Category: The Universe

Shouldn't we be looking for life on planets that formed over 10 billion years ago as they've had more time for life to form?

Planets that formed over 10 billion years ago are about 5 billion light years from us, meaning that if we could somehow study planets that far away (we can’t) the light reaching us from there would have taken 5 billion years to reach us. Therefore, we’d be seeing what the planet looked like 5 billion years ago, not what it looks like now. Below is what we are able to see of the most distant galaxy that we have seen to date. It’s about 13 billion light years and we are just seeing the early stages of development because it took light 13 billion years to reach us.

As you can see from the image, Hubble can barely make out the galaxy, what to speak of any planets that might be orbiting the billions of stars inside that galaxy. The best we can do is study planets in our vicinity of the Milky Way.

What's the use of the universe if Earth is the only habitable planet?

First, we don’t know Earth is the only habitable planet. However, until we have some proof, we have no way of knowing for sure. That’s why we’re searching so hard for extraterrestrial organisms.
Second, who says the universe has to have a use? It just is. Similarly, you could say what’s the use of living if you die in the end. That kind of view doesn’t do anyone any good. Just go with it and enjoy the exploration and discovery life offers us, like whether or not life exists elsewhere in the Universe.

How can we believe in God, but not in alien/extraterrestrial life or vice versa? This seems like a paradox to me.

I don’t see either as being dependent on the other. In other words, you can believe in God and not in extraterrestrial life. Many religious people do in fact hold that view. On the other hand, you can believe in extraterrestrial life and not believe in God. I know many people who hold that view.

So I don’t see a paradox at all. According to the Google dictionary, a paradox is “a seemingly absurd or self-contradictory statement or proposition that when investigated or explained may prove to be well founded or true.” I fail to see a contradiction that two different people can hold either view. It’s all theory.

In reality, we do not know for sure that life exists anywhere other than Earth because we have never found any evidence of life, although we continue the search. We have yet to find even a fossil of a microbe from space. However, the laws of mathematical probability suggest that with billions of planets in this galaxy and billions of other galaxies, it is likely that there is at least microbial life somewhere, if not something more advanced. We just haven’t the proof yet.

Similarly, except for subjective experiences, there is no proof that God exists either, although people believe that God exists. Maybe both exist. Maybe neither exists. I suppose it’s a question of faith in either view.

Using our current technology, how close to us would an alien spacecraft have to be before it could detect Life on Earth?

During Earth’s night you can see the lights of major cities from the moon. So this would imply that further out from the moon one could detect light. Then there are the radio and television waves. They go out infinitely into space, but they become four times weaker every time the distance doubles. In any case, we pick up radio signals from Voyager I and II even though they have left the solar system, so I would suppose people could pick up our radio signals quite far away.

Why is there a stigma around attempting to discover extraterrestrial life?

There is no stigma. All of science is dedicated to discover extraterrestrial life. We would be completely excited to find even a fossil of a microbe from space because it would be the ultimate affirmation that life can evolve from matter on another world other than Earth. Our best hope at present is to find some kind of life on one of the moons of Jupiter or Saturn, or perhaps some fossils on Mars as of yet undiscovered. We are even spending billions of dollars with the SETI program to listen for radio waves from space!

However, much to the surprise and dismay of scientists, we have yet to discover anything at all.

Perhaps human race's home was not Earth in the first place, but in another planet, and we came here to prevent extinction

Mechanical, intentional interstellar travel is unlikely since the distances are far too great to imagine. The best anyone could achieve is interplanetary travel within one’s own solar system. Therefore, if we pass the buck and say life didn’t start here but started somewhere else and arrived here, it would have had to arrive on a rock or asteroid as a microbe and somehow survive a fiery entry through Earth’s atmosphere and it would have had to survive the vacuum and temperature extremes of space. If the rock came from outside the solar system it would have had to survive a long, long time.

How did life on Earth first get formed?

We don’t know. Some people think we know, but a real scientist will agree with my first sentence.
The theory, still unproven, is that life evolves from dead matter. We’re still searching for life on other planets to prove this wet-dream of scientists, but still we have no proof of concept – just a concept – to the chagrin of science. We are frankly disappointed we haven’t found life elsewhere than Earth.
Evolution starts with creation of stars that create elements like the ones we have on Earth. We think when conditions are right that the chemicals develop amino acids (this is proven), which are the basic building blocks of life.
From there, eventually by combination and permutation it develops into something that could be called life.
Again it’s not proven but widely accepted. We don’t know for sure, hence my first sentence.