this one?
No, the one I’m thinking of was at an angle, and I think the reference frame was specified as being off Earth. I think it was one panel of a 16-panel collection of mini-strips.
So how long does it take to perfectly toast a marshmallow this way?
I think it’s in the ballpark of several seconds. Not too different than putting it in the hottest part of a campfire.
The heat flux from LEO is on the order of 1000 kW/m^2. A 4-cm marshmallow has a cross-sectional area of about 0.0016 m^2, which makes the total heating about 1.6 kW.
That’s high, but not crazy-high. Similar to taking a hairdryer directly to the marshmallow. It’s a lot of heat, but it doesn’t vaporize the thing instantly. It’ll take several seconds to brown the surface and heat the inside.
The heat flux from further out than LEO can get much higher. Perhaps 2500 kW/m^2 from the moon, and >10 MW/m^2 from interplanetary transfers. It would take under a second to cook the marshmallow in that case.
Videos of re-entry show the capsules surrounded by what appears to be orangeish flames (they’re not literally flames, not being the result of something combining with oxygen, but close enough). Orangeish flames are also what a campfire produces, and color indicates temperature. So yeah, it’d be the same ballpark.
I’m really curious about the 1500 years figure… It’s not just the time it takes to make a single circumnavigation, because at any reasonable windspeed, he’ll make several of those per year. But nor does it seem to be the time, allowing for random perturbations, that it would take him to pass close by the net again (“close by” meaning “close enough to be able to toss the ball in”), because 1500 years is long enough that he could have diffused to anywhere in the hemisphere, or probably even anywhere on Earth, and at several circumnavigations per year, a ball-toss-width band will cover only a small fraction of the hemisphere.
Yeah, I don’t get it either.
That’s why they have a shot clock, isn’t it?
Yikes. I went to the usual explainxkcd.com, but they’ve been hacked or maybe just vandalized, and the main page is has some horrific medical images on it. Hopefully that gets fixed soon.
I’d been thinking that maybe there’s some 1500-year atmospheric cycle, but couldn’t find anything. I searched for “cycle”, “recurrence time”, and a few other things. While there are some multi-year cycles, none were close to 1500 years.
Looks like land overrides ocean. I.e., a union operation with respect to the landmasses. But why should ocean get the shaft? I say the map should be the union of the water, not land.
But the ocean gets the whole back side!
I’ve heard astronomers point out that it’s probably pretty unusual for an earth-sized rocky world to have a moon this size, and that the tidal effects it has on our oceans may have been key to the development of life in tidal pools.
Interestingly enough, things that seem immutable like the being moon the right distance to allow for total solar eclipses that reveal the Sun’s corona, and Saturn’s rings, and Jupiter’s big red spot, are actually all temporary. The Red Spot may be gone in another 100 years, Saturn’s rings in 100 million years, and after 620 million years every eclipse on Earth will be an annular eclipse.