Question will we ever be able to go in a different galaxy?

[Atlan0001]

Absolutely NOT. 2 reasons. First is speed. c will only allow us travel in our solar system. For star travel we need 100 to1000 times c. Even for generational travel.

And 2, most important.......which way do we go? What is your course? We only know where a galaxy was, we don't know where it is now, and we don't know where it will be when we arrive.

So no, no star travel for us.

How fast are you traveling in the space of the universe sitting at rest where you are sitting (infinite '0' float gravity) relative to the '300,000kps speed of light constant ('c') to it?!

 

[billslugg]

I've run the numbers on interstellar travel within a human lifetime and it boils down to this: You would need the most energetic fuel there is - antimatter, and about half the original mass of the ship would need to be made of it.
Figure you might get away with only 100 tons of antimatter and then consider that all our efforts using accelerators over the last 100 years have produced but a few nanograms. At this rate we will need 10^16 years. This is 4 million times the age of the universe.
If, instead, we covered the entire surface of the Earth with solar cells and used that elecricity (2e16 watts) to make antimatter, at a 1e-9 efficiency, at 9e16 joule/kg, we could make a kg of antimatter in about 142 years. A hundred tons would take 140 million years.
If we harnessed the entire output of the Sun, 4e26 watts, using 25% efficient solar cells , we could make a kg/sec of antimatter. Our fuel could be ready in 100,000 years.

 

[Atlan0001]

I've run the numbers on interstellar travel within a human lifetime and it boils down to this: ....

Providing the universe is just as completely inertially inert as you make it out to be, Bill. Me, I believe it is just as inertial-less -- thanks to a seemingly accelerating expansion of the universe to a seeming infinite nowhere (an intersecting gravitational wave interface physics (fractal zooms universe structure)) without any point-singularity -- as it is locally inertial (the singularity is a quantum physic, not a gravity physic). That alone changes the picture of SPACE FRONTIERS and the timely ability of (potential fusion or otherwise) powered flight (constant accelerations) to get around . . . to superconduct and/or just go freer of any drag, any inertia . . . in them.

Since the constant of the speed of light, 'c'.is a "go with" constant, it is no limiting barrier to an ever expanding, ever-increasing, distance-speed in a self-accelerating gravity wave hopping and surfing (hyperspace interfacing) drive. Also, distant observers at any distance will never observe travelers except within the framework of a Heisenberg uncertainty principle-like scenario of "if you know the velocity, you cannot possibly know the position" / "If you know the position, you cannot possibly know the velocity."

And if the observer observes a distant image -- at any distance -- traveling close to the speed of light, the likelihood is that the objectively real on the spot is, or was, far ahead of the observed image in distance and speed and traveling beyond the speed of light relative to the observer! The universe splits in two or more universe spaces / spatial universes and past-future (clock) times (image in the 'past' frame / real in the 'future' frame).