Out of order snippet? WHAT out of order snippet?

How much, really, would Lagrange points matter to a civilization with counter gravity?

At least theoretically you could park anything anywhere you wanted to (and more importantly at any velocity you wanted to) and have a reasonable expectation it would stay that way until if or when it collided with something.

So it would be plausible to have objects in "geosynchronous orbits" over any point on a planet, not just over the equator. And at most any altitude.

drinksmuchcoffee wrote:How much, really, would Lagrange points matter to a civilization with counter gravity?

At least theoretically you could park anything anywhere you wanted to (and more importantly at any velocity you wanted to) and have a reasonable expectation it would stay that way until if or when it collided with something.

So it would be plausible to have objects in "geosynchronous orbits" over any point on a planet, not just over the equator. And at most any altitude.

Counter-gravity, besides violating the laws, seems to be mostly useful for getting things up and down in the gravity well and presumably matching orbits. It doesn't seem to be all that useful for moving massive objects, or else there would be no need for thrusters or impellers.

kzt wrote:You get less points if there is not a large satellite. IIRC, you get the leading and trailing points and the one between the planet and the sun. The other 2 don't exist.

No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

aairfccha wrote:

kzt wrote:You get less points if there is not a large satellite. IIRC, you get the leading and trailing points and the one between the planet and the sun. The other 2 don't exist.

No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

Exactly. Earth has 10 Lagrangian points. 5 belong to the Sun-Earth and 5 belong to Earth-Moon. Going back to the original issue, the L1 that's being talked about is the one that belongs to Mesa-(hypothetical)Moon.

JohnRoth wrote:

aairfccha wrote:
No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

Exactly. Earth has 10 Lagrangian points. 5 belong to the Sun-Earth and 5 belong to Earth-Moon. Going back to the original issue, the L1 that's being talked about is the one that belongs to Mesa-(hypothetical)Moon.

Isn't that an assumption? All the text said was the habitat was called Lagrange One. Nothing I recall about whether its Planet - Moon or Planet - Sun L1 point.

aairfccha wrote:
No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

JohnRoth wrote:Exactly. Earth has 10 Lagrangian points. 5 belong to the Sun-Earth and 5 belong to Earth-Moon. Going back to the original issue, the L1 that's being talked about is the one that belongs to Mesa-(hypothetical)Moon.

Jonathan_S wrote:Isn't that an assumption? All the text said was the habitat was called Lagrange One. Nothing I recall about whether its Planet - Moon or Planet - Sun L1 point.

True.

A scratch calculation using the values from Wikipedia for Earth gives the Earth-Moon L1 as 3.2639 * 10**8 km away, while the Sun-Earth L1 is 15.0 * 10**8 km away - somewhat less than 5 times as far and over four times as far as the Moon itself is from earth.

IMO, this is a bit too far to be viable as a habitat for several million people. At least, that's the way I see it.

JohnRoth wrote:

aairfccha wrote:
No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

JohnRoth wrote:Exactly. Earth has 10 Lagrangian points. 5 belong to the Sun-Earth and 5 belong to Earth-Moon. Going back to the original issue, the L1 that's being talked about is the one that belongs to Mesa-(hypothetical)Moon.

Jonathan_S wrote:Isn't that an assumption? All the text said was the habitat was called Lagrange One. Nothing I recall about whether its Planet - Moon or Planet - Sun L1 point.

True.

A scratch calculation using the values from Wikipedia for Earth gives the Earth-Moon L1 as 3.2639 * 10**8 km away, while the Sun-Earth L1 is 15.0 * 10**8 km away - somewhat less than 5 times as far and over four times as far as the Moon itself is from earth.

IMO, this is a bit too far to be viable as a habitat for several million people. At least, that's the way I see it.

Makes my head hurt contemplating a Jupiter or a Saturn.

I suppose it would depend on the purpose of the habitat? If you're anore smelting or other heavy indusrial platform processing the ores from an asteroid belt to feed into a closer in manufacturing facility, maybe not.

Where better to stow a few onioneers at least on paper than some processing plant way out in the nosebleed LaGrange point? Or actually stow them until their transport ship comes in? Probably the latter since the former would be part of FF. And it would fit perfectly with Why TF blow up something like that?

aairfccha wrote:
No, two bodies always have the full set of five Lagrange points as they are the result of a special case of the three-body problem. However, a large moon gives a planet another independent set.

JohnRoth wrote:Exactly. Earth has 10 Lagrangian points. 5 belong to the Sun-Earth and 5 belong to Earth-Moon. Going back to the original issue, the L1 that's being talked about is the one that belongs to Mesa-(hypothetical)Moon.

Jonathan_S wrote:Isn't that an assumption? All the text said was the habitat was called Lagrange One. Nothing I recall about whether its Planet - Moon or Planet - Sun L1 point.

JohnRoth wrote:True.

A scratch calculation using the values from Wikipedia for Earth gives the Earth-Moon L1 as 3.2639 * 10**8 km away, while the Sun-Earth L1 is 15.0 * 10**8 km away - somewhat less than 5 times as far and over four times as far as the Moon itself is from earth.

IMO, this is a bit too far to be viable as a habitat for several million people. At least, that's the way I see it.

pappilon wrote:Makes my head hurt contemplating a Jupiter or a Saturn.

