Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 07-14-2017, 08:48 AM   #1
vicky_molokh
GURPS FAQ Keeper
 
vicky_molokh's Avatar
 
Join Date: Mar 2006
Location: Kyv, Ukraine
Default Zodiacal Dust and Spaceship Detection

Greetings, all!

In a thread far away a long time ago, upping the amount of zodiacal dust in the setting's solar system(s) was mentioned as a way of making detection of objects in space harder. The question is: how much can it be upped without having other unforeseen/undesirable consequences and how much would it reduce the detection bonuses?

Also, if there are other plausible ways to achieve a similar outcome, they're welcome.

Thanks in advance!
__________________
Vicky 'Molokh', GURPS FAQ and uFAQ Keeper
Also, GURPS Discord is a nice place for (faster) Q&A and overall GURPS dicussion.
vicky_molokh is online now   Reply With Quote
Old 07-14-2017, 05:16 PM   #2
johndallman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: Zodiacal Dust and Spaceship Detection

Well, trying to figure this out, the dust is responsible for the brightness of the sky in the 5-50 micron infra-red band. Increasing the amount of dust will start to reduce the +24 bonus for a target silhouetted against deep space (Spaceships, p44-45). However, I don't know how to work out how much dust you need to reduce the bonus.

The mass of the solar system's dust cloud is small on a solar system scale (about a 15-killometre asteroid), but quite large on a human industry scale. You also have to grind it remarkably fine, and disperse it very widely, which sounds expensive. I think you'll need to be really quite high-tech to do enough of this to be noticed, never mind to have any side-effects other than annoying astronomers.
johndallman is online now   Reply With Quote
Old 07-14-2017, 05:44 PM   #3
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Zodiacal Dust and Spaceship Detection

Quote:
Originally Posted by johndallman View Post
The mass of the solar system's dust cloud is small on a solar system scale (about a 15-killometre asteroid), but quite large on a human industry scale. You also have to grind it remarkably fine, and disperse it very widely, which sounds expensive. I think you'll need to be really quite high-tech to do enough of this to be noticed, never mind to have any side-effects other than annoying astronomers.
That's assuming we're talking our solar system, and deliberate action. A protoplanetary disk is probably something like 10^12 times the density of our dust cloud.

As for the effects on detection: it depends on detector details, because it varies with sensor resolution, but a decent rule of thumb is to reduce range by the fourth root of sky brightness, so 10,000 times brighter would be 1/10 detection range (side note: the +24 should really replace the +10 for in plain sight, not add to it).
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Old 07-15-2017, 05:17 AM   #4
vicky_molokh
GURPS FAQ Keeper
 
vicky_molokh's Avatar
 
Join Date: Mar 2006
Location: Kyv, Ukraine
Default Re: Zodiacal Dust and Spaceship Detection

Quote:
Originally Posted by Anthony View Post
That's assuming we're talking our solar system, and deliberate action. A protoplanetary disk is probably something like 10^12 times the density of our dust cloud.

As for the effects on detection: it depends on detector details, because it varies with sensor resolution, but a decent rule of thumb is to reduce range by the fourth root of sky brightness, so 10,000 times brighter would be 1/10 detection range (side note: the +24 should really replace the +10 for in plain sight, not add to it).
And how much denser and how much brighter can it reasonably get without upsetting planetary formation, climates, requiring a very specific solar history etc.?
__________________
Vicky 'Molokh', GURPS FAQ and uFAQ Keeper
Also, GURPS Discord is a nice place for (faster) Q&A and overall GURPS dicussion.
vicky_molokh is online now   Reply With Quote
Old 07-15-2017, 06:37 AM   #5
johndallman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: Zodiacal Dust and Spaceship Detection

Quote:
Originally Posted by vicky_molokh View Post
And how much denser and how much brighter can it reasonably get without upsetting planetary formation, climates, requiring a very specific solar history etc.?
Dust has quite a short lifespan in the inner solar system, compared to the lifespan of the solar system. A dust grain will usually be gone within ten million years: they get swept away by the solar wind and radiation pressure, collide with planets, and so on.

The sources of present-day dust include short-period comets, collisions between asteroids and Kuiper Belt Objects, and interstellar dust grains.
johndallman is online now   Reply With Quote
Old 07-15-2017, 07:14 PM   #6
Calvin
 
Join Date: Jan 2014
Location: Calgary
Default Re: Zodiacal Dust and Spaceship Detection

There's a book by Ian M. Banks called Feersum Ennjin which has an incoming interplanetary dust cloud as one of the major plot points for the book. The idea being that it's substantial enough to block a substantial amount of sunlight, which does all sorts of bad things to crops.

If you wanted a hard(ish) sci-fi way of having a thick enough dust cloud for your needs, you might set the campaign during such an event. The dust might not stick around very long on a stellar level, but that could still mean several generations of people living with the dust cloud as a reality.

Granted, being thick enough to make agriculture much more difficult probably goes against your desire to avoid "unforeseen/undesirable consequences", but you could tone it down a little.

As for a scientific basis for reducing the modifiers to detect something, I couldn't really give you a proper answer.
Calvin is offline   Reply With Quote
Reply

Tags
detection, spaceships, zodiacal dust

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 03:11 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.