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Message no. 1
From: Jester <jester@**********.NL>
Subject: thermographic vision-question
Date: Tue, 2 Feb 1999 20:40:17 +0100
O.K. Surely you guys/and gals on this list, can help me. I have this
player in the group who sees thermographic vision as the ultimate
solution to perception tests. He states that with thermographic
vision you can see nearly (through) everything. I think he's
mistaking it for IR-vision, but I can't get that in his head.

Could someone please post a mail explaining what thermographic vision
is, and how it works. Preferably long, with lot's of difficult words
in it (his English isn't that good:)).

Many thanx,

--
When you're frozen solid, you really don't think much about sex anymore.
--Buck Bundy--
Jester
<jester@**********.nl>

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Message no. 2
From: Max Rible <slothman@*********.ORG>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 12:00:28 -0800
At 20:40 2/2/99 +0100, Jester wrote:
>O.K. Surely you guys/and gals on this list, can help me. I have this
>player in the group who sees thermographic vision as the ultimate
>solution to perception tests. He states that with thermographic
>vision you can see nearly (through) everything. I think he's
>mistaking it for IR-vision, but I can't get that in his head.
>
>Could someone please post a mail explaining what thermographic vision
>is, and how it works. Preferably long, with lot's of difficult words
>in it (his English isn't that good:)).

Thermographic vision is IR vision. Seeing into the IR far enough
to spot body heat is basically magical: the problem is equivalent
to taking pictures with a camera whose metal is glowing.

It seems to me that thermographic vision is just an extra cone
that picks up where the red one leaves off and covers the IR
down to the range where room-temperature bodies emit. (There's a
bit in one of the Denizens of Earthdawn books that mentions that
the races that have thermographic vision have three extra colors
in their rainbow.)

It does make it easy to see where people have applied makeup that
might be invisible to ordinary sight; it will alter the pattern
of radiation of heat, and will seldom be designed to have the same
IR reflective characteristics as skin.

As far as I know, most substances are not transparent to IR. A
corp that wanted to make life difficult for folks with IR
could make the walls of their building radiate at the same temperature
as the guards; the guards would then have camouflage bonuses to negate
any advantages that go with someone seeing into the IR.

Give the player the bonuses on the Perception table and make him
bring in articles from reputable journals like Scientific American
to convince you of anything more.


--
%% Max Rible %%% max@********.com %%% http://www.amurgsval.org/~slothman/ %%
%% "Ham is good... Glowing *tattooed* ham is *bad*!" - the Tick %%
Message no. 3
From: Mongoose <m0ng005e@*********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 14:23:47 -0600
O.K. Surely you guys/and gals on this list, can help me. I have this
player in the group who sees thermographic vision as the ultimate
solution to perception tests. He states that with thermographic
vision you can see nearly (through) everything. I think he's
mistaking it for IR-vision, but I can't get that in his head.

Could someone please post a mail explaining what thermographic vision
is, and how it works. Preferably long, with lot's of difficult words
in it (his English isn't that good:)).


+++++++++++++++++

Simple question that might clear things up,in small words- if
thermovison (which IS vision of IR radiation) lets you see through walls,
why do people build houses to keep warm?
IR radiation does not pass though solid objects, as demonstrated when
using, say, a common TV remote control, which emits pulses of IR "light",
which the controlled device has a sensor for. I does mostly pass through
smoke, cloth, and other (occasionally light opaque) thin materials. Also,
it is partially blocked by some materials that do not block light- like
common window glass.

Mongoose
Message no. 4
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 15:16:00 -0500
On Tue, 2 Feb 1999, Jester wrote:

> Could someone please post a mail explaining what thermographic vision
> is, and how it works. Preferably long, with lot's of difficult words
> in it (his English isn't that good :) ).

Okay, here's how it works: Infrared radiation behaves pretty much
like any other form of electromagnetic radiation. It is directly
analogous to light or radio or microwaves.
Typically, the infrared band is considered to be more or less in
the 3 to 20 micron range (i.e. the wavelength of the waves as they
propagate is 3-20 microns long). Whether or not a substance is
transparent to radiation of a given wavelength depends largely on the
size of the crystal structure of the object in question. Most objects
(wood, concrete, rock, water, and even some types of glass) are more or
less opaque to radiation of this wavelength. As such, you won't be able
to "see through" these kinds of materials when using thermographic vision.
However, having said that, I will point out that thermal energy is
transferred around by a variety of different mechanisms, of which
radiation is only one. Heat is also transferred directly via conduction.
That it, if two objects are touching, heat will move from the hot one to
the cool one. This is how an electric stove works. The water is in
contact with the pan, and the pan is in contact with the heating element.
Heat moves from the hot heating element to the pan, and then to the water.
It doesn't radiate through the pan directly to the water (although that
would be kind of cool).
This phenomenon can be used to one's advantage however. As
something cools, the heat needs to go somewhere (a la conservation of
energy). If something warm sits in one place for a while, its heat will
bleed off into the surrounding environment as it cools. This raises the
ambient temperature of things around it. Something that generates its
own heat (like a warm-blooded mammal, perhaps), it will continue to heat
the things around it. For example, if you sit in a chair for a while and
then get up, the chair is still warm, because it has been heated by your
body.
How does this help you? If a security guard has been leaning up
against the same wall for a half hour, his body heat will have "bled
through" the wall to some extent, simply because his body is heating the
wall via conduction. As an object heats up, it will radiate or conduct
the heat away just like the thing that heated it. So the wall will
conduct heat to the floor and ceiling, but more importantly, it will
radiate thermal energy in this same 3-20 micron wavelength band. It is
this energy that your thermographic vision sees. So when the guard leans
against the wall for a half hour, he creates a warm spot that you can see
on the other side.
How long does it take this heat signature to propagate through a
material? It depends on the thermal conductivity of the material. Some
materials (like metal) conduct heat very quickly (which is why they make
good pots and pans). Others, like fiberglass, conduct heat very slowly
(which is why they make good thermal insulation for your house). Also,
you need to consider the mass of the object. Density, thermal
conductivity, and thermal capacitance (how much heat a material can
"hold") are very important to determining how long it takes to be able to
see someone's heat signature through another object. Obviously 3 feet of
concrete warms up an awful lot slower than a 1" piece of steel plate.
Basically, the longer something stays in one spot, the easier it
will be to see. Leave it up to GM discretion as to how long it will take.
But even if the person's heat signature bleeds through an object,
it may still be a fuzzy, indistinct blob, especially if the barrier is
very thick or has poor thermal conductivity. As such, I generally apply
some modifier (+2 to +4) to shots through barriers or whatever, as you
can't quite tell where a person is and just sort of aim for the middle of
the blob.

I hope this answers your question.

