Do you think any aliens exist in the universe?

[lpetrich]

The apparent rarity of phosphorus may be a limiting factor for life in the universe.

That's a problem for our biochemistry, but is that a universal problem? Some other biochemistry might make much less of phosphorus compared to ours, and I don't know of any good biochemical argument for its proposed ubiquity. What is supposed to be so essential about that element?

 

[steve_bank]

To some the bible myths provide hope.

To some belief in going to Mars and beyond is a mythical source of hope. The original Star Trek TV series were a hopeful positive vision of the human future. The series came along at a time of civil rights unrest, social change, the Cold War, and the Vietnam War.

Some copare going to Mars to Columbus, but it does not compare. Columbus did not have to provide O2 and luckily ran into land before they starved. He did not have to create an ecosystem wherever he went.

 

[Loren Pechtel]

By comparison to Mars, Antarctica is a paradise for humans. The temperatures are balmy, the air is breathable, there’s abundant fresh water (albeit mostly in the form of ice), there are fish off the coastline, and you can eat penguins, and even seaweed.

Antarctica is like Mars on ‘super easy’ mode. It’s a comparative paradise.

Yet humans struggle to survive there, and can only do so with massive support and regular resupply from elsewhere.

If you can’t walk, it’s a pretty reasonable assumption that you can’t win the Olympic Marathon. If you can’t colonise Antarctica, it’s equally reasonable to assume that you can’t colonise Mars.

Except Antarctica has nasty weather. Mars doesn't. The Martian environment is far more hostile but it's far more passive, also.

But Antarctica's winds (pretty much Antarctica's only weather) would be an energy source for a colony using wind turbines. Wind turbines would be worthless on Mars and solar panels would be poor at providing power during the global dust storms.

The shifty, melty "ground" is also a considerable problem.

 

[Loren Pechtel]

So fl, fi, and fc are very much up in the air, and I now turn to L, which is even worse.

There are several possible limiting factors:

1. Wars
2. Diseases
3. Environmental problems
4. Resource depletion
5. Loss of interest

(1) This was rather obvious from the Cold War. Both the United States and the Soviet Union built enough nuclear bombs to turn each other’s cities into radioactive wastelands, and other nations have tried to join in.

(2) That is a bit farfetched, but not impossible with suitable genetic engineering, like creating a time-bombed microorganism that spreads without causing symptoms, and then starts attacking its hosts.

(3) These include various ways of impairing the habitability of one’s homeworld, like ruining farmland and altering the climate.

(4) This includes running out of fossil fuels, metal ores, and the like, without developing good substitutes. I think that energy resources are especially critical, since without energy, you can’t do anything else. So it is important to learn how to use long-lived energy sources like the light of one’s homeworld’s star.

(5) There are several ways that this can happen.

1. Reversion to a lower level of technology
2. Turning inward
3. Feeling threatened by the possibility of intelligent entities elsewhere in the Universe
4. Deciding that such entities cannot exist
5. Quitting after failing to discover such entities
6. Considering self-advertisement too dangerous or too expensive
7. Considering searches likewise too dangerous or too expensive

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

 

[DBT]

The apparent rarity of phosphorus may be a limiting factor for life in the universe.

That's a problem for our biochemistry, but is that a universal problem? Some other biochemistry might make much less of phosphorus compared to ours, and I don't know of any good biochemical argument for its proposed ubiquity. What is supposed to be so essential about that element?

How are we to know? It may be a huge limiting factor, or not. We know that phosphorous is essential for life on Earth and that it is a relatively rare element elsewhere.

 

[excreationist]

More basic. LOT and entropy. Can O2 and H2O be recycled indefinitely without loss. Can you recycle 1kg of water and always get back 1kg of water.

The Biosphere experiment in the 80s was an attempt at an isolated self sustaining habitat.

Biosphere 2 - Wikipedia

en.wikipedia.org

Simply saying anything can be spun is more a scifi approach.

On Mars they can get the oxygen from water elsewhere on the planet rather than having to get oxygen from plants and always reusing the water....

