Icon from a picrew by grgikau. Call me Tir or Julian. 37. He/They. Queer. Twitter: @tirlaeyn. ao3: tirlaeyn. 18+ Only. Star Trek. Sandman. IwtV. OMFD. Definitionless in this Strict Atmosphere.
Sadly, the upper limit on the estimated age of HD 140283 was incorrect and based on older models. Further study has shown that while it is truly ancient - one of the last survivors of its generation - it was formed in the very early years of our own universe.
Due to much different conditions in the early universe, most stars that formed at that time were huge and extremely short-lived. Their light (and eventual supernovae) re-ionized interstellar gas and seeded it with heavier elements, leading to the formation of the larger numbers of smaller stars we see today. Methuselah has only 1/250 of the heavy elements of our sun, suggesting that it was created after some of that initial seeding, but still fairly early on.
Almost all of the stars we see in the Milky Way from this time period are late G-type stars (stars with about 80% of the sun’s mass) that are starting to die; this is not surprising as this also coincides with an increase in brightness. Larger stars would not have survived as long, and smaller stars (if they formed) would likely still be too faint to see.
As for “normal” matter making up only 5% of stuff in the universe: yeah. Most of the universe appears to be a soup of dark matter and dark energy. If you don’t count dark energy (which is more of a property of space itself), the ratio is still 5:1 dark matter to normal matter.
Unfortunately, other than adding structure to the universe and allowing for the formation of our current galaxies, dark matter isn’t very interesting. It’s probably just a bunch of really light particles that kind of slosh together and don’t do anything.
The current most popular guess for the composition of dark matter is something called an axion (named after the detergent), which is unremarkable other than if our theories about them are correct, you could conceivably use them to communicate through arbitrary amounts of solid matter. Note that you can do this with neutrinos, but you need a particle accelerator at the sending end and a huge tank of water at the other end to catch them; if the mass of the axion is in a particular range all you need is a laser and a pair of really strong magnets.
Actually, that’s the perfect way to think about it!
ID: Tags reading “so dark matter is sort of the broth of the ramen? that’s fine”. End ID.
In hopes of inspiring younger
generations, NASA created this series
of gorgeous retro travel posters that
encourage you to imagine a future
where common space travel is a
legitimate possibility. Source
that’s not even boring though. like there being other life in our own solar system would be insane and awesome and discovering it will literally change everything forever.
like i get what you mean but if we discover aliens on europa our models for the abundance of alien life would have to be entirely remade because it would mean that, not only is life common enough to occur twice in one solar system, but is capable of independently developing in two WILDLY different ecosystems with wildly different requirements for life. europa is dark, very cold, and significantly smaller than earth; not to mention, y'know, any living beings on the planet would have to survive under ~20km of ice so like. wildly different. if we discover life on europa it will be weird and we can learn so much from it and that would be SO much more exciting than finding another one of five trillion potential earthlike planets lightyears away
you’re right. i’m sorry potential tiny swimming things on europa
Hey. Why isn’t the moon landing a national holiday in the US. Isn’t that fucked up? Does anyone else think that’s absurd?
It was a huge milestone of scientific and technological advancement. (Plus, at the time, politically significant). Humanity went to space! We set foot on a celestial body that was not earth for the first time in human history! That’s a big deal! I’ve never thought about it before but now that I have, it’s ridiculous to me that that’s not part of our everyday lives and the public consciousness anymore. Why don’t we have a public holiday and a family barbecue about it. Why have I never seen the original broadcast of the moon landing? It should be all over the news every year!
It’s July 20th. That’s the day of the moon landing. Next year is going to be the 54th anniversary. I’m ordering astronaut shaped cookie cutters on Etsy and I’m going to have a goddamn potluck. You’re all invited.
We really do owe the Moon a lot. I mean, she’s HUGE compared to the sorts of moons a planet like ours usually gets. A planet our size can usually expect a couple of decent asteroid captures, but nothing like her. And because she’s so big, ¼ of our mass, her gravity deflects so much space crap from coming near us. She’s like a big, burly knight with a big shield. I like her.
