'Hundreds of Worlds' in Milky Way

Raphael Emportu writes "BBC news is reporting that rocky planets, possibly with conditions suitable for life, may be more common than previously thought in our galaxy, a study has found. New evidence suggests more than half the Sun-like stars in the Milky Way could have similar planetary systems. There may also be hundreds of undiscovered worlds in outer parts of our Solar System, astronomers believe. Future studies of such worlds will radically alter our understanding of how planets are formed, they say."

No shit.

No shit that there are other planets like ours out there. The incomprehensibly massive scale of the universe dictates it to be true, statistically-speaking.

Today, children receive next to no education in the field of astronomy. Were they to have a proper understanding of what lies beyond Pluto, they'd probably grow up to realize how silly it is to believe that there is only one planet like Earth.

Re:No shit.

That the chance of a star to have planets is one in a million. Doesn't seem impossible, does it? The survey of the closest stars around our solar system seem to contradict this. I don't have exact numbers, but too many planets were discovered within a 50 light-years radius to conclude that only one star in a million has a planet.

Of course the Earth could be located in a statistical anomaly within the Milky Way, but if you posit a uniform repartition of planets, there has to be more.

I am just nit-picking however. I fully agree with the rest of your post.

Re: bad guess

I disagree. I understand the argument you are trying to make, but your "1 in a million" suggestions are really more akin to wild stabs at the biggest number you can think of, than they are reasonable guesses. 1:1000000 is really an unusually small ratio, and not as common as you intimate. It certainly has no actual relation to the situations that present themselves in the formula.

You can't simply spout a bunch of hyperbole and expect to be taken seriously. Especially in reply to an article that attempts to actually determine those numbers and percentages based on facts. This kind of talk is really no different from the comedy statement that "90% of people know that you can prove anything with statistics." It's meaningless.

While we will likely have to wait a whole lot longer for meaningful answers to the Drake equation, attempts at putting fact-based numbers on the variables should be applauded, and discounting them with what amounts to emotional hyperbole should be discouraged IMO.

Re:No shit.

Imagine we discover: That the chance of a star to have planets is one in a million. Doesn't seem impossible, does it? The chance of a star with planets to have one at the correct distance (taking star heat in consideration) to be between 0 and 100 C, one in a billion. The chance of a planet in the correct position to have water. One in a million.

Point 1: very long odds, given the number of extrasolar planets we've already discovered.
Point 2: extremely long odds. It's a reasonably wide zone for the Sun, from about halfway between Earth and Venus out to Mars - which would probably be inhabitable if it were larger and could hold a thick atmosphere. Moreover the zone will shift as the star evolves and brightens, so a planet that starts out frozen may spring to life in later years. Come the red giant phase even Titan might bear life.
Point 3: totally redundant. It just repeats point 2, but for some reason does so with a probability greater by a factor of one thousand. Counting the same criterion twice just to get the numbers down by a factor of a million is cheating.

So, we still have nine planets. Now, cross your fingers that one of those is not radioactive, doesn't show the same side to the star (that happens quite often), is big enough to have enough gravity to hold an atmosphere, etc.

How do you know that tidally locked planets are commonplace? There are none in our system.

Well, it's nice to have a destination...

Now, if we only had some means of reaching it...

The speed of light is a barrier like few the humanity has ever found.

Energy is the issue

The speed of light is not a deal-breaker. It means that, from *our* perspective, we'll send people to distant planets and never hear from them again. But from their perspective, it may be a few years. If interstellar travel actually happens, then the speed of light issue is just a managable logistical issue. It means that space-farers must be able to think for themselves. They already must be self-sufficient in other respects.

If there is a deal-breaker, then it is contruction and propulsion of such a craft. The vaster the craft, then the more unlikely it's construction. We might be able to fire ourselves off in a single direction, but how do we slow down, and what if we need to change course. If we need to come home, then we've doubled the energy required!

Then there are complex issues with people - our fragile minds and bodies. How do we react to the stress of space-travel, can we do it?

The speed of light seems like a comparatively simple issue.

Re:Well, it's nice to have a destination...

And to be intelligent on top of that.

That barrier is so high that most humanity never got to surpass it.

Re:Well, it's nice to have a destination...

The probability for intelligence seems to me to be the biggest hurdle. That humans are intelligent at all seems nothing more than a genetic fluke, and not a guaranteed outcome.

However, given our understanding for life, and how it evolved, it would seem that complex life forms would probably NOT be rare at all.

The biggest hurdles for human-like intelligence probably includes the following:

1. Self replicating molecules. I'm not sure how precise the conditions for getting life started are, but it probably isn't something we would see very often.
2. Conditions remaining stable for those molecules for a very long time.
3. Symbiotic relationships developing between organisms. (requirement for multi-cellular life)
4. The creativity mutation. (for lack of a better term.)

In between, it seems that the process of natural selection would be the driving factor, but those 4 items listed are probably the most important 'leaps'.

