DescentBB

There's gotta be a first.

http://www.centauri-dreams.org/?p=1200

Smack in the middle of its star’s habitable zone
Average temp between 0 and 40 degrees Celsius

1.5x Radius of Earth
5x Mass of Earth

Day length: *unknown*
Year length: equiv 13 earth days.

Orbiting a Brown Dwarf, 20.5 light years away.

Atmosphere: *unknown*
Native life: *unknown*

...
brb, goin to Gliese 581!

Only 20.5 light years away. You should be back by dinner

It could be the next vacation destination. All we need to do now is develop warp drive.

5x mass of earth. Wouldn't gravity be a problem?

woodchip wrote:5x mass of earth. Wouldn't gravity be a problem?

Probably for us, but not for possibly native lifeforms living there. Too often we thing in "earth-standards".
I'm not an expert, but I think if there's an atmoshpere, life will find it's way.

The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

What interests me is how they are going to go about getting more data about the planet, and whether that data will closely match their models of the planet, or not.

Foil wrote:The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

For sure. But I won't give up the hope. For me it's too egoistic to think we are the only one lifeforms in - at least - our galaxy.
When we can say 0.000001% of star systems in our galaxy MAY (if right circumstances given) contain life, then we have masses of life with the countless stars in this galaxy...

Richard Cranium wrote:All we need to do now is develop warp drive.

Or Trans Warp Drive, it would be really cool to go through one of those slipstreams... Maybe we could even find the Starship Voyager

Look: ANY planet that hasn't been analysed properly can be home to life: water or not!

d3jake wrote:

Richard Cranium wrote:All we need to do now is develop warp drive.

Or Trans Warp Drive, it would be really cool to go through one of those slipstreams... Maybe we could even find the Starship Voyager

LOL 20.5 light years? heck.. that's hardly the 7-11 "down the street" for Start Trek.

Foil wrote:The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

After viewing the way life here on earth can living around boiling hot vents on the ocean floor, or strongly acid cave water...why would you think life has a low probability on other planets or moons?

woodchip wrote:After viewing the way life here on earth can living around boiling hot vents on the ocean floor, or strongly acid cave water...why would you think life has a low probability on other planets or moons?

Why?



Well, if you don't believe in a God, then you would have to believe that we (and other lifeforms) arrived on the scene by chance. Obviously then one may look at the chances of something mathematically. Take for instance simple proteins (a building block of life).

Bear with me here...

Since the blueprint for building a protein is stored in the nucleus of the cell and the actual site for building proteins is outside the nucleus, help is needed to get the coded blueprint from the nucleus to the “building site.” RNA (ribonucleic acid) molecules provide this help. RNA molecules are chemically similar to those of DNA, and several forms of RNA are needed to do the job. Take a closer look at these extremely complex processes for making our vital proteins with the help of RNA.

Work starts in the cell’s nucleus, where a section of the DNA ladder unzips. This allows RNA letters to link to the exposed DNA letters of one of the DNA strands. An enzyme moves along the RNA letters to join them into a strand. Thus DNA letters are transcribed into RNA letters, forming what you might call a DNA dialect. The newly formed chain of RNA peels away, and the DNA ladder zips up again.

After further modification, this particular type of message-carrying RNA is ready. It moves out of the nucleus and heads for the protein-production site, where the RNA letters are decoded. Each set of three RNA letters forms a “word” that calls for one specific amino acid. Another form of RNA looks for that amino acid, grabs it with the help of an enzyme, and tows it to the “construction site.” As the RNA sentence is being read and translated, a growing chain of amino acids is produced. This chain curls and folds into a unique shape, leading to one kind of protein. And there may well be over 50,000 kinds in our body.

