The DYSONSPHERE: one of ST's, & Sci-Fi's, greatest mysteries.

[Aquehonga]

The DYSONSPHERE:

Was it built over centuries, if not millenia, or even millions of years?

Was it built in a day? Or less?

What of it's builders?

What level of science & technology must they have been, or are, at?

How does it work so efficiently?

How did it's builders construct it?

How does it maintain gravity, or maybe gravities, atmospheric pressure(s), day/night cycles, heat balance, etc, etc?

Would a species, or maybe groups of species, intelligent & powerful enough to build a Dysonsphere be so ignorant, blind, deaf & dumb to build such a thing around an unstable star?

Was the 1701-D's scan of the star within the Dysonsphere correct or a false scan, for defensive puposes, given the Enterprise by the Dysonsphere's managing computers?

The same applies to Data's surface scan.

I haven't seen “Relics” in a while. I could swear I remember Data's surface scans revealed no life. But I could be wrong/misremembering.

Was the 1701-D pulled into the Dysonsphere on purpose? Were the Dysonsphere's computers &/or it's builders/inhabitants “testing” Picard & crew somehow? And simultaneously studying the 1701-D & crew?

If the Dysonsphere's computers &/or possible inhabitants were examining &/or ”testing” Picard & crew, it wouldn't, doesn't explain why the derelict USS JENOLEN was ignored for the roughly 80 years it sat on the Dysonsphere's front door.

Well, that would explain a civilizationless Dysonsphere perhaps. The computers ignored the JENOLEN after it crashed.

And if the civilization(s?) that built the Dysonsphere reside within(?), perhaps they leave only every few centuries or so & vice-versa Maybe the Dysosphere's surface relays them information from all over observable space Who knows

Who built it?:

Iconians? T'Kon? Ancient Talosians? The Q? The Preservers? The aliens Gary 7 works for? The civilization whose comet-buried artifact devolved the 1701-D crew?The H'urq? The Metrons? The Andromedan civilization who sent Norman & his fellow androids? The Xindi? The Cytherians? The Old Ones of Exo III? Who?

The DYSONSPHERE is another great mystery of STAR TREK, & science fiction in general.

How would such a *David Niven object come into being?


*Wrote a novel called Ringworld which inspired Freeman Dyson to invent the star-surrounding sphere. I am correct about Niven influencing Dyson yes If not

 

[GodThingFormerly]

*Wrote a novel called Ringworld which inspired Freeman Dyson to invent the star-surrounding sphere. I am correct about Niven influencing Dyson yes If not

"Some science fiction writers have wrongly given me credit for inventing the idea of an artificial biosphere. In fact, I took the idea from Olaf Stapledon, one of their own colleagues:

Not only was every solar system now surrounded by a gauze of light traps, which focused the escaping solar energy for intelligent use, so that the whole galaxy was dimmed, but many stars that were not suited to be suns were disintegrated, and rifled of their prodigious stores of subatomic energy.

This passage I found in a tattered copy of Stapledon's Star Maker which I picked up in Paddington Station in London in 1945." - Quoted from Page 211 of Disturbing the Universe by Freeman Dyson (Basic Books, 1979).

TGT

 

[uniderth]

Well the sphere couldn't spin to create gravity or it would force everything to the equator. So gravity would either come from gravity generators which would require massive efforts to create. Or simply build the shell of the sphere as thick as a planet. That wouldn't take as much technology but a heck of a lot more material.

 

[Neopeius]

The DYSONSPHERE:

How would such a *David Niven object come into being?


*Wrote a novel called Ringworld which inspired Freeman Dyson to invent the star-surrounding sphere. I am correct about Niven influencing Dyson yes If not

Freeman Dyson came up with the Dyson Sphere although he did not posit a solid shell as that would be unstable and more difficult to construct.

*Larry* Niven wrote Ringworld. His structure was a simpler, easier to build structure inspired by the Dyson Sphere.

*David* Niven, around the same time, was a famous actor.

As for why there is a Dyson sphere in TNG, I'm not really sure. It's pretty much a throwaway playing second fiddle to an implausible and silly crossover situation.

A real Dyson sphere should be a HUGE deal, no pun intended. It indicated a technology far in advance of any others the Feds had discovered.

There are countless reasons why a Dyson sphere would be abandoned if found. Honestly, the focus of the episode should have been the investigation of the artifact. Heck, you could have written a story arc about it.

Instead we got the Scotty episode. One of TNG's worst.

 

[Aquehonga]

Alas, so Olaf Stapledon is the father of the Dysonsphere, not David Niven.

Here I go again ing names. The Niven who wrote Ringworld isn't DAVID. Isn't it LARRY

DAVID Niven was an actor yes?