With regard to the creativity mutation: As I recall, there was a proto-human homonid that DID use tools, but never developed on that tool (The stone axe they used at the beginning of their existance was the same stone axe that they used at the end of their existance) And that period of time wasn't short, something on the order of millions of years where they used the exact stone axe. While they were using a tool, there was no real thought behind it. In that respect, it seems that it was much like a spider's web, a very precise tool for survival but instinct rather than a developed idea.

Re:Well, it's nice to have a destination...

With regard to the creativity mutation: As I recall, there was a proto-human homonid that DID use tools, but never developed on that tool (The stone axe they used at the beginning of their existance was the same stone axe that they used at the end of their existance) And that period of time wasn't short, something on the order of millions of years where they used the exact stone axe.

I believe the specific hominid you are referring to is Homo Ergaster (Working Man).

While they were using a tool, there was no real thought behind it. In that respect, it seems that it was much like a spider's web, a very precise tool for survival but instinct rather than a developed idea.

I don't know if I agree with that assessment. It seems to me as if H. Ergaster simply progressed as far as his brain would allow, and no farther. A simple hand axe was just the apex of his ability. Looking at H. Ergaster makes me rather worried about the future of our species...after all, we haven't been around nearly as long. What if we run up against an innate limit in our brains, and our technology can proceed no further?

Re:Well, it's nice to have a destination...

Not necessarily. Look at Conway's life cellular automaton. There are many valid configurations within the game that can never be reached without setting it that way to begin with. They are called 'garden of eden' configurations. And given any particular starting configuration, there are plenty of configurations that won't ever be reached. And if you define 'possible' as 'any condition that can be reached from a given starting condition,' then you have constructed a tautology and have not said anything useful at all. You are basically defining possible as 'that which happens, given enough time.'

Put another way, "given enough time, monkeys will fly out of my ass." Now, evolutionarily speaking, flying monkeys are possible. It is also possible, given enough mechanical force, that my ass could be stretched large enough to fit the wingspan of an average flying monkey. But I really doubt that even if you waited around for an eternity, you'd ever see a monkey fly out of my ass.

Not so Rare Earth

Interesting, considering that just last night I was watching a documentary, on BBC4 no less, about rare earth theory and how miraculous it was that the conditions on earth are as they are.

Funny but, I couldn't shake the feeling that the reason conditions here on earth are so 'perfect' for life as we know it was more to do with life as we know it evolving to fit the conditions ...

Re:Not so Rare Earth

This new information kinda blows a hole in that theory, huh?

Yes, but His Spaghettiness is most forgiving. May you be touched by His Noodly Appendage forever. Hang on, that sounds a bit like icky things Japanese do with tentacles... oh second thoughts...

TFA is confused...

... there may be hundreds of worlds in the solar system. In the Milky Way, expect trillions. The distinction between the Solar System and the Galaxy is a subtle one, similar to that between a grain of sand and Saudi Arabia, so it's easy for the likes of the BBC to confuse the two.

Drake Equation

Given hundreds of worlds within our own galaxy, if we apply the Drake Equation [wikipedia.org], there's a good chance that there's another intelligent species out there, although the chances of it being of a sufficient technological development to make its presence known is slim. Also, the 'accepted values' for the various parts of the Drake equation are subject to (sometimes intense) debate.

This being said, given that most of these "nearby" worlds are tens of thousands of light-years away, with the current state of our technology, we might as well be alone.

And all of them are ours

except Europa. I'll not be attempting any landings there.

Re:sweet

Now to find a way of this rock onto one of those.

Just keep typing stuff like of instead of off and leaving out conjunctions like and in between rock and onto and sooner or latter someone around here is sure to get pissed off enough to help you off of this rock. Getting onto one of the others is an entirely different story.

Re:sweet

I'm all for shipping grammar nazis off to the most distant rock available.

By the way, it's "later", not "latter" ;)

Re:sweet

The explanation for the "write" vs. "write to" distinction, at least, is pretty simple. The nouns taking the verb "write" are dative case. That's not obvious in English, but it's there, and it underlies the apparent form.

German is useful here because 1) it's the root language for English and 2) its sentence structures can be perfectly analogous. Take the German sentence Schreib deiner Mutter einen Brief which is translated word-for-word as Write your mother a letter. In German, the deiner is a clear marker that Mutter is dative. The exact same thing is happening in English, but since we don't decline our articles or possessive adjectives and rely instead on word order, it's not obvious to the typical native speaker.

Re:Aquatic life?

Wouldn't it be feasible that intelligent life could arise on a planet that is liquid?

Our own earthly cephalopods are pretty darned smart. Given the right conditions, it's not difficult to imagine a similar species attaining greater intelligence. Of course, such an intelligence, having developed in such an alien environment, would be radically different from ours. As Larry Niven says, there are brains out there that think just as well as yours...but differently.

