Life May Have Spread Through the Galaxy Like a Plague

[IDemo]

Finding alien life, be it microbes or Vulcans, would revolutionize our understanding of our place in the universe, not only because we would no longer be alone in the galaxy, but also because it may help us figure out the origins of life on Earth.

Panspermia is the theory that the seeds of life somehow came to our planet from another world. The idea is controversial at best—most biologists would tell you that it just pushes the problem back a step, because we still wouldn't know what sparked life in the first place. And so far, there’s little reason to think life on other planets should be anything like what we see on Earth.

Now Henry Lin and Abraham Loeb of Harvard University say that if we do see evidence of alien life, the distribution of inhabited planets would be a “smoking gun” for panspermia. According to their model, if life arises on a few planets and spreads through space to others, inhabited planets ought to form a clumpy pattern around the galaxy, with voids between roughly spherical regions. This bubble pattern appears no matter how the distribution happens, whether its aliens traveling by spaceship or comets carrying life’s building blocks.

“It’s not that different from an epidemic,” says Lin, an undergraduate with the Harvard-Smithsonian Center for Astrophysics and lead author of the study, which was accepted by the Astrophysical Journal. “If there’s a virus, you have a good idea that one of your neighbors will have a virus too. If the Earth is seeding life, or vice versa, there’s a good chance immediate neighbors will also have signs of life.”

http://www.smithsonianmag.com/science-nature/life-may-have-spread-through-galaxy-plague-180956425/?no-ist

[longship]

6. Not likely a good candidate for life.

Kapteyn b is 4.8 the mass of Earth with an orbital period of about 48 days.

Kapteyn c is 7 times the mass of the Earth with an orbital period of about 122 days.

Neither are Earthlike.

Plus, then there's the fact of tidal locking and M-dwarf's tendency to flair up.

Are they even rocky planets? I think not likely. Too massive.

But I agree, M-dwarfs are a good place to look. Especially since over 75% of stars are M-dwarfs. But those systems have some significant problems for life, in spite of the fact they are extraordinarily long lived, which balances the liabilities.

[longship]

8. A lot to consider.

One thing is for sure. M-dwarfs are problematic for life. Their habitable zone is both narrow and close-in to the star, which means tidal forces become important. However, the vast percentage of stars in the universe are M-dwarfs. And they live for an extraordinarily long time. (It is likely that all M-dwarfs ever made are still in their adolescence, destined to slowly burn for trillions of years.) So they have those things going for them.

But you are correct, we just don't know.

Interesting shit. My regards.

[tclambert]

13. Longship said M-dwarfs "flair up," which means they like to decorate themselves to look fabulous.

To "flare up" would be dangerous for surface life, but "flairing up" is just entertaining. It's easy to confuse these two scientific concepts, but they do differ considerably in meaning and effect.

[tclambert]

18. That is one of my favorite movies.

And, yes, I do own a red stapler.

[longship]

24. Oopsy! But because of your LOL response, I'll leave it.

DOH!

[MillennialDem]

23. Wrong reason. Those planets could well be rocky, but there is a reason M dwarfs are bad for

life.

They flare. A lot.

[immoderate]

3. OTOH, life might be a result of *emergent behavior* which is a result of ANY behavior physically

allowed by the energy bath of the environment.

In other words, under certain conditions, matter with the ability to freely associate, will find organizations which favor their own organization over others.

--imm

[Maedhros]

4. I think life is a result of the inevitable fractionation of matter.

Inorganic materials precipitate and form planets, and the thin film of organic matter left over begins to "precipitate" amino acids, etc.

[immoderate]

5. I see. 'In every life, a little "precipitation" will fall...'

--imm

[airplaneman]

14. I think your just about correct.

My take is that Methane, Water, Sulfur, Nitrogen, and many other components are already on all planets and given time and the right conditions will assemble into more complex forms of organic matter. Deep in the mantle pressure and heat are the catalyst to make more complex organic compounds. I think oil and coal probably have their origins on non-life formations of this type and if the conditions are good enough life will take hold. Life used and moved into coal the spores being evidence (I don't think oil show signs of life).
-Airplane

[Maedhros]

17. I have a background in igneous petrology and high-pressure geochemistry.

The composition and behavior of mantle-derived fluids was a significant portion of my thesis studies. I don't believe coal and petroleum have their genesis in the mantle. I understand that there are some Russian scientists that have put forth a mantle origin for petroleum deposits, but I don't agree with their conclusions.

Organic components in mantle fluids are very simple: carbon dioxide, carbon monoxide, methane, water, hydrogen sulfide, sulfur dioxide. Samples from deep-mantle diamond inclusions show absolutely no trace of more complex molecules such as ethane or octane.

