SFRPG

The forum for Science Fiction Role Playing Game inspiration and information! So Say We All!
It is currently Fri Nov 24, 2017 2:12 am

All times are UTC




Post new topic  Reply to topic  [ 20 posts ]  Go to page Previous 1 2
Author Message
PostPosted: Sun Jun 05, 2016 12:02 pm 
Offline

Joined: Thu Sep 18, 2008 12:41 pm
Posts: 409
Location: Northern California
Belatedly, tall and skinny I think comes from the idea that gravity is pulling us down, compacting us. This actually does happen, but the effect is apparently pretty small (I remember apocryphal "statistics" saying it's a few centimeters from "science" books from when I was a kid, but I can't find such lavish numbers these days). The idea is (somehow) without gravity to pull down and compact our bones, we'd grow taller.

I personally don't believe this, I think genetics says when our bones start and stop growing; if this were true, someone who is bedridden since they were a child due to some sort of injury or something would end up 2m or 3m tall or something -- they're laying down, no longer being compressed by the typical axis of gravity, but this doesn't happen. Similarly, those of us in the modern "western" world should have very long femurs - again, we spend an inordinate amount of time sitting so again, the femur is no longer performing its job holding us up against gravity, so shouldn't it grow? But it doesn't. (Perhaps it does happen, but I think the difference would be small - not significantly taller than the norm.)

My personal opinion is that your spacer won't even be skinnier. If I had to bet, I'd say your spacer will be fatter; modern day space travelers often talk about how out of shape they get, how much weight they gain, simply because low gravity means moving around is easier. If he spends a lot of time in space, osteoporosis is going to be a serious issue - the bones are going to be the same size as someone on Earth with a similar genetic make up / diet, but the bones are going to be a lot less dense. Apparently, there's all kinds of other issues that are caused by low gravity, like blood pooling in certain parts of the body, blood valve weakening, and so on.


Top
   
PostPosted: Sun Jun 05, 2016 1:35 pm 
Offline
User avatar

Joined: Wed May 18, 2011 7:01 pm
Posts: 335
Location: Bristol
Thanks.
I can now see the dieting fad of the future: Hey Martians & Spacemen - want to lose weight fast? Visit Earth and shed pounds without having to do all that dull visiting the gym stuff! :-)


Top
   
PostPosted: Fri Jun 10, 2016 3:04 pm 
Offline

Joined: Thu Jul 12, 2012 10:11 pm
Posts: 314
Location: Near Frankfurt, Germany
strontygirl wrote:
Another gravity question... can anyone think of any settings (books especially, but RPGs as well) where artificial gravity exists BUT varying gravity on planets is still important to the plot? The kind of thing where you have artificial gravity on your ship, your space station or possibly even your house. But as soon as you nip down the road to the shops or take the dog for a walk you have to cope with the normal planetary gravity.

I'm asking, 'cos I'm coming to realise that many of the books I'm reading seem to think that "We have artificial gravity" seems to mean "We can rock up to Mars and change THE WHOLE PLANET'S gravity to 1g"!!! WTF?

Seriously if you have that kind of technology, why haven't you weaponised it?! Defeat the enemy by turning the gravity of their homeworld up to 11... :-)


The Honor Harrington series comes to mind. Various characters (including the protagonist) are from high-gravity worlds.

Artificial gravity exists, and they *are* weaponizing it. A lot of weapons down to, IIRC, small arms use gravity rather than chemical propellants or electromagnets to accelerate projectile.

_________________
Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards. Sir Frederick Hoyle
Earth is the cradle of humanity, but one cannot live in a cradle forever. Konstantin Tsiolkovsky
Man has earned the right to hold this planet against all comers, by virtue of occasionally producing someone completely bat**** insane. xkcd #556
Just like people, stars can be very important without being terribly bright. Phil Plait, "Bad Astronomy"


Top
   
PostPosted: Fri Jun 10, 2016 4:21 pm 
Offline
User avatar

Joined: Wed May 18, 2011 7:01 pm
Posts: 335
Location: Bristol
thanks. I read the first few Honor Harrington books aeons ago. Probably need to re-read them.


Top
   
PostPosted: Sat Jun 11, 2016 1:01 am 
Offline
User avatar

Joined: Thu Jul 03, 2008 1:07 pm
Posts: 992
Location: MA, USA
strontygirl wrote:
Thanks.
I can now see the dieting fad of the future: Hey Martians & Spacemen - want to lose weight fast? Visit Earth and shed pounds without having to do all that dull visiting the gym stuff! :-)


That'd be some advertising campaign! :lol: Do it for any sci-fi campaigns you're in, it's good.

As for the Honor Harrington books, I liked the first 7 or so and then the author should've started a new series.

_________________
"Are you in charge here?"

"No, but I'm full of ideas!"

-----------------------------------------------------------
Also not a Dave.


Top
   
PostPosted: Sat Jun 11, 2016 3:37 am 
Offline

Joined: Thu Sep 18, 2008 12:41 pm
Posts: 409
Location: Northern California
strontygirl wrote:
Thanks.
I can now see the dieting fad of the future: Hey Martians & Spacemen - want to lose weight fast? Visit Earth and shed pounds without having to do all that dull visiting the gym stuff! :-)


Visiting worlds with higher gravity may result in problems including but not exclusive to lightheadedness, broken and bruised bones, heart attack, vericose veins, disorientation, nausea, movement injuries, immune system disorders, injuries to the foot from falling items, trauma and even death from falling, the need to determine "floors" and "ceilings" and "walls" of a room. Results will vary. Trips to Earth are not recommended for all persons, particularly those with a history of heart problems, low bone density, or those requiring immune system boosters. Consult with your doctor before undertaking this or any other dietary regimen.