Marc
Message no. 5
From: Joshua Mumme <Grimlakin@**********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 14:25:01 -0600
Ahh the ever present of xray super duper whammy I see you vision.


Natural Thro-Graphic vision is cool cause you can see invisible people and
through smoke and stuff. unless it is themal smoke. But that is another
story. Themo-Graphic vision or however it is spelled correctly is cool
stuff at night and whatnot. You see differences in temerature. Gradiants
as it would be. These gradiants give off light in the thermal optic
spectrum. Seeing through walls is generally not something in the world of
possibilities. I personally rule that thermal optics can only see through
substances that don't give off a temperature. So useing themal visoion to
see through a window is a near impossibility. That is how I would use
it. People can still hide from Thermal Graphic vision.


Grimlakin
Message no. 6
From: David Buehrer <dbuehrer@******.CARL.ORG>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 13:40:10 -0700
For the mere cost of a Thaum, Jester wrote:
/
/ O.K. Surely you guys/and gals on this list, can help me. I have this
/ player in the group who sees thermographic vision as the ultimate
/ solution to perception tests. He states that with thermographic
/ vision you can see nearly (through) everything. I think he's
/ mistaking it for IR-vision, but I can't get that in his head.
/
/ Could someone please post a mail explaining what thermographic vision
/ is, and how it works. Preferably long, with lot's of difficult words
/ in it (his English isn't that good:)).

I take it he's seen the Robocop movie where Robo uses his "IR" vision
to see through walls :)

It doesn't work that way.

A better representation would be the Predator movies. That's how
thermographic vision works. Combine it with the ability to see in the
"normal" spectrum and you'll get an idea of how metahumans with
thermographic vision see the world.

Other members can explain the physics of it better.

-David B.
--
"Earn what you have been given."
--
email: dbuehrer@******.carl.org
http://www.geocities.com/TimesSquare/1068/homepage.htm
Message no. 7
From: Oliver McDonald <oliver@****.SPYDERNET.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 13:13:51 -0800
On Tue, 2 Feb 1999 12:00:28 -0800, Max Rible wrote:

>As far as I know, most substances are not transparent to IR. A
>corp that wanted to make life difficult for folks with IR
>could make the walls of their building radiate at the same temperature
>as the guards; the guards would then have camouflage bonuses to negate
>any advantages that go with someone seeing into the IR.

All substances are somewhat transparent to IR. If a corp were to make their walls radiate
at the same temperature as their guards, most people in the building would have severe
problems, as this would be close to 30 degrees (F) above a comfortable working
environment. If the guards (presumably wearing bulky armour and such like) had to
chase down a team of runners, they may just pass out from heat prostration. All that the
person with IR vision would have to do to avoid this problem would be to see the green
uniform against the white wall.
---------------------------------------------------------------------
Oliver McDonald - oliver@*********.com
http://web2.spydernet.com/oliver/shadowrun.html
---------------------------------------------------------------------

"We all enter this world in the same way: naked, screaming, and soaked in blood. But
if you live your life right, that kind of thing doesn't have to stop there."
Dana Gould.

Space. The Final Frontier. Let's not close it down.
Brought to you via CyberSpace, the recursive frontier.
Message no. 8
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 21:19:20 +0000
Jester wrote:
>
> O.K. Surely you guys/and gals on this list, can help me. I have this
> player in the group who sees thermographic vision as the ultimate
> solution to perception tests. He states that with thermographic
> vision you can see nearly (through) everything.

No. Your player is assuming the crap Hollywood version of IR (i.e.
Predator I and II). Assume any solid object (including glass) is opaque
to IR.

If you can see through everything you can't see anything!

Very thin plastics sheets like bin-liners are quite transperent and so
are some *very* expensive materials used to make lenses for IR cameras.
So if you find a window that you can see though with Thermographic
Vision, steal it.

> I think he's
> mistaking it for IR-vision, but I can't get that in his head.

Thermographic vision is IR vision.

> Could someone please post a mail explaining what thermographic vision
> is, and how it works. Preferably long, with lot's of difficult words
> in it (his English isn't that good:)).

Thermographic vision allows you to see temperature differences. A person
is generally warmer than his surroundings and so he will appear as a hot
shape against a cold background.

In SR this ability is very precise, so very small temperature changes
will be seen. This allows for a good perception of the surroundings,
although not as good as normal vision. Thermographic vision is in fact
more limited than normal vision; reading number plates for instance
would be impossible or at least very difficult. Recognising faces would
also be impossible/v.difficult.

Different materials give out different IR profiles. So two different
materials at the same temperature should be distinguishable if the
vision was good enough. A lizard on a rock might be seen by a Dwarf, but
a Sammy with the Cyber version might miss it.

Basically Thermographic Vision is nice in the dark, but normal vision is
visually superior.

Regards

- David Woods
Message no. 9
From: David Buehrer <dbuehrer@******.CARL.ORG>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 14:32:05 -0700
For the mere cost of a Thaum, David Woods wrote:
/
/ No. Your player is assuming the crap Hollywood version of IR (i.e.
/ Predator I and II). Assume any solid object (including glass) is opaque
/ to IR.

Okay, I'll bite. How is the Predator version crap? IIRC Predator couldn't
see through anything with his IR. I'm genuinly curious :)


-David B.
--
"Earn what you have been given."
--
email: dbuehrer@******.carl.org
http://www.geocities.com/TimesSquare/1068/homepage.htm
Message no. 10
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 21:30:02 +0000
Joshua Mumme wrote:
>
> Ahh the ever present of xray super duper whammy I see you vision.
>
> Natural Thro-Graphic vision is cool cause you can see invisible people

Is this canon? Doesn't Invisibility effect any sort of vision? The mana
version doesn't actually do anything physically with light anyway.
Doesn't it just mess with the viewer's mind?

Regards

- David Woods
Message no. 11
From: "Davidson, Chris" <Christopher.Davidson@***.BOEING.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 13:28:42 -0800
> For the mere cost of a Thaum, David Woods wrote:
> /
> / No. Your player is assuming the crap Hollywood version of IR (i.e.
> / Predator I and II). Assume any solid object (including glass) is opaque
> / to IR.
>
> Okay, I'll bite. How is the Predator version crap? IIRC Predator couldn't
> see through anything with his IR. I'm genuinly curious :)
>
Not with is IR, but with his Ultraviolet vision he
could. I think he also had sonicvision too.

-Toffer
Message no. 12
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 21:35:12 +0000
David Buehrer wrote:
>
> For the mere cost of a Thaum, David Woods wrote:
> /
> / No. Your player is assuming the crap Hollywood version of IR (i.e.
> / Predator I and II). Assume any solid object (including glass) is opaque
> / to IR.
>
> Okay, I'll bite. How is the Predator version crap? IIRC Predator couldn't
> see through anything with his IR. I'm genuinly curious :)

Perhaps I'm thinking of Predator II. That film had the alien looking
through wombs to see foetuses.

