Elisa is flying high, running through the multiverse. A science fiction story.

The goal of the journey? She wanted to explore the infinity.

Not really impossible for her as a finite being. With this ship she was able to use quantum mechanics relations and extreme relativistic flight. And she could use the geodesics of space time. If she was able to enter the null geodesics without being torn into pieces, infinity was reached.

Maybe a little bit dangerous, but scientific research can not reach goals without any risks. She thought so. Try and error is a part of it. Hopefully that some higher cosmic beings will protect her. Yes, she believed in higher cosmic beings.

Her space ship was very beautiful. It reminded of the bloom of the large ball rose and it had a diameter of about 5 meters. Enough space for her and the most important thinks she wanted to take with her on this journey.

The space ship was compressed, she could blow it up to a size of 2500 meters. She had no weapons on boards because she didn't want to fight a war. But who knows. Her ship was able to produce a lot of things if they are needed.

If danger threatened she could flee and last not least, she had a very effective defense system. After having it activated there was no risk to fly through a sun with her space ship. This even gave her a possibility to hide it.

There was a time machine on board. Necessary for her to go back to the past if relativistic flight will push her into the future.

Relativistic flight can cause the so called twin paradox.

Yes, this journey should go through space and time.

The ship could gather energy and transform it into matter. In this way it was possible to create foods for her. The energy reserve inside the ship reached for 5000 years. After this time there was a need to discover an external source of energy, maybe a sun.

Inside the universe no problems should occur, because the curvature of space time allowed a lot of movements and suns exist elsewhere.

She could use black holes for transferring from one point of the universe to another one, but she didn't know exactly where she will come out. Maybe she will go through a white hole and this could lead her to a parallel universe.

Not all black holes connected one range of space time with another one.

Some of them had no outgoing door. So she must be carefully using them.

She wanted to leave the universe, to go outside, exploring the great empty space, looking for other universes.

For not getting lost in a flat space time, if the quantum engine and the movement along the geodesics fails, the ship had an impulse engine using antimatter. With this engine she could reach the extreme relativistic flight. At one point probably extreme enough to go through infinity. That could happen if the flight will overcome the discrete substructure of the universe.

The relativistic flight contracts the universe being outside for the person inside the travelling ship, and if this contraction is smaller than the discrete bubbles of space time?

Extreme relativistic flight, this will transfer her into the future. Maybe in a future that is infinite far away.

It seems not reasonable to think about infinity. Everything seems to be finite, but ... ? There is no limit in reaching velocities, but space time seems to be discrete. A frontier that has not been explored yet. Exists there a continuum underlying the discrete bubbles of space time? To reach the continuum could result in discovering objects that can not be separated from each other, although they are different.

Think about the continuum of real numbers underlying the discrete set of rational numbers. It is not possible to distinguish two real numbers that are neighbours. How is it then possible to have two different real numbers?

What means difference? Are physical objects at a distant part from each other always different? Think about elementary particles, they are identical.

She will find it out.

To reach extreme relativistic velocities could also be possible if she was circling around a big galaxy black hole.

And going back to the past?

The time machine. A black box answer "grin"

There was a memory with negative energy inside the space ship. One of the sources for the time machine.

Negative energy was used to move back in time, positive energy to go forward into the future.

Positive energy means increasing entropy, negative energy allowed her to decrease entropy. Positive energy could lift her from a lower entropy space to a higher one.

How to get negative energy?

It comes from white holes, she had to find a white hole. They spread negative energy out into the universe. One of the sources for the cosmic inflation. Another possibility, she could separate the vacuum energy. It seems to be zero, but it isn't. There is a lot amount of neutral energy that has no repulsive or attractive effect.

The big zero.

Maybe. She lived in a space time filled with positive energy but also with a repulsive background, but she didn't know if it has an equivalent negative part.

If this repulsive part comes from the distribution of gravity? Not from a mathematical point of view, the gravity force seemed not to be strong enough.

But if there is a continuation at infinity? Who knows.

From a theoretical point of view it could happen that a singular point inside a black hole could have connection to a world filled with negative energy. But it makes no sense to use it. A space ship consisting of positive energy will be torn into pieces, entering a negative world.

...

The ship started it's journey.

...

The planet was left behind.

She enjoyed the view in the outer space. The lighting of thousands of stars. Yes, she flew against the stars.

...

Now she was already three weeks on the way. The galaxy dropped back behind her. A fantastic large disk. She entered the empty space between the galaxies.

...

The neighbour galaxy passed.

...

After 2 months she left the galaxy cluster. Now she could use the full velocity of her space ship. She put billions of light years back and so she reached the frontier of the universe.

Yes, there was a frontier, instead of the expected cosmic inflation. Maybe the observed ret shift had another meaning, the big curvature of the whole universe. Or the photons get tired with time. They loose energy travelling this mountain up, caused by the matter of the universe. Who knows.

Are photons individuals? Then they probably have a finite life time. But they have now proper time and no volume. Something that has a connection to infinity, because anything that may reside inside needs no time for reaching any point of an infinite space-time.

From Elisa's point of view, material objects seemed to be localized inside a sphere, the outer space was empty.

And now? She entered the great empty space. If there exists something? She wanted to find it out.

The instruments delivered no input. Exists there anything to be explored?

...

Already half a year she moved through the cosmic empty. Nothing seems to be changed, endless flat space time. A little bit she feared to get lost.

But space time still exists outside her ship. Who is responsible for that?

The relativistic flight. Using it, there were always photons that had travelled the way before her and photons that reached her from behind. Only space time was contracting.

So she still had light signals from her own universe, although she was already 20 billions of light years away. If there is a limit in contracting space time or if photons have a finite life expectancy, she didn't know it. But what will happen if this orientation is lost? Alone in the far nothing?

Then it happens. There were no more light signals from behind.

And the light signals before her?

No problem, they still exist because she never could reach the velocity of light relative to her starting point.

Then suddenly there was nothing any more.

How is it possible that light disappears?

She was alone.

...