Blog from my website on the probability of alien contact. So near yet so far.

http://claytongraham.com.au/alien-civilisations-contact-probability/

ALIEN CIVILISATIONS – CONTACT PROBABILITY
Contact probability between Earth and other civilisations in the universe occupies some of the greatest minds on our planet. It’s only when you start looking at the mathematical chances that it all makes sense. A new study suggests that other planets throughout the universe probably hosted intelligent life long before Earth did. Adam Frank, a professor of physics and astronomy at the University of Rochester in New York says, “You’d be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet was, say, one in a trillion. But even that guess — one chance in a trillion — implies that what has happened here on Earth with humanity has in fact happened about 10 billion other times over cosmic history.” Such is the magnitude of the numbers.

THE MATHEMATICS
In 1961, astronomer Frank Drake devised a formula to estimate the number of extraterrestrial civilizations that may exist today in the Milky Way. Here is a link for those into the more severe mathematics: DRAKE EQUATION http://www.space.com/25219-drake-equation.html
You notice the use of the expression ‘cosmic history’ in the initial paragraph. That is is key expression. For cosmic history, of course, is vast in the dimensions it traverses. Adam Frank and co-author, Woodruff Sullivan of the University of Washington, were interested in the odds that intelligent aliens have ever existed anywhere in the universe. So they tweaked the Frank Drake equation, coming up with an “archaeological version” that doesn’t take into account how long alien civilizations may last. They also incorporated observations from NASA’s Kepler space telescope and other instruments, which suggest that about 20 percent of all stars host planets in the life-friendly, “habitable zone,” where liquid water could exist on a world’s surface.

HAS IT HAPPENED BEFORE?
“The question is, ‘Has it ever happened anywhere before?'” Frank said. “Our result is the first time anyone has been able to set any empirical answer for that question, and it is astonishingly likely that we are not the only time and place that an advanced civilization has evolved.” But this doesn’t mean that there are lots of intelligent aliens out there, just waiting to be contacted, the researchers stressed. Try this link: ALIEN CIVILISATIONS http://www.space.com/31662-alien-civilizations-when-make-contact.html
“The universe is more than 13 billion years old,” Sullivan goes on to say. “That means that even if there have been 1,000 civilizations in our own galaxy, if they live only as long as we have been around — roughly 10,000 years — then all of them are likely already extinct. And others won’t evolve until we are long gone. For us to have much chance of success in finding another ‘contemporary’ active technological civilization, on average they must last much longer than our present lifetime.”

TIMING AND LINKING
So I guess it’s all a matter of timing; our relatively small time span to date compared to the vastness of ‘everywhere else’. But wait – our concept of time may not be all what it’s cracked up to be. The facts are that alien civilisations, past, present and future are extremely likely, given our current abilities in the mathematics of probability. But are they existent in OUR TIME – that is the leading question.

Somewhere along the line someone has to show that the probability of human and alien civilisations ‘overlapping’ in our current concept of time is possible. Who would have thought that the mathematics of probability we all struggled through at school would be the key to alien contact?

Here’s another link which explains things in a reasonable manner: WHAT ARE THE REAL CHANCES? https://qz.com/704687/there-have-probably-been-trillions-of-alien-civilizations-and-yet-we-may-still-never-see-one/