Bad news for alien life

[Cypress]

An estimated 75 to 80 percent of the stars in the Milky Way are M-class red dwarfs, and if they are highly unlikely to support planets with life, that rules out a huge proportion of star systems that could possibly host advanced intelligent alien life, or any life at all.



A new study of red dwarf stars has revealed that even the quietest examples of this stellar class are more active and wild than the sun.

Red dwarfs, officially known as "M dwarfs" by astronomers, are the most common stars in the Milky Way and can remain placid for long periods of time before erupting with huge "superflares." These flares have previously been measured to be 100 to 1,000 times more powerful than similar flares from the sun, with young red dwarfs particularly tumultuous.

These outbursts, as well as eruptions of scorching-hot plasma known as coronal mass ejections (CMES), can be incredibly destructive to planets orbiting red dwarfs, stripping their atmospheres and emitting enough radiation to boil away liquid water even in the so-called habitable zone around them  — the region around a star in which liquid water can exist on a world's surface.

Such high activity might therefore make it tough for life to take root around red dwarfs, some scientists say.

Because astronomers have struggled to study individual red dwarfs in detail, the next best thing is looking at a lot of these stars over a long time period. A long view is needed to really get a clear picture of red dwarf variability,

Bad news for alien life? Even calm red dwarf stars rage more violently than the sun

Red dwarfs are small, but their outbursts are not.

www.space.com

 

[T. A. Gardner]

Okay...

There's about 100 billion stars in the Milky Way galaxy. That only leaves 20 billion stars or so for life to possibly exist on in the above scenario.

 

[BartenderElite]

There are still a ton of stars that could support planets w/ life - not just in this galaxy, but in the hundreds of millions of others.

 

[Cypress]

Okay...

There's about 100 billion stars in the Milky Way galaxy. That only leaves 20 billion stars or so for life to possibly exist on in the above scenario.

The gas giants burn up their nuclear fuel too fast and don't exist long enough for biological evolution to take hold on orbiting planets.

Our sun is somewhat unusual in being a solo star system. The majority of star systems are binary or trinary star systems, and that could introduce an element of orbital eccentricity to any orbiting planets and make them less stable for viable ecosystems.

Then you have to account for the other 'perfect storm" factors: the presence of liquid water (a very narrow temperature range), a stable magnetic field, stable orbital dynamics, no potential for deadly gamma radiation from gas giants that will supernova within 25 light years distance.

 

[Cypress]

Some people are using the Drake Equation to estimate there are currently 12,500 advanced civilizations in our galaxy.

I looked up the data from the Star Trek canon. The Federation at its height had 350 advance alien species and covered an galactic area of 8,000 light years.

The Milky Way is 100,000 light years, so the Federation was eight percent of the galactic volume.

Assuming advance sentient life was equally spread throughout the galaxy, the Star Trek data would imply there are ~ 4,400 advanced civilizations in the galaxy. That is only about one-third of the estimate provided in the Drake equation.

Star Trek made is seem like the galaxy was absolutely pregnant with life. But these Drake equations estimates are claiming that the galaxy is even more densely populated with advanced sentient life than Star Trek made it seem. I personally think people are misusing the Drake Equation

 

[Nomad]

I personally think it's utterly pointless to speculate about something we will never (in this life anyway) know the truth about.

 

[NiftyNiblick]

The life that we have contaminating this tiny planet is troublesome enough, I would think.
Have you read threads on this forum?

I shan't include myself among those looking for even more trouble.

 

[T. A. Gardner]

Some people are using the Drake Equation to estimate there are currently 12,500 advanced civilizations in our galaxy.

I looked up the data from the Star Trek canon. The Federation at its height had 350 advance alien species and covered an galactic area of 8,000 light years.

The Milky Way is 100,000 light years, so the Federation was eight percent of the galactic volume.

Assuming advance sentient life was equally spread throughout the galaxy, the Star Trek data would imply there are ~ 4,400 advanced civilizations in the galaxy. That is only about one-third of the estimate provided in the Drake equation.

