After we drain the Sun and migrate, why would humanity find the Solar System important?

Question

Long ago, our ancestors worked out how to travel faster than light: by sending craft directly into the Sun, employing fusion, quantum entanglement, and a healthy dose of handwavium/science indistinguishable from magic to skip between the stars.

We did this enough that we drained the Sun's fuel in a matter of a century. By the time we realised what we'd done, the Sun was whimpering its way into a brown dwarf, and the Earth was doomed to be a cold, irradiated husk, with the only life surviving underground.

But that didn't matter, because humanity had spread in a great migration across the stars! It's been thousands of years, and humans have refined star-skipping technology to be more sustainable and created dozens of empires across the known universe.

So why do we keep coming back to the remnants of our cooling, dying Solar System? What's left for us here? Why are we spending money, resources, and human lives to keep up a presence in our ancient home?

Answer 1

Good old tourism.

Why people go visiting caves with painting on their walls, or ruins of ancient cities, even though they have much more comfortable houses?

Because they are curious about their past and find interesting to share with their friend that they have visited the ruins of the ancient city of XXX.

And where there are tourists there are money, and where there are money there is a reason to be.

Answer 2

Pilgrimage to Holy Terra, Cradle of Humanity and Birthplace of the Savior.

Religion, sports, economy, reality TV, pick your poison.

Surely, most citizens pay no mind to religion, but I doubt any advanced human civilization would give it up entirely.

It is the birthplace of Jesus, Buddha, and Donald Trump IV, the winner of World War VII, after all.

Religious fanatics keep coming to the frozen ball of silica orbiting the brown dwarf in droves, sparking fights in high orbit every now and then.

Entire solar systems fund these wars, and then there's midiatic cover of the clashes, mercenary companies rent their fleets for the fighting, there's even some reality TV shows where contestants hop into junky burger-shaped Core-lion freighters and attempt to land on the planet while every faction with a mass driver attempts to shoot them down like titanium piñatas for prizes.

Last season of Naked and Spaced: Earth or Gamma Bust won a EmmyLY award (LY = Light Year) for best reality show.

Answer 3

Because Asimov was right (Foundation series)

There is only one planet, out of all those empires across the universe, where humanity actually began. Where we lived at a time where incredibly, nobody flew, nobody knew flight was possible,and generations lived and died pre space flight. Where evolution happened and humans began. Cells began. Where 2 billion years passed to get past simple celled mats, or whatever it was.

It all happened on this one, incredible planet, halfway across that galaxy. Whether they are from here or the next supercluster... We all began in that one place. Its all our family and origin.

That's a hell of a powerful thought. Out of a few billions or trillions, even a tiny percentage a year will be a huuuuge amount of visitors.

Answer 4

It's a Tax Haven

Why are totally disproportionate numbers of companies based in Ireland or the Caymans? Because despite being small countries with hardly any consumers, companies 'based' there save a fortune.

Variants of this reason include:

1. Regulatory havens (traditionally Delaware, at the moment due to Covid, Florida).

2. Countries that allow shipping flags of convenience. Those multinational shipping companies aren't actually run by Liberians.

3. Free cities and trade corridors. Historically, sometimes a politically contentious city would be made a free city. Two enemy states would then use it as a trading spot / negotiation place / espionage base. I don't think there are any at the moment, but there are a few trade corridors; these are little strips of land belonging to country A but with guaranteed access to B to prevent B from starting a war. I think there are a couple in South America.

4. DMZ: Maybe all the core worlds serve as a DMZ within one large empire that has had it imposed on it after a losing war. Such places often have a little more freedom than elsewhere within a repressive empire.

5. Litigation centres: The local judges are either waaaay too quick or waaaaay too slow to strike down patents / award litigation damages. As a result, everyone judge shops and files lawsuits there. See: Delaware (again). Progressives always try to file lawsuits for highly contentious political causes in DC as the courts there are so left wing, while conservatives pick districts that have the 5th Circuit of Appeals overlooking them.

Poor Earth, 3000 years and the death of its sun still couldn't remove all the damn lawyers!

Answer 5

It's (like) the Vatican

The pope is still based in Rome, and the galaxy's Catholics go on pilgrimage. It also serves as a convenient politically neutral refuelling/resupplying/duty free stop.

EDIT: Insert future religion or Jerusalem/Jews or Mecca/Islam as needed.

Answer 6

Earth is the source of the handwavium.