David Niven? was I thinking?

I always screw up & mix-up the 4 & 7 in Species 8472 alot also. They ARE Species 8472, not Species 8742 right

Anyway thanks a trillion TGT. Would LOVE to read STARMAKER.

 

[ancient]

Well the sphere couldn't spin to create gravity or it would force everything to the equator. So gravity would either come from gravity generators which would require massive efforts to create. Or simply build the shell of the sphere as thick as a planet. That wouldn't take as much technology but a heck of a lot more material.

It doesn't matter how thick you make the sphere, the center of mass would always be the same - the center of the sphere (where the sun is). And since any mass in a spherical body further from the center of mass than you cancels itself out, there would be no noticeable gravity inside the sphere (other than the sun's gravity). The only way to go is artificial gravity if you want the inside of the sphere to be habitable.

Incidently, I think the Enterprise would go through one hell of a tidal force entering the sphere.

 

[Deks]

Not necessarily.
The Federation was able to master artificial gravity in the mid 22nd century.
If the race that constructed the Dyson Sphere were far more technologically developed compared to the federation ... then there is a very good possibility that any heavy gravitational forces would be canceled out near the entry gate.
Think of the approach as if you are protecting a certain area with simple force-fields as Federation ships do when opening their shuttlebay doors for example to let the smaller vessels through.
The force-field is keeping the gravity/air/atmosphere within the ship while the bay doors are open.
I would imagine a similar procedure would be used around the entry hatch area that would allow ships safe/undisturbed passage.

 

[Psion]

Well the sphere couldn't spin to create gravity or it would force everything to the equator. So gravity would either come from gravity generators which would require massive efforts to create. Or simply build the shell of the sphere as thick as a planet. That wouldn't take as much technology but a heck of a lot more material.

It doesn't matter how thick you make the sphere, the center of mass would always be the same - the center of the sphere (where the sun is). And since any mass in a spherical body further from the center of mass than you cancels itself out, there would be no noticeable gravity inside the sphere (other than the sun's gravity). The only way to go is artificial gravity if you want the inside of the sphere to be habitable.

Almost ... but there would be gravity from the Dyson Sphere, towards the center of mass. In empty space, with no central star, an unfortunate visitor to such a desolate sphere would experience a combined gravitational attraction of all far walls greater than that nearby. Ultimately, the poor soul would eventually be stuck by gravity dead center in the sphere.

But anyone on the outside would find the experience indistinguishable from walking on a planet.

To make it possible to live and build on the world, one would have to spin the construction, meaning that the habitable zone would be concentrated on the equator, with less and less gravity farther out from that. Spin gravity should cancel out with mass gravity between latitude 45 and 60, and above that, everything that isn't anchored will fall into the central star.

 

[ancient]

Not necessarily.
The Federation was able to master artificial gravity in the mid 22nd century.
If the race that constructed the Dyson Sphere were far more technologically developed compared to the federation ... then there is a very good possibility that any heavy gravitational forces would be canceled out near the entry gate.

Yeah, I could see the problem being solved with antigrav, if it was still working. Which it probably would be, since the auto grab beams were still working just fine.

Well the sphere couldn't spin to create gravity or it would force everything to the equator. So gravity would either come from gravity generators which would require massive efforts to create. Or simply build the shell of the sphere as thick as a planet. That wouldn't take as much technology but a heck of a lot more material.

It doesn't matter how thick you make the sphere, the center of mass would always be the same - the center of the sphere (where the sun is). And since any mass in a spherical body further from the center of mass than you cancels itself out, there would be no noticeable gravity inside the sphere (other than the sun's gravity). The only way to go is artificial gravity if you want the inside of the sphere to be habitable.

Almost ... but there would be gravity from the Dyson Sphere, towards the center of mass. In empty space, with no central star, an unfortunate visitor to such a desolate sphere would experience a combined gravitational attraction of all far walls greater than that nearby. Ultimately, the poor soul would eventually be stuck by gravity dead center in the sphere.

That's how it works with a solid sphere, such as Earth. With a hollow sphere, if you're in the exact center you feel no gravity. If you're off-center, but still inside the shell, the walls closer to you are pulling stronger - since you're closer. However there is always more mass further from you balancing it out, essentially making the entire hollow inner part "the center".

But anyone on the outside would find the experience indistinguishable from walking on a planet.

Yeah, on the outside a solid and hollow sphere act exactly the same.

To make it possible to live and build on the world, one would have to spin the construction, meaning that the habitable zone would be concentrated on the equator, with less and less gravity farther out from that.

Maybe next time they'll build a Dyson Barrel instead...

