What are the odds of life developing on a planet?
That actually isn't the big question, but, people imagine it is. The big question is, what is the probability of two intelligent, technologically astute, civilizations interacting?
Let's suppose the timeline of life on Earth is typical with a standard deviation of a million years. Earth is 6 billion years old. Life, 3.8 billion. Humans 6 million. Modern, technologically, nuclear, humans, 70 years, so far.
Let's suppose our species lives 5,000 years in a state of technological advancement during which we can recognize extra terrestrial, intelligent, life.
Anyone familiar with statistics can see where I am going.
There isn't any guarantee human advanced civilization will last 5,000 years. It could last 100,000 or 1,000.
A standard deviation of a million, 0.1%, sounds reasonable when discussing the development of life.
Unless humans and at least one other species exist as a technologically advanced species for one standard deviation on the "life timeline" the odds of humans and another species being able to interact socially are minimal.
Then there is the distance issue, which I addressed in my blog entry discussing the infinite monkey theory. Let's assume 1/10 solar systems have a planet capable of supporting intelligent life. Let's assume an average distance between planets of ten light years. A range those ten solar systems in a spherical distribution around Earth. Let's assume a fifty/fifty chance of intelligent life. We need to travel 20 light years to find a planet with intelligent life, and there is a 1/200 chance, based on our stdev of 1M and 5k civilization span, that we find a concurrent intelligent species so we need to travel 4,000 light years.
Let's suppose parallel universes are governed with the same assumptions, 1M stdev, we will assume 20K of civilization, 5K intelligent civilization, 50/50 life develops at all.
1M/20K = 1 in 50 universes with concurrent civilization. 1 in 200 with advanced technology. Double that cause of the 50/50. We would explore 400 universes to find one similar to ours.
There are "infinite" universes so there could be one where things are almost identical to this one, but, then we run into the same scale of odds that we had with infinite monkeys banging on an infinite number of 101 key keyboards producing all of Shakespeare's plays, which are an average of about 80,000 characters. 1/keys*1/characters.
Sliders, alternate universes, etc. All crap.
In addition, if you tried to travel to an alternate universe you would have to travel to where the planet in the alternate universe would be, not where it is.
Let's suppose the solar system is moving just 100,000 miles an hour. It moves faster, Google how fast you are moving when you are standing still.
Okay, suppose it takes 1 second to travel to a different universe. You are now 30 miles (more like over 150 miles, but we agreed only 100Kmph ) from where you started. Not thirty miles on the ground. Thirty miles along a tangential line drawn from where you started before the Earth turned under you, spun along the axis of the solar system and the galaxy and the universe, which is expanding. You are falling like a rock towards the planet, exactly like a skydiver without a chute.
Toward a planet where you have about a 1 in 400 chance of finding technologically developed civilization.
Okay, so you do your work. You invent a craft capable of traveling at the speed of the Earth moving through the universe, which is wicked faster than you probably believe and way faster than people have traveled so far. You plug this supper engine on a shuttle capable of landing and taking off from a planet and figure out a way to jump between universes.
Our space ship, which unlike the ship in Interstellar does not need a rocket to escape Earth's gravity, and like the space ship in Interstellar can land and take off other planets without a rocket. The Interstellar ship only needs a rocket to escape Earth gravity because it's fictional. We have a "real" fictional ship that doesn't need a rocket to leave any planet.
We have to play catch up with the alternate planet which was traveling past us, if we are smart enough to avoid getting t-boned by another planet or the sun. We wave to travel several million miles "up", away from the plane of the Earth's orbit just to avoid the sun, which is coming at us like a bullet train, and it's gravitational pull.
Yes, our velocity and direction of motion remains the same
Imagine even microscopic variations in velocity or direction of motion between alternate universes that have had billions of years to magnify.
So, travel to alternative universes is out until we can predict planetary motion in alternative universes and we have craft capable of velocities that allow us to correct for the travel time differentials between universes. Once we do that...We have to deal with our odds, as explained earlier.
This is wicked complex and most people have no clue how complex this really is because fiction makes it seem as if it is nothing.
Just dealing with travel to other planets is, literally, dealing with astronomical odds, even if we try alternative universes.