There's some unique material on earth from some unknown alien race that is needed to calibrate the jump engines of ftl. Removing it from earth seems to break the quantum resonance. Various technologies have been made to copy that resonance but for complex quantum mechanical reasons each copy degrades the quality of the engine.

Each jump also degrades the quality, and it is necessary to renew engines every few decades.

The best starships, especially military grade ones, personally visit earth to tune up their engines. The cheaper engines are just a few copies away from earth. Unless another source of this material is found, ftl travel is dependent on Earth.

Answer 7

Astrology

Earth is literally the only place in the universe where accurate astrological readings can be made.

(I'm not into astrology, so I'm sure I'll get some of these details wrong.)

First, the star constellations that make up the signs of the zodiac are all defined with respect to an observer on Earth. While it's true that the constellations will look essentially the same from Earth's moon, and probably even from other bodies in the solar system, they will look very different from any other place in the universe. And if you're already going to the trouble of traveling back to the Sol system to take readings, you might as well travel the last few AU to visit Earth.

Second, the zodiacal year is also defined with respect to an observer on Earth:

The zodiac is the belt or band of constellations through which the Sun, Moon, and planets move on their journey across the sky... twelve of the constellations through which the sun passes throughout the year -- Wikipedia

If you really want an accurate reading of the current zodiacal moment, the best way is to bring your kit to Earth and take a look.

Now, you may be thinking that a person could save themselves the effort by just using software that accurately simulates the view from Earth. Software like that exists today (astronomers use it). But I'd remind you that astrology is a pseudo-science (i.e. a crock of ****), and we can probably assume that any future adherents who care enough about getting a "true" reading are the same kind of people who are unlikely to put their trust in a piece of man-made software.

And, in defense believers: everyone must acknowledge that a simulation is only as good as its data and models, so if there really were some kind of mystical truth in astrology, it seems quite possible a simulation based exclusively on hard observation would be unable to anticipate a novel occurrence. And there's Humean skepticism: the recognition that we have no good reason to believe the future will be like the past. These people will not trust a mere app.

So, I'd expect permanent astrological observatories on the cold Earth, who sell their observations to humans across the galaxy. I'd also expect there to be some very wealthy lunatics who insist on traveling to Earth to make their own observations. And possibly some people who are unable or unwilling to pay the fee charged by the observatory, who therefore have no alternative but to visit Earth to take their own measurements.

---

Just to be clear: when I talk about readings and measurement, I am not talking about writing horoscopes or making predictions for individual people. That stuff is built on top of the readings. The readings are just this: stand on Earth and look into the sky to observe the apparent positions of the sun, moon, and constellations. That is how you determine the "current zodiac time."

Folks who want their horoscope would pay the Earth-based astrologers to tell them that info as it was at the moment of their birth, which is how the person determines their "sign." (A person would presumably only need to do this once per lifetime.) And then they can go and get a horoscope from their preferred local astrologer.

Answer 8

Random ideas:

1. Coincidental proximity

Earth just happens to be near a conjunction of interstellar trade routes. Combined with the curiosity of being the Homeworld, it's ended up as the equivalent of a medium sized town in a very large, thinly populated area.

Think Alice Springs in Australia; it's not that big, but compared to everything around it, it's huge.

2. Reconstruction

Some people just won't let Earth be dead. Inspired by paintings of lush, bucolic meadows with sunsets in the background, organisations are painstakingly reconstructing the sun over decades. Ironically, its solar death has probably been the best thing to happen to its economy. It has been for ages, and is even more so now that a rather profligate government has decided to fund what a lot of people consider a pointless environmental project.

3. The underground construction was really, really successful

You've heard of the Mall of America? Now it actually is the Mall of (the entirety of) America. Continent-wide halls, nation size shops, cathedrals with spires 500m high all abound. After 4000 years of building underground, the underground world is arguably more interesting than the surface ever was! Maybe even more beautiful. It's a bit like Vegas; without constant outside supply it'd die, but seeing as its outlasted the death of the sun, what are the chances?

Answer 9

It is in the middle

Since Mankind explored the universe in all directions from Earth, Mankind has spread through an sphere, at the center of which is the Earth. This makes it still politically and strategically important

It has lots of routes

Your technoquantum travel goes through stable "tunnels" that connect the stars. Since exploration began from Earth, it has discovered most of the valuable trade routes that exist. Most of the transport, both of goods and people, must go through its space.