[airplaneman]

20. Thanks for sharing your thoughts and background.

My background is in Math, Biochemistry, and science in general. I have read the Russian theories on adiabatic oil. I think there was a Swedish scientist that produced more complex organic molecules in a mantle like conditions experiment but I don't recall name date. I find this subject fascinating and will do more reading on the subject.
Airplane

[Doctor_J]

10. unfortunately earth was contaminated with the Homo Conservatus strain

which is incurable and fatal.

[N_E_1 for Tennis]

11. Imo, to find life elsewhere...

We may need to redefine our thinking about just what life is.
Our scope may be too narrow.
If two planets in two different galaxies were seed by the same spore from one older planet, that does not mean they will be in any way similar. Or maybe they will be. I feel we just need to readjust our parameters. Silica instead of carbon based, for example.

[PeoViejo]

12. 11 Billion Years

Is a long time to maintain Core temperature and fluidity. The consequences are well known. Loss of Magnetic Field and heat transfer to the surface can seriously affect the chances of survival.

[Nitram]

16. "Like a plague?" Why not like...life?

[StarzGuy]

19. It All Does Not Matter

Because if the astrophysicist are correct the universe is heading for the Big Rip. If the big rip happens then even atoms will be ripped apart and nothing survives. All galaxies not in our local group will be beyond our horizon due to dark energy ever speeding up the universe's expansion, stars will all be burnt out, life is an impossibility then. With further dark energy expansion even atoms will not survive. The universe will be a cold (absolute zero) dark place where nothing survives.

[Peace Patriot]

22. Yeah, but we can all party in the meantime...

...the long, long, long, long, LLLL-OOOOO-NNNNNNN-GGGGGGGGGGG meantime.

Come on, put your party hat on! We're here, now. Ain't that a kick?! And with plenty of time to invite the neighbors over.

Don't be so down-in-the-mouth! And, anyway, a hundred years from now, maybe sooner, they're going to laugh their heads off at the wild theories we came up with, not very long after we dropped out of the trees.

The Big Bang? Dark Matter? Dark Energy? Black Holes?

[kenfrequed]

27. Even that model...

Is both highly speculative and cosmically far out in time scale. Let us save "end times" drama for the religious and focus on preserving the biosphere on this planet where our actions can have impact..

[Enthusiast]

21. Fascinating concept.

[passiveporcupine]

25. Atlas Sneezed!

Sorry...it just had to be said.

[Amimnoch]

26. heh, or ejaculation on a cosmic scale.

[WestCoastLib]

28. Life is very plague-like on this planet alone.

Swarm, overwhelm & spread....It's what we do, from microbes to plants to animals...

This theory is not only very plausible, but almost more of "common sense" thought about the universe. It's not always the case, but much that is true on a micro level is also true on a macro level.

[Nitram]

29. That's a facile characterization of life.

Look at a rainforest or coral reef ecosystem, for example. Every form of life an essential part of the whole, populations in perfect balance. It is when disruptions take place that an exotic invasive species get an opportunity to overwhelm the native species and biological diversity plummets. Over geologic time, though, life always creates a new balance with new species.

[WestCoastLib]

30. a coral reef or rainforest tries to expand

What you are describing is a balance brought upon by biodiversity in relative harmony.

Each individual form of life, however, is attempting to expand on it's own. They have to be stopped by some external force. Often that force is humans today.

A coral reef grows and expands as much as it can. A rainforest grows and expands as much as it can. If conditions would let it, the Amazon rainforest would cover the earth. It's trying to, it's just badly losing that battle at this point. Likewise the tomato garden in your yard is trying to blanket the world with tomatoes.

[Nitram]

31. No, you don't understand how ecosystems work, WCLib.

A diverse range of species adapted to a particular climate, topography, etc gradually come into balance together. They don't spread beyond their range because beyond their range they don't have the support of the rest of the interacting species and cannot survive. Coral reefs don't spread without limit, and neither do rainforests. They have natural limits. What we humans have done is both disrupt habitats by removing key elements such as trees or wetlands, and we have introduced exotic invasive species that never would have traveled there without our help. it takes both that disruption and introduction of new species to get runaway dominance by invasives and a dramatic reduction in diversity as the balance breaks down.

[WestCoastLib]

32. No. You seem to be missing the point

Coral reefs and rainforests have limits from external forces (as I said in my previous post).

"They don't spread beyond their range" because they can't- not because they don't try to.

This is the way of all life. It will try to expand indefinitely until an external force prevents it.