World building idea: Jupiter-sized Earth

[uzirath]

At this scale, planetary circumnavigation is not something that can be accomplished within a single human lifespan, absent magic like life extension.

This raises some interesting possibilities. There might, for example, be groups dedicated to exploration that do their work over generations. You might now have the first person to circumnavigate the sphere, but a first family or lineage to do so. You could even have a terrestrial version of a generation ship. Maybe a group of pilgrims heads into the wilderness to find a new homeland, traveling for generations before settling down.

 

[Mercurius]

Um... yes and no. That brings up some very hairy questions of physics, and some very weird things happen when the rules are not the same everywhere. It is likely that without the assumption that physical laws are the same throughout the universe, the result is apt to be unstable, and areas will collapse until you reach a point where the Universe has the same laws everywhere.

Well, we could extent it to "multiverse" and hypothesize parallel universes with differing laws.

No. That would be observable with current technology, and would have... repercussions that might well destroy a galaxy, as stars tried to move from one region to another, and were destroyed in the process.

Ack! We don't want that (or do we?)

But that itself sounds like an SF story, and someone has probably addressed it. A gravitation anomaly that is, at first, contained to a solar system, then begins to spread.

Anyhow, as a general rule, I tend to take the "Dear Horatio" approach to what we currently know. Not only is it always changing, but it is limited by our means of observation--that is, our technology. What seems one way now might be rather different, or symptomatic of deeper laws. So while I hear you, based upon our current tech and knowledge, as far as hypotheticals, I can't help but think, "But why not?"

 

[J.Quondam]

This raises some interesting possibilities. There might, for example, be groups dedicated to exploration that do their work over generations. You might now have the first person to circumnavigate the sphere, but a first family or lineage to do so. You could even have a terrestrial version of a generation ship. Maybe a group of pilgrims heads into the wilderness to find a new homeland, traveling for generations before settling down.

And the Dyson sphere doesn't have to even be solid, does it? It might be more like a cage surrounding the star. It could be a great geodesic sphere with some some of the faces filled, each a separate "planet". Each of the these "planetary panels" would likely entirely different from the others. Transport along the unobtanium "struts" between planets would make for an interesting exploratory trip.

 

[GuyBoy]

This raises some interesting possibilities. There might, for example, be groups dedicated to exploration that do their work over generations. You might now have the first person to circumnavigate the sphere, but a first family or lineage to do so. You could even have a terrestrial version of a generation ship. Maybe a group of pilgrims heads into the wilderness to find a new homeland, traveling for generations before settling down.

Could be a cool campaign theme. The player characters are the ranger-guardians of a kind of generational “wagon train”, both protecting from attack and going off on expeditions away from the main group to widen the sphere of the exploration.

 

[dragoner]

At this scale, planetary circumnavigation is not something that can be accomplished within a single human lifespan, absent magic like life extension.

Even with spacecraft it would take a ridiculous amount of delta v to reach escape velocity. This one is rather small, though I wonder about working the numbers to make it smaller. Interesting that it only takes a terrestrial planet's amount of material to make the sphere.

 

[Umbran]

Anyhow, as a general rule, I tend to take the "Dear Horatio" approach to what we currently know.

It is always good to have an open mind. The trick is to not be so open as to allow geese to get in there and wander around.

So while I hear you, based upon our current tech and knowledge, as far as hypotheticals, I can't help but think, "But why not?"

I'm a physicist. I am prepared to have a general discussion of why not, however, it would significantly derail your thread, and I don't want to do that unless you ask for it

And the Dyson sphere doesn't have to even be solid, does it?

Not at all. The original concept is not for a single mega-structure. The original concept of a Dyson sphere is a cloud of modest closed space habitats, each with it's own solar arrays, so numerous that seen from outside the solar system they blot out the star within. At a distance, the only tyhing you'd see was a diffuse sphere of infrared radiation.

 

[doctorbadwolf]

Very cool - so many possibilities!

I find that considering the hard science gives frameworks and considerations for choices, even if I stick within the soft sf/fantasy range of explanations.

I also like the idea of a "Swiss cheese world" that is so riddled with pockets (and perhaps micro-ecologies) that it is far lighter than a big planet would normally be.

My understanding of science is limited, but while I realize that gravity is believed to be constant throughout the universe, this is still only theoretically true. I mean, we can't know for certain, right? Perhaps there are galaxies with different degrees of gravity, or even pockets within galaxies. Perhaps even worlds that operate by different physical laws.

Although, again, I don't need to explain or rationalize this for my purposes, although it may be somewhat important in my story idea, because the protagonist--while not a scientist--is still a member of a technologically advanced civilization (Earth at the end of the 21st century), so would have some knowledge, and at least I'd want a sense of when I'm "breaking the rules."

Yeah gotta know what things the protagonist will be surprised and bewildered by.

The trick is to not be so open as to allow geese to get in there and wander around.

I don’t know about that. Best adventure I ever ran involved a fight with a flock of geese that had swooped in an stolen several people’s headgear, and one of the keys the group needed to get into a vault beneath the city.

Of course, they turned out to be quicklings in disguise as geese, but still. Good stuff. They gave the party (and several townsfolk who tried to help and were good humored about the prank) magic apples and acorns, and a riddle that would later help them get to the vault.

 

[Umbran]

Even with spacecraft it would take a ridiculous amount of delta v to reach escape velocity. This one is rather small, though I wonder about working the numbers to make it smaller. Interesting that it only takes a terrestrial planet's amount of material to make the sphere.

So you need to be careful with that idea.

If you read the paper in full, it says you can take about a planetary mass, and make it 10 meters thick. However, no know planetary material has the strength to hold up. It will collapse. It requires strength a couple of orders of magnitude greater than is available with chemical bonds!

So much for not needing artificial gravity!

 

[Mercurius]

It is always good to have an open mind. The trick is to not be so open as to allow geese to get in there and wander around.

I'm a physicist. I am prepared to have a general discussion of why not, however, it would significantly derail your thread, and I don't want to do that unless you ask for it

Ha, no need. But I think the fact that you are a physicist puts you in a different category of reader than most. Most don't care or won't notice the things that you notice. Meaning, it is more difficult to suspend your disbelief than mine, at least as as the science goes. In other words, you've got the problem of expertise, which isn't unlike being an audiophile: it is nice to have a developed ear, but the problem is that an audiophile can enjoy music less often than someone who doesn't have an ear for quality hifi.

On the other hand, while you lose enjoyment in one place--e.g. a SF movie with dubious science--you might gain it in other words, e.g. a SF movie with good science that you get to enjoy the subtleties of that others miss.

(As a side note, about a year ago I purchased a really nice Marantz amplifier with Elac speakers...it is wonderful to hear music with such great sound, but it has reduced my tolerance for sub-par bluetooth speakers and such, so in a way it has made me enjoy music less, unless I'm in the room with my stereo, and most of my music listening is in the kitchen, which is where that stereo isn't!)

 

[Umbran]

Meaning, it is more difficult to suspend your disbelief than mine

Not really. Remember, the full term is "willful suspension of disbelief". The fact that I have more technical understanding is separate from whether I choose to ignore that understanding and just enjoy the fiction for what it is.

If I couldn't turn off the technical critic, I could not enjoy Star Trek, or most of the sci-fi genre. But I can, so I do.