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This is huge: *current* liquid water on Mars.

Started by trdsf, July 25, 2018, 03:26:12 PM

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Unbeliever

God Not Found
"There is a sucker born-again every minute." - C. Spellman


Gawdzilla Sama

We 'new atheists' have a reputation for being militant, but make no mistake  we didn't start this war. If you want to place blame put it on the the religious zealots who have been poisoning the minds of the  young for a long long time."
PZ Myers

trdsf

Quote from: Gawdzilla Sama on September 15, 2018, 11:30:25 AM
"where is everyone"? Maybe billions of light years away, and millions of years in the past or future. Fermi booted that one, he assumed that aliens would be interested in us, could get to us, and would get to us. All assumptions without basis in fact.
Well, and the other problem is that "where is everybody" is a reasonable question only in a steady-state universe (which was still a viable theory of the universe at the time he said it in 1950).  If the universe has a beginning, there are reasons you can't have an arbitrarily old civilization that could have explored the galaxy by now â€" the need for metal-rich1 interstellar clouds, at a minimum, and that takes two or three generation of heavy stars going supernova to collect.  So it may well take nearly ten billion years for there to be enough stuff that's not primordial hydrogen and helium to make a world that has all the ingredients to make life possible.

I think it's entirely plausible that while we're not necessarily the first, we're among the first wave of intelligences to arise in the universe.  And looking around at this world, I can well believe we're a rough draft.




1: 'Metal' in astronomers' usage: any element that isn't hydrogen or helium
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Gawdzilla Sama

That assumes a model for intelligent life that is the same as ours.
We 'new atheists' have a reputation for being militant, but make no mistake  we didn't start this war. If you want to place blame put it on the the religious zealots who have been poisoning the minds of the  young for a long long time."
PZ Myers

SGOS

Quote from: trdsf on September 16, 2018, 09:32:47 AM

1: 'Metal' in astronomers' usage: any element that isn't hydrogen or helium
That's strange.

Baruch

#216
Quote from: SGOS on September 16, 2018, 09:38:22 AM
That's strange.

Almost all elements are in stars.  So basically it is plasma, no matter what element you are talking about.  The amount of room temperature elements is tiny, however normative and essential to life.  So what are even regular metals, when they are a conductive gas?  They don't have the usual metallic properties.  Just as hydrogen under high pressure, in the core of Jupiter, exists as a metal (hence the strong magnetic field of Jupiter).

So in nucleo genesis, there are three generations ... Big Bang (Hydrogen + Helium + trace Lithium).  Regular stellar fusion (Lithium up to Iron).  Supernova formation (all elements with heavier nuclei than iron).  The lower elements are exothermic, but above iron they are endothermic.
Ha’át’íísh baa naniná?
Azee’ Å,a’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't do that.

trdsf

Quote from: SGOS on September 16, 2018, 09:38:22 AM
That's strange.
Strange, perhaps, but true.  Since the vast majority of the universe -- by mass or by particle count -- is either hydrogen or helium, astronomers use 'metal' to mean anything heavier.  70.57% of the universe's mass and 91.00% of the universe's atoms is hydrogen alone; helium makes up 27.52% of the mass and 8.87% of the atoms.  Everything else: the carbon we're made of, the oxygen we breathe, the nitrogen that makes up the bulk of our atmosphere and the silicon that makes up over a quarter of our planet, that's in that leftover 1.91% of mass and 0.13% of atoms.  So for astronomers, there is a great convenience in just bundling those leftover crumbs up under the generic term 'metals'.

So when they talk about a metal-rich Population I star like our Sun, they don't just mean aluminium and iron, they also mean neon and carbon.
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Unbeliever

Quote from: trdsf on September 16, 2018, 09:32:47 AM
And looking around at this world, I can well believe we're a rough draft.
It would be nice to be able to think of humanity as a diamond in the rough, that will one day outshine the galaxy.

But that's a bit too optimistic for my taste.
God Not Found
"There is a sucker born-again every minute." - C. Spellman

Unbeliever

Came across this interesting tid-bit this morning:

Half the universe’s missing matter has just been finally found

It's not an unexpected finding, but it was apparently pretty hard to pin down. It had to be somewhere, and intergalactic space was about the only place left to look.

Still no God, though...
God Not Found
"There is a sucker born-again every minute." - C. Spellman

Baruch

#220
Quote from: Unbeliever on September 16, 2018, 05:27:30 PM
It would be nice to be able to think of humanity as a diamond in the rough, that will one day outshine the galaxy.

But that's a bit too optimistic for my taste.

Only if you are named Aladdin, and you have a genie working for you.

A partial explanation of missing mass.  Doesn't help with "dark energy" pushing galaxies apart, or "dark matter" controlling part of the rotation of galaxies.  But definitely leading edge science.  This was previously discounted, though I think an upper limit to the amount could have been estimated earlier.
Ha’át’íísh baa naniná?
Azee’ Å,a’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't do that.

Gawdzilla Sama

We 'new atheists' have a reputation for being militant, but make no mistake  we didn't start this war. If you want to place blame put it on the the religious zealots who have been poisoning the minds of the  young for a long long time."
PZ Myers

Cavebear

Quote from: Unbeliever on September 15, 2018, 07:17:22 PM
Yeah, I'm not holding my breath, either.

The problem is that you can't really know what is on (or in) Mars until people go there and look. 
Atheist born, atheist bred.  And when I die, atheist dead!

Unbeliever

I'd volunteer to go in a heartbeat, even if it meant I'd never make it back to Earth.
God Not Found
"There is a sucker born-again every minute." - C. Spellman

Cavebear

Quote from: Unbeliever on September 19, 2018, 01:58:36 PM
I'd volunteer to go in a heartbeat, even if it meant I'd never make it back to Earth.

Commercial companies will get experts there.  There might be gold in them thar hills.  Or even, better, water.
Atheist born, atheist bred.  And when I die, atheist dead!