Why We Don’t Know About Life In Outer Space (infographic)

This infographic does not tell enough of the story.

Why we are almost certainly not alone in the universe: number of potential planets.
Our Milky Way galaxy has approximately 100 billion star systems. Each may contain any number of planets from zero to hundreds.
There are much larger galaxies, with the largest yet discovered, IC1101, having an estimated 100 trillion stars.
It is believed there may be 2 trillion or more galaxies in the universe.
Do the math.

Why we will almost certainly never come into contact with an alien species: distance and time (which are actually part of the same fabric).
Imagine an alien race on the far side of our galaxy, say 70,000 light-years away from earth.
Were we to send a signal out in their general direction, it would take 70,000 years to reach them, and another 70,000 for their signal to reach us, and we would have to be listening carefully for it.

Now, if there were no alien civilization within our galaxy, but elsewhere in the universe, you're talking about millions, even billions of years to send signals - each way.

We have only had this ability to transmit radio signals for just over 100 years. Now, consider that we humans will most likely destroy ourselves within the next few thousand years. It's in our nature - we will never stop killing one another.
Is it possible in such an incredibly brief time that we could make contact? Yes.
Is it probable? Unlikely in the extreme.

you are quite right (except for a few details, which could be discussed) :) it is nice to know there is somebody using the squishy part between ears :)

but this cannot be explained to 90-95% of population - for example the part, that first radio signal EVER that maybe COULD left earth COULD be just 120 light years away theoretically (distance like be on a doormat or at a garden gate - in the terms of galaxy, not mentioning the universe)
that there are serious issues receiving signal from special antenna carefully aligned towards our planet - at the distance 30 light minutes away
people cannot accept that radio/light signals are not easy to receive on a long distance - and the same people are having issues with their wifi 5 meters far away

it is a waste of time trying to explain something to most of them
some "mysteries" are over their minds forever (and if they "get it" a bit, they forget the very next day)

p.s. this infographic is not so good anyway, although it contains some relevant informations

kuban,

I'm waxing Mr. Spock of Star Trek: "Fascinating." You make a good point. I did not think about signal strength, and would have not attempted to explain it had I done so.

I'm always up for discussion, and you're probably right about me getting some details wrong.

Your reply coaxed me to bring up another point; trying to point the hypothetical signal at a moving object such as a planet would present myriad difficulties. If I'm not mistaken, you would have to time your broadcast so that it arrives at the intended destination planet within the width, breadth, and beam of your signal. With this in mind, it seems you would have to know the planet's velocity, distance, and orbital trajectory before transmitting. I can't even imagine the amount of calculation it would take to factor all the variables.

Then, throwing many more potential hiccups into the bargain, you'd need to consider their star system's path around the galaxy, and the paths of potentially billions of large objects that could intersect the signal and cause distortion or block it altogether

Even infinitesimally small variations would under such circumstances create errors so great as to make direct contact extremely problematic, if not impossible, given our current technology.

All this is way over my head anyway. Cheers for adding food-for-thought to the table. :)