Regards

- David Woods
Message no. 13
From: David Buehrer <dbuehrer@******.CARL.ORG>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 14:44:03 -0700
For the mere cost of a Thaum, David Woods wrote:
/
/ David Buehrer wrote:
/ >
/ > Okay, I'll bite. How is the Predator version crap? IIRC Predator couldn't
/ > see through anything with his IR. I'm genuinly curious :)
/
/ Perhaps I'm thinking of Predator II. That film had the alien looking
/ through wombs to see foetuses.

...oh yeah. Okay, you're right. That was pretty bogus.

And another thing that was bogus was the fact that the Predators hunted
during the hot season based on the idea that they came from a hot
world. I'm sorry, but I don't think thermographic vision would evolve
in a warm environment. It would probably evolve in a cold environment
that would let you see your warm-blooded targets standing out against a
cold background. In a hot environment critters don't have to expend as
much energy to keep warm and would fade into the background, or
cold-blooded critters (like lizards and snakes) would be damn near
invisible.

</end rant?>

Not that I didn't like the movies (loved 'em in fact :)

Anyway, if the player is still causing problems send his character on a
run in the desert and sick cold blooded critters on him <EG>.

-David B.
--
"Earn what you have been given."
--
email: dbuehrer@******.carl.org
http://www.geocities.com/TimesSquare/1068/homepage.htm
Message no. 14
From: Paul Gettle <RunnerPaul@*****.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 18:09:04 -0500
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At 01:40 PM 2/2/99 -0700, David Buehrer wrote:
>I take it he's seen the Robocop movie where Robo uses his "IR" vision
>to see through walls :)
>
>It doesn't work that way.

Another movie guilty of this is Blue Thunder. (If I remember
correctly, the TV show spinoff also had an incorrect portrayal of IR,
as did Knight Rider. Blame it on all the TV Action-Dramas we all
watched when we were 7.)

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Message no. 15
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 23:00:14 +0000
"Davidson, Chris" wrote:
>
> > For the mere cost of a Thaum, David Woods wrote:
> > /
> > / No. Your player is assuming the crap Hollywood version of IR (i.e.
> > / Predator I and II). Assume any solid object (including glass) is opaque
> > / to IR.
> >
> > Okay, I'll bite. How is the Predator version crap? IIRC Predator couldn't
> > see through anything with his IR. I'm genuinly curious :)
> >
> Not with is IR, but with his Ultraviolet vision he
> could. I think he also had sonicvision too.

Really? Irrc the transmission of most glasses drops quite rapidly
<400nm. I would have thought that most objects, opaque in the visible,
would be opaque in the UV range. Unless you know different.

As for Sonar, I can't imagine solid objects being transparent to sound
waves. Although, admittedly it's not my field.

Regards

- David Woods
Message no. 16
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 23:20:00 +0000
David Buehrer wrote:
>
> For the mere cost of a Thaum, David Woods wrote:
> /
> / Perhaps I'm thinking of Predator II. That film had the alien looking
> / through wombs to see foetuses.
>
> ...oh yeah. Okay, you're right. That was pretty bogus.
>
> And another thing that was bogus was the fact that the Predators hunted
> during the hot season based on the idea that they came from a hot
> world. I'm sorry, but I don't think thermographic vision would evolve
> in a warm environment. It would probably evolve in a cold environment
> that would let you see your warm-blooded targets standing out against a
> cold background.

If irrc there are snakes with recessed pits containing IR sensitive
cells. They use them to sense small mammals. I'm not sure, but I think
they live in jungles.

Generally speaking an IR sensor has to be at a lower temperature than
the target. Modern passive IR cameras use semi-conductor devices that
break this. It's hard to imagine how a biological system could do
something similar.

Since Mother Nature hasn't come up with anything close to SR Thermo
Vision, it's probably impossible. Magic is a wonderful thing.

> In a hot environment critters don't have to expend as
> much energy to keep warm and would fade into the background, or
> cold-blooded critters (like lizards and snakes) would be damn near
> invisible.

Of course as I mentioned previously, with enough thermal resolution,
objects can be picked out even at ambient temperature.

- David Woods
Message no. 17
From: Bob Tockley <zzdeden@*******.COM.AU>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 10:29:33 +1000
>Could someone please post a mail explaining what thermographic vision
>is, and how it works. Preferably long, with lot's of difficult words
>in it (his English isn't that good:)).

Here's the Thermographic Vision excerpt from Fields of Fire.

##############################################
Thermographic Systems
Thermographic systems read heat (infrared energy) emitted by a target.
This type of system provides few details about the target, because it
reveals only degrees of heat. SRII assumes that modem (2050) thermal
systems actually superimpose the thermographic display over a basic,
amplified low-light display for better detail. The result provides
insufficient data to gain a bonus or modifi-er, but does allow the user to
navigate past obstacles or differentiate between objects while using the
system.
Different systems use different color scales to represent the levels of
heat, but most use the following standard. Hot objects (an engine block, a
pot of boiling water) show as white, while cool objects (room temperature)
show as black, with every temperature difference in between displaying as
shades of red or green. Remember that the system judges "hot" and
"cold"
in relation to the local air or room temperature. For example,
thermographic systems used outside in the winter easily spot a person or
vehicle, because they will appear "hot" compared to the air temperature.
On the other hand, in the rain forests of South America little difference
exists between the ambient temperature (the forest's "room temperature")
and the radiated body heat of a human being, making thermographic systems
all but useless for differentiating between the forest and a person. (Odds
are that motion will give the target away, but that's a different modifier.)
When characters are using thermographic systems, the gamemaster must
consider the relative temperature of objects viewed against the ambient
temperature to determine if the system detects the target. In other words,
objects at a similar temperature show up on the display as similar colors,
making it difficult to differentiate between them if they overlap.
By definition, thermographic systems also require technology and cannot
be used when casting magic. Because the user has paid Essence for
thermographic cybereyes, however. the system becomes an accepted part of a
character's body and can be used to cast magic.

