Sci Fi TV science or fiction?

Chances are any sentient alien life form would neither be bipedal nor human-like in form. They might share some characteristics with humans, such as the ratio of their mass against the host planet mass, but probably not much more than that.

Equality 7-2521 wrote: Space is certainly isotropic so they would face the same physical hurdles that we do even if their engineering difficulties are different. In my opinion, Aliens have certainly not visited Earth in the past and are not likely to do so in the small-scale future. I'm not an expert on evolution nor abiogenesis.  The question you ask would be best answered by someone who is or is close to being. The reasons for bipedalism are unclear. It developed in humanoids before the large scale growth of our brains, but it's not clear that it was a necessary precursor (nor am I saying in any case that there's one way to grow a brain which would be ridiculous). Many of the reasons theorized are very local reasons applicable to where humanoids where developing on Earth (to limit sun exposure or increase vision in a vertically growing landscape etc). In my very uniformed opinion, I wouldn't expect it to be associated with intelligence. And I certainly wouldn't expect intelligent life to human-like in appearance as a whole.

I concur with the first part.  I do not believe any life-form from other planets has visited Earth.  The chances of life on habitable planets is likely small anyway but even if there is life (however advanced) on far distant planets, they would, as said, have the same issues regarding physics as we have and I feel it is unlikely any other life-forms are likely to have advanced enough to develop the necessary technology.  It's obviously not absolutely impossible reasoning they may have but that would depend on their evolution.

I did see an article recently positing the idea that life on earth would not have been possible without life originally existing on Mars.

http://www.bbc.co.uk/news/science-environment-23872765

Is this credible?

Edited by VanderGraafKommandöh - November 24 2013 at 09:20

Equality 7-2521 wrote:   Is there really a debate?

VanderGraafKommandöh wrote:   I did see an article recently positing the idea that life on earth would not have been possible without life originally existing on Mars. http://www.bbc.co.uk/news/science-environment-23872765 Is this credible?

Thank you guys for the help understanding.  I'll try to clarify, I was not asking about any matter, but rather a fixed coordinate in space, an exact location represented by an imaginary dot/point.  So let's say your backyard represents a huge section of vast open space, and at the top of your fencepost we have our fixed location point.  I was asking if that point in open empty space was still floating there prior to being reached by the bang.  If I understand, the bang dispersed matter and changed the local environment of the point when it got there, but it doesn't actually create the existence of the point's locale.  So if the big bang went off in the middle of your backyard, it expands outward and eventually envelops the coordinate location at the top of the fence post....and then keeps going beyond it to your neighbors yards.  But we can say with certainty that the fencepost (fixed point) did exist prior to the bang's wave reaching it?  And we can say that the distance between two coordinate location points (two of your fence posts) is the same despite the changed environment and new matter created by the bang coming through?

One analogy I read likened it all to an expanding balloon.  As the balloon gets bigger, the printed designs on the balloon also stretch and get bigger, and farther apart.  But I was trying to grasp that a point/coordinate outside the balloon has always been there, even before the balloon expanded to it's location and then beyond.

Sorry to be unclear, the last science class I had was in HS and I wasn't paying attention even then.     I was much more interested in Physical Graffiti than space at that moment. 

VanderGraafKommandöh wrote: Dean, I noticed a post from you earlier in this thread regarding the Moon landings and I wasn't sure if you were being serious or not.  Are you suggesting we never went to the Moon or that we have and there's no real point of going back there and that's why we're focusing on Mars instead?  Or indeed, was it just an amusing remark?

You're going to have to refresh my memory because I don't recall making such a post.