It is insignificant

Since the Sun is almost spent, it has no resources to compete militarily or economically with the colonies. This makes it a safe zone, a place for the actual powers to meet on neutral ground, but that none of them would want to incorporate into their empires because the costs of defending and maintaining it, and of the interplanetary condemnation of this act, would outweight whatever benefits would be expected.

Answer 10

Time Travel

Not sure if you wish to have this possible in your world, it could also only be of that "viewing back in time" kind. But often time travel itself in Sci-Fi is bound to the location, thus if you want to travel back (or see back) into earths history, you need to do it on earth.

This could also make the whole solar system be kind of an archaeology hive of the galaxy, possibly with a sort of library of all the knowledge still stored at the place where everything began. After all, why move it when there is still research ongoing?

Answer 11

For ecological reasons:

Suppose that all the planets humans have chosen to colonize had a native ecosystem to begin with. This is pretty plausible; a totally dead planet will always take much more time and effort to terraform than one which already has liquid water, oxygen in the atmosphere etc., and that's likely to be because life already evolved there. If you have faster-than-light travel, it might well be easier to find these planets than to spend the effort setting up new ones from scratch.

That being the case, all humans would now live on worlds where Earth life is competing and/or intermingling with alien life. It may be that the alien ecologies are harmful, or simply not as pleasant for humans – say, you plant a beautiful forest of Earth hardwoods, but after a few hundred years it's starting to take on the weird smells / sounds / colors etc. of the native life.

So the galaxy's ecological engineers need the Earth as a pristine, full-scale reference model for the optimal human environment. They can maintain gene banks and terrariums, but nothing can capture all the detail and nuance of the original.

The problem with this, of course, is that once the Sun has died (or even been changed slightly), the Earth's ecosystem will be very different, if it even survives at all. So there would need to be massive interventions to keep it in the chosen ideal state (which in itself isn't "natural").

Still, this seems more believable to me than the idea that large numbers of people would care greatly about Earth in the distant galactic future. (It's a pet peeve of mine that people in SF stories are always obsessed with rediscovering Earth 50,000 years after leaving it. I mean, do you even care about the suburb where your grandparents grew up 50 years ago? It undermines the whole point of SF that the interesting stuff is out there, not back here).

Answer 12

There were too many survivors and not enough life boats

Warp ships are expensive and few in number; so, as the sun cooled down, most humans were trapped inside the solar system. Only the a select few out of the 10s of billions of people living here could make it out... especially with each ship making the problem worse; so, nearly all of humanity was stuck here. Even with massive die-offs the number of people living in artificial habitats far outnumbered the amount of people to ever leave the Earth.

Sure Kepler 186F may have a less harsh climate, but even after a few thousand years its total population from its original seed colony may still quite small by comparison. Earth's population has only grown by about 20 fold in the past 2000 years; so, if most of the original colonies had less than 10,000 people, then even after 2000 years, its possible that worlds with over 1 million people would be pretty rare. In contrast, if Earth saw a 99% population reduction from today's values from the great cool down, you'd still have a population on Earth of around 80 million.

Also... Sol has Venus

What is more is that the cooling of Earth also means a cooling of Venus; so, it does not take long for Venus become a much more Earth like world. Since shipping inside a solar system is much cheaper than between star systems, the millions of Earthlings who weathered the cooling of the sun now have a perfect near by world to call home; so, once Venus is ready the bulk of Earth's surviving population moves there.

So yeah, Earth is now just a frozen husk of its former glory, but Venus quickly replaces it as the most highly populated world, while becoming just as nice a place to live as any of those almost earth like exoplanets we've also claimed. Combine that with the cultural significance of being in the Sol system, Venus could quickly become the most important world in human space.

Answer 13

Science has progressed

Humans now have the technology to restore the Sun by funnelling the asteroid belt into it and re-igniting it.

The Earth will once again be a beautiful place to live. It will coincidentally be a great place to invest in real-estate as well as appealing to galaxy-wide nostalgia.

Answer 14

Monument to Stupidity/Nostalgia

We just can't believe humans refused to notice the major changes to the Sun over such a length of time. We have to visit it as individuals just to convince ourselves. As others have stated, we also want to visit the birthplace of humanity. After all, with portals provided by other stars, we can easily and cheaply visit for a day.

Answer 15

The Data

Our evolution is inescapably tied to our environment. Anatomically modern humans have been on Earth for at least hundreds of thousands of years. There is so much data on Earth and that can help us understand ourselves better.