Natural Low-Light and Thermal Vision
Natural low-light or thermographic vision, such as the vision elves and
dwarfs are born with, or the enhanced senses available to a physical adept
or critter, is magical in nature. This type of vision works along
principles similar to those of low-light and thermographic systems, but
performs better than any technology can. Though a certain biological basis
exists to explain this visual ability, much of the effect can only be
explained through the application of magic.
Natural low-light or thermographic vision is assumed to be always
operating, providing vision enhancements automatically as needed. For
example, a troll sees exactly what humans see when looking at the same
view, except that every object, person, and so on is tinged with the heat
it radiates. The hotter an object, the more brilliant the color the troll
sees. Objects that are much hotter than their environment appear whiter,
surrounded by a faint glow. Trolls see this way normally, and therefore
can instantly perceive, process, and interpret what they see. Natural
low-light or thermal vision is an advantage, not a handicap.
##############################################

Here's the basics of Thermographic Vision:

+ You can't see through things. IR radiation doesn't work that way (check
out the remote control to your video control - it won't work through your
hand for instance). However, a significantly powerful heat source on the
other side of the person might be visible by the aura of heated air around it.

+ Thermographic bleeding (ie. heating up materials in contact with a warm
object) happens fairly slowly. It will take several minutes (or more
depending on the density and heat conducting properties of the wall) for
someone to heat up a wall to an extent where it is visible on the other side.

+ Thermographic Vision can be flared similarly to normal vision. All it
takes is a somewhat hot/bright heat source/light to erupt in a previously
dark area (can we say incendiary grenades, anyone?)

+ Players who try to abuse the rules in this sort of completely
unrealistic manner really piss me off. Kill them all, that's what I say.

(>) ARKHAM
"The difference between a clown and a mime? Easy. People care if the
clown gets killed."
Message no. 18
From: Jon Szeto <JonSzeto@***.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 19:41:41 EST
In a message dated 2/2/99 15:18:29 Eastern Standard Time, renouf@********.COM
writes:

> Typically, the infrared band is considered to be more or less in
> the 3 to 20 micron range (i.e. the wavelength of the waves as they
> propagate is 3-20 microns long).

Just a slight correction: the infrared band actually extends from 30 to 0.76
micrometers in wavelength (with 1 micrometer being equal to 1E-6 meter, or
one-millionth of a meter). (This according to US Army Field Manual 3-50.)
Thermographic vision, as described in SR, exists in the far-infrared spectrum
between 14 and 30 micrometers. It's at these wavelengths that the blackbody
radiation at low temperature ranges (0-100 C or thereabouts) are the greatest.
At shorter IR wavelengths (less than 14 micrometers) the amplitude for this
temperature range is too small to be detected.

Other than that you're pretty much spot on.

-- Jon
Message no. 19
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 19:52:10 -0500
On Tue, 2 Feb 1999, David Woods wrote:

> Really? Irrc the transmission of most glasses drops quite rapidly
> <400nm. I would have thought that most objects, opaque in the visible,
> would be opaque in the UV range. Unless you know different.

Transmission of UV drops off pretty quickly. Typically, if you're
doing anything with UV you need quartz or fused silica lenses. The only
reason I know this shit is because I was working on constructing a UV
Lidar for work. What a pain in my ass. "Yes, we need a huge-ass
telescope, and by the way it needs a Schmidt corrector plate that runs all
the way down to 308 nm." At which point the telescope guy says, "Okay,
but it's gonna cost ya." Trust me, this is something you *never* want to
hear from an optics supplier.

> As for Sonar, I can't imagine solid objects being transparent to sound
> waves. Although, admittedly it's not my field.

Your gut instinct is right. Glass is opaque to ultrasound.

Marc
Message no. 20
From: Joshua Mumme <Grimlakin@**********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 19:04:56 -0600
David Woods wrote:

> Joshua Mumme wrote:
> >
> > Ahh the ever present of xray super duper whammy I see you vision.
> >
> > Natural Thro-Graphic vision is cool cause you can see invisible people
>
> Is this canon? Doesn't Invisibility effect any sort of vision? The mana
> version doesn't actually do anything physically with light anyway.
> Doesn't it just mess with the viewer's mind?

I don't know if it is Canon or not. But my GM uses that rule and I like it
being that I am a physad!

>
>
> Regards
>
> - David Woods

Grimlakin
Message no. 21
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 20:04:00 -0500
On Tue, 2 Feb 1999, Jon Szeto wrote:

> Thermographic vision, as described in SR, exists in the far-infrared spectrum
> between 14 and 30 micrometers. It's at these wavelengths that the blackbody
> radiation at low temperature ranges (0-100 C or thereabouts) are the greatest.
> At shorter IR wavelengths (less than 14 micrometers) the amplitude for this
> temperature range is too small to be detected.

Thanks for the Field Manual cite, Jon. The only thing I would add
is that the shorter wavelengths have their uses (mainly for atmospheric
correction of satellite-collected infra-red data). By looking at
atmospheric absorption across a couple of the shorter IR wavelengths, you
can figure out what attenuating effect the atmosphere in having and then
take it out. While this isn't appropriate for cybereyes, but might be
handy to keep in mind for vehicular sensors (especially for aircraft).

Marc
Message no. 22
From: Paul Gettle <RunnerPaul@*****.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 20:30:40 -0500
-----BEGIN PGP SIGNED MESSAGE-----

At 11:00 PM 2/2/99 +0000, David Woods wrote:
>As for Sonar, I can't imagine solid objects being transparent to
sound
>waves. Although, admittedly it's not my field.

You've obviously _NEVER_ lived in a college dorm then. :)

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-- Paul Gettle, #970 of 1000 (RunnerPaul@*****.com)
PGP Fingerprint, Key ID:0x48F3AACD (RSA 1024, created 98/06/26)
C260 94B3 6722 6A25 63F8 0690 9EA2 3344
Message no. 23
From: "D. Ghost" <dghost@****.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 20:13:43 -0600
On Tue, 2 Feb 1999 20:30:40 -0500 Paul Gettle <RunnerPaul@*****.COM>
writes:
>-----BEGIN PGP SIGNED MESSAGE-----
>At 11:00 PM 2/2/99 +0000, David Woods wrote:
>>As for Sonar, I can't imagine solid objects being transparent to sound
>>waves. Although, admittedly it's not my field.

Disclaimer: What follows is what I remember of the physics of sound... :)

Actually, the speed at which sound travels depends on the state of
matter: Sound travels through Gas the slowest. Faster through Liquid and
fastest through Solid. In fact the reason sounds sound funny underwater
is because the sound moves so fast that it messes with your ability to
tell where it's coming from.

>You've obviously _NEVER_ lived in a college dorm then. :)

No kidding.

--
D. Ghost
(aka Pixel, Tantrum, RuPixel)
"We called him Mother Superior because of the length of his habit" --
Trainspotting
"A magician is always 'touching' himself" --Page 123, Grimoire (2nd
Edition)

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Message no. 24
From: Patrick Goodman <remo@***.NET>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 21:13:32 -0600
From: David Buehrer
Sent: Tuesday, February 02, 1999 3:44 PM

> Anyway, if the player is still causing problems send his character
> on a run in the desert and sick cold blooded critters on him <EG>.

