Is it posible to do an equation to know if the extraterrestrials

No.

>>18816829
no to first question or to the second question?

>>18816819
Ecuation? Based on probability of life in universe it's very certain. But it's easy to be UFO nutcase and see them everywhere, that's bullshit...

Thinking about how old earth is and how humans have existed only a small small percentage of time of earth actual lifespan I believe they have probably visited before humans existed.

There's probably lot of buried evidence but too bad internet is cluttered with bullshit and lies so much to a point finding credible evidence strictly from online research is bit hard or something.

1+1=yes

File: Maybe+if+i+keep+watching+_7af6b68a2f3e501c562cc98eb1242ae7.jpg (9KB, 200x200px) Image search: [Google]

9KB, 200x200px

>>18816855

Only if they hail from our cosmic neighborhood and their civillization is billion years ahead of us. Otherwise chances are virtual zero.

>>18816894
I'm from Sirius.

>>18816819

No and yes.

There are too many unknown variables to make that prediction with any kind of certainty.
We can do PARTS of the equation, and make some interesting observations at least.

First, some traits will be true for all forms of advanced life. Terrestrial or otherwise.
It'll have a way of multiplying, because in order to reach the insanely complex composition capable of intelligent thinking and building spaceships it must evolve and improve over time.
Since it evolves, it will diversify and seek out different ecological niches (different species).
Since there are different species, there will be a competition for resources. Threats like starvation, environmental threats and likely predation will lead to reasonably fast multiplication cycles.
Population growth is not a limiting factor.

Second, the lifeform will want to spread out into space.
Us humans could, reasonably, with near-future technology traverse the 10 light-years to a nearby star in just 90 years with a colony ship.
The ship can then build a copy of itself and set up a colony in 10 years, using raw resources from asteroids, comets and planets.
One hundred years after leaving Earth, two ships can depart the new star system, leaving behind a self-sustaining colony.
In two hundred years, you have 4 ships. three hundred years, you have 8 ships, and so on.
Due to the exponential growth of a population, after the first interstellar colony ship is launched, it'll take 30 000 years to have as many ships as there are stars in the milky way, and less than 1 million years to cross to the other side of the galaxy, colonizing every single suitable system many times over.
Even if these numbers are off by some orders of magnitude, we're still talking 300 000 years to flood the galaxy with ships and just 10 million years to reach the other side with slow space travel.
Technology is not a limiting factor.

>>18817492

Thirdly, time.
Our sun is 4600 million years old, life is about 3700 million years old, modern humans have been around for 0.2 million years, and have had something resembling a civilization for 0.01 million years.
Even if a race takes several times longer than us to reach the spacefaring age, once they're intelligent enough to have a culture it'll happen in less than million years.
And because life formed so quickly on Earth, in just a few short hundred million years, it could happen around a young star with a suitable planet almost anywhere.
Time is not a limiting factor.

So, with numbers like these, there are two statistically important outcomes:
>Aliums are everywhere, in every system, and their hydrogen trails and megastructures litter the cosmos. They've had a headstart measured in millions or billions of years.
This is obviously not the case, or we'd have spotted them or their vast sea of relics ages ago with our telescopes and sensors.
>The one factor we can't account for. Probability of advanced life. It's possible intelligent life is exceedingly rare, and we're the first species who will colonize the galaxy.
Once the next species do evolve in 1 000 million years from now, we'll be the one to contact them, or they'll spot our relics with their early telescopes. Until that, we're all alone. Just us, and maybe some goo-ball worlds with primitive life like our own was for so many million years.

The probability that we'd have run into life just a few thousand or millions of years more advanced than us anytime in our short, short existence as a culture is microscopically small.