I thought Vulcan was supposed to be a high G planet

[Deimos Anomaly]

I remember reading that, but I can't remember if it was from a canon source, or just a novel or such like.

I have half a notion it may have been mentioned somewhere during TOS. Supposedly it was the actual reason behind the Vulcans' elevated physical strength.

But then in any episode where Vulcan appears, offworlders used to ostensibly lower gravity (humans for example) seem to move around completely at ease and unencumbered, which should not be the case.

I've recently been watching season 4 of Enterprise where Archer goes on a long march through a desert on Vulcan and appears completely not-weighed-down. Reed and Mayweather don't seem unduly gravitated either, when investigating the bombed embassy.

 

[Hando]

Well, a number appeared in the Decipher RPG as 1.4G.

And all of them are supposed to be trained Starfleet officers so ...

Although Mayweather felt the difference between 1G and 0.8G.

 

[CorporalCaptain]

IIRC, it's been in at least one Trek Lit novel that Spock upped the gravity setting for his cabin, causing Kirk (I think) to nearly trip over the "gravity shelf" when entering it. Can't remember which book(s) though.

 

[Christopher]

You know, I've always thought the same thing, that Vulcan was supposed to be a high-gravity planet. But I just checked the online transcript site, and that was never actually stated onscreen in TOS or the movies, or anywhere onscreen as far as I can tell. I checked the original proposal document from 1964 and the writers' bible from '67, and neither of them says anything about Vulcan's gravity. Nor does Spock's "biography" chapter in The Making of Star Trek. The earliest reference that even comes close is in James Blish's adaptation of "Amok Time," where he refers to the tri-ox compound as a "high-G vitalizer shot" instead -- but even so, he has McCoy say it's only to compensate for the heat and thin air. Aside from that one word, he doesn't say anything about Vulcan's gravity.

The earliest reference I can find to Vulcan having high gravity is in The Star Fleet Medical Reference Manual from 1977. There was also the 1980 USS Enterprise Officers Manual by Geoffrey Mandel (one of the writers of the SFMRM) which said Vulcan's gravity was 1.251g. (I haven't checked every source available, though; it would take too long to page through all the Bantam novels predating 1977 even if I still had them all.)

So there doesn't seem to be any official word on how Vulcan's gravity compares to Earth's. The high-gravity thing appears to be one of those bits of conventional wisdom that originated in unofficial sources or in fandom but have been taken for granted for so long that we don't realize they're not canonical. It's a logical (pardon the expression) conjecture that high strength would result from high gravity, but apparently that's all it is.

And "high gravity" is a relative term. I don't think anyone's ever proposed that Vulcan was a superterrestrial planet with gravity, say, 3 or 4 times that of Earth, anything really crushing. If Vulcan's gravity were 25% higher as Mandel proposed, then that would mean that a 160-pound man would only be carrying an extra 40 pounds of weight around -- equivalent to carrying a heavy backpack. Someone in good physical condition, as a Starfleet officer would be, could probably handle carrying such a load without showing obvious strain. And since that's a conjectural figure, it could be that Vulcan's gravity is more like 10% higher than Earth's, or some modest increase like that. Enough that it would tire people out more quickly but not enough to actually impair their mobility.

 

[Timo]

We could also argue that Vulcan's thin air is the very thing that makes Spock strong. His entire respiratory and circulatory systems are designed to "compensate" for that, that is, thrive on Vulcan - so when he gets a higher partial pressure of oxygen, he gets a bit giddy (but hides it well), but his muscles can now sustain exhaustive activity for considerably longer than human muscles, thanks to the extra oxidizer inflow. The inherently lesser-capacity copper-based circulation is simply "overengineered" suitably to produce this result.

Do Vulcans lose their edge over aliens when on Vulcan? It's difficult to tell from "Amok Time" where all sorts of weird factors are at play. But I remember people complaining about Vulcan lack of fighting prowess in those ENT episodes taking place on Vulcan, and this might be part of the explanation.

Timo Saloniemi

 

[MacLeod]

How much of a difference in gravity would there have to be before it become problomatic for humans. .2G, .5G, 1G, 2G?

 

[Hando]

How much of a difference in gravity would there have to be before it become problomatic for humans. .2G, .5G, 1G, 2G?

I would go with the limit of 1.6G (meaning a difference of 0.6G from Earth gravity), as a sustainable gravity - no idea about the maximal.

But I base this on average/overweight difference, not on actual studies.

 

[JarodRussell]

For what it's worth, thin air, hot temperatures and stronger gravity are mentioned in the novelization of The Voyage Home.

 

[Christopher]

How much of a difference in gravity would there have to be before it become problomatic for humans. .2G, .5G, 1G, 2G?

Depends on the human. As I said, think of it as carrying a weight equivalent to the added percentage of your own body weight -- or, more accurately, like having weights strapped to your arms and legs as well as on your back. The stronger and more physically fit you are, the better you'd be able to handle it.

Although having to carry that extra weight all the time would put more strain on the body, and on the heart. Again, the better your fitness, the longer you could stand it. (Although just living in high gravity would pretty much compel you to get into better shape.)

