Every once in a while I like to watch 2001: A Space Odyssey to see
what our life in cislunar space could have been like :)

So I'm watching the movie last night, and on board the Discovery, in
the rotating section there are a number of control stations and
other equipment which monitors the rest of the vessel.

If there is hard wiring, rather than radio connection, between the
control stations and the equipment on the rest of the ship, my
question is how do they make the hard wire connection when the
control station is rotating with respect to the stationary equipment
on the Discovery?

Anyone care to explain this to me?

TangoMan

> Every once in a while I like to watch 2001: A Space Odyssey to see
> what our life in cislunar space could have been like :)

Or still could be. :)

> So I'm watching the movie last night, and on board the Discovery,
> in the rotating section there are a number of control stations and
> other equipment which monitors the rest of the vessel.

Wish NASA would take note of this, and drop the "we need medical
breakthroughs to allow people to go to Mars w/o getting brittle
bones" stuff. Just send two ships and cable them together! GGGRRR!!!

> If there is hard wiring, rather than radio connection, between the
> control stations and the equipment on the rest of the ship, my
> question is how do they make the hard wire connection when the
> control station is rotating with respect to the stationary
> equipment on the Discovery?
>
> Anyone care to explain this to me?

My first reaction is to say, "The same way Taco Bell can have a
rotating, light-up sign." But then I realized that I'm not sure how
Taco Bell does that, and now I am curious too.

Xenophile (eating his tostada)

That is accomplished one of a few ways.
1. Conductive rings meet each other at the point of rotation, in direct contact
2. A ring on one side, and brushes on the other the drag around the ring keeping
contact (used in old generators and amusement part rides)
3. Same concept as rings, but