Star Trek made is seem like the galaxy was absolutely pregnant with life. But these Drake equations estimates are claiming that the galaxy is even more densely populated with advanced sentient life than Star Trek made it seem. I personally think people are misusing the Drake Equation

Well, as far as Star Trek goes, they don't generally interact with civilizations and species that aren't capable of interstellar travel. Thus, an intelligent civilization on the level of say 1800 Earth wouldn't show up in that count generally. If the estimate of 12,500 were about right, that puts one advanced civilization ever 500,000 square light years, or about 1400 light years apart from another such civilization.

 

[Cypress]

I personally think it's utterly pointless to speculate about something we will never (in this life anyway) know the truth about.

Scientists speculate all the time. That's how they come up with ideas and hypotheses.

Besides, as we gather more data, the estimates get better. I remember back in the 1970s people were using the Drake equation to optimistically assert there would be millions of planets in the galaxy with advanced intelligent life. As we came to know more about stellar and planetary dynamics, those estimates have turned much more pessimistic.

 

[Nomad]

I know a lot of people like to think of and assume that advanced life forms from far away worlds are peaceful and wise, but others have posited the notion of horrifyingly violent and savage beings with highly developed minds and technological know how.

Think ALIEN.

I'm guessing both exist given the logical assumption that if it's within the realm of the possible, it probably exists.

Anything that can happen will happen.

Or has happened.

 

[Nomad]

Scientists speculate all the time. That's how they come up with ideas and hypotheses.

Besides, as we gather more data, the estimates get better. I remember back in the 1970s people were using the Drake equation to optimistically assert there would be millions of planets in the galaxy with advanced intelligent life. As we came to know more about stellar and planetary dynamics, those estimates have turned much more pessimistic.

That's all well and good when talking about some finite entity like our galaxy which we are a part of and can measure.

But go beyond that, out to the far reaches where our most powerful telescopes cannot detect, and it's anybody's guess.

 

[Cypress]

That's all well and good when talking about some finite entity like our galaxy which we are a part of and can measure.

But go beyond that, out to the far reaches where our most powerful telescopes cannot detect, and it's anybody's guess.

I don't think there's any point talking about intelligent life in other galaxies, we will never be able to investigate or communicate with them.

The Milky Way is a very large galaxy and a good assumption is that it's fairly representative of the universe of galaxies. If we surmise intelligent life is exceedingly rare in our galaxy, balance of probability is that it's exceedingly rare in other galaxies, and vice versa if intelligent life is ubiquitous here.

 

[Dutch Uncle]

An estimated 75 to 80 percent of the stars in the Milky Way are M-class red dwarfs, and if they are highly unlikely to support planets with life, that rules out a huge proportion of star systems that could possibly host advanced intelligent alien life, or any life at all.



A new study of red dwarf stars has revealed that even the quietest examples of this stellar class are more active and wild than the sun.

Red dwarfs, officially known as "M dwarfs" by astronomers, are the most common stars in the Milky Way and can remain placid for long periods of time before erupting with huge "superflares." These flares have previously been measured to be 100 to 1,000 times more powerful than similar flares from the sun, with young red dwarfs particularly tumultuous.

These outbursts, as well as eruptions of scorching-hot plasma known as coronal mass ejections (CMES), can be incredibly destructive to planets orbiting red dwarfs, stripping their atmospheres and emitting enough radiation to boil away liquid water even in the so-called habitable zone around them  — the region around a star in which liquid water can exist on a world's surface.

Such high activity might therefore make it tough for life to take root around red dwarfs, some scientists say.

Because astronomers have struggled to study individual red dwarfs in detail, the next best thing is looking at a lot of these stars over a long time period. A long view is needed to really get a clear picture of red dwarf variability,

Bad news for alien life? Even calm red dwarf stars rage more violently than the sun

Red dwarfs are small, but their outbursts are not.

www.space.com

That helps explain Fermi's Paradox.

More about M class Red Dwarf stars:

https://www.sciencedirect.com/topics/physics-and-astronomy/m-dwarf-stars

 

[Dutch Uncle]

I know a lot of people like to think of and assume that advanced life forms from far away worlds are peaceful and wise, but others have posited the notion of horrifyingly violent and savage beings with highly developed minds and technological know how.

