I've never really understood the physics of this. Obviously it works somehow -- I'm not a moonlanding denier or anything -- but my (admittedly primitive) brain continues to insist that a rocket thruster needs something to push against in order to work.

So what is it pushing against if space is essentially a void?

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1.2k comments

140

Posted by4 hours ago

Biology

ELI5: Why puking gives us so much relief after feeling sick and nauseous?

140

39 comments

2.1k

Posted by20 hours ago

Biology

ELI5: Why does only nose breathing produce nitric oxide?

I was reading about the differences between mouth and nose breathing, and it seems that nitric oxide is beneficial to cardiovascular health, but that only breathing through one's nose produces it. I couldn't seem to find a simple explanation for it.

Edit to add: I thought this was a genuine question about something I didn't understand but wanted to. So much(passive) aggression in the comments. Apologies. I was just trying to learn.

2.1k

236 comments

58

Posted by3 hours ago

Biology

ELI5: Why do humans laugh? How does our brain determine what's funny and what's not?

58

13 comments

129

Posted by8 hours ago

Physics

ELI5: Are explosions in space really that dangerous?

Not talking about your ship exploding, that's obviously bad. I'm talking about how much damage would a bomb actually do if exploded in the moon for example. I understand there is no atmosphere to push against, but I don't understand what else appart from the shrapnel could cause damage. Isn't most of a bomb's damage produced by the shockwave? And shockwaves cannot be produced in a vacuum, right? Also, let's say it's a nuclear bomb. The radiation is obviously bad, but with some shielding, same here, what damage will it actually do?

129

51 comments

35

Posted by10 hours ago

Technology