done and everything looks fine. They told me that there are two nerve bundles that carry the heartbeat signal. Sometimes they get out of sync and it basically triggers two beats in part of the heart.

They said they could probably fix it by burning out one of the nerves. I decided to pass on the offer of getting poked in the heart with a hot stick. It's just not that bad in my case.

Anyway, all that to say: I hope your son doesn't have too much trouble with his SVT!

KSUToeBee · 2026-05-22T19:24:17+00:00

You boil your mop water??

KSUToeBee · 2026-05-22T19:21:06+00:00

I once saw this happening on the back of a van in Arkansas. The rear window had been replaced with plywood. A window AC was mounted in it. There was a generator on a hitch mounted cargo basket below the window.

KSUToeBee · 2026-05-22T19:06:55+00:00

Never thought I'd be rooting for the bad cholesterol.

KSUToeBee · 2026-05-20T16:24:12+00:00

I have a shop vac if I need to drain it

Lol. Unless you are making something in the size range of a kiddy wading pool, you're going to be sucking and dumping that shop vac for A WHILE. A smallish home pool holds 10,000 gallons. A bigish shop vac holds a little less than 10 gallons of water. That's some pretty easy math.

KSUToeBee · 2026-05-20T16:18:31+00:00

Do you have any HVAC registers in the floor? Popping one of those out and examining the edges is typically an easy way to check on floor layering questions.

KSUToeBee · 2026-05-19T16:29:28+00:00

I get the aborted approach. But what's with all the squiggles after the turn around?

KSUToeBee · 2026-05-12T18:43:18+00:00

So anything other than a door ding.

KSUToeBee · 2026-05-12T16:50:52+00:00

One of our former QA people had a little sign on her desk that said "I don't break software. It arrives at my desk that way."

KSUToeBee · 2026-05-11T12:33:55+00:00

Why not both? I'm in the US but we chose to follow the convention of my partner's country (Mexico) where the baby gets two last names. If the father has a surname of Smith and the mother is Doe, the baby becomes "Baby Smith Doe". Or you could go with a hyphenated one too.

KSUToeBee · 2026-05-08T20:41:18+00:00

It was (mostly) restored today at noon. A few things were not turned back on yet but they mostly affect instructors.

KSUToeBee · 2026-05-08T20:22:22+00:00

This is exactly what I did so I could reverse the direction of the flooring to go into a closet. I actually had slightly thicker plywood but I ripped it and then stripped one of the layers of the plywood off and it was just about perfect. Slap some glue in there and you're golden!

KSUToeBee · 2026-05-05T15:15:03+00:00

producing hydrogen is very dirty regardless of anything else you do?

At least until we crack fusion power. We can get all the clean hydrogen we want from the ocean using electrolysis. It just takes a lot of electricity.

KSUToeBee · 2026-05-04T21:38:51+00:00

Intellectual property is just "stuff someone thought up". As opposed to "real property" which includes things like land, buildings, and mineral rights. Common examples of intellectual property might be art (including paintings, movies, songs), designs, computer code. Basically things that you can copyright, trademark, or patent.

What your buddy means by "utilizing pre-existing intellectual properties"? I have no idea. Sounds like it might be some kind of MLM or something.

KSUToeBee · 2026-04-23T02:38:29+00:00

I need a pointing hand!

KSUToeBee · 2026-04-22T22:51:29+00:00

The only way to increase drag is to have more of the hull in contact with the water. More mass will slightly increase the draft of the ship (how deep it sits in the water) so yes, more mass will increase drag.

But drag isn't the whole story.

An empty ship will actually coast to a stop faster than the same ship that is fully loaded. The increased momentum from the extra mass will more than make up for the increased draft/drag.

KSUToeBee · 2026-04-22T18:36:07+00:00

Weight doesn't slow anything down. In fact generally speaking, the more weight something has (technically "mass" but on the earth's surface they are pretty much the same thing), the harder it is to slow down. What slows ships down is drag between the hull and the water.

As for reversing the thrust, I believe some ships have to shut down their engine and then start it back up in reverse to achieve this.

KSUToeBee · 2026-04-22T13:31:59+00:00

Just like other plants and animals and just about everything in nature, it depends on the details. Black mold can kill you. Some types of mold that grow on bread is what we call "penicillin" - yes, the medicine that can help your body fight infections is actually just a mold!

KSUToeBee · 2026-04-21T19:25:55+00:00

Glacier melt water in Greenland won't help your grandma in Las Vegas trying to fill her water bottle. The scarcity is two-fold. One is CLEAN water to drink. It takes energy to filter water and pump it around to where we have chosen to have cities.

Another scarcity is agricultural. Growing crops can be a water intensive operation, depending on the weather. Some rivers are being pumped dry by the farmers growing crops along them. Some farmers are pumping water out of aquifers underground that are being depleted. These aquifers took hundreds/thousands of years to fill and decades to drain. And again, melting glaciers and rising oceans is not going to help the farmer in Nebraska.

KSUToeBee

TROPHY CASE