Even this process of protein folding is significant. In 1996, scientists around the world, “armed with their best computer programs, competed to solve one of the most complex problems in biology: how a single protein, made from a long string of amino acids, folds itself into the intricate shape that determines the role it plays in life. . . . The result, succinctly put, was this: the computers lost and the proteins won. . . . Scientists have estimated that for an average-sized protein, made from 100 amino acids, solving the folding problem by trying every possibility would take 10 to the 27 power (a billion billion billion) years.” A number mathemeticians deem as not a chance, but purely impossible at that point.



I don't think many people fully understand the complexity that surrounds our life - even in life's "simplest" form. That's why.

Sniper wrote:

woodchip wrote:After viewing the way life here on earth can living around boiling hot vents on the ocean floor, or strongly acid cave water...why would you think life has a low probability on other planets or moons?

Well, if you don't believe in a God, then you would have to believe that we (and other lifeforms) arrived on the scene by chance. Obviously then one may look at the chances of something mathematically. Take for instance simple proteins (a building block of life).

. . . Scientists have estimated that for an average-sized protein, made from 100 amino acids, solving the folding problem by trying every possibility would take 10 to the 27 power (a billion billion billion) years.” A number mathemeticians deem as not a chance, but purely impossible at that point.

A real mathematician would never say something like 1/(10^-27) = 0.

Maybe I should clarify my earlier statement:

I'm not saying life has a low probability of surviving on that planet. As you pointed out, life is incredibly adaptive.

I meant to say that life has a low probability of naturally developing (by chance). Of course, that's not factoring in the possibility of God creating life there, or that life somehow travelled there.

hey that's pretty cool, roid.

now watch as this turns into another god/bible/creationism thread.

Foil wrote:A real mathematician would never say something like 1/(10^-27) = 0.

Because it would equal 10^27?

Sniper wrote:Well, if you don't believe in a God, then you would have to believe that we (and other lifeforms) arrived on the scene by chance. Obviously then one may look at the chances of something mathematically. Take for instance simple proteins (a building block of life).

This sort of reasoning seems guilty of some sort of probabilistic fallacy.

edit: Corrected, thanks Lothar.

Consider this. I went to two classes today. Let's say that each classroom had 20 desks and 20 students and that each student chose at random from the available desks upon entering the room. The odds of us sitting in the arrangement that we did would thus be 1 in 20*19*18*17*...*1 or 1 in 20! (20 factorial). I went to two classes today, so the odds of us sitting in the arrangements that we did for both classes would be 1 in 20!^2. Suppose I went to two similar classes five times a week and that I've completed the fourteenth week in the semester. Then the odds of us sitting in the arrangements that we did for each class throughout the semester would be 1 in 20!^(2*5*14), a very large number.

Now are we to conclude then that the way that the students in my classes this semester chose our desks is too unlikely to have ever occurred and thus never happened the way that I described? (Perhaps a deity must have inspired us to choose the desks that we did?) No, it just seems like to reason like that would be to ignore that we could have chosen our desks in any other way each class and that we could still make the same claim. The only reason why we are asking the odds of the students choosing seats in the way that we did is because that's the way we did. Otherwise, we would just be asking about the odds of some other way.

Anyone ever read Nemesis by Asimov?

Jeff, your argument touches on something Dembski tries to deal with in his ID stuff (with moderate success) and that Drakona has done a better job dealing with. Consider the following:

There's only a 1 in [big number*] chance of you all choosing those specific seating arrangements over the course of a semester (provided the choices are purely random.) But, provided your seating arrangement wasn't particularly interesting, there's a nearly 1 in 1 chance of you all choosing an equivalently interesting seating arrangement. That's what we should really be looking at the odds of -- not \"this exact pattern\", but \"all patterns that are equally as interesting as this one\".