I suppose it would depend on the purpose of the habitat? If you're an ore smelting or other heavy indusrial platform processing the ores from an asteroid belt to feed into a closer in manufacturing facility, maybe not.

Where better to stow a few onioneers at least on paper than some processing plant way out in the nosebleed LaGrange point? Or actually stow them until their transport ship comes in? Probably the latter since the former would be part of FF. And it would fit perfectly with Why TF blow up something like that?

It's too far out for anything other than automated scientific instruments (which is what we're using it for today.) One of the major insights from Lean Manufacturing is that shipping stuff is one of the major Wastes - excessive movement is to be eliminated whenever possible. A Lagrange point doesn't have any natural resource that warrants shipping intermediate products in, creating another intermediate product and then shipping that somewhere else.

I thoroughly agree that the reason for blowing up the orbital habitat is that there were either people or evidence on it. We can, in fact, probably name a couple of them.

drinksmuchcoffee wrote:How much, really, would Lagrange points matter to a civilization with counter gravity?

At least theoretically you could park anything anywhere you wanted to (and more importantly at any velocity you wanted to) and have a reasonable expectation it would stay that way until if or when it collided with something.

So it would be plausible to have objects in "geosynchronous orbits" over any point on a planet, not just over the equator. And at most any altitude.

No. Countergravity doesn't move anything. It's about protecting the humans from being squashed by acceleration. Ships still move on their drives.

You might have planetside contragravity but it's still about protecting the humans, not getting on or off the planet.

Loren Pechtel wrote:

drinksmuchcoffee wrote:How much, really, would Lagrange points matter to a civilization with counter gravity?

At least theoretically you could park anything anywhere you wanted to (and more importantly at any velocity you wanted to) and have a reasonable expectation it would stay that way until if or when it collided with something.

So it would be plausible to have objects in "geosynchronous orbits" over any point on a planet, not just over the equator. And at most any altitude.

No. Countergravity doesn't move anything. It's about protecting the humans from being squashed by acceleration. Ships still move on their drives.

You might have planetside contragravity but it's still about protecting the humans, not getting on or off the planet.

Counter-grav can be used to hang items over a planet, but seem to be primarily used for hanging smaller satellites where they are needed, with larger space stations using standard orbital mechanics:

Echoes of Honor, Chapter 9 wrote:Fortunately, Hell seemed to have fallen a bit behind on its upgrades since then. The planetary garrison had an impressive satellite net—why shouldn't they, when counter-grav made it dirt cheap to hang comsats and weather sats wherever you wanted them?—but their ground stations were getting a little long in the tooth. And, of course, the people they didn't know were trying to eavesdrop on them just happened to have a pair of assault shuttles which, up until very recently, had also belonged to StateSec . . . and had been fitted with the very latest in secure communication links. In fact, the systems Sanko was using were probably at least fifteen or twenty T-years newer than the Peep ground stations, and they'd been expressly designed to interface with older equipment as well as their own contemporaries. Which meant Sanko and Mayhew—and Senior Chief Harkness and Lieutenant Commander Tremaine, or Lieutenant Commander Lethridge and Ensign Clinkscales, who'd pulled the other two watches for the same duty—ought to be able to open up that "secure com net" like a pack of e-rats.

Italics are the author's, boldface and underlined text is my emphasis.

Counter-grav can also be used to move people and goods from a planetary surface to orbit and back down, or vertically within the atmosphere, although counter-grav only works vertically against a gravity well--to move horizontally, either air-breathing turbines (air & ground cars), reaction drives (cutters) or impellers (pinances, shuttles) are used:

More Than Honor, The Universe of Honor Harrington, (1) Background (General) wrote:In 1502 pd, the first practical countergravity generator was developed by the Anderson Shipbuilding Corporation of New Glasgow. This had only limited applications for space travel (though it did mean cargoes could be lifted into orbit for negligible energy costs), but incalculable ones for planetary transport industries, rendering rail, road, and oceanic transport of bulk cargoes obsolete overnight. In 1581 pd, however, Dr. Ignatius Peterson, building on the work of the Anderson Corporation, Dr. Warshawski, and Dr. Radhakrishnan, mated countergrav technology with that of the impeller drive and created the first generator with sufficiently precise incremental control to produce an internal gravity field for a ship, thus permitting vessels with inertial compensators to be designed with a permanent up/down orientation. This proved a tremendous boon to long-haul starships, for it had always been difficult to design centrifugal spin sections into Warshawski Sail hyperships. Now that was no longer necessary. In addition, the decreased energy costs to transfer cargo in and out of a gravity well, coupled with the low energy and mass costs of the Warshawski sail itself and the greatly decreased risks of dimensional and grav shear, interstellar shipment of bulk cargo became a practical reality. In point of fact, on a per-ton basis, interstellar freight can be moved more cheaply than by any other form of transport in history.

Italics are the author's, boldface and underlined text is my emphasis.

Protecting people from the effects of acceleration aboard ships is primarily done via the interaction of the inertial compensator and the impeller wedge in normal space or in a hyperspace rift, or via the interaction of the inertial compensators and the Warshawski sails interacting with a grav wave in hyperspace. Gravity plates (not quite the same as counter-grav, but applying the same basic gravity technology in a different way can also be used to protect people from the effects of acceleration aboard ships, but is much less effective than being able to use an inertial compensator.