I got 7569 in the galaxy.
Here's what I love, about thinking about this (and it's not my idea, but I don't know where it comes from originally) : Either we are utterly alone in the Universe, and Earth is the only place Life has arisen;
Or, there is (or was) Life elsewhere. Both are mind-blowingly awesome ideas - and we know that one of them is true.
We are the only life in the universe its our duty to populate it we are the beginning or all life. To get the same conditions on another planet exactly like Earth is impossible even though the universe is infinite you cannot assume the qualities of space or the laws of the universe are constant. If you draw a mathematical universe based solely on the observations of our own known universe its impossible to measure any difference in such a small area. The Earth is unique! I also would love my idea / theory to be proven wrong.
If there were ever to be alien contact on earth it would probably be by machines.
That is the assumption that we are working under, however; and so far, every thing we see seems to be composed of the same elements, which does suggest the same physics and chemistry. IMHO it would be difficult to find a planet exactly like Earth, but I think it is extremely likely there are many very similar. Even if there is a 0.000000001% chance per star of having an Earth-like planet, there would still be about 10,000,000,000,000 of them in the observable universe. Also, we only have an example of life on our planet, it could actually be more likely on other types of planets. Probably no more likely, but even if it can happen on other planets, that only increases the odds.you cannot assume the qualities of space or the laws of the universe are constant.
when you say Earth like at what stage of earth's development are they talking about when they look for the signs of life? does this 0.000000001% chance account for the process earth has been through? or an assumption of the state of a current planet being similar to ours?
The idea about extraterrestrial life that excites me most is that, if it exists, and considering that we have imagined so many hypothetical forms it could take, there's a still a good chance that it would be manifested in a way that is beyond our collective wildest dreams.
There's not a chance there is a certainty. Imagine how weird it would be if we found extra-terrestrial life and it was exactly how we imagined.
I think the drake equation is too Anthropocentric it assumes what I think are strange things. Life has to be based on liquid water, radio is somehow obvious and inevitable.
My bet is that there is a much better way to chat between stars than EM, which drops off as the inverse square of the distance, and travels at c. It's terribly inefficient. We might outgrow radio in 50 years, and thereafter consider our SETI radio efforts as quaint.
I was just watching the great Neil deGrasse Tyson talking about that. The most common elements in the universe are, from most common going down: hydrogen, helium, oxygen and carbon. So if water is just two atoms of hydrogen and one of oxygen, it might not be all that unlikely and maybe even the rule. Anyway, it looks like the best bet. https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elem...
I think even the great Tyson may be thinking like a human on this one. To think that life has to be chemical is also Anthropocentric. The requirements are complex systems that can ratchet and allow emergence. The number of those is measurable.
I was not thinking quite as exotic but I like where you are coming from. Physics:
Mechanical processes weather, erosion have emergent properties.
gravity is not impossible N object systems where N>2 tend to be chaotic and thus have a possibility of emergence and ratcheting. The universe is chock full of chaotic and emergent systems really it is harder to find one that is not. If a system has the properties of variation and selection than it can produce life.