To see why this is interesting, consider the possibility that you had all chosen, at random, to sit in alphabetical order by last name in every single class. There's a 1 in [the same big number] chance of that happening -- exactly the same odds as any other particular seating arrangement. But the pattern is far more interesting... other patterns of the same level of coolness** might be: alphabetical by last name, in birthday order (yearly), in birthday order (absolute), in order of height, and perhaps a few dozen others. You could also take those things in reverse, or in rows rather than columns, or a few other ways of tracing out the pattern. All told, you can make maybe a couple thousand patterns that would be just as cool as \"alphabetical order by first name\". Which means the seating arrangement you saw has a coolness-probability factor of a few thousand in [big number]... which knocks a whole 3 orders of magnitude off of 2,574 orders of magnitude.

So if you'd managed to sit in alphabetical order by first name in every class, 2 classes a day, 5 days a week, 14 weeks... we could reject the hypothesis that you took your seats randomly, with a very high level of confidence. That doesn't tell us exactly why you were arranged that way (seating chart? student collaboration? a subconscious/telepathic suggestion?) but it does tell us that it's not real rational to assume it happened by chance.


** now, the concept of a pattern being \"cool\" or \"interesting\" is contextual. If your class happens to be a genetics course focused on a specific gene/allele on a particular chromosome and everyone is seated in alphabetic order by their sequence at that exact point in their DNA, that's impressive. If the class has nothing to do with genetics, and everyone happens to be sitting alphabetically according to one of their millions of genes... not nearly so cool.

* your \"big number\", by the way, was miscomputed. You're right to start with 20! for one class. For two classes, it's (20!)^2, not 2*20!. This is going to make your \"big number\" an awful lot bigger by the end of two classes, 5 times a week, for 14 weeks -- (20!)^(2*5*14) = (20!)^140 ~= 10^2574. That's a lot of orders of magnitude.

Gah, fixed.

This is just reminding me about how I miss Drakona's posts.

Ferno wrote:hey that's pretty cool, roid.

now watch as this turns into another god/bible/creationism thread.

Geez I hope not. It will force me to provide data showing that life does not have to start on a host planet or the new one found. When our star system was very young, Earth was continually bombarded with comets and meteors which carried water-ice, amino acids, and the building blocks of life. Our life may very well have started with the seeds planted by them.

BTW it isn't a brown dwarf star but a red dwarf which burns slower and cooler and will far outlive ours.

Bee

Jeff250 wrote:

Foil wrote:A real mathematician would never say something like 1/(10^-27) = 0.

Because it would equal 10^27?

D'oh! Leave it to a math geek to confuse his numbers.

(I was thinking of 10^(-27), or 1/(10^27), and somehow mixed them up.)

1. the info we have on this planet is at least 20 years out of date. For all we know its a big pile of rubble now.

2. the number of potential planets that can support life is finite, and the number that cannot is infinitely larger, divide the two together and you get how unlikely it is for there to be life on a given planet(yes, the H2G2 explanation, but its a good one).

fliptw wrote:...the number of potential planets that can support life is finite, and the number that cannot is infinitely larger...

"infinitely larger"? No, not unless there are an infinite number of planets.

It's one thing to say there is a "huge/gigantic/extremely-large number" of planets, quite another to say there is an "infinite number".

(By the way, your idea to "divide" the numbers breaks down if the denominator is infinite.)

Anyway, the ratio of habitable/unhabitable planets does imply something about the question, "How likely is it to find life on a given planet?" But the question here is, "Given that the planet is habitable, how likely is it to find life there"?

And habitable to whom? If we buy into the Star Trek idea that alien life could be represented by a giant ball of gas, then this level of generality opens the door to really any planet being habitable.

As for gravity, it not only depends on mass, but density and rotational velocity play a factor in how \"heavy\" you are.

As far as life, I'd say theres probably a pretty good chance of life... now, intelligent life thats another story.

What interests me is how they are going to go about getting more data about the planet, and whether that data will closely match their models of the planet, or not.

From what I understand about the quest to find a habitable planet, a big problem with finding them is the lack of techniques to do so. One of the reasons we've only been finding gas giants is because thats all we know how to look for.

I think foil is alluding to this in his post.

Point being, there may be more habitable planets out there then we think there are. We just don't know how to see them.