Mars colonists could get fuel and oxygen from water on the Red Planet

Colonists on Mars could one day generate fuel and oxygen from saltwater on the Red Planet, a new study finds.

www.space.com

As far as nutrition requirements go they could use nanotechnology and genetic engineering....

 

[skepticalbip]

So fl, fi, and fc are very much up in the air, and I now turn to L, which is even worse.

There are several possible limiting factors:

1. Wars
2. Diseases
3. Environmental problems
4. Resource depletion
5. Loss of interest

(1) This was rather obvious from the Cold War. Both the United States and the Soviet Union built enough nuclear bombs to turn each other’s cities into radioactive wastelands, and other nations have tried to join in.

(2) That is a bit farfetched, but not impossible with suitable genetic engineering, like creating a time-bombed microorganism that spreads without causing symptoms, and then starts attacking its hosts.

(3) These include various ways of impairing the habitability of one’s homeworld, like ruining farmland and altering the climate.

(4) This includes running out of fossil fuels, metal ores, and the like, without developing good substitutes. I think that energy resources are especially critical, since without energy, you can’t do anything else. So it is important to learn how to use long-lived energy sources like the light of one’s homeworld’s star.

(5) There are several ways that this can happen.

1. Reversion to a lower level of technology
2. Turning inward
3. Feeling threatened by the possibility of intelligent entities elsewhere in the Universe
4. Deciding that such entities cannot exist
5. Quitting after failing to discover such entities
6. Considering self-advertisement too dangerous or too expensive
7. Considering searches likewise too dangerous or too expensive

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

That seems to make an awfully big assumption or maybe several big assumptions. To me Fermi's Paradox strongly suggests that there is a hell of a lot that we don't know.

 

[bilby]

So fl, fi, and fc are very much up in the air, and I now turn to L, which is even worse.

There are several possible limiting factors:

1. Wars
2. Diseases
3. Environmental problems
4. Resource depletion
5. Loss of interest

(1) This was rather obvious from the Cold War. Both the United States and the Soviet Union built enough nuclear bombs to turn each other’s cities into radioactive wastelands, and other nations have tried to join in.

(2) That is a bit farfetched, but not impossible with suitable genetic engineering, like creating a time-bombed microorganism that spreads without causing symptoms, and then starts attacking its hosts.

(3) These include various ways of impairing the habitability of one’s homeworld, like ruining farmland and altering the climate.

(4) This includes running out of fossil fuels, metal ores, and the like, without developing good substitutes. I think that energy resources are especially critical, since without energy, you can’t do anything else. So it is important to learn how to use long-lived energy sources like the light of one’s homeworld’s star.

(5) There are several ways that this can happen.

1. Reversion to a lower level of technology
2. Turning inward
3. Feeling threatened by the possibility of intelligent entities elsewhere in the Universe
4. Deciding that such entities cannot exist
5. Quitting after failing to discover such entities
6. Considering self-advertisement too dangerous or too expensive
7. Considering searches likewise too dangerous or too expensive

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

Not really. The solution to Fermi’s Paradox is likely similar to the solution to Olber’s Paradox - the universe is big, young, and has c as a hard speed limit. Add to that the inverse square law and the inherent difficulty it provides in detecting signals at long distances even if they’ve had time to reach us, and Fermi’s Paradox is defeated.

Fermi fans are victims of both an over optimistic expectation for our future technology (and by extension, the technology that aliens might employ), and an over pessimistic expectation for our short to medium term survival prospects.

 

[bilby]

The apparent rarity of phosphorus may be a limiting factor for life in the universe.

That's a problem for our biochemistry, but is that a universal problem? Some other biochemistry might make much less of phosphorus compared to ours, and I don't know of any good biochemical argument for its proposed ubiquity. What is supposed to be so essential about that element?

How are we to know? It may be a huge limiting factor, or not. We know that phosphorous is essential for life on Earth and that it is a relatively rare element elsewhere.

It’s also a relatively rare element here, but we get by.

 

[bilby]

As far as nutrition requirements go they could use nanotechnology and genetic engineering...

To do what?

