Do you think we are alone in the Milky Way?

originally posted by: scrounger
The first thing that should be easy to answer is can we travel vast distances in a reasonable amount of time.

the answer now is YES. Our own science has now advanced that it isnt science fiction, but rational science theory of FTL travel.
we now can quantify and attempt to achieve things like space folding, worm holes, ect where that wasnt even theoretical before.

Scrounger

That is possibly the most outrageous abuse of optimism I’ve seen in a while!

Firstly, what is your ‘before’ and ‘now’ scale or timeframe? Some of the base FTL theories have been around for decades. Secondly, all of these theories, old and new, make HUGE leaps of faith on bending, distorting or abandoning current scientific laws. I remember reading about ten years ago that it would take more energy currently in the universe to create a wormhole large enough to transport just one photon. Has that estimation changed recently?

You make FTL sound like current technology, but it’s much more factual that it will remain science fiction.

originally posted by: alfa015
So.. recent estimations for the Drake Equation (Maccone, 2012) suggest that there could be around 4,600 civilizations in our galaxy that are able to release detectable signals.

I find this number a little bit excessive, so I plugged some of the values of our Solar System into the equation and I obtained a smaller yet more realistic result, in my opinion: 50 civilizations.

Just in case someone is interested, I made a video showing the values I used: youtu.be/j2AIWIcn7Ig

Do you think 50 is a more realistic number?

The correct values are 1 per 10 galaxies not 50/galaxy. By 'are we alone?' I assume you mean human-like or human-acceptable sentient beings with the ability to receive radios signals.

Evolution does not, unfortunately, favor intelligence (which requires high calorie support of neural tissue/brains) it favors size and aggression (survival).

Since we can only communicate with the gravitationally-locked systems (the Local Group) there are about 5 sentient civilizations that were ever available, and most of those are not going to share our current time.

originally posted by: alfa015
Do you think 50 is a more realistic number?

No. With all the filters, with all the insanely improbable things that happened that brought our humble little species to the point we are today, I'm thinking that if we're not unique then we're extremely rare. My gut feeling is that there are no other technologically advanced civilizations in the Milky Way. (If you want to call us "technologically advanced." We don't even have interstellar flight.) And at this point in time there are maybe a half dozen such civilizations in the entire universe, and they are all so far away in both space and time that we'll never, ever interact with them.

Our universe is young, though, so maybe more will rise up later. But at the moment. No.

Thing is it isn't just the vast distances involved it's the time involved the chances of intelligent life living at the same time and meeting each other I feel is very rare. We may meet just long dead civilizations if we ever get to the stars.
We may be that long dead civilization tbh soon enough.

I'm going to reiterate what the last three posters mentioned in that there may not be a lot of technological civilizations in the galaxy exist right now, and that could be why we're not noticing them.

Sure, the galaxy has billions of stars that might be potential places for a technological civilization to arise, but the time frame "window" during which a suitable technological civilization might arise, thrive then die out on those planets exists over a span of 100s of million -- and billions -- of years. And that time span "window" during which a civilization exists is likely short --- maybe only a few million years at best.

So in the 4 billion years that life on Earth existed, there might have been many thousands of other civilizations to rose up and died out long before homo sapiens existed -- heck, even before animal life existed on Earth (which is a relatively recent thing, maybe 800 or 900 million years)

And then there might be many thousands more civilizations in our galaxy that will rise then die out again in the few billion years life has left on Earth -- and after our civilization has died out, with maybe no intelligent life left on our planet.


So, yeah -- The billions of stars in the galaxy right now a lot of places for a civilization, but those places exist for billions of years during which they might only have small windows of time that civilizations arise.

a reply to: alfa015

All you have to do is look at the sky to figure that out...and watch a couple of good alien docs.