The Astronomy Thread

meStevo

I think your wife's a bigfoot gus.
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1569623496529.png
 
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Oldbased

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just saw this post. wow, that's terrifying. sounds like an initial generation full of sociopaths.
Really it makes great sense and I hadn't thought of it before.
The only thing is the freezer they send the eggs in will need to have been made before 1985 so it A-lasts more than 3 years and B-Keeps cool for more than 5.
 
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meStevo

I think your wife's a bigfoot gus.
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Yeah, he's helming an agency spending billions ordering space capsules, while Musk is on a trajectory to be crusing around in starships.

NASA announced Monday it will order at least six reusable Orion crew capsules from Lockheed Martin for $4.6 billion to fly astronauts to the vicinity of the moon in the 2020s, and the agency said it plans to purchase hardware for up to 12 Orion vehicles by 2030.​
 
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meStevo

I think your wife's a bigfoot gus.
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Liked this Twitter thread from Katie Mack.

Right now, in the center of the Sun, there's a nuclear reaction converting hydrogen to helium, producing neutrinos, photons, & positrons. A neutrino from this reaction will pass through you just over eight minutes from now. The photons won't arrive for at least 100,000 years.​
It's not that neutrinos are inherently faster than light. It's that they can pass through the Sun -- and everything else -- without interacting, but gamma rays can't. It takes a photon over 100,000 years to fight its way out of the Sun, and 8.3 minutes to reach Earth from there.​
Neutrinos don't travel through the vacuum of space *quite* as fast as light does (nothing with any amount of mass can), but it's close. When a supernova occurs in another galaxy, we receive a neutrino burst before the light, because the light got trapped but the neutrinos didn't.​
So far, we've only managed that detection once (with Supernova 1987a and the Kamiokande neutrino detector), but next time the right kind of supernova happens close enough to Earth, we should see it again. aavso.org/vsots_sn1987a
There is something called the SuperNova Early Warning System that astronomers can sign up to in order to receive an alert of a neutrino burst, to give us time to point our telescopes in the right direction. It hasn't been triggered yet, but we wait in hope snews.bnl.gov
By the way, that neutrino from the core of the Sun that just passed through you wasn’t alone. There are 100 BILLION of them zooming through just your thumbnail EVERY SECOND​
You won’t feel it, though. Chances are, not a single one of those neutrinos will interact at all with a particle in your body over the course of your entire life.​

 
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khorum

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Yeah, he's helming an agency spending billions ordering space capsules, while Musk is on a trajectory to be crusing around in starships.

NASA announced Monday it will order at least six reusable Orion crew capsules from Lockheed Martin for $4.6 billion to fly astronauts to the vicinity of the moon in the 2020s, and the agency said it plans to purchase hardware for up to 12 Orion vehicles by 2030.​
EFgTYKqXoAE4nVi.jpg:large
 
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Oldbased

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Ya as I said before, until it looks like this with hanger bays it ain't no damn spaceship.
This hull design is rocking from Stargate for several reasons BTW. Layered hull design, wing bays for smaller craft, actual turret tech such as rail guns in the start.
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Aldarion

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That's because you tend to think of the filter as something ahead. Each filter ends more stuff than a civilization; the first ends entire worlds. It's just hard to think about it because we obviously have passed it.

My personal two "old" filter candidates:

- Complex life. Life arose fast, chemistry tend to create biological components with ease, and we have no less than three different orders of life (some parts of which use RNA instead of DNA) that tend to suggest that life might be easy. By comparison, there's mounting evidence, genetic and otherwise, that the procaryote->eucaryote jump occurred exactly ONCE in our history. Now, maybe it did occur multiple times, and some latecomers got outcompeted because eucaryote evolve scare fast. Or maybe it couldn't, and we got lucky to get complex cells, and the rest of the Galaxy is covered in bacterial mats.