Neither technology lends itself in an obvious or direct way to solving the problem of feeding people on Mars.

 

[DBT]

The apparent rarity of phosphorus may be a limiting factor for life in the universe.

That's a problem for our biochemistry, but is that a universal problem? Some other biochemistry might make much less of phosphorus compared to ours, and I don't know of any good biochemical argument for its proposed ubiquity. What is supposed to be so essential about that element?

How are we to know? It may be a huge limiting factor, or not. We know that phosphorous is essential for life on Earth and that it is a relatively rare element elsewhere.

It’s also a relatively rare element here, but we get by.

We do, we have an adequate supply to get by. There may not be a high percentage of planets in the universe with an adequate supply of phosphorus to support life on the scale of earth. I guess that is yet to be discovered.

 

[excreationist]

As far as nutrition requirements go they could use nanotechnology and genetic engineering...

To do what?

Neither technology lends itself in an obvious or direct way to solving the problem of feeding people on Mars.

Are you saying that there aren't enough resources for a Mars colony to grow the food it needs? Note that for quite a while they would be able to import large quantities of water, etc, from other parts of the planet.

 

[bilby]

As far as nutrition requirements go they could use nanotechnology and genetic engineering...

To do what?

Neither technology lends itself in an obvious or direct way to solving the problem of feeding people on Mars.

Are you saying that there aren't enough resources for a Mars colony to grow the food it needs?

No, I am questioning the exact way in which either nanotechnology or genetic engineering might help in securing those resources for feeding colonists.

Are you just chucking buzzwords around, or do you have an actual application of these technologies in mind, that would be useful in achieving the goal?

 

[excreationist]

Are you saying that there aren't enough resources for a Mars colony to grow the food it needs?

No, I am questioning the exact way in which either nanotechnology or genetic engineering might help in securing those resources for feeding colonists.

Are you just chucking buzzwords around, or do you have an actual application of these technologies in mind, that would be useful in achieving the goal?

I'm not an expert but people need a lot of different vitamins, etc, which are basically just molecules.... genetic engineering could make plants that have a bigger range and higher concentration of nutrients (possibly by combining different species' DNA) that require less resources. About using nanotechnology to create molecules:

Molecular assembler - Wikipedia

en.wikipedia.org

I learnt about that last part by reading "The Spike" from Damien Broderick from 1997.

 

[lpetrich]

So fl, fi, and fc are very much up in the air, and I now turn to L, which is even worse.

(huge list of possible limiting factors snipped for brevity)

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

That's one solution: short lifetimes.

Another solution is the Great Filter. It is that there is at least one very improbable step on the way to a sentient species that can communicate across interstellar distances, and that means great rarity. Looking at the Drake Equation, it means that at least one of fl, fi, and fc is very small. Of the other parameters, observations of exoplanets indicate that fp is close to 1 and ne is unlikely to be very small.

The Great Filter may also be interpreted as including small L.

Rarity can mean that we are the first to emerge in our Galaxy, or even in the observable Universe.

 

[steve_bank]

Subjectively I'dd say life in some form probably exists elsewhere. It is the only reason to go to Mars.

The discovery of black smokers, deep sea volcanic vents, was a major discovery. Complete ecosystems based on direct chemical energy and heat toxic to surface life. No sunlight.

Bacteria in deep mines have been found that feed on rocks.

 

[Loren Pechtel]

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

That seems to make an awfully big assumption or maybe several big assumptions. To me Fermi's Paradox strongly suggests that there is a hell of a lot that we don't know.

We are based with two basic possibilities:

1) Intelligent aliens do not colonize.

2) No intelligent aliens capable of colonizing arise.

#1 leaves the question of why do they all stay home? This seems unlikely.

#2 leaves the question of why they don't. While we are not capable of it yet there is no reason to think it's something that can't be done in the not too distant future. No aliens reach this point--which says it's either incredibly unlikely to reach where we are now, or it's incredibly unlikely to go from where we are now to starfaring.

Thus either we have faced a barrier in history that was exceedingly hard to cross (observer effect--only the planets that cross the barrier can observe the situation, so us being a billions-to-one longshot isn't unreasonable) or we will face such a barrier in the near future.

