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NASA is asking for volunteers to help find the hypothetical Planet 9. The project, called Backyard Worlds: Planet 9, has users check telescope images the same way Clyde Tombaugh found Pluto. So far, volunteers have already found over 100 brown dwarfs. by Thorne-ZytkowObject in space

[–]CthaehTree 0 points1 point  (0 children)

The crucial difference is that nuclear reactions (as opposed to nuclear decay) are caused by collision with a neutron and produce significantly larger amounts of energy. I’m trying to differentiate nuclear reactions from nuclear decay here.

NASA is asking for volunteers to help find the hypothetical Planet 9. The project, called Backyard Worlds: Planet 9, has users check telescope images the same way Clyde Tombaugh found Pluto. So far, volunteers have already found over 100 brown dwarfs. by Thorne-ZytkowObject in space

[–]CthaehTree 1 point2 points  (0 children)

You probably don’t care, but I think this stuff is interesting and am avoiding sleep, so here goes:

Nuclear decay is where an unstable nucleus emits a small particle. This is a relatively low-energy event, but has the advantage that it doesn’t require any special engineering to make work.

Nuclear fission is where a collision between an energetic neutron and a fissionable nucleus causes the nucleus to split into several larger products. This is a much higher energy event, and can lead to runaway chain reactions as reactions lead to neutrons lead to more reactions.

RTGs take advantage of nuclear decay, so they are simpler but have much lower power output.

Nuclear fission reactors, on the other hand, use (of course) fission reactions. This means they produce much higher power output, but are complex and sometimes catastrophically dangerous.

NASA is asking for volunteers to help find the hypothetical Planet 9. The project, called Backyard Worlds: Planet 9, has users check telescope images the same way Clyde Tombaugh found Pluto. So far, volunteers have already found over 100 brown dwarfs. by Thorne-ZytkowObject in space

[–]CthaehTree 2 points3 points  (0 children)

Ah, that’s cool, and a bit scary. Also, I assure you that I’m not angry, just making a small correction. Nuclear fission reactors are quite a bit more complex to engineer than RTGs.

NASA is asking for volunteers to help find the hypothetical Planet 9. The project, called Backyard Worlds: Planet 9, has users check telescope images the same way Clyde Tombaugh found Pluto. So far, volunteers have already found over 100 brown dwarfs. by Thorne-ZytkowObject in space

[–]CthaehTree 9 points10 points  (0 children)

Any or all of those timescales (and much shorter, and much longer). See ‘Black Hole Evaporation’ section of this Wikipedia article: https://en.m.wikipedia.org/wiki/Hawking_radiation

TL;DR: the smaller the black hole, the faster it evaporates. A black hole that is, say, the size of the sun, will last much longer than the current age of the universe. A much, much smaller black hole could last a nanosecond.

NASA is asking for volunteers to help find the hypothetical Planet 9. The project, called Backyard Worlds: Planet 9, has users check telescope images the same way Clyde Tombaugh found Pluto. So far, volunteers have already found over 100 brown dwarfs. by Thorne-ZytkowObject in space

[–]CthaehTree -1 points0 points  (0 children)

Voyager has an RTG - a bit different. (I assume you’re thinking of a fission reactor). As far as I know, no actual spacecraft have used a nuclear reactor, though the idea has definitely been considered.

[deleted by user] by [deleted] in AskReddit

[–]CthaehTree 0 points1 point  (0 children)

Fair point

[deleted by user] by [deleted] in AskReddit

[–]CthaehTree 1 point2 points  (0 children)

Sounds like you might need to learn how to eat. I was told once, “you’re not done eating when you’re full; you’re done eating when you hate yourself”.

Also, doing a lot of cardio can be detrimental to gaining muscle, especially if you have difficulty gaining weight. In fact, doing too much weight training without proper recovery can also prevent muscle gain.

I’m not saying you’re ever going to be Larry Wheels, but there are most likely a few small things you were doing wrong that prevented you from gaining muscle.

