The headfuck for me is when astronomers talk about being able to see further with new telescopes, such as JWST, which means we are observing things so far in the past that actually they're fairly soon after the Big Bang. That's fine - I get that. But space is expanding from a single point, so those objects wouldn't have been so far from our relative position in the cosmos, so light wouldn't have had to travel so far, so why is the first bit true?
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MIT: 3 Temperate Earth-sized Planets Found Orbiting Dwarf Star 40 Light-years Away
- Thread starter cameron
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The headfuck for me is when astronomers talk about being able to see further with new telescopes, such as JWST, which means we are observing things so far in the past that actually they're fairly soon after the Big Bang. That's fine - I get that. But space is expanding from a single point, so those objects wouldn't have been so far from our relative position in the cosmos, so light wouldn't have had to travel so far, so why is the first bit true?
What "announcement of an announcement" by NASA hasn't turned out to be exciting news?
NASA: "hold onto your butts - we have an incredible announcement incoming. It has something to do with life on other words"
NASA: "we've discovered arsenic-based life on Earth - which can only have evolved independently of all other life. This improves the likelihood of life evolving elsewhere in the galaxy by several orders of magnitude."
Scientific community: "that thing NASA said they found? Yeah, that's bullshit."
When the universe was in it's infancy, less thank 400k years old, it was nothing more than a mass of super hot plasma that was so dense, that light itself could not escape. After that period, it cooled enough to become mostly gaseous, which let the photons trapped inside escape. Those photons are still travelling and that is what we are trying to detect.
Also, space is not really expanding from a single point though, just like a load of bread doesn't expand from a single point when it bakes. It's more like a loaf of raisin bread where the space between raisins expands. In fact, this expansion occurs at all levels to the point where one of the leading theories is that the universe will eventually die because the space between subatomic particles will be so great, that atoms will no longer be able to hold themselves together. The universe will be a giant soup of particles too far away from each other to interact. So that's a fun thought.
TangoAlphaLima
Member
This sounds like a super depressing way to die.
Well this is trillions of years into the future, so like, you probably won't be around for that.
Could you provide links, please? Google is failing me.
If it makes you feel any better, that particle soup could one day potentially spawn another vacuum bubble due to quantum fluctuations and lead to the birth of the next universe.
UnemployedVillain
Member
Literally the plot of Interstellar, except replace "dwarf star" with "blackhole"
Melon Husk
Member
Leave your number, if you're serious.
TangoAlphaLima
Member
Link
The Autumn Wind
Melon Husk
Member
Watch CrashCourse Astronomy y'all and you'll know a shitton more than Isaac Newton ever did: https://www.youtube.com/watch?v=0rHUDWjR5gg&list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL (about astronomy).
We'll probably have a few of our own universes going on at that point. Pointless to speculate that far when humanity as a species has existed for only ~5000 generations and civilization has been a thing for only 500.
efyu_lemonardo
May I have a cookie?
supposedly happening this week for these particular planets.
you know, I've never looked at it like that before. It's a great way to see how far we've come in such a short time, and how significant each successive generation still is, relative to the entirety of human history.
lastplayed
Member
Oh just 40 light years... that's spittin' distance!
FelixOrion
Poet Centuriate
Probably that you'd be able to measure levels of gases in the atmosphere that are the result of biology.
Yeah, the size of the universe and the time of it being born, living, and eventually dying that we're talking about are incomprehensible to comprehend really.
Horizontal axis is logarithmic base 10. So when the last supermassive black hole evaporates in 10^100 years give or take several orders of magnitude, we still have a looooooooong way to go till particles start getting ripped apart.
We don't know where the original point was because space is expanding equally in all directions. We know where the center of our galaxy is but we don't have a good frame of reference for the origin point of the big bang.
UberTag
Member
I'll be extremely disappointed if we discover any of these planets are harboring life and this doesn't play to ring in the news.
Stuff was still a lot closer together, was my point. Where the "centre" is should be pretty irrelevant.
Slayer-33
Liverpool-2
efyu_lemonardo
May I have a cookie?
It turns out there are some other worthwhile indicators we could look for, such the polarity distribution of sunlight reflected off the planets' atmosphere. A while ago I read that molecules of opposite chirality return oppositely polarized light, and it turns out having a dominant chirality is something biochemists believe is important for life to form, or even evidence of it having already formed.
FelixOrion
Poet Centuriate
Chiral compounds are optically active and have a property known as specific rotation - which direction is a function of the compounds handedness.
I'm not sure exactly what chiral molecules they'd look for, but you're probably thinking of amino acids, which make up proteins and enzymes. On Earth, biology is almost exclusively uses L-amino acids (ignoring glycine, which is achiral). The enantiomer of them, D-amino acids, do exist in biology but are quite rare to find. (A very similar situation exist with sugars.) Why biology on Earth evolved to favor one specifically rather than than the other is one of the greatest mysteries of biology; that is, it makes sense that evolution would chose to have a library of a single amino acid type (and this dominance is important, like you said), but we don't know why L-AAs specifically.
I don't think there's any reason to rule out that life on other worlds could be made of D-amino acids, though, so, if they would look for amino acids, it would be quite fascinating (beyond finding evidence of life) to see D-amino acids instead.
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