Mathematical nonsense. 
There are hundreds of billions of stars in this galaxy alone, with hundreds of billions of galaxies.
Each star has multiple planets.
Eventually, we will find some that support our life.
Chemical nonsense. There are hundreds of billions of stars in this galaxy alone, with hundreds of billions of galaxies.
Each star has multiple planets.
Eventually, we will find some that support our life.
You won't find an oxygen atmosphere on a planet by chance; oxygen is far too reactive to exist naturally in a free state. You know why water's the most common compound in the universe? Because hydrogen is the most common element, so whenever there's oxygen around - BOOM! Oxygen also reacts with carbon to form carbon oxides, silicon to form rock, and metals to form rust: all of which can be found in varying levels of abundance on other planets, but no free oxygen.
The only reason Earth has oxygen in its atmosphere is because algae and plants are constantly producing it as a waste product, and the only way another planet can have oxygen is if it already has life like ours, which may be inconvenient for colonists.
Good point. But the real issue is that at the moment there is not even the slightest scientific clue that a long distant space travel may ever be possible. Sleeping during long trips is just a science fiction trick, no concrete reason it will ever be possible. At the moment we can't even be sure to be able to ship human safely beyond the Van Allen belts, BTW.
Our technology is really making a fast change and innovating our lives at a much faster rate but we don't have enough resources, pieces of knowledge, and facts about another planet we can't even find the truth about the first expedition on the moon by Neil Armstrong. There's many theories and hoax about the landing on the moon what more if we can find a way to get to Mars.