Re: Blacker than Black

I had thought space was (for the most part) temperature-less rather
than cold. As I understood it, near vacuum i slow in molecules and
temperature is effectively a result of molecules absorbing thermal
energy.

This explanation seemed to cover why the space shuttle can't get rid
of heat easily (no convenient molecules to radiate things away to by
contact) and it covered why space is seen as 'cold' (few molecules to
aboorb heat per unit volume).

Of course, this doesn't cover radiation via waves very well, but I
figured that they still weren't temperature until they transferred
their energy to a molecule (ie that an infrared wave was effectively
not by itself 'hot' until such time as it was transferring the energy
to a molecule, it wasn't really temperature). I sort of thought of
this as the difference between potential energy and kinetic energy
(potential energy for instance, would not be easily observable, while
kinetic energy in the form of a moving object, would be).

That understanding is probably incorrect, but it did seem to cover
most of the bases in some fashion.

The reason I am curious about stealth in space being so hard: I agree
that camouflage in all spectra is harder against a negligible
background. Light sources in space are point sources (so are heat and
x-ray sources and perhaps general EM, but that's a bit vaguer to me as
there is a level of cosmic background radiation that seems to suggest
general EM is 'all over the place').  So for the most part, hiding
using any of them as background would require either being (and
staying) in LoS between potential observer and background cover (tough
in a moving universe, but perhaps not impossible) or else simply
having the searcher miss you.

Now, you say to the last one: What?

I sort of think of the Mark I eyeball connected to the brain. We do a
lot of looking around us for threats and oddities which might be
threats. But we still often fail to note stuff. Part of this is the
visual complexity of our enironment, part of it our level of
distraction, and part of it not recognizing certain risks as to what
they are.

So how is that transferrable to space:

1. I assume that sensor have a certain sensitivity. If they aren't
good enough, they might not see the threat, given certain assumptions
about how visible it is and how capable they are.

2. I assume sensors have a certain scan rate - how fast they can sweep
an area of space.

3. Sensors may be subject to depth issues (I'm not sure if such
sensors instantly see everything at all depths equally well or need to
scan varying depths meaning more scan passes to determine accurately
what might be thee). Space is 3-D and perhaps like the Mk I eyeball, a
sensor has to focus on areas close, medium or far to get accuity.

4. Data processing systems are finite and must process the scan data.
If they have to process different wavelengths or energy types
seperately, that magnifies the task. Perhaps they can only process
accurately a portion of the total depth, energy types, or spherical
segments of the sky. If the rate at which they can scan those regions
with high enough accuity is low enough, then that opens a window for
stealth.

5. Similar to how a human may be distracted, ships may have other
complex activities to carry out such s handling jump drives, power
cores, nav calcs, and other such things. This may limit how many of
the finite compute resources can be tasked to processing scan data.
This may be doubly true at times when a threat is not known to be out
there (at battle alert levels, scan processing may get a fairly high
priority from the task engine). So this may impede ability to detect
by virtue of limiting processing time or accuity.

6. Much like a human trying to hear a conversation in a bar, if there
happen to be a pile of other noises going on in the bar, the human
won't hear. If there are a pile of ships emitting in local space
(merchants, other warships, buoys, etc) plus natural sources, then
maybe there is a lot of signal bouncing around in various spectra that
could confuse the issue. In terran ESM (Electronic Signal Measures),
one of the big challenges is knowing, from moment to moment, what a
potential bit of contact data means. Are two data points referencing
the same thing? Maybe, maybe not. Is there enough to tell if they are
the same class? Maybe, maybe not. Can they be spoofed? Perhaps. Even
if they are the clear sign of an enemy active system, they may not
show the same from emission to emission. If they are passive, is it
two ships on slightly variable courses or one ship? Is it civilian or
military? The other side of ESM is worried about confusing people by
virtue of spoofing (having your frigate emit signature like a
commerical hauler, for instance). Now, on Earth, this happens in busy
waterways where it is the worst. It also happens with some
itnerference from weather and seas. And incomplete data in the first
place as to what the enemy's signature may be.

So, I was wondering what the aggregation of these factors is actually
going to do to detection. Space right now around our world is fairly
empty (except directly in orbit, full of junk). If space was busy with
lots of civilian shipping and spoofing might be in play, how much
harder would that make things? If you had to try to scan everything
from Earth Orbit to out beyond (whatever object we call the farthest
planet in our system these days.... poor Pluto!), can you actually
process all of that fast enough to tell you what you need to know at
all ranges? And not 'what can you do with the science-specific
platform' but what can you do with the system installed on a typical
warship?

Traveller: New Era made a big deal out of your sensor system size in
detecting objects. It had unfoldable arrays and the bigger your array,
the more you'd take in. But unfolding an array took time and if you
ended up having to move quick or get shot at, I imagine it could be
damaged. Without the array out, your sight (electronically speaking)
would be very limited.

So, what can we practically expect to see in these environments? Is it
possible we will miss or dimiss contacts that are threatening? Is it
possible we will mis-classify incoming traffic? Is it possible we will
not be able to process enough of the sky to see a new object before it
becomes dangerous?

That's what I still don't quite understand. Stealth when someone has
the resources to look right at you, at whatever range you are at, and
process that data without distraction, I accept as being difficult.
But is real stealth, which includes the effects of 'friction' (in the
Clausewitzian sense) on detection systems and those involved in
interpreting their data, actually impractical?

Maybe I can't sneak up easily on your frontier outpost if it has top
of the line sensors. But maybe it often doesn't because it is a
frontier outpost. Maybe sneaking up on your shipping hubs and typical
busy systems with space commerce is much easier.

Thoughts?