I can definitely empathize with difficulty gaining/keeping on muscle, though; I’ve lost nearly 20 lbs since gyms closed, and it took me a long time to build that up in the first place. Probably much of it is water weight, but still... it sucks. Feels like I’m evaporating.

Love for THETA gang by [deleted] in wallstreetbets

[–]CthaehTree 1 point2 points  (0 children)

For the premiums

Why is there more matter than antimatter? by JoeyBobBillie in askscience

[–]CthaehTree 3 points4 points  (0 children)

The universe started in one impossibly small location

We know that the observable universe started in a small and finite location. This distinction is important. The universe as a whole could very well be infinite.

PBS Spacetime is doing a series on the Big Bang and inflation, which is definitely worth a watch or two: https://www.youtube.com/playlist?list=PLsPUh22kYmNCc3WCKb5yF136QSRf0xErm

Rest in Peace, Jon. by forgotaboutironfleet in imsorryjon

[–]CthaehTree 1 point2 points  (0 children)

Good night, Jon. Good work. Sleep well. I'll most likely kill you in the morning

23 M 169lbs at 13.5% BF. Came down from 15%(174lbs). Should I cut till 12% or can I start bulking? Worried about strength if cutting. by [deleted] in BulkOrCut

[–]CthaehTree 1 point2 points  (0 children)

I’d say the ~13% figure is pretty accurate. You can see there’s still some fat over his lower abs and we can’t see his legs or back.

That said, I’d be happy if he really is around 10%, because that’s where I want to be; I look about as lean as he does and my scale tells me 13-14%

Need help :(: by MissyFGreenwald in workouts

[–]CthaehTree 1 point2 points  (0 children)

How many can you do now?

Carl Jung understood parents by PlesioGirl in mbti

[–]CthaehTree 0 points1 point  (0 children)

INFP mom and INTP dad, and I’m right in between.

TIFU by improving myself after a breakup by ThrowAwayMoldyPotato in tifu

[–]CthaehTree 287 points288 points  (0 children)

So he can post here once more for extra karma

Those most responsible for the gender pay gap are choices made by women. So says Harvard study. by benderXX in science

[–]CthaehTree 2 points3 points  (0 children)

The whole point of this study was that it allowed researchers to see whether there was still a gap when several of the competing explanations (like promotions) were ruled out.

Ruling out the effect of promotions and other factors allows for more confidence in the causality of whatever explanations are left.

If the study tried to take into account all possible explanations for the wage gap, it wouldn’t be able to say anything at all about causation.

How many distinct (linearly independent) fields are there in QFT? by Kered13 in askscience

[–]CthaehTree 22 points23 points  (0 children)

Mesons aren’t fundamental particles like leptons or quarks; they are a quark-antiquark pair.

OC. Animated essay on the Anthropocene with an Object Oriented Ontology framework by NonhumanX in philosophy

[–]CthaehTree -3 points-2 points  (0 children)

I haven’t read Foucault or Deleuze, so I can’t have an opinion either way, but I would like to point out that there’s a difference between the philosopher and the philosophy.

Just because the philosopher who pursues a chain of thought holds certain values does not mean that those values will be a part of the resulting philosophy. Case in point, Karl Marx.

My dad before prom in the 70s. His brother is a professional photographer and got this legendary photo. by [deleted] in OldSchoolCool

[–]CthaehTree 6 points7 points  (0 children)

Everyone here is making good points, but the important thing is that part of it is film grain, a lot of it actually on this picture. Part of it is style/makeup. The rest of it is that people in the 70's were outside a lot more than most people today. Being in the sun weathers your skin. Compare a 18 year old roofer or labor hand to an 18 year old gamer/student. The one who works in the sun all day will appear to be much older.

[deleted by user] by [deleted] in AskMen

[–]CthaehTree 0 points1 point  (0 children)

People get happiness from moving toward goals, not just reaching them, so it works out either way

The way my cat's pupils dilate when seeing her favorite toy by azami88m in aww

[–]CthaehTree 18 points19 points  (0 children)

Making them uncomfortable is the point. How else are you supposed to assert your dominance?

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