 

[Timo]

Prolonged exposure to low gravity in the ongoing space programs has yielded surprising results on the bodily effects. Nobody has so far managed prolonged exposure to high gravity - quite possibly, surprises might await us there as well, and a human sent to live on a world of 1.05 G would be doomed to a horrible death within months.

On the other hand, our heroes are beneficiaries of highly advanced medical science. It might be that they have been engineered not so much to cope with high gee or low gee, but to be more robust overall. And not by making the organs better, but by switching off a few genes so that their bodies don't adapt to the gravity changes in any manner and thus don't do harm to themselves.

Timo Saloniemi

 

[JarodRussell]

If low gravity reduces muscles and bone stability, high gravity might strengthen muscles and bones for one thing?

 

[Greg Cox]

If low gravity reduces muscles and bone stability, high gravity might strengthen muscles and bones for one thing?

Given time to adjust, maybe, but I wonder what the immediate effects of high-gravity would be on an average human? And just how high is too high to cope?

And, yeah, the idea that Vulcan has a slightly higher gravity than Earth does seem to have seeped into our collective understanding somehow. I'm pretty sure I've alluded to in my book and nobody, not fans, not Pocket, has ever flagged it . . . .

 

[Christopher]

But it's reasonable to assume that its gravity isn't much higher, because Vulcans still have a humanoid frame equivalent in height and build to humans.

 

[Hartzilla2007]

IIRC, it's been in at least one Trek Lit novel that Spock upped the gravity setting for his cabin, causing Kirk (I think) to nearly trip over the "gravity shelf" when entering it. Can't remember which book(s) though.

It's Enterprise: The First Adventure.

 

[CorporalCaptain]

IIRC, it's been in at least one Trek Lit novel that Spock upped the gravity setting for his cabin, causing Kirk (I think) to nearly trip over the "gravity shelf" when entering it. Can't remember which book(s) though.

It's Enterprise: The First Adventure.

Thank you. I thought so, and was gonna check that tonight, but thanks.

 

[JoeZhang]

But it's reasonable to assume that its gravity isn't much higher, because Vulcans still have a humanoid frame equivalent in height and build to humans.

It would have to be virtually the same - even minor differences would have an high impact on the evolutionary development of the species (there was a great BBC documentary on this very subject a few years ago but sadly it is not available online).

 

[CorporalCaptain]

But it's reasonable to assume that its gravity isn't much higher, because Vulcans still have a humanoid frame equivalent in height and build to humans.

It would have to be virtually the same - even minor differences would have an high impact on the evolutionary development of the species (there was a great BBC documentary on this very subject a few years ago but sadly it is not available online).

Hang on just one second.

You can't seriously be making inferences about Vulcan's gravity from the humanoid frame of Vulcans, can you—a frame which is astronomically unlikely for the Vulcans to have had in the first place, "Hodgkin's Law" notwithstanding?

Why not 1.4G?

 

[Christopher]

Of course, realistically, aliens wouldn't be humanoid at all. But it doesn't pay to approach these as black-and-white questions. Yes, it's a work of fiction, but it's one that's generally made at least something of an effort to justify its conceits. Roddenberry's original series proposal and bible stated that the Enterprise would preferentially visit worlds whose gravity, atmosphere, climate, etc. were fairly close to Earth-normal, as a justification for why the "alien" characters they met were so humanlike and the environments they visited were so much like a studio backlot or a Los Angeles-area hillside or desert or park. It's about striking a balance between plausibility and necessity -- using human actors and Earthly locations for lack of an alternative, but trying to justify it scientifically to the extent that one could.

Why not 1.4g? Because that's high enough that human characters would be noticeably affected by it and would be likely to remark on it, neither of which is the case in canon. What we see onscreen is that Vulcan gravity is not noticeably an issue for humans; therefore the logical conclusion is that it's fairly close to Earth gravity. Even Mandel's 1.251g might be a bit steep.

 

[CorporalCaptain]

Why not 1.4g? Because that's high enough that human characters would be noticeably affected by it and would be likely to remark on it, neither of which is the case in canon. What we see onscreen is that Vulcan gravity is not noticeably an issue for humans; therefore the logical conclusion is that it's fairly close to Earth gravity. Even Mandel's 1.251g might be a bit steep.

OK, now this is fair.

Note on notation: According to http://en.wikipedia.org/wiki/Standard_gravity, one standard gravity is often written as g, although they claim that usage is incorrect. http://en.wikipedia.org/wiki/Earth's_gravity clarifies the notation as correct, though (allowing two different senses of it).

The Memory Beta page at http://memory-beta.wikia.com/wiki/Vulcan_(planet) depicts Vulcan gravity as "1.4 G", with a capital G. Looks like that is nonstandard.

 

[Christopher]

Yes, the capital G in physics notation is generally used for the universal gravitational constant, 6.67 x 10^-11 Nm^2/kg^2. (And I remembered the numbers off the top of my head but had to look up the units. I'm out of practice.)

As for the mixed messages about g, I think what it's saying is that the proper label for the standard gravity at the Earth's surface is g-sub-0 or sub-n; but a g (sometimes rendered "gee") is a unit of acceleration equal to the standard gravity, which is 9.8 m/s^2. If you're a jet pilot and you do maneuvers that subject you to an acceleration of 98 m/s^2, then you've experienced 10 g of acceleration -- or you've pulled ten gees, more informally.