- Intelligence. Khorum alluded at extinctions, but even without extinctions, there's lots of evidence that evolution is not teological (goal-driven), and that intelligence is not an ecological niche that a species has to fill. Meaning that sapients are maybe the conjunction of a significant number of random factors (we have a number of pre-sapient species around, primates, corvids and possibly cetaceans, but they all lack stuff, even if we didn't outcompete them - except probably primates). So we might be the lucky ones to get high tool-making intelligence. After all, our most significant evolutionary advantage isn't that we're intelligent, it's that we're the Terminators of the natural kingdoms. When any other creature ends up panting after running for an hour, we keep coming after them. When they can no longer run because their body heat is above all limits... we still run to them. And kill them. And eat them.
There is a fundamental difference between a force that prevents an infinite number of different hypothetical species from coming into existence , vs a force that drives an actual species to extinction. The former affects hypothetical species. The latter affects actual species

It's a semantic distinction that deserves recognition.
 
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iannis

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There is a fundamental difference between a force that prevents an infinite number of different hypothetical species from coming into existence , vs a force that drives an actual species to extinction. The former affects hypothetical species. The latter affects actual species

It's a semantic distinction that deserves recognition.

It is until we have a more comprehensive understanding of life. Trying to give a context where the two things you're talking about is the same thing is trying to contextualize that life.

I think we don't know if the rules apply differently to life yet, but we find it incredibly hard to believe that they do, can prove that in almost all cases they do not apply differently (there are some specific instances where it sure LOOKS like they apply differently, but that may be our ignorance) and a great deal of tedious science is aimed at this question directly. The self animation of matter is a strange thing that we don't understand the root causes of. So is that distinction that you're talking about meaningful outside of the context of US asking it? That's actually not semantics, it's a different conceptual structure.

Frankly I'm not smart enough to be able to guess which of these two ideas is more accurate. I think Ukers view has a lot of weight to it, and it is well worth intellectual investment. But i'm hedging my bets, I don't think it's going to be completely satisfactory.
 
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Ukerric

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Yeah, he's helming an agency spending billions ordering space capsules, while Musk is on a trajectory to be crusing around in starships.
He's also getting punched in the nuts by the Senate Committee which is cutting his funding for the Moon 2024 because he doesn't want to spend it on the doomed and wasted SLS, and the senators want to teach him who really orders NASA around.

AKA "I give you money to spend on my state, don't you dare spend it on useful stuff!"
 

Ukerric

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Liked this Twitter thread from Katie Mack.
Solar Neutrinos are nice.

Anytime you hear about astronomers being bothered by models of solar neutrinos it's because of this. If your model says that you should get This amount of solar neutrinos, but you get That, then either your model is wrong... or the rates of nuclear reaction at the core have changed from what we observe from outside, and we're a few millenia away from having the Sun start to baloon or cool down once the photons heating the surface layers reach those.

(okay, the former is far, far more likely than the latter)
 

Ukerric

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There is a fundamental difference between a force that prevents an infinite number of different hypothetical species from coming into existence , vs a force that drives an actual species to extinction. The former affects hypothetical species. The latter affects actual species

It's a semantic distinction that deserves recognition.
Yes, but in the context of the Drake Equation, the accepted meaning of the term Great Filter is "all the things that drastically cut down on potential galaxy-visible civilizations". If you want to refer specifically to "the last Great Filter we are potentially facing", then you probably need a different term.

It's like saying "the only real hackers are the ones who write worm code".
 
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meStevo

I think your wife's a bigfoot gus.
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Elon tweeted some engine porn, 3 raptors mounted in starship:

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khorum

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Are they still just testing the raptors at this point or the starship itself? There are supposed to be FORTY ONE of those things on the first stage of the BFR.... that's more than N1's 30 engines and an extra 11 possible points of failure.
 

Mudcrush Durtfeet

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I think they're always looking for things in their equipment, and they are certainly always looking for ways to improve things, but I think the Raptor is meant to be 'done' at this point. Note that Falcon 9s use 9 engines (and 27 on the Falcon Heavy) so they do seem to understand something about making reliable engines.
 
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