Or juggernauts, which don't exhibit an IR signature even though they're
(presumably) warm-blooded.

Here's a question: How tall are those damn things? I know they reach
lengths (on average) of 14 or 15 meters, but how tall are they?

--
(>) Texas 2-Step
El Paso: Never surrender. Never forget. Never forgive.
Message no. 25
From: Logan Graves <logan1@*****.INTERCOM.NET>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 22:20:00 -0500
In our last episode, Marc Renouf wrote:
>
> > As for Sonar, I can't imagine solid objects being transparent to sound
> > waves. Although, admittedly it's not my field.
>
> Your gut instinct is right. Glass is opaque to ultrasound.

Of course it is.

Sound travels better through liquids, than it does through gases.
AND it travels *even* better through solids!
Otherwise, it'd be pretty pointless to get an ultrasound.

Of the three, air (a gas) is the poorest medium for propagating sound
waves (discounting vacuums, that is).

-Fenris

______________________________________________________logan1@*****.intercom.net
ARES MACROTECH
Pac Northwest Tour: 2057
========================
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Saeder-Krupp Aeronautics Research Center, Renton
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Council of Princes, Tir Tairngire-Sold Out!!
UCAS Conquest-Cancelled due to Dragon.
Message no. 26
From: K in the Shadows <Ereskanti@***.COM>
Subject: Re: thermographic vision-question
Date: Tue, 2 Feb 1999 23:14:06 EST
In a message dated 2/2/1999 6:13:44 PM US Eastern Standard Time,
RunnerPaul@*****.COM writes:

>
> Another movie guilty of this is Blue Thunder. (If I remember
> correctly, the TV show spinoff also had an incorrect portrayal of IR,
> as did Knight Rider. Blame it on all the TV Action-Dramas we all
> watched when we were 7.)

hey now, wait a second. I thought IR *could* see through walls, but IMO, I
would apply the barrier rating to the perception target number. Just the
*possibility* of seeing through a wall like that would be nice.

-K
Message no. 27
From: ArcLight <arclight@**************.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 12:03:13 +0100
> -----Original Message-----
> From: Shadowrun Discussion [mailto:SHADOWRN@********.ITRIBE.NET]On
> Behalf Of K in the Shadows
> Sent: Wednesday, February 03, 1999 5:14 AM
> To: SHADOWRN@********.ITRIBE.NET
> Subject: Re: thermographic vision-question

<snip>

> hey now, wait a second. I thought IR *could* see through walls,
> but IMO, I
> would apply the barrier rating to the perception target number. Just the
> *possibility* of seeing through a wall like that would be nice.

What about this situation: some guard hides behind a wall, as you hosed
enough lead to his direction that he dived into cover. So he is, as I said
before, behind a wall. Now, if he is in physical contact to him, eg not
just standing there but leaning to that wall, would he reveal his position
by changing its temperature? How long would this take?

ArcLight
ICQ 14322211
NO ONE IS SAFE FROM A MICROWAVE
Message no. 28
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 08:21:31 -0500
On Wed, 3 Feb 1999, ArcLight wrote:

> What about this situation: some guard hides behind a wall, as you hosed
> enough lead to his direction that he dived into cover. So he is, as I said
> before, behind a wall. Now, if he is in physical contact to him, eg not
> just standing there but leaning to that wall, would he reveal his position
> by changing its temperature? How long would this take?

Like I said before, it depends on the thickness of the wall and
what it's made of. For something like a typical cinder-block exterior
wall, it would take a few minutes, especially because they tend to be
filled with insulating foam, something that takes a while to bleed heat
through. If it's something like a carpet-backed plywood cubicle wall, it
may only take a few seconds.

Marc
Message no. 29
From: Jill <jmenning@*****.EDU>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 07:49:35 -0700
Logan Graves wrote:
> Sound travels better through liquids, than it does through gases.
> AND it travels *even* better through solids!
> Otherwise, it'd be pretty pointless to get an ultrasound.

Hmmm... our main use of ultrasound is to get around those thermal
smoke grenades the GM likes to throw at us. 'course, we throw them
back to screw up her snipers...

Jill
Message no. 30
From: Adam Getchell <acgetchell@*******.EDU>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 09:34:34 -0800
>Just a slight correction: the infrared band actually extends from 30 to 0.76
>micrometers in wavelength (with 1 micrometer being equal to 1E-6 meter, or
>one-millionth of a meter). (This according to US Army Field Manual 3-50.)
>Thermographic vision, as described in SR, exists in the far-infrared spectrum
>between 14 and 30 micrometers. It's at these wavelengths that the blackbody
>radiation at low temperature ranges (0-100 C or thereabouts) are the greatest.
>At shorter IR wavelengths (less than 14 micrometers) the amplitude for this
>temperature range is too small to be detected.

I did this calculation awhile back the last time the thermographics thread
came up: using Wien's displacement law for a temperature of 300 K (28 C)
the peak wavelength is 9.66 microns.

The peak wavelength for 0C is 10.06 microns, while the peak wavelength for
100C is 7.77 microns. Note that these are maxima for a Maxwell-Boltzman
distribution (which looks somewhat like a skewed, asymmetric normal
distribution with a sharp rise and logarithmic "tail").

Next, atmospheric absorbsion of 2.5 microns and 25 microns is almost
minimal (ie transmissivity approaches 99%), so these wavelengths are of
interest for long range imaging. Yes, transmissivity for visible light (300
- 760 nanometers or so) is also quite high in our atmosphere.

Finally, the sun's surface mean temperature is ~ 6000 K; a blackbody
radiating at that temperature would show maximum emission at 480
nanometers. Our eyes are most sensitive to 555 nm, which is close to the
sun's maximum light output.

>-- Jon

--Adam

acgetchell@*******.edu
"Invincibility is in oneself, vulnerability in the opponent." --Sun Tzu
Message no. 31
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 18:40:33 +0000
Marc Renouf wrote:
>
> On Wed, 3 Feb 1999, ArcLight wrote:
>
> > What about this situation: some guard hides behind a wall, as you hosed
> > enough lead to his direction that he dived into cover. So he is, as I said
> > before, behind a wall. Now, if he is in physical contact to him, eg not
> > just standing there but leaning to that wall, would he reveal his position
> > by changing its temperature? How long would this take?
>
> Like I said before, it depends on the thickness of the wall and
> what it's made of. For something like a typical cinder-block exterior
> wall, it would take a few minutes, especially because they tend to be
> filled with insulating foam, something that takes a while to bleed heat
> through. If it's something like a carpet-backed plywood cubicle wall, it
> may only take a few seconds.

The surface temperature of a human is very dependent on ambient
temperature. In the average run most people will be wearing clothes :).
So the surface in contact with the wall will be fairly close to ambient,
not blood temp.