 

[Loren Pechtel]

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

Not really. The solution to Fermi’s Paradox is likely similar to the solution to Olber’s Paradox - the universe is big, young, and has c as a hard speed limit. Add to that the inverse square law and the inherent difficulty it provides in detecting signals at long distances even if they’ve had time to reach us, and Fermi’s Paradox is defeated.

Fermi fans are victims of both an over optimistic expectation for our future technology (and by extension, the technology that aliens might employ), and an over pessimistic expectation for our short to medium term survival prospects.

c isn't very relevant here, we aren't looking that far into the past in looking at our galaxy. And even if a civilization doesn't go starfaring why would they not become a K2 civilization? We can detect those at great range even now.

 

[Loren Pechtel]

So fl, fi, and fc are very much up in the air, and I now turn to L, which is even worse.

(huge list of possible limiting factors snipped for brevity)

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

That's one solution: short lifetimes.

Another solution is the Great Filter. It is that there is at least one very improbable step on the way to a sentient species that can communicate across interstellar distances, and that means great rarity. Looking at the Drake Equation, it means that at least one of fl, fi, and fc is very small. Of the other parameters, observations of exoplanets indicate that fp is close to 1 and ne is unlikely to be very small.

The Great Filter may also be interpreted as including small L.

Rarity can mean that we are the first to emerge in our Galaxy, or even in the observable Universe.

Looking at Earth it's unlikely that fl is low. That leaves only fi (which I would break down into the two phases we see on Earth: Multicellular and intelligence) and fc as limits. If the limit is fi we are fine. If it's fc then we are soon to face that filter--and if the filter simply hinders we would in time work our way past it. Thus the filter must be incredibly destructive.

While a low L very well might be the limit it means we are about to destroy ourselves.

 

[bilby]

Yes, this is the nasty one. Fermi's Paradox strongly suggests that civilization is inherently self-destructive.

Not really. The solution to Fermi’s Paradox is likely similar to the solution to Olber’s Paradox - the universe is big, young, and has c as a hard speed limit. Add to that the inverse square law and the inherent difficulty it provides in detecting signals at long distances even if they’ve had time to reach us, and Fermi’s Paradox is defeated.

Fermi fans are victims of both an over optimistic expectation for our future technology (and by extension, the technology that aliens might employ), and an over pessimistic expectation for our short to medium term survival prospects.

c isn't very relevant here, we aren't looking that far into the past in looking at our galaxy. And even if a civilization doesn't go starfaring why would they not become a K2 civilization? We can detect those at great range even now.

Why would you expect them to do either?

Starfaring is fairly pointless for short-lived species, and there’s good reason to think that humans are at the high end of the individual longevity spectrum, whose driver is evolution.

Becoming a K2 civilisation assumes that the energy available to a K1 civilisation will become insufficient; But if that civilisation has a stable population and isn’t expanding beyond its own solar system, why would they need all that energy?

A lot of the assumptions made about the total energy consumption of advanced civilisations in the twentieth century were made with the implicit belief in continuing exponential growth in population - something the we now observe to have been a short term ‘blip’ in human history, and not the inevitable result of decreasing infant mortality that it was believed to be in the mid-C20th.

We don’t need to advance beyond K1; And we don’t live long enough to leave our solar system.

Our life expectancy (when measured in heartbeats) is a significant outlier amongst mammals, probably because of our technology (particularly, but not exclusively medical technology); We live far longer than most mammals have evolved to live, yet still far too short a life to visit the stars.

I see no reason to expect intelligent aliens to live vastly longer lives. Their evolutionary history would likely not differ vastly from ours, and lifespan is an evolutionary compromise between having time to support the younger generations and thereby increase their survival and reproductive chances; and not getting in their way enough to reduce their survival and reproductive chances, or to allow competitors with shorter lives (and hence faster evolution) to outcompete them, thereby doing more harm than good.

Never mind why would they not; Why do you assume that they would? We haven’t; And likely we won’t.