How many Earths?

[MartinW 0]

Looking up at the night sky, it's hard not to wonder how many other planets might be circling those pinpricks of light – and how many are home to beings gazing back at us.

Today, we are starting to get a handle on the number of roughly Earth-sized exoplanets that might be suitable for life.

 

You probably think there are quite a few, I know I did, but the answer shocked even me...

http://exoplanets.newscientistapps.com/

[ddavid 149]

Your version of iOS is out of date and cannot display this content. Try running a system update, or use a different device.

Very helpful - Thank You New Scientist, I'll certainly take out a subscription!

Cheers -Dai.

[MartinW 0]

It's not their fault your ios is out of date.
 
But to help you, the conclusion drawn is...


Earths galore

After extrapolating for all the missing worlds, Kepler's field of view becomes dense with planets that may be like Earth.

Now consider this: Kepler observed just 0.28 per cent of the sky. And the telescope was able to peer out to only 3000 light years away, studying less than 5 per cent of the stars in its field of view. So how many Earths might really be out there?


Expanding our view from Kepler's corner of the galaxy to show more of the Milky Way, the sky fills with billions of potentially life-bearing worlds. If we showed them all, the sky would be a mass of green. So now the green dots illustrate stars that might host such planets, visible with a good pair of binoculars on a dark night here on Earth.

From this perspective, the chances that we're alone in the cosmos seem very slim, indeed.


The Kepler telescope may no longer be hunting for alien Earths, but more discoveries are sure to come as researchers work through the backlog of data it gathered. In 2017, the search will be taken up by the Transiting Exoplanet Survey Satellite, which will survey nearby stars across the entire sky.

[ddavid 149]

We're not alone, but G*d help us if any of them come visiting! Mind you, that is as unlikely as they're not being there in the first place! Work out the math, Martin, please.

Cheers - Dai.

[MartinW 0]

God help us: There are two ways of looking at this.
 
1. Our own history tells us that when we've come across less advanced civilisations, it's been disastrous for the inferior ones. This doesn't bode well for contact of the first kind with an advanced alien civilisation.

2. If you look at our history, it will be apparent that our civilisation is far less violent than it was in the past. I know it doesn't seem that way when you read the tabloids, but it's a fact. In medieval times they didn't think twice about mutilating individuals for all manner of minor crimes. These days we have progressed. This might suggest that an alien species, thousands of years more advanced than us, might have evolved beyond violence. It may well be that in order to survive long enough to develop the technology necessary to travel such immense distances, an alien species would have had to overcome its tribal territorial nature and violent instincts.  
 
 Work out the math, Martin, please
 
 
I'm crap at maths. So the best I can do is refer you to the Drake equation.
 
What is interesting though, is that the estimate above for Earth like worlds is for our galaxy only. Then we have to consider that according to a German supercomputer there could be 500 billion galaxies or more. That's a rough estimate though, we don't know for sure.
 
As for it being unlikely that an alien species could get here due to the immense distances involved. Who knows. Einstein may have told us we can't travel faster than light, but we can cheat. Something like an Alcubierre drive would do it. Similar to a Star Trek warp drive if you like. The space ship doesn't move, space does. Space is compressed in front of the vehicle and stretched behind it.
 
Given that we're only scratching the surface in regard to our understanding of the laws that govern reality, we can't rule out aspects of reality yet to be discovered that enable us to travel such huge distances.
 
Forgot to mention. There is recent research that suggests that the black hole at the centre of our galaxy "might" be a stable traversable worm hole. I kid you not.

[ddavid 149]

Pauli said "... not even wrong" and Feynmann called it "Cargo Culture". Better minds than me, Martin...

Cheers - Dai.

[MartinW 0]

Feynmann called it "Cargo Culture".

I recall it was "cargo cult". If I remember correctly he was referring to mysticism, ghosts the paranormal, reflexology, pseudo science basically. I believe he did refer to UFO's. He was referring to the absence of the scientific method and the nonsense associated with those things.