Finnforest wrote: Thank you guys for the help understanding.  I'll try to clarify, I was not asking about any matter, but rather a fixed coordinate in space, an exact location represented by an imaginary dot/point.  So let's say your backyard represents a huge section of vast open space, and at the top of your fencepost we have our fixed location point.  I was asking if that point in open empty space was still floating there prior to being reached by the bang.  If I understand, the bang dispersed matter and changed the local environment of the point when it got there, but it doesn't actually create the existence of the point's locale.  So if the big bang went off in the middle of your backyard, it expands outward and eventually envelops the coordinate location at the top of the fence post....and then keeps going beyond it to your neighbors yards.  But we can say with certainty that the fencepost (fixed point) did exist prior to the bang's wave reaching it?  And we can say that the distance between two coordinate location points (two of your fence posts) is the same despite the changed environment and new matter created by the bang coming through? One analogy I read likened it all to an expanding balloon.  As the balloon gets bigger, the printed designs on the balloon also stretch and get bigger, and farther apart.  But I was trying to grasp that a point/coordinate outside the balloon has always been there, even before the balloon expanded to it's location and then beyond. Sorry to be unclear, the last science class I had was in HS and I wasn't paying attention even then.     I was much more interested in Physical Graffiti than space at that moment.

The balloon analogy is really nice but referencing two points on the surface is essentially two dimensional (I said my earlier example was one-dimensional) and the Universe is three dimensional so not only are two points on the surface of the balloon getting further apart, but two points anywhere within the balloon are also getting further apart.

Gerinski wrote: Equality 7-2521 wrote:   Is there really a debate?  That's what I get from what I read but sure I might be wrong. What do you think, do 'new space' ('new miles') get created as the universe expands, or do 'the existing miles just get bigger'?

These things are not defined very well. As I said, they are really just us trying to interpret the physics in the framework of the universe as we usually think it. I can explain very clearly how we have an intrinsic metrical change which comes very naturally from integrating on manifolds with the curvature that ours has at large scales.

Dean wrote: Finnforest wrote: Thank you guys for the help understanding.  I'll try to clarify, I was not asking about any matter, but rather a fixed coordinate in space, an exact location represented by an imaginary dot/point.  So let's say your backyard represents a huge section of vast open space, and at the top of your fencepost we have our fixed location point.  I was asking if that point in open empty space was still floating there prior to being reached by the bang.  If I understand, the bang dispersed matter and changed the local environment of the point when it got there, but it doesn't actually create the existence of the point's locale.  So if the big bang went off in the middle of your backyard, it expands outward and eventually envelops the coordinate location at the top of the fence post....and then keeps going beyond it to your neighbors yards.  But we can say with certainty that the fencepost (fixed point) did exist prior to the bang's wave reaching it?  And we can say that the distance between two coordinate location points (two of your fence posts) is the same despite the changed environment and new matter created by the bang coming through? One analogy I read likened it all to an expanding balloon.  As the balloon gets bigger, the printed designs on the balloon also stretch and get bigger, and farther apart.  But I was trying to grasp that a point/coordinate outside the balloon has always been there, even before the balloon expanded to it's location and then beyond. Sorry to be unclear, the last science class I had was in HS and I wasn't paying attention even then.     I was much more interested in Physical Graffiti than space at that moment.   The balloon analogy is really nice but referencing two points on the surface is essentially two dimensional (I said my earlier example was one-dimensional) and the Universe is three dimensional so not only are two points on the surface of the balloon getting further apart, but two points anywhere within the balloon are also getting further apart.   The problem with the balloon analogy is air. For the balloon to exist that has to be air on the inside, and there also has to be air on the outside maintaining the pressure equilibrium of the inflated rubber sack - when the balloon expands we add more air to the interior and the balloon expands into the air around it until a new pressure equilibrium is reached.   The Universe is not a balloon and it doesn't work like that, there is no rubber membrane at the edge of the Universe holding it all together, inside the Universe there is space and matter but outside the Universe there is no "space", there is no "open empty space", there is nothing to expand into so it expands into nothing. The Universe is all there is, there is nothing outside the Universe, not even "space". Here I am really saying that "space" is different to "nothing".

I don't think the balloon is a bad metaphor. You just look at the surface of the balloon and forget that surrounding or enclosed space exists. It's meant to explain the way something expands not why, or where.

So prior to the big bang there was no infinite space?