Recent comments in /f/askscience

Aseyhe t1_jdihufb wrote

Reply to Could a black hole just be a big neutron star that just has gravity so high light cant escape? by SlyusHwanus

To the extent our current best theory of gravity (general relativity) is accurate, it is not possible for a static extended structure to exist inside the event horizon of a black hole. Gravity there is so strong that even outgoing photons move toward the center; that's why there's an event horizon. If a static structure existed, its material would have to move outward faster than light, which is impossible.

Also: > As the mass rises for a neutron star, it reaches a point where that mass at that diameter no longer allow light to escape the surface.

This would happen for an idealized rigid body, but it's not really what happens to a neutron star. As the neutron star's mass rises, the repulsive interaction between neutrons is no longer able to support the star against gravity, and it collapses (see the TOV limit). That's when the black hole forms.

(If a neutron star could maintain its structure up until the event horizon enveloped it, the maximum mass of a neutron star would be at least 4 solar masses. Instead it's 2-3 solar masses.)

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ChimoEngr t1_jdi3p4w wrote

Reply to How do astronauts deal with periods in ISS? by LorDzkill

There's a story about Sally Ride being asked if 100 tampons or pads would be enough for her during a shuttle mission, so it sounds like at least back in the 80s, they just used the same as what is common on earth.

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BloodshotPizzaBox t1_jdhwv4s wrote

Reply to Now that the appendix's usefulness has been discovered, isn't it dangerous to deliberately remove it? or try to heal him in another way. Does a person without an appendix have a permanently bad microbiota? by RetroStationGas

When the appendix gets surgically removed, it's typically because it's in the process of dying and trying to take the patient out with it. So its usefulness has already ended at that point.

There are cases of appendicitis that are treatable with antibiotics, but in general it tends to come on too quickly and severely for that.

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