He wasn't referring to the possibility of technologically advanced civilisations existing elsewhere, and the chances of a percentage of those civilisations having advanced to the level where they can traverse the huge distances we are referring to.

Yes, he was sceptical of the so called UFO cult, because it is based on no solid evidence, but Feynman, the great man that he was, would I'm sure be the first to admit that we lack the knowledge to state with any certainty that a technology that enabled rapid interstellar travel would be impossible. Miguel Alcubierre has demonstrated that it "may" well be feasible.

In addition, as I mentioned, a team of scientists have "suggested" that it's a possibility that at the centre of our galaxy there "may" reside a traversable Morris-Thorne worm hole. Unlike a Einstein-Rosen bridge it would be stable and thus traversable. This is of course controversial, perhaps unlikely to be correct, but it does illustrate that our knowledge is still very limited. There is much to learn, and we may learn that reality is not what we think it is, in fact far more bizarre and offering far more possibilities. One of those possibilities... may enable FTL, or the equivalent! We can't rule it out!

[J G 927]

It strikes me that they have spent a lot of money to find out the bleeding obvious.

 

Space is infinite, so the numbers of stars in that space is infinite.

 

If the number of stars is infinite, and, say, one in a billion billion stars has an earth like planet in it system, then there are an infinite number of such planets.

 

If, say, one in a billion billion such planets can support life, then there are an infinite number of life supporting planets.

 

Do you see where I am going with this?

 

Perhaps we should be asking how far away is the nearest planet that supports life? And more importantly, how fast can they travel? - because if it is faster than us then we are likely to be the enslaved and not the enslavers.

 

 

 

[ddavid 149]

Please, Martin, put me out of my misery and give me one piece of experimentally confirmed data that supports the view that there is, indeed, a traversible worm-hole at the centre of the Milky Way galaxy.

Thanks.

Cheers - Dai.

[hifly 925]

JG. We have been enslaved by aliens already, They have infiltrated governments, bureaucrats, banks, large corporations and "managers". 

[MartinW 0]

Please, Martin, put me out of my misery and give me one piece of experimentally confirmed data that supports the view that there is, indeed, a traversible worm-hole at the centre of the Milky Way galaxy.

Thanks.

Cheers - Dai.

Dai... you didn't read my post properly.

one piece of experimentally confirmed data that supports the view that there is, indeed, a traversible worm-hole at the centre of the Milky Way galaxy.

 

There isn't any. Of course it's not experimentally confirmed. This is a team of scientists that have crunched the numbers, done the maths, and suggested that it's a "possibility". No one has said that this is definitive. No different to the "possibility" that there's a multiverse. M-Theory for example appears to be feasible mathematically, but we have no evidence that it's actually a fact.

 

As I said above...

 

In addition, as I mentioned, a team of scientists have "suggested" that it's a possibility that at the centre of our galaxy there "may" reside a traversable Morris-Thorne worm hole. Unlike a Einstein-Rosen bridge it would be stable and thus traversable. This is of course controversial, perhaps unlikely to be correct, but it does illustrate that our knowledge is still very limited. There is much to learn, and we may learn that reality is not what we think it is, in fact far more bizarre and offering far more possibilities. One of those possibilities... may enable FTL, or the equivalent! We can't rule it out!

 

 

[MartinW 0]

It strikes me that they have spent a lot of money to find out the bleeding obvious.

Space is infinite, so the numbers of stars in that space is infinite.

If the number of stars is infinite, and, say, one in a billion billion stars has an earth like planet in it system, then there are an infinite number of such planets.

If, say, one in a billion billion such planets can support life, then there are an infinite number of life supporting planets.

Do you see where I am going with this?

Perhaps we should be asking how far away is the nearest planet that supports life? And more importantly, how fast can they travel? - because if it is faster than us then we are likely to be the enslaved and not the enslavers.

Well no, not really. Keplar only looked at 0.28% "of the galaxy". Even the estimate once that percentage is expanded, still only covers part of our galaxy. In other words the density of Earth like worlds is high "in our galaxy". In your scenario, an infinite universe with fewer earth like worlds, the density would be lower and fewer earth like like worlds in our galaxy, or Keplars field of view.