Think ALIEN.

I'm guessing both exist given the logical assumption that if it's within the realm of the possible, it probably exists.

Anything that can happen will happen.

Or has happened.

A lot of those fears are based upon humanity's bloody history. Guilt and paranoia. LOL

While there may be other species as vicious as humans, the tech required for interstellar flight and the time involved makes it very unlikely that we'll be visited anytime soon much less invaded by little green spacemen.

 

[Dutch Uncle]

Scientists speculate all the time. That's how they come up with ideas and hypotheses.

Besides, as we gather more data, the estimates get better. I remember back in the 1970s people were using the Drake equation to optimistically assert there would be millions of planets in the galaxy with advanced intelligent life. As we came to know more about stellar and planetary dynamics, those estimates have turned much more pessimistic.

Agreed about science. In the case of the OP, it becomes a math problem: 100B to 400B stars in the Milky Way depending upon average star mass. Since 70% are lighter, M-class red dwarfs, then the total number of stars goes up. Since Red Dwarfs are unlikely to harbor life due to stellar radiation/coronal mass ejections, the odds of other life drop precipitously.

Rule out stars without planets and those in the galactic core due to life being wiped out by novas within 25 LY, and the odds of advanced interstellar civilizations goes down.

 

[Nomad]

I don't think there's any point talking about intelligent life in other galaxies, we will never be able to investigate or communicate with them.

I agree about likely never being able to observe them first hand, although I will say that fun is one point in talking about it.

The Milky Way is a very large galaxy and a good assumption is that it's fairly representative of the universe of galaxies. If we surmise intelligent life is exceedingly rare in our galaxy, balance of probability is that it's exceedingly rare in other galaxies, and vice versa if intelligent life is ubiquitous here.

"Exceedingly rare" in one galaxy of billions of potential suns that could support life on nearby planets, could still mean planets with intelligent life could number in the thousands.

Then there are the billions or trillions of galaxies in the universe.

I agree with those who say it's a statistical impossibility that Earth is the only planet upon which intelligent life exists.

 

[Cypress]

Agreed about science. In the case of the OP, it becomes a math problem: 100B to 400B stars in the Milky Way depending upon average star mass. Since 70% are lighter, M-class red dwarfs, then the total number of stars goes up. Since Red Dwarfs are unlikely to harbor life due to stellar radiation/coronal mass ejections, the odds of other life drop precipitously.

Rule out stars without planets and those in the galactic core due to life being wiped out by novas within 25 LY, and the odds of advanced interstellar civilizations goes down.

^^ Earth seems to have been the product of a perfect storm of conditions when you really start thinking about stellar and galactic dynamics in a sophisticated way like that.

There still is no solid consensus on what the WOW interstellar radio signal was detected in 1977 at Ohio State University, so I cling to hope!

 

[Cypress]

I agree about likely never being able to observe them first hand, although I will say that fun is one point in talking about it.



"Exceedingly rare" in one galaxy of billions of potential suns that could support life on nearby planets, could still mean planets with intelligent life could number in the thousands.

Then there are the billions or trillions of galaxies in the universe.

I agree with those who say it's a statistical impossibility that Earth is the only planet upon which intelligent life exists.

I think the balance of probability is that there is intelligent life in our galaxy or elsewhere in the universe, rare or not.

The question is, what is 'intelligence'? Dolphins, Orcas, and mountain gorillas are very intelligent. That kind of intelligence is not uncommon on Earth.

Abstract thinking, sentient consciousness, higher rationality was a unique event in four billion years of Earth history, and with no guarantee that it isn't just a brief and ephemeral evolutionary fluke.

 

[PostmodernProphet]

Drake's Equation is scientifically incorrect......the number of planets that any given star can have, capable of supporting life as we know it are limited to 0, 1, or 2......two would be possible only if the two were in an identical but opposite rotation.....

obviously, any mathematical equation where something can be multiplied by zero is an invalid equation......

 

[NiftyNiblick]

Abstract thinking, sentient consciousness, higher rationality was a unique event in four billion years of Earth history, and with no guarantee that it isn't just a brief and ephemeral evolutionary fluke.

We can only hope so.