If aliens in our galaxy are exponentially super advanced, why have they not completely colonized the entire Milky Way by now?

Well, let’s not put the cart before the horse. Right now we don’t know for sure that any life exists anywhere other than Earth. We suppose it does by mathematical calculations, but we haven’t even found a fossil of a microbe from space.

Secondly, suppose there is some super advanced civilization (your use of “exponentially” doesn’t seem to make any sense), the reason they probably haven’t completely colonized the entire Milky Way Galaxy is that for them, as for us, the laws of physics make it pretty much impossible to achieve interstellar travel because of the vast distances involved. And even if they could colonize some surrounding systems by now, it would take light and radio waves 100,000 years to reach us from the other side of the galaxy.

How will space be used for military purposes in the future?

It already is being used for military purposes right now as in spy satellites. Even very recently SpaceX was tasked to launch a U.S. spy satellite into orbit but it exploded and the satellite didn’t make it.

In 1984 a Titan 34D rocket launched the KH-9 and KH-11 satellites for “reconnaissance,” and the DSP-2-6R satellite for missile detection. The list just starts there and goes into the hundreds including many intelligence-gatheringsatellites and so on.

And, by the way, not just by the United States, but other governments as well.

Furthermore, the Chinese government once shot a missile to destroy their own satellite in space just to say the could, and they succeeded, vastly increasing the dangerous debris cloud floating now in orbit. It was a military demonstration.

Spaceships and Hollywood

Spock and Kirk
First officer Spock (left) and Captain Kirk on the Starship Enterprise didn’t float inside their spaceship because of “artificial gravity.”

Spoiler alert – in the future there never will be artificial gravity – astronauts won’t be able to walk around in spaceships.

In the movies most spaceships like the Starship Enterprise employ a convenient technology they call “artificial gravity” to overcome this weightlessness problem. In a few movies they even rotate parts of the ship, though the part of the ship that rotates often has no relevance to the part of the space ship people are walking around in.

No matter. Walking around is a convenient way to avoid a big budget.

Battle-Spaceship - gravity inside will not exist
This battle-spaceship shows not even an attempt to justify how people inside seem to have no problem walking around.

Weightlessness is a pesky little problem and we’ve become comfortable accepting that on spaceships of the future you’ll be solidly on the floor. Venture outside to fix anything and you’ll be weightless maybe (unless you use something they call “gravity boots”) but inside, put something on a table and it stays on the table. People won’t be weightless in spaceships in the future.

That’s why they call this stuff science fiction. There won’t be any artificial gravity and to the dismay of Kirk and Spock a spaceship that looks like their’s will have weightless people inside.

Von Braun Spacewheel
The Von Braun Spacewheel is the only design occupants could have “artificial gravity” via centripetal acceleration.

Another design, a real design, for a spaceship that would actually have “artificial gravity” is called the Von Braun spacewheel, and envisioned in movies wanting more realism. The Von Braun spacewheel looks like this contraption. Of course, it spins and as it does the occupants inside experience centripetal acceleration, also sometimes known as artificial gravity.

So why doesn’t NASA build one of these?

Well, along comes the real world, pushing Hollywood right outta there.

  1. They don’t have the lifting power to get all the parts up there. It’s doubtful the Falcon-heavy will be utilized for such a project.
  2. Assembly and then pressuring it inside are formidable obstacles. This is not impossible, but beyond available budgets.
  3. Zero gravity laboratories, like the present International Space Station have taught us that research in microgravity environments is valuable.
  4. With exercise, astronauts do just fine, so why bother?

Alas, we may send people to Mars one day, but those poor ol’ chaps will be weightless all the way, and exercise like they do on the ISS.

Why do scientists think there might be life on earth like planets when aliens might survive hot temperatures with no water?

Good point. Great question. We just look for the most “likely” places life might develop. Interestingly, though, there are lifeforms like the ones you describe here on Planet Earth!

You can find these lifeforms in Chile, specifically the Atacama desert. This place is burning hot and has had no significant rainfall in at least 250 years.

According to express.co.uk “While in the central valleys [of the Atacama desert], researchers found 70 species of microorganisms and further inland, the team made another shocking discovery.” What they found, 1 meter deep, was actual living bacteria.

Life does exist in extreme conditions sometimes on Earth. Why not elsewhere, like Mars for instance?

So far, however, we haven’t found any life or former evidence of life, anywhere except here on Earth.

It leads us to believe that if life is out there somewhere, the most likely place to find it would be in conditions that are similar to various climates and places on Earth.

Is it possible for a planet, such as Mars, to develop a liveable atmosphere on its own? What would it take?

If you placed a 100 kg steel ball on the surface of Jupiter, how deep would it descend until it vaporizes?

Let’s turn this around and look at the one place on Earth we know has more pressure than anywhere else: Challenger Deep, the deepest part of the Mariana Trench. It’s almost 7 miles down. If you drop a 100 kg steel ball down into the ocean there, that ball will not vaporize. It might, however, get smaller.

The same would happen to the steel ball on Jupiter. It’s thought that somewhere down there inside Jupiter the gravity is so intense that gas forms a solid core, and the pressures are much greater than at Challenger Deep. So your steel ball might get crunched down, but never vaporized.