Surely, we have reached star-skipping technology. But why do we turn against each other? Is the utopia possible? Why do we wage wars against people we've never known? The answer may be lying on Earth, or rather, our history.

Those who cannot remember the past are condemned to repeat it.

Answer 16

Its still in the middle for historical reasons

It still has gravity, and a star providing energy. Its not habitable, but the service stations orbiting it are still useful. Not because of what they are orbiting, but because its right in the middle of everything.

Having been the central point of human expansion out into the galaxy, it's still in the middle and if you are passing it, you may as well stop there to refuel, take shore leave, or piratise others.

Answer 17

Gaia. We cannot (cheaply) replicate the outputs of the impossibly complex ecosystem of earth. Parts of the old earth are kept going, artificially, at great expense.

We terraform the new worlds, but every copy is imperfect, and copies of copies get worse. The only place we seem to really get the biological machine going just right is good old earth. Therefore, the earth will be import to human beings, as long as we have not evolved to deal with another biosphere.

Some system, with a long copied-from-copy biosphere and an independence streak, has recently stopped trading with earth. Rumor has it that the people from there look weird, like they have hastened evolution somehow.. Are they still human?

Answer 18

Some people don't like to move. No, really.

In history, every time a new land was opened for colonization, a small portion of the population went to colonize, while the majority of people remained at home.

For example, the majority of population growth in the U.S. since 1850 has been from births, not immigration. (sorry, there was no data before 1850)

https://www.census.gov/library/visualizations/2014/demo/the-second-great-wave-of-immigration-growth-of-the-foreign-born-population-since-1970.html

There is a history of people staying in place even when the area becomes less hospitable.

In southern California, the Los Angeles River and Colorado River are usually dry before they reach the ocean, and frequent droughts cause a large strain on water resources.

Damascus, despite still being considered the world's least habitable city due to the aftermath of the brutal war, only lost about 10% of its population in 2012-2014, and is now growing again.

https://www.macrotrends.net/cities/22610/damascus/population

The city of Yakutsk regularly gets dangerous and deadly low temperatures of approximately -40 degrees every day all winter, yet still has a population of 310,000.

https://en.wikipedia.org/wiki/Yakutsk#Climate

The sea will rise into Miami by 11 inches by 2040, but people are not leaving at a significant rate.

https://www.miamiherald.com/news/local/environment/article258409363.html

https://www.biggestuscities.com/city/miami-florida

Answer 19

The reason could easily beSentimentality. If I had a chance to go visit the remains of the ancestral home of all humans, the place where history began and technological advancements began to happen, I would go. Earth is the planet where everything truly began, so it would have a certain significance.

That reason alone would probably suffice for humans returning.

Answer 20

Neutrality:

Every human stellar empire formed by colonizing new stars or conquering really valuable ones. But Earth was never colonized. Earth had nothing worth fighting for. So Earth by it's neutrality in interstellar politics has become the core for the new United Nations.

Geography:

If you look at a map of human civilization, an odd detail is noticed. At the dead center of all of it lies the home world. Mankind extended more-or-less equally in all directions (this was already brought up). But further, all those empires extend outward as cones from the center. Every empire shares a border with Sad little Sol. This is part coincidence (how the empires evolved) and part design (during colonization, everyone still wanted access to Earth). Further, Earth has massive facilities for docking ships and managing shipping as it's heritage from the exodus.

So everyone who needs goods from anywhere else can get access to Sol without passing through rival territory.

Infrastructure:

The huge infrastructure of Earth has become self-serving, and it is the perfect place to handle trade because it's already the perfect place to handle trade. A factory on Earth can ship stuff out through the biggest commercial and industrial network in the galaxy. A mineral exchange on Earth will have more of everything on sale there, so people bring more of their minerals there. People looking for goods or services go there to look, and people selling goods and services go there to sell.

Earth Was already Artificial:

Earth had already been so radically transformed from what it was before that there was little or no surface left on Earth. The planet is one giant city. All food was already produced in hydroponic facilities with grow lights. Any "nature" was encased in domes or buildings to protect it from the pollution. Waste heat was a massive problem, so The Earth cooling has been a godsend for the planet. Geothermal power has gone huge, and the sun still puts out solar energy - the power stations just need to be a little closer. After a few adaptations, Earth is about as warm as it was before the industrial revolution.