Perhaps we should be asking how far away is the nearest planet that supports life? And more importantly, how fast can they travel? - because if it is faster than us then we are likely to be the enslaved and not the enslavers.

We have already addressed that in this thread. And I'm about to eat sweet potato mash. Perhaps we can expand on it tomorrow

[J G 927]

I think I have said all I am going to.... sounds like its getting far to serious for me.

[ddavid 149]

There isn't any. Of course it's not experimentally confirmed.

nuff said, Martin.

Cheers - Dai.

[MartinW 0]

I think I have said all I am going to.... sounds like its getting far to serious for me.

 

Huh, how do you mean "far too serious". It's just a run of the mill discussion. Nothing serious at all.

[MartinW 0]

 

There isn't any. Of course it's not experimentally confirmed.

nuff said, Martin.

Cheers - Dai.

 

 

I'm not sure what your thinking there to be honest. 

 

It's no different to any "possibility". My point was that there are "possibilities", and thus, there may be aspects of reality that render FTL and the Alcubierre drive, or what seem to us at present to be fantastical concepts, feasible.

 

At this very moment the LHC is preparing to fire up at very high energies, one of the things they're looking for is micro wormholes, which would be evidence for other dimensions.

 

And then we have gravity of course, which isn't fully understood. Yep, Einstein is probably right when he tells us it's  warped space-time. However, there are alternative theories. For example we are yet to discover the graviton, that may be because the graviton is actually a gluon. The universe replete with gluons, and the interaction between them responsible for gravity. Some have even suggested that gravity may be all down to entropy.

 

As I said previously, we are just scratching the surface in terms of our understanding, so don't rule out the possibility that a civilisation, somewhere, has indeed developed an FTL [or equivalent] capability.

[Captain Coffee 2,030]

I once heard a theory that passing though the gap between two or more orbiting black holes whose orbits are close enough that their Schwartzsometing fields almost touched...could lead to a navigable wormhole...Because obviously flying into a single black hole can only lead to a SPLAT/SQUISH. If such is the case, somewhere near the core of a galaxy would be as relatively target rich an area to find such a system as one could hope for.

[ddavid 149]

@ Martin - apologies for appearing curt, but I have a short fuse on cosmological hypothesising since reading a book on time travel which involved lining up a number of neutron stars, in a row, and taking advantage of the induced gravitational field. I can just about get my head around electron degeneracy, thanks to Pauli, but neutron (and, possibly, quark) degeneracy leaves me cold. Please continue to post the odd hypothesis - I will try to remain calm...

Cheers - Dai.

[MartinW 0]

I once heard a theory that passing though the gap between two or more orbiting black holes whose orbits are close enough that their Schwartzsometing fields almost touched...could lead to a navigable wormhole...Because obviously flying into a single black hole can only lead to a SPLAT/SQUISH. If such is the case, somewhere near the core of a galaxy would be as relatively target rich an area to find such a system as one could hope for.

 

Not heard that one.

 

But to traverse a wormhole you first need to be able to prop it open, otherwise the instant you pass through it collapses. You need exotic matter, negative energy or matter. 

 

The team I mentioned though, that suggested that there may be a worm hole at the centre of our galaxy, suggest that the dark matter at the centre of our galaxy may sustain it. It's a possible hypothesis though, that's all.

[MartinW 0]

@ Martin - apologies for appearing curt, but I have a short fuse on cosmological hypothesising since reading a book on time travel which involved lining up a number of neutron stars, in a row, and taking advantage of the induced gravitational field. I can just about get my head around electron degeneracy, thanks to Pauli, but neutron (and, possibly, quark) degeneracy leaves me cold. Please continue to post the odd hypothesis - I will try to remain calm...

Cheers - Dai.

 

No problem.

 

A hypothesis is a hypothesis though. Not proven, just a suggested possibility. So we shouldn't get too serious. Just interesting stuff to contemplate.