Imo very little heat would be transferred to the wall. It would be tens
of minutes before a noticeable change was seen. IR cameras are used to
find people under collapsed buildings, so it is possible. I just does
think it would be any use during a fire fight.

Regards

- David Woods
Message no. 32
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 18:48:03 +0000
"D. Ghost" wrote:
>
> On Tue, 2 Feb 1999 20:30:40 -0500 Paul Gettle <RunnerPaul@*****.COM>
> writes:
> >-----BEGIN PGP SIGNED MESSAGE-----
> >At 11:00 PM 2/2/99 +0000, David Woods wrote:
> >>As for Sonar, I can't imagine solid objects being transparent to sound
> >>waves. Although, admittedly it's not my field.
>
> Disclaimer: What follows is what I remember of the physics of sound... :)
>
> Actually, the speed at which sound travels depends on the state of
> matter: Sound travels through Gas the slowest. Faster through Liquid and
> fastest through Solid. In fact the reason sounds sound funny underwater
> is because the sound moves so fast that it messes with your ability to
> tell where it's coming from.

After a little thought I've realised something.

To sound, density would be a lot like refractive index to light. So a
sound wave travelling through air encountering a solid would tend to be
strongly reflected.

> >You've obviously _NEVER_ lived in a college dorm then. :)

I was the one making the noise. (I wish)

Regards

- David Woods
Message no. 33
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 20:16:53 +0100
According to Jester, at 20:40 on 2 Feb 99, the word on
the street was...

> O.K. Surely you guys/and gals on this list, can help me. I have this
> player in the group who sees thermographic vision as the ultimate
> solution to perception tests. He states that with thermographic
> vision you can see nearly (through) everything. I think he's
> mistaking it for IR-vision, but I can't get that in his head.

Sounds like he watched Blue Thunder one too many times :) Thermographic
vision picks up heat patterns given off by whatever it is you're looking
at; you see where an object is warm and where it is cold, but that's it.
Sure, if you lean against a wall, the wall will heat up and someone on the
other side will (eventually) see where you are, but you can't see
_through_ a wall with it -- only through materials that are transparent to
infrared light (Adam Getchell will be able to name you some, I'm sure :)

> Could someone please post a mail explaining what thermographic vision
> is, and how it works. Preferably long, with lot's of difficult words
> in it (his English isn't that good:)).

I thought Martijn didn't play in your group? :)

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
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Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 34
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 20:16:53 +0100
According to Patrick Goodman, at 21:13 on 2 Feb 99, the word on
the street was...

> Or juggernauts, which don't exhibit an IR signature even though they're
> (presumably) warm-blooded.

So? They have roughly the same temperature as the area around them. That
makes them hard to spot on thermographic, but not impossible (just get it
between yourself and a warmer or colder object, for instance the sky).

> Here's a question: How tall are those damn things? I know they reach
> lengths (on average) of 14 or 15 meters, but how tall are they?

Judging from the picture in PANA, I woul say 3 or 4 meters, maybe. If it
walks with its legs sticking straight down (whether or not it does this is
difficult to tell from the picture) that height might even be doubled.

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
PE Y PGP- t(+) 5++ X++ R+++>$ tv+(++) b++@ DI? D+ G(++) e h! !r(---) y?
Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 35
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 20:16:53 +0100
According to ArcLight, at 12:03 on 3 Feb 99, the word on
the street was...

> What about this situation: some guard hides behind a wall, as you hosed
> enough lead to his direction that he dived into cover. So he is, as I said
> before, behind a wall. Now, if he is in physical contact to him, eg not
> just standing there but leaning to that wall, would he reveal his position
> by changing its temperature? How long would this take?

Long enough to warm up the wall by something like 0.5 degrees (which,
IIRC, is about the sensitivity of modern military systems, and thus IMHO a
reasonable gauge for SR's tech). That would depend on the material the
wall is made of, as some materials heat up faster than others, and also
its thickness: to warm a 1 mm thick piece of plastic sheeting takes a lot
less energy than warming up a 10 cm thick concrete wall.

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
PE Y PGP- t(+) 5++ X++ R+++>$ tv+(++) b++@ DI? D+ G(++) e h! !r(---) y?
Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 36
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 20:16:53 +0100
According to David Woods, at 21:30 on 2 Feb 99, the word on
the street was...

> > Natural Thro-Graphic vision is cool cause you can see invisible people
>
> Is this canon? Doesn't Invisibility effect any sort of vision? The mana
> version doesn't actually do anything physically with light anyway.
> Doesn't it just mess with the viewer's mind?

In SR1 and SRII the decscription for the Invisibility spell specifically
stated that thermographic vision was not affected. In SR3, no such mention
is made, so you can assume that with third edition rules, the spell fools
everyone regardless of the way their eyes are built (which is only
logical, IMHO).

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
PE Y PGP- t(+) 5++ X++ R+++>$ tv+(++) b++@ DI? D+ G(++) e h! !r(---) y?
Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 37
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 14:21:03 -0500
On Wed, 3 Feb 1999, David Woods wrote:

> The surface temperature of a human is very dependent on ambient
> temperature. In the average run most people will be wearing clothes :).
> So the surface in contact with the wall will be fairly close to ambient,
> not blood temp.

Not so, my good man. Your clothes are typically warmer that the
surrounding environment. Easy example? Grab a shirt out of your closet.
Now take the shirt you're wearing off. Hand them to someone. They will
be able to tell you (without even having to smell them! ;) ) which one
you were wearing, simply because that shirt will be warmer than the
other (which is at ambient temperature because it's been sitting in your
closet).
Further, if you're leaning up against a wall, there is no air flow
between you and your shirt, or between the shirt and the wall. This
airflow is necessary for convective heat transfer (heretofore
undiscussed). Convective heat transfer is what keeps your clothes cooler
than your body. In the absence of such convection, your shirt will
rapidly heat up to your body temperature, and will rapidly begin heating
up the wall. Easy example? Driving your car on a hot summer day. Even
if the rest of you is cool and dry, your back gets all sweaty because
there's no cooling convective airflow between you and your seat.

> Imo very little heat would be transferred to the wall. It would be tens
> of minutes before a noticeable change was seen.

Again, it depends on the wall. In some cases, you might be able
to discern the change in just a few seconds. You may not be able to tell
whether the guy hiding behind the wall is an elf or a human, but you know
there's a guy hiding behind the wall.

Marc
Message no. 38
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 14:31:55 -0500
On Wed, 3 Feb 1999, Gurth wrote:

> In SR1 and SRII the decscription for the Invisibility spell specifically
> stated that thermographic vision was not affected. In SR3, no such mention
> is made, so you can assume that with third edition rules, the spell fools
> everyone regardless of the way their eyes are built (which is only
> logical, IMHO).