Sir Chaos wrote:
Artificial gravity exists, and they *are* weaponizing it. A lot of weapons down to, IIRC, small arms use gravity rather than chemical propellants or electromagnets to accelerate projectile.


I understand that Honor Harrington is total Space Opera, but admittedly that makes me shakes my head a bit. Gravity is pretty inefficient as a propulsion system for such small devices.

I guess it could theorhetically be done, but I think by the time you could make gravity efficient enough to use in pistols or rifles, it'd be easier to just use gravity directly as a weapon. Instead of spinal mounts or lasers, you'd have "mass collapsers" or something.


Top
   
PostPosted: Sat Jun 11, 2016 1:57 pm 
Offline

Joined: Thu Jul 12, 2012 10:11 pm
Posts: 314
Location: Near Frankfurt, Germany
epicenter wrote:
I understand that Honor Harrington is total Space Opera, but admittedly that makes me shakes my head a bit. Gravity is pretty inefficient as a propulsion system for such small devices.

I guess it could theorhetically be done, but I think by the time you could make gravity efficient enough to use in pistols or rifles, it'd be easier to just use gravity directly as a weapon. Instead of spinal mounts or lasers, you'd have "mass collapsers" or something.


There´s always the question how easy it is to project gravity, the inverse square law being what it is. Generating gravity in a missile tube to fire a missile is one thing, generating gravity strong enough to damage a target a million kilometers away - without it damaging by own ship in the process - could be an entirely different challenge.

For that matter, a "mass collapser" missile warhead would not be too feasible, either, since existing warheads are effective at ranges in the hundreds of thousands of kilometers, and point defense becomes disproportionately more effective the closer a missile approaches - inverse square law again.

The closest they get, IIRC, is that their counter-missiles - small missiles intended to intercept bigger missiles with anti-ship warheads - do not carry a warhead at all, but are intended to intersect their own gravity drive field with that of the anti-ship missile, which results in destruction of both missiles. (This mutual drive field kill only works if both fields are within a range strength range relative to each other - a missile could not destroy a starship by drive field intersection)

Or rather, that´s the closest intended use of gravity technology. At one point, the protagonists remote-control a small craft to power up its gravity drive field while it´s still in the hangar of its mothership - with predictably spectacular and catastrophic results.

_________________
Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards. Sir Frederick Hoyle
Earth is the cradle of humanity, but one cannot live in a cradle forever. Konstantin Tsiolkovsky
Man has earned the right to hold this planet against all comers, by virtue of occasionally producing someone completely bat**** insane. xkcd #556
Just like people, stars can be very important without being terribly bright. Phil Plait, "Bad Astronomy"


Top
   
PostPosted: Tue Jun 14, 2016 9:53 am 
Offline

Joined: Thu Sep 18, 2008 12:41 pm
Posts: 409
Location: Northern California
Yeah, but you were talking about small arms in the post I was replying to, not the missiles or space combat weapons you're talking about now. If you can create efficient propulsion using gravity for small arms, it'd be easier to use gravity as the weapon itself for small arms. The ranges are much less.


Top
   
PostPosted: Tue Jun 14, 2016 2:28 pm 
Offline
User avatar

Joined: Tue Jul 08, 2008 8:42 pm
Posts: 2661
Location: Texas, USA
The inverse-square law applies to light too, but Lasers appear to be an effective weapon. I think that if you are going to postulate artificial gravity fields (projections of gravity waves), then a gravitic weapon that can act similar to a laser (range etc.) should be a reasonable extension at a higher tech level.

_________________
My friends call me Richard. You can call me Sir.
www.XmasDragon.com


Top
   
PostPosted: Thu Jun 16, 2016 12:34 pm 
Offline

Joined: Thu Jul 12, 2012 10:11 pm
Posts: 314
Location: Near Frankfurt, Germany
Cyborg IM1 wrote:
The inverse-square law applies to light too, but Lasers appear to be an effective weapon. I think that if you are going to postulate artificial gravity fields (projections of gravity waves), then a gravitic weapon that can act similar to a laser (range etc.) should be a reasonable extension at a higher tech level.


True enough.

It would still be a matter of energy, though - how much energy does it take to generate a laser beam capable of damaging a target, and how much to project sufficient gravity to do similar damage to the target over the same distance? And even for handguns - would the extra energy expenditure to project gravity by handgun be worth it, compared to gravity-accelerated projectiles?

Also, while we already know how to focus light into a sufficiently tight beam, even people in the Honor Harrington universe might not have figured out how to focus gravity tightly enough. We´d need fairly strong gravity in a localized area, not a diffuse "wave" of minor gravitational force. Though come to think of it, that sort of wave could, since gravity can bend light, too, theoretically be used as a defense against laser and similar energy weapons.

_________________
Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards. Sir Frederick Hoyle
Earth is the cradle of humanity, but one cannot live in a cradle forever. Konstantin Tsiolkovsky
Man has earned the right to hold this planet against all comers, by virtue of occasionally producing someone completely bat**** insane. xkcd #556
Just like people, stars can be very important without being terribly bright. Phil Plait, "Bad Astronomy"


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 20 posts ]  Go to page Previous 1 2

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Limited