 

[Psion]

That's how it works with a solid sphere, such as Earth. With a hollow sphere, if you're in the exact center you feel no gravity. If you're off-center, but still inside the shell, the walls closer to you are pulling stronger - since you're closer. However there is always more mass further from you balancing it out, essentially making the entire hollow inner part "the center".

But anyone on the outside would find the experience indistinguishable from walking on a planet.

Yeah, on the outside a solid and hollow sphere act exactly the same.

I did the math on this two decades ago ... everything is pulled to the center where forces cancel out. Don't take my word for it, to be sure, but if you work it through, you'll see there's little difference (gravitationally) between a hollow world and a solid one.

 

[Forbin]

Maybe next time they'll build a Dyson Barrel instead...

And that would be more of an O'Neil Colony than a Dyson Sphere.

 

[Aquehonga]

What would the sky look like from the inside surface of the Dysonsphere in “Relics”?

 

[ancient]

That's how it works with a solid sphere, such as Earth. With a hollow sphere, if you're in the exact center you feel no gravity. If you're off-center, but still inside the shell, the walls closer to you are pulling stronger - since you're closer. However there is always more mass further from you balancing it out, essentially making the entire hollow inner part "the center".

But anyone on the outside would find the experience indistinguishable from walking on a planet.

Yeah, on the outside a solid and hollow sphere act exactly the same.

I did the math on this two decades ago ... everything is pulled to the center where forces cancel out. Don't take my word for it, to be sure, but if you work it through, you'll see there's little difference (gravitationally) between a hollow world and a solid one.

I'm sorry, but I'm afraid this is not correct. Let's just say that Newton and I disagree.

I suggest you visit this page for a general rundown: http://en.wikipedia.org/wiki/Shell_theorem

Important part:

If the body is a spherically symmetric shell (i.e. a hollow ball), no gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell.

 

[Silvercrest]

What would the sky look like from the inside surface of the Dysonsphere in “Relics”?

I think it would look white (except for the sun, of course). If you were standing on the surface, every point above your head would be reflecting light back at you, just like the moon does. But it's unlikely you'd be able to make out any physical features like you can on the moon. The opposite side of the sphere would be hundreds of times farther away than the moon is. Just pure, featureless, brilliant white.

 

[Kaziarl]

That's how it works with a solid sphere, such as Earth. With a hollow sphere, if you're in the exact center you feel no gravity. If you're off-center, but still inside the shell, the walls closer to you are pulling stronger - since you're closer. However there is always more mass further from you balancing it out, essentially making the entire hollow inner part "the center".

Yeah, on the outside a solid and hollow sphere act exactly the same.

I did the math on this two decades ago ... everything is pulled to the center where forces cancel out. Don't take my word for it, to be sure, but if you work it through, you'll see there's little difference (gravitationally) between a hollow world and a solid one.

I'm sorry, but I'm afraid this is not correct. Let's just say that Newton and I disagree.

I suggest you visit this page for a general rundown: http://en.wikipedia.org/wiki/Shell_theorem

Important part:

If the body is a spherically symmetric shell (i.e. a hollow ball), no gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell.

Well, those calculations are complete gibberish to me. I was pretty good at math, just didn't get to far past algebra once I graduated high school.

So, forgive me if I'm wrong, but if I'm understanding this correctly then the inside of the sphere has no gravity? Even standing on the inner surface there is no gravitational effect? That seems... well, unreal that something that big doesn't effect you if you're inside it.

I mean I guess it makes sense that the pull from apposing sides of the shell would cancel each other, as I think is whats being said, but wow.

 

[Timo]

Odds are, on a structure that large, the imperfections on the surface would be large enough to create some noticeable local gravitic pull. Say, if you tried to stand on a hill, you would be floating near-weightlessly above the ground - but a nearby mountain range would be pulling you to the left with a gentle force that you might just barely feel.

On whether the TNG sphere was inhabited or not, I don't think we need to assume that somebody was jamming Data's sensors for him to get a false negative. Remember that it generally takes at least a few seconds to scan a planet for lifesigns. At that rate, Data should have spent hundreds of thousands of seconds scanning the inner surface of the sphere - which means a day or more. Data didn't spend a day at it. His scans were probably really cursory, and might have missed entire planetfuls of advanced lifeforms.

Timo Saloniemi

 

[ancient]

I did the math on this two decades ago ... everything is pulled to the center where forces cancel out. Don't take my word for it, to be sure, but if you work it through, you'll see there's little difference (gravitationally) between a hollow world and a solid one.

I'm sorry, but I'm afraid this is not correct. Let's just say that Newton and I disagree.

I suggest you visit this page for a general rundown: http://en.wikipedia.org/wiki/Shell_theorem

Important part:

If the body is a spherically symmetric shell (i.e. a hollow ball), no gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell.