Not necessarily. The way I've always had to rationalize the
thermographic thing is that your body does not actively emit light, and
thus it is easy to fool someone into thinking you're not there. Your body
*does* actively emit heat, though, and disposing of this energy is not
feasible.
But this just goes back to the age old discussion that physical
illusions should be manipulation spells, and mana illusions shouldn't care
what form of perception the person is using. But I digress...

Marc
Message no. 39
From: Joshua Mumme <Grimlakin@**********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 14:44:24 -0600
Gurth wrote:

> According to David Woods, at 21:30 on 2 Feb 99, the word on
> the street was...
>
> > > Natural Thro-Graphic vision is cool cause you can see invisible people
> >
> > Is this canon? Doesn't Invisibility effect any sort of vision? The mana
> > version doesn't actually do anything physically with light anyway.
> > Doesn't it just mess with the viewer's mind?
>
> In SR1 and SRII the decscription for the Invisibility spell specifically
> stated that thermographic vision was not affected. In SR3, no such mention
> is made, so you can assume that with third edition rules, the spell fools
> everyone regardless of the way their eyes are built (which is only
> logical, IMHO).

Shrug.. it is a GM call I suppose. Besides it isn't common fair to run into
opposition that has natural Thermal Vision. By Gm call I mean a call my GM
made.

>
>
> --
> Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html

Grimlakin
Message no. 40
From: Paul Gettle <RunnerPaul@*****.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 16:24:46 -0500
-----BEGIN PGP SIGNED MESSAGE-----

At 02:31 PM 2/3/99 -0500, Marc Renouf wrote:
>> In SR1 and SRII the decscription for the Invisibility spell
specifically
>> stated that thermographic vision was not affected. In SR3, no such
mention
>> is made, so you can assume that with third edition rules, the spell
fools
>> everyone regardless of the way their eyes are built (which is only
>> logical, IMHO).
>
> Not necessarily. The way I've always had to rationalize the
>thermographic thing is that your body does not actively emit light,
and
>thus it is easy to fool someone into thinking you're not there. Your
body
>*does* actively emit heat, though, and disposing of this energy is
not
>feasible.

So, if you were GMing and I had a mage who cast an invisibility spell
on a firefly, what would happen?

Or on someone with a headband mounted flashlight?

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--
-- Paul Gettle, #970 of 1000 (RunnerPaul@*****.com)
PGP Fingerprint, Key ID:0x48F3AACD (RSA 1024, created 98/06/26)
C260 94B3 6722 6A25 63F8 0690 9EA2 3344
Message no. 41
From: David Woods <david@*******.FREESERVE.CO.UK>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 21:04:54 +0000
Marc Renouf wrote:
>
> On Wed, 3 Feb 1999, David Woods wrote:
>
> > The surface temperature of a human is very dependent on ambient
> > temperature. In the average run most people will be wearing clothes :).
> > So the surface in contact with the wall will be fairly close to ambient,
> > not blood temp.
>
> Not so, my good man. Your clothes are typically warmer that the
> surrounding environment. Easy example? Grab a shirt out of your closet.
> Now take the shirt you're wearing off. Hand them to someone. They will
> be able to tell you (without even having to smell them! ;) ) which one
> you were wearing, simply because that shirt will be warmer than the
> other (which is at ambient temperature because it's been sitting in your
> closet).

Well, it a difference of degree. Clothes will be warmer than ambient,
but by how much? 2-3, 10 degrees?

> Further, if you're leaning up against a wall, there is no air flow
> between you and your shirt, or between the shirt and the wall. This
> airflow is necessary for convective heat transfer (heretofore
> undiscussed).

Assuming your only wearing a shirt. If your wearing armour it's not
going to be far above ambient.

> Convective heat transfer is what keeps your clothes cooler
> than your body. In the absence of such convection, your shirt will
> rapidly heat up to your body temperature, and will rapidly begin heating
> up the wall. Easy example? Driving your car on a hot summer day. Even
> if the rest of you is cool and dry, your back gets all sweaty because
> there's no cooling convective airflow between you and your seat.

Yes, but what if it's about 12C with a stiff wind and your wearing
insulating clothes plus a flak jacket. You lean up against a brick wall.
How long would it take to see noticable heating of the oposite side?
Would it ever, or would the large heat capacity and rapid conduction
along the wall render it beneath delectability?

> > Imo very little heat would be transferred to the wall. It would be tens
> > of minutes before a noticeable change was seen.
>
> Again, it depends on the wall. In some cases, you might be able
> to discern the change in just a few seconds. You may not be able to tell
> whether the guy hiding behind the wall is an elf or a human, but you know
> there's a guy hiding behind the wall.

I'm not convinced it would ever be seconds. But I might be wrong. GM's
call really.

Regards

- David Woods
Message no. 42
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 16:45:13 -0500
On Wed, 3 Feb 1999, David Woods wrote:

> Well, it a difference of degree. Clothes will be warmer than ambient,
> but by how much? 2-3, 10 degrees?

It really depends on the type of clothes and the ambient
temperature. A light shirt will be a lot warmer externally than a parka
that insulates well. Systems even today can distinguish fractions of a
degree.

> Assuming your only wearing a shirt. If your wearing armour it's not
> going to be far above ambient.

It doesn't matter. You're still in physical contact with it, and
thus still talking about conductive heat transfer.

> Yes, but what if it's about 12C with a stiff wind and your wearing
> insulating clothes plus a flak jacket. You lean up against a brick wall.
> How long would it take to see noticable heating of the oposite side?
> Would it ever, or would the large heat capacity and rapid conduction
> along the wall render it beneath delectability?

It very well may. However, the colder the ambient temperature is,
the more likely you are to be able to see someone with thermo. It's not
in the arctic that you have problems, it's in the jungle. Conductive heat
transfer is proportional to the difference in temperature of the objects
in question. The greater the difference, the faster the cold one will
heat up and the hot one will cool down. In a situation where you have an
extreme gradient, changes in temperature will happen quickly.

> I'm not convinced it would ever be seconds. But I might be wrong. GM's
> call really.

Like I said, it really depends on the type and thickness of the
material in question. But for thin materials with a high thermal
conductivity, seconds is certainly within reason.
Also, keep in mind what that means. It means that you know that
the wall is warmer. It doesn't mean you know what's behind the wall or
what position the person is standing in. You may be able to see a
person's general location long before you'll have enough information to
get off an accurate shot.

Marc
Message no. 43
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 16:51:15 -0500
On Wed, 3 Feb 1999, Paul Gettle wrote:

> So, if you were GMing and I had a mage who cast an invisibility spell
> on a firefly, what would happen?
>
> Or on someone with a headband mounted flashlight?

