Recent comments in /f/askscience

drakens6 t1_j5xp3of wrote

Reply to Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology by AutoModerator

Amateur (albeit incredibly notorious) theology/anthropology scholar here.

Has it been put forth amongst you professional anthropologists that the stories of Sumerian culture (particularly the Enuma Elish) seem to provide metaphorical corroboration of events that closely mirror what we see in geological record?

I for one am particularly interested in the possibility that the tale of Tiamat's destruction was describing the great cataclysm that ended the Dinosaurs' reign on earth.

The implications are immense from that particular interpretation of the text.

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Mispunt t1_j5xnwyd wrote

Reply to comment by fishling in Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725

There isn't really an opposite direction or a perpendicular direction though. If you circularize on the 'right' side you go left around the planet, on the 'left' side right. Edit: once you match the orbital plane of the ISS you can catch up or slow down for a rendezvous by changing orbit height.

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Flannelot t1_j5xnts5 wrote

Reply to comment by radioactive_dude in How hot is the steam coming out of nuclear power plants? by ivy-claw

> This water is not used to drive the steam turbine directly.

Just to clarify, in Pressurised Water Reactors this is true, but in Boiling Water Reactors the steam forms directly in the reactor vessel and goes straight to the turbine.

This results in two different control strategies. Both are still popular designs.

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mancapturescolour t1_j5xn7bv wrote

Reply to comment by FelisCantabrigiensis in What determines whether we can create a vaccine for an illness or not? by ShelfordPrefect

> Fortunately, we have very effective treatments to suppress it and we can, if we deploy these widely enough, expect to suppress it out of transmission in the foreseeable future. HIV isn't very easy to transmit so if you suppress it in the people who have it, it should die out when the oldest person with HIV dies of other causes, after spending their life with suppressed HIV.

Yes, it's effective and cheaper than ever.

> If properly adhered to, ARV treatment, which costs as little as 20 cents a day, not only keeps an HIV-positive person alive and healthy, but also reduces the risk of transmission.
Source: https://www.red.org/our-impact-areas/#testing-and-treatment

Now the game-changer in all this, for me, is that supressing HIV during pregnancy prevents mother-to-child transmission of the virus. That means a child to a HIV+ parent can be HIV free at birth! So, we don't have to wait for HIV to die out with old age, there are people already born HIV- thanks to these drugs. The United States have made a significant impact through PEPFAR in the last 20 years (this Saturday!) but we rarely hear about that success story.

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fishling t1_j5xmq9a wrote

Reply to comment by CountingMyDick in Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725

You're still assuming that the path is coming up from behind the ISS, in the same direction ISS is moving. If it's moving in the opposite direction, it would have to come to a stop and then accelerate to catch up to the ISS. Or, if it coming in at a right angle, it would have to shed all that extra perpendicular velocity and add all the parallel velocity. Only in the most perfectly aligned case could it be 4 km/s.

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oz6702 t1_j5xlhp5 wrote

Reply to comment by fishling in Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725

> The sample return mission is almost certainly not going to be coming on a path aligned with the ISS orbit that only needs to slow 4 km/s to meet it.

To be fair, this is a trivially easy problem to solve. A change of a few cm/s when you're a million clicks away can result in huge differences in your destination, so setting things up such that your incoming deep space probe lines up with the ISS' direction of orbit and plane of orbit and whatnot would be quite easy, and pretty cheap as far as dV is concerned. Still, slowing down to match orbit with the ISS is something that's gonna cost you a ton of fuel either way - unless you aerobrake, in which case you might as well just do that instead of bring the fuel along to begin with.

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MazerRakam t1_j5xj36h wrote

Reply to comment by smash8890 in What determines whether we can create a vaccine for an illness or not? by ShelfordPrefect

Combination of a lot of factors, vaccine research was still fairly new and virology wasn't nearly as well understood as it is now. They were targeting the wrong proteins and getting frustrated that they weren't getting the results they expected. Come to find out, RSV actually changes shape (protein unfolding) after it enters the cell. This is important because antibodies can only prevent a cell from getting infected, antibodies cannot enter a cell and push the virus out. So researchers were taking infected cells, analyzing the virus in those cells (after it changed shape) and tried to make a vaccine that would teach the immune system target those structures. But those structures weren't found outside the cell, and the immune response was hindered because of that.

Luckily, someone figured that out, and they redirected their focus and were able to create a vaccine that teaches the immune system to target the virus structure before it enters the cell and now RSV vaccines actually work the way they should.

https://www.nature.com/articles/d41586-021-03704-y#:~:text=Tragically%2C%20the%20shot%20did%20the,the%20trial%20and%20killed%20two.

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