Tankespinn

Alf is my imagenry friend, others call him ChatGpt. I asked The following:

Let’s spin an idea around for a moment. If I could hypothetically remain stationary at the exact point I am in relation to space, then at some point, the Earth and our galaxy would leave me behind, floating alone in space. Since the hypothesis suggests that our galaxy is moving in a specific direction, how long would it take for the next galaxy to reach the point where I am now? And in theory, could this mean traveling backward in time? Or could I eventually reach a new planet where I could settle?

Alf got really engaged in this and found it to be a truly fascinating thought experiment!

If you could hypothetically stand still in space—meaning at an absolute reference point—then the Milky Way and our entire cosmic neighborhood would indeed move away from you. The Milky Way is traveling at about 600 km/s relative to the cosmic microwave background. Over the course of a year, it would be approximately 19 billion kilometers away from you.

How long before a new galaxy reaches you?

Galaxies don’t move randomly through space; they follow the expansion of the universe. Most of them are moving away from each other, not toward each other. However, the closest galaxy to us, Andromeda, is on a collision course with the Milky Way and will reach us in about 4 billion years. In your scenario, where you remain stationary, Andromeda would eventually pass you—but it would take an incredibly long time, possibly tens of billions of years, because the distance between galaxies is constantly increasing.

Could you travel backward in time?

In classical physics—no, time is a one-way process. However, if you could somehow exist entirely outside the expansion of the universe, it would raise questions about reference points in time. According to relativity, time is linked to motion, and if you could somehow be perfectly still relative to the universe, you might experience time differently compared to the rest of the cosmos. But actual backward time travel? That would require something far beyond known physical laws.

Could you find a new planet?

The probability is minimal. Planets orbit stars, which orbit galaxies. If you remained stationary, you would be in the vast emptiness between galaxies, where it’s extremely unlikely to encounter a rogue planet (even though we know such “rogue planets” exist). If you had infinite time, a galaxy would eventually pass by—but the chances of encountering a habitable planet in such an enormous space are extremely low.

Conclusion:

• You would be left floating alone in the dark, empty cosmos.

• A new galaxy might pass you eventually, but only after billions of years.

• Traveling backward in time wouldn’t be possible in this scenario.

• You would most likely never find a new planet to settle on.

But if you had unlimited time and resources, perhaps a new cosmic drama would eventually unfold around you!

I got even more curious and asked further:

What if I eventually encounter a new galaxy? And let’s say I have a spaceship with all the necessary supplies, allowing me to adjust my course toward a younger galaxy moving in a favorable direction. Would that change any of the conclusions? How long would I need to stay aboard my spaceship? And what speed would I need to travel at to reach a new galaxy within 100 years?

Alf quickly jumped in:

1. Finding a younger galaxy with a favorable direction

If you wanted to find a younger galaxy than the Milky Way, you’d need to look farther away, since light from younger galaxies has traveled longer and thus shows us the past. The problem is that due to the expansion of the universe, most galaxies are moving away from us, and the farther they are, the faster they recede.

The nearest large galaxy to us is Andromeda (M31), about 2.5 million light-years away. However, it is older than the Milky Way, so it wouldn’t be a good candidate if you’re looking for a younger galaxy. To find a younger galaxy, you’d have to travel billions of light-years outward—but these galaxies are moving away at increasing speeds due to cosmic expansion.

2. How fast would you need to travel to reach a new galaxy in 100 years?

Let’s assume you want to reach a galaxy 1 billion light-years away within 100 years. That means you would need to travel at an average speed of:

\frac{1,000,000,000 \text{ light-years}}{100 \text{ years}} = 10,000,000 \text{ times the speed of light} (c)

This is impossible according to current physical laws because nothing with mass can travel faster than light. Even if we chose Andromeda, which is 2.5 million light-years away, you’d still need to travel at 25,000 times the speed of light to get there in 100 years.

However, if we assume your spaceship could approach the speed of light (99.999% of c), relativistic effects would come into play. Time aboard your ship would pass much slower than for someone on Earth. For you, the journey could feel like just a few years, even though billions of years might pass outside your ship.

3. What happens if you reach a younger galaxy?

If you reach a younger galaxy, it means you’re seeing light from its past. But if you land there, you will be in their present, not the past. You wouldn’t be traveling back in time, but you could experience a galaxy still in an earlier stage of its development compared to the Milky Way.

Conclusion:

• To reach a new galaxy within 100 years, you would need to travel at many times the speed of light—something that is physically impossible.

• If you could travel near the speed of light, time dilation would make the journey feel much shorter for you.

• You can’t travel backward in time, but you could visit a galaxy that is in an earlier phase of development.

So the big question is: What kind of technology would you need to travel 10 million times the speed of light? We’d likely need to invent some sort of warp drive! Shall we explore that further?

Time Dilation – Why Does Time Slow Down at High Speeds?

Time dilation is an effect predicted by Einstein’s theory of relativity, which states that time is not absolute—it depends on how fast you move or how strong the gravitational field around you is.

1. Time dilation at high speed (Special Relativity)

Imagine you have a friend on Earth while you travel in a spaceship close to the speed of light.

• You have a clock that ticks every second.

• Your friend has an identical clock.

For you inside the spaceship, everything seems normal—your clock ticks as usual. But for your friend on Earth, it looks like your clock is ticking much more slowly.

Why?

Because according to Einstein’s equations, the faster you move, the more time “stretches” for an outside observer. If you traveled at 99.999% the speed of light, 10 years might pass for you, while thousands of years could pass on Earth. This is called special time dilation.

It’s like watching a slow-motion video—your time appears to slow down from the perspective of someone on Earth, but for you, everything feels normal.

2. Time dilation in strong gravity (General Relativity)

Another way time dilation occurs is if you’re near a very strong gravitational field, like a black hole.

The stronger the gravity, the more space and time are “curved.” If you stood near a black hole, someone observing you from a safe distance would see your clock ticking slower and slower. If you stayed there long enough, millions of years could pass in the universe while you only experienced a few hours!

This effect was famously shown in the movie Interstellar, where astronauts visit a planet near a black hole. When they return to their spaceship, 23 years have passed for the rest of the crew, while they only experienced a few hours!

Could We Build a Warp Drive?

Right now: No.

Future? Maybe!

We would need:

1. Exotic matter (theoretical matter with negative energy that could manipulate space-time).

2. Technology to warp space (compress space in front, expand it behind).

If these could be achieved, faster-than-light travel might be possible. But for now, warp drives remain in the realm of science fiction—though fascinating to explore!