Foil wrote:The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

Foil, This is bothering me enough to ask where you got this from. Knowing what I know, I'm just curious.

Bee

Day length: most likely it is tidally locked because of its close proximity to the sun. That means one side will roast, while the other freezes.

Don't get excited about this - it is NOT habitable, unless by habitable, you mean \"Doesn't crush you with gravity, but still boils or freezes you, and if you can see the sun, you've already taken a lethal dose of radiation.\"

I give it 300 years before the first Starbucks opens.

Mobius, you can't make those assumptions from here.

Dedman wrote:I give it 300 years before the first Starbucks opens.

Jeff250 wrote:And habitable to whom? If we buy into the Star Trek idea that alien life could be represented by a giant ball of gas, then this level of generality opens the door to really any planet being habitable.

True enough - carbon and water-based life is certainly not the only possible form of life, but it may very well be the most likely.

http://www.centauri-dreams.org/ is pretty excited, and is still talking about it. this youtube vid was posted:

which gives some clues as to what \"habitable zone\" means. It means that there is a high chance of there being liquid water on the planet, i suppose because of the planet's likely Earth-like temperature of approx 0 - 40 Celcius.

What the atmosphere is, is another matter entirely. So it's not like you could just go there and stroll around.

the habitable zone must be important coz we expect life to be water based. Coz hey what else do we have to go on . On Earth we have a lot of life that can survive in extreme temperatures, and even extreme radiation, but we don't yet know of anything that can live without some form of liquid water. So i guess it makes sense to concentrate on that, for now

I read somewhere that the dwarf star gives out mostly IR radiation, and very little light. So the days would be dark, but you'd still feel the sunlight warm your skin. Weird!

Bet51987 wrote:

Foil wrote:The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

Foil, This is bothering me enough to ask where you got this from. Knowing what I know, I'm just curious.

Bee

You may know more than I do about it.

I was basing that statement on my understanding of the odds of life developing by itself on a given planet, due to the complexity of the most basic living structures.

Note: I was excluding divine intervention, as that's not something that one can really put "odds" on.

Foil wrote:The odds of life existing on a single given planet are still very low, even if it has water/atmosphere.

Agreed!

http://www.space.com/scienceastronomy/0 ... lanet.html

\"Gliese 581 C is the smallest extrasolar planet, or “exoplanet,” discovered to date. It is located about 15 times closer to its star than Earth is to the Sun; one year on the planet is equal to 13 Earth days. \"

I'm trying to figure out how much closer to the sun that planet is. How far away from the sun is Earth? If we put Gliese 581 in our system, would it be closer to the sun than Venus or Mercury?

I wish I have kept up with my astronomy hobby. Since I graduated high school, other things took over and my telescope is broken and covered in dust

If it's running 13 days an orbit, it's definitely closer than Mercury unless it's going very fast (Mercury has an orbital period of 88 days).

We still don't seem to be able to detect planets at much of a distance from stars unless they're huge; that is waiting for the right technology. Got lucky with this one because it's a dwarf.

At any rate, 15 times closer is about 10 million kilometres ... so yeah, I think Mercury was a fair bit more than that (I know Venus was about 100-110). The sun is around a million kilometres wide by itself, so it'd be incredibly hot on Mercury if it were that close.

So the sun over there would be smaller than ours because the planet is so close there and is a habitable planet?
*edit* Oh it's a dwarf star that the planet's orbiting around. How big would that be?

Diameter of 528,000 km apparently (i.e. the radius is 250,000 or so). It would appear larger in this planet's sky than the Sun by far, but also dimmer because it's a red dwarf.

it may appear bigger, but it'd probabaly still appear a LOT dimmer because dwarf stars don't give out much visible light at all.

They recon there is a lot of nearby dwarf stars around that we still dont' even know about. Coz they are hard to detect, and you sure can't see them with the naked eye. There might even be one closer than Alpha Centauri