Well, those calculations are complete gibberish to me. I was pretty good at math, just didn't get to far past algebra once I graduated high school.

So, forgive me if I'm wrong, but if I'm understanding this correctly then the inside of the sphere has no gravity? Even standing on the inner surface there is no gravitational effect? That seems... well, unreal that something that big doesn't effect you if you're inside it.

I mean I guess it makes sense that the pull from apposing sides of the shell would cancel each other, as I think is whats being said, but wow.

Newton's law of gravitation requires calculus. Which is why I think he invented calculus to begin with, if I recall my history right.

Anyway, I believe anyone who took a physics sequence in college knows about the shell method and the interesting results.

There is gravity inside, but no net gravity, since all the forces oppose and cancel the effects of eachother out.

Odds are, on a structure that large, the imperfections on the surface would be large enough to create some noticeable local gravitic pull. Say, if you tried to stand on a hill, you would be floating near-weightlessly above the ground - but a nearby mountain range would be pulling you to the left with a gentle force that you might just barely feel.

The law requires a perfect hollow sphere - a hollow Earth wouldn't work since it's actually flattened.

But the bigger the structure, the bigger the imperfections would have to be in order to make any difference. If ever you could get an almost perfect sphere it would be something as big as a dyson sphere, which is huge and engineered, so not as prone to natural deformations.

Of course, the star is still going to pull you to the middle. But the Net gravity from the sphere would be virtually non-existant, even with planet-sized imperfections.

On whether the TNG sphere was inhabited or not, I don't think we need to assume that somebody was jamming Data's sensors for him to get a false negative. Remember that it generally takes at least a few seconds to scan a planet for lifesigns. At that rate, Data should have spent hundreds of thousands of seconds scanning the inner surface of the sphere - which means a day or more. Data didn't spend a day at it. His scans were probably really cursory, and might have missed entire planetfuls of advanced lifeforms.

None of which decided to help them or ask for ID at the entrance? Oh look, another random alien ship just came into our sphere. Oh look, another one is jamming the door open. Well, that's nice, la la la la...

 

[Psion]

That's how it works with a solid sphere, such as Earth. With a hollow sphere, if you're in the exact center you feel no gravity. If you're off-center, but still inside the shell, the walls closer to you are pulling stronger - since you're closer. However there is always more mass further from you balancing it out, essentially making the entire hollow inner part "the center".

Yeah, on the outside a solid and hollow sphere act exactly the same.

I did the math on this two decades ago ... everything is pulled to the center where forces cancel out. Don't take my word for it, to be sure, but if you work it through, you'll see there's little difference (gravitationally) between a hollow world and a solid one.

I'm sorry, but I'm afraid this is not correct. Let's just say that Newton and I disagree.

I suggest you visit this page for a general rundown: http://en.wikipedia.org/wiki/Shell_theorem

Important part:

If the body is a spherically symmetric shell (i.e. a hollow ball), no gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell.

Damn, that looks right, so I must have been thinking about solutions including a star in the center ... or just flat-out erred in my original simulation. My methodology was to place a subject mass at a random location within a ring of 360 point masses (representing a two-dimensional shell of a Dyson sphere). I then calculated the gravitational attraction of each point mass on the subject mass and summed the vectors, yielding a force and direction. This would have been tedious by hand, but that's what a TRS-80 was for. I still have that computer packed away in my basement, so there's a chance I could dig out the program and figure out where I went wrong ... that's an awful lot of effort to go to, so I'll just be gracious and concede the point. Well done, sir.

On the bright side, I did advise you not to take my word for it.

 

[ancient]

You had me doubting, so I had to look it up to make sure I wasn't misremembering. It's one of those neat counter-intuitive laws that will come in really handy if we ever build a dyson sphere. Until then, it's just a way to calculate a solid sphere of varying density in a simpler way.

Anyway, that was why I brought up the tidal force at the door.

 

[Timo]

None of which decided to help them or ask for ID at the entrance? Oh look, another random alien ship just came into our sphere. Oh look, another one is jamming the door open. Well, that's nice, la la la la...

"The" door? I'd wager it's only one of hundreds of thousands, if not billions. It was barely bigger than the ship, the size of a city at most...

And the civilizations living on the inside need not be in possession of technologies for spotting something as small as a starship. Or, indeed, in possession of the means to operate the doors or observe their operation from afar.

Really, if Data can't spot them, then it would be near-impossible for them to spot Data. Even advanced civilizations have sometimes been unable to spot ships sneaking into their (non-shrouded) star systems until they are at Earth's orbital radius or two.

Timo Saloniemi