See what I mean? This is why physical illusions should be
manipulation spells. Then you can come up with a consistent way of
handling them.

Marc
Message no. 44
From: David Buehrer <dbuehrer@******.CARL.ORG>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 14:57:41 -0700
For the mere cost of a Thaum, Marc Renouf wrote:
/
/ On Wed, 3 Feb 1999, Paul Gettle wrote:
/
/ > So, if you were GMing and I had a mage who cast an invisibility spell
/ > on a firefly, what would happen?
/ >
/ > Or on someone with a headband mounted flashlight?

The mage would still be invisible. However, his light would still work. A
viewer wouldn't be able to see the mage or his flashlight, however they
would be able to see the circle of light on the ground/wall/whatever
created by the flashlight.

/ See what I mean? This is why physical illusions should be
/ manipulation spells. Then you can come up with a consistent way of
/ handling them.

Not so old timer :)

If it's a physical manipulation spell then you run into all sorts of
problems. If the spell bends/wraps the light around the target how
does the target see?

Surely you've seen this come up enough on ShadowRN to know that there's no
good answer ;)

-David B.
--
"Earn what you have been given."
--
email: dbuehrer@******.carl.org
http://www.geocities.com/TimesSquare/1068/homepage.htm
Message no. 45
From: Mark A Shieh <SHODAN+@***.EDU>
Subject: Re: thermographic vision-question
Date: Wed, 3 Feb 1999 17:07:45 -0500
David Buehrer <dbuehrer@******.CARL.ORG> writes:
> For the mere cost of a Thaum, Marc Renouf wrote:
> / On Wed, 3 Feb 1999, Paul Gettle wrote:
> / > So, if you were GMing and I had a mage who cast an invisibility spell
> / > on a firefly, what would happen?
> / >
> / > Or on someone with a headband mounted flashlight?
>
> The mage would still be invisible. However, his light would still work. A
> viewer wouldn't be able to see the mage or his flashlight, however they
> would be able to see the circle of light on the ground/wall/whatever
> created by the flashlight.

I think for consistency, the mage will have to nullify the
illumination effects from the light as well. Otherwise, if you can
see reflected light off the ground, why can't you see the invisible
target's reflection in a mirror?

Mark
Message no. 46
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Thu, 4 Feb 1999 11:59:00 +0100
According to David Woods, at 21:04 on 3 Feb 99, the word on
the street was...

> > Further, if you're leaning up against a wall, there is no air flow
> > between you and your shirt, or between the shirt and the wall. This
> > airflow is necessary for convective heat transfer (heretofore
> > undiscussed).
>
> Assuming your only wearing a shirt. If your wearing armour it's not
> going to be far above ambient.

Not immediately. But if the armor is pressed against your body (which it
will be, if you're leaning against a wall with the armored part of your
body) it will eventually heat up, and after that the wall will heat up
with it. It might take longer, but it _will_ happen.

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
PE Y PGP- t(+) 5++ X++ R+++>$ tv+(++) b++@ DI? D+ G(++) e h! !r(---) y?
Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 47
From: Gurth <gurth@******.NL>
Subject: Re: thermographic vision-question
Date: Thu, 4 Feb 1999 11:59:00 +0100
According to Joshua Mumme, at 14:44 on 3 Feb 99, the word on
the street was...

[thermo and invisibility spells]
> Shrug.. it is a GM call I suppose. Besides it isn't common fair to run into
> opposition that has natural Thermal Vision.

It doesn't matter if it's natural or not, and thermo is easily the best
vision enhancement for seeing in darkness that you can get installed in
your (cyber)eyes, IMHO, so I expect most street sams and similar types to
have it.

--
Gurth@******.nl - http://www.xs4all.nl/~gurth/index.html
If it's no use pretending, then I don't want to know.
-> NERPS Project Leader * ShadowRN GridSec * Unofficial Shadowrun Guru <-
->The Plastic Warriors Page: http://shadowrun.html.com/plasticwarriors/<-
-> The New Character Mortuary: http://www.electricferret.com/mortuary/ <-

GC3.1: GAT/! d-(dpu) s:- !a>? C+(++)@ U P L E? W(++) N o? K- w+ O V? PS+
PE Y PGP- t(+) 5++ X++ R+++>$ tv+(++) b++@ DI? D+ G(++) e h! !r(---) y?
Incubated into the First Church of the Sqooshy Ball, 21-05-1998
Message no. 48
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Thu, 4 Feb 1999 09:01:49 -0500
On Wed, 3 Feb 1999, David Buehrer wrote:

> / See what I mean? This is why physical illusions should be
> / manipulation spells. Then you can come up with a consistent way of
> / handling them.
>
> Not so old timer :)

Yeah, I seem to remember having this same discussion with you
three years ago. Plus ca change, and all that. :)

> If it's a physical manipulation spell then you run into all sorts of
> problems. If the spell bends/wraps the light around the target how
> does the target see?

My assertion of having the mage channel magical energy into making
light of the proper wavelength would solve the problem, but that in turn
gets into questions of just what sort of energy transmutation you could
accomplish with magic (which is a whole different can o' worms).

Marc
Message no. 49
From: Jester <jester@**********.NL>
Subject: Re: thermographic vision-question
Date: Thu, 4 Feb 1999 20:31:27 +0100
At 15:16, 2 Feb 99, Jester was told by Marc Renouf:


Each time, someone posts a question on this list it wonders me, how
many respons there is on the question asked:).

Many thanks to all of you who did take the time to answers a question
asked by a total stranger, with special thanks to Marc R. whose mail
I used for explaining the works of thermo-vision to my group (many,
many difficult words:), I actually had to translate the mail on the
spot, 'cause he just didn't understand it (EG)).

--
When you're frozen solid, you really don't think much about sex anymore.
--Buck Bundy--
Jester
<jester@**********.nl>

-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GS d s: a22? c- U? P? L? E? W N- o? K- w+ O--- M? V? PS PE-
Y PGP- t+ 5+++ X+ R+>++ tv++ b+++ DI? D- G e>+ h! r++ y+
------END GEEK CODE BLOCK------
Message no. 50
From: Marc Renouf <renouf@********.COM>
Subject: Re: thermographic vision-question
Date: Thu, 4 Feb 1999 14:34:06 -0500
On Thu, 4 Feb 1999, Jester wrote:

> Many thanks to all of you who did take the time to answers a question
> asked by a total stranger, with special thanks to Marc R. whose mail
> I used for explaining the works of thermo-vision to my group (many,
> many difficult words:), I actually had to translate the mail on the
> spot, 'cause he just didn't understand it (EG)).

You're welcome. <egmg> :)

Marc

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