Also, although an aquatic species could conceivably develop intelligence, I can't imagine what form its technology would take. With such elementary things as fire denied to them, it's doubtful that they could progress to any reasonable level.

Re:Aquatic life?

As long as the temperature of the liquid is sufficiently stable, there are sufficient chemical building blocks and there is not too much current, single cell organisms and then multi cell organisms could emerge..

      Depends on how you define "intelligence". Our liquids are certainly teeming with intelligent life. Life itself apparently began in our oceans. Fish are certainly very smart - they feed themselves, find mates, defend territory, build defensive structures, some species live and travel in social groups, etc. These are all signs of "intelligence". Then if you want to cheat a bit and look at the ocean mammals - seals, porpoises, whales, these are extremely intelligent aquatic beings.

      Arthur C. Clarke, however, argued that CIVILIZATION, however, could not evolve in an aquatic environment, for the simple reason that you cannot have fire underwater. His interesting theory claims that fire, and our control of fire - has been a driving force in our technology. First the fire we would use for slash and burn agriculture - which while being devastating for the environment over the long term gave many short term advantages to the primitive farmer. Fire to make steam is what drove the industrial revolution. And that same power is still in use today, though we get our "fire" in the form of Uranium, or by burning fossil fuels. Then there is the "fire" from the sky - electricity. Harnessing this particular "fire" would be pretty tricky underwater.

      I guess it's an interesting concept to play with, and surely there are many possibilities that we biased, land dwelling humans could never dream of, but I respect Mr. Clarke and his idea. I think it would be difficult for an aquatic civilization to arise here or anywhere else.

Re:Aquatic life?

There are plenty of volcanoes under the water here on Earth. Could those serve as a source of fire?

Perhaps primitive marine creatures would realize that some sort of algae-like food source grows better in the warmer waters around these "glowing liquid not-water" sources and start building walls around them to hold in that temperature. Sort of like farming - but with algae instead of regular "crops". This would give them a stable food source and they could get to thinking about other things.

not very wrong

a planet would not be 100% uniform liquid at room temperature. You don't get planet sized blobs of water. Our planet is a lot of liquid around a fairly small probably solid iron core. The most common liquid component of planet earth by a long way is magma. The solid rock crust and liquid water in the seas is so insignificant by comparison it is surprising we even bother to talk about it. Anyhow what you were probably thinking about is a planet with a surface completely covered by liquid water or something like it. I think something could arise on such a planet, at the surface (or possibly below it if we are allowed to assume a hot core with volcanic vents.) You could get algae mats forming and sinking when they die off. Huge floating mats could then provide an ecosystem for other things to evolve around. At some point there could be fishlike animals under the mats and amphibious creatures walking on top of the mats. I can't see any real limit to the size and stability of the floating mats. Any creature looking to develop technology would have to use organic materials, which makes electronics a bit tricky. In terms of leaving the planet, fuel and a launch pad wouldn't be too tricky, building the rocket might be though.

Re:Aquatic life?

Not every day or time, it all comes down to in which environment it has to survive. And we have examples of tool-compatible appendages in aquatic life here on earth: the octopus that can open plastic bottles http://www.youtube.com/watch?v=wfRqYjv9QgA [youtube.com]. And then there are other aqautic life that seems to do very well without fins such as crustaceans.

Re:Aquatic life?

    Except, we are in the midst of people arguing about exactly how intelligent cephalopods and sea based mammals are.

    The truth of the matter is that we have no real way to gauge the intelligence of other alien life forms. Almost all tests are based on a set of assumptions. It is only fairly recently that we have even defined classes of intelligences within humans (Linguistic, Spatial, Musical, Body-Kinesthetic, Interpersonal, Intrapersonal, Logical/Mathematical). It is entirely possible that intelligent life could evolve in aquatic environments that score extremely high in multiple categories there and we would have no real way of knowing. We know that there are a number of species that have highly evolved linguistic characteristics. But, what are they saying? Is it "See Spot Run"? Is it something profound? Is it elaborate fart jokes? It is entirely possible that the social structures are subtle enough that we have no means of determining how complex they are. When whale song can be heard from thousands of miles away, how do you determine the society that hears it and responds and the relationship between the one singing and the ones listening?

    Someone once said that either we are alone, or we are not. Either answer is mind boggling.

    My view is that we don't even know if we alone here on Earth, much less the universe.

Re:can we make our minds up?

First 9, then posibly 10, then back to 9, then 8.. now we have..
"Our old view, that the Solar System had nine planets will be supplanted by a view that there are hundreds if not thousands of planets in our Solar System,"

The first release of Solaris was Solaris 2. This replaced SunOS 4.x. There were a number of Solaris 2.x point releases, with the last being Solaris 2.6. Solaris 7 was released in November, 1998, followed by Solaris 8 in 2000, Solaris 9 in 2002, and Solaris 10 in 2005.

Although Sun's marketing dept. sometimes comes up with fucked version numbering conventions, the progression is actually quite linear.