General Science Thread

Anti-bullying program focused on bystanders helps the students who need it the most

This seems like a ridiculously obvious conclusion, why was this not tested before now?

Humans speeding up evolution by causing extinction of ‘younger’ species

ATLASGAL survey of Milky Way completed

Computers can tell if you're bored, shows new study

Consumers have huge environmental impact

Wi-Fi achieved at 10,000 times lower power

Genomic evidence sheds new light on our understanding of spider evolution

Dodos might have been quite intelligent, new research finds

Malaria family tree has bird roots

Efficient methane C-H bond activation achieved for the first time

Deadly stars: Our sun could also be superflare star

Earth's moon wandered off axis billions of years ago

First evidence found that 'cryptic female choice' is adaptive

Groundbreaking trial to see if it is possible to regenerate the brains of clinically dead people

What would or could happen if one could "break" scientific laws like the laws of thermodynamics?

Depends on which law under which conditions. You may end up with Alien Geometries and other unimaginable stuff.

If you could casually break the law of entropy, stars would be impossible.

O.K, here's a specific question: what if you could destroy energy?

Not sure what entropy has to do with stars.

Well, when can energy be destroyed?

Amusingly, NASA's peer-reviewed EM Drive paper has finally been published.

That drive might have its recoil taken up by an unidentified medium - "rocket fuel" is not the only thing that can. Light can carry momentum, for example (E/c, to whit). Or the research may be wrong, as OPERA was about FTL neutrinos.

The basic idea is, if there was a mechanism that could cause a system to go from high entropy to low entropy in stars, then it would happen. Any such mechanism is self reinforcing, and so would lead to a runaway effect and explode the star.

Um, no? It would need to overcome gravity for starters. And that it can happen under some circumstances does not mean that it will happen, let alone in a star which may not have the circumstances required.

It can happen with some such mechanisms.

Can you think of a physical circumstance where entropy could be broken that could occur naturally on earth, but not in a star? Also, can you think of an exception to entropy that would not lead to a runaway effect that could destroy a star?

A low temperature quantum mechanical effect that only happens in superfluid media where the particle nature of matter disappears, for example. Something that most definitively does not happen in a star.

Okay. Here's the idea I had. Imagine a region of space gets cold enough to reach superfluidity. If entropy shrinks under this circumstance, part of this region will get hotter, and part will get colder. due to heat diffusion, the cold region will get larger. Eventually, the phenomenon will infect the nearest star, creating pockets of super cold superfluid regions inside the star.

I am fairly sure that no place in space can reach lambda temperature. Just not dense enough. You'd need solid material for that.

Apparently, one of the scientists who discovered dark matter, Vera Rubin, passed away at age 88. Reddit link, which in turn links to a tweet. Some discussion about historical research of dark matter and physics in the comments, which I found interesting.

Is this thread for anything other than posting links? Like, answering science questions?

I've noticed that after a few days of warm weather, there tends to be some form of precipitation, followed by a few days of cold weather, followed again by warm weather, in a repeating cycle. I have an inkling this is related to hydrogen bonds and the water cycle, and probably works on the same principle that sweat having a cooling affect on the body does, but I can't work out the details.

I wouldn't read too much into the hydrogen bonds. The same thing can happen around hear sometimes. It's just the water cycle in action. The weather heats up, more water evaporates and if it sticks around it causes rain. The water soaks up heat from the ground and then runs off, causing local cooling before the weather warms up again.

This is all going to affected by things like wind and other factors which means that warm, moist air that would cause rain is carried off elsewhere if the winds are right and they get the rain while you're stuck with the heat.

What would it take to liquefy a human body? Specifically, though G-Forces?

Not sure if G forces can "liquefy" a body. Certainly needs more than 300G, however.

Increased pressure is more likely to turn the body into a solid!

edited 9th Feb '17 11:46:51 AM by Victin

Perhaps not the entire body, but what about the internal organs? A lot of the human tissue types are technically closer to being "sacs" filled with a liquid solution than a proper solid mass, IINM.

So, statement and a question for the eggheads in this thread. (If home science experiments are unsuitable for the thread, feel free to point me to somewhere better.)

See, I was trying to make a homemade sports drink to help treat my stomach flu, using Safeway-brand Refreshe lemon-lime soda. I tried to do this by pouring salt into it - and my woeful lack of chemistry knowledge surprised me as the bottle immediately went volcano on me, spilling lemon-lime foam all over the countertop. It was rather awesome, even if I wasn't quite prepared (and needed to clean up).

So, the question: Anyone know a good way to get salt into lemon-lime soda without triggering a bottle rocket, or am I better off just buying some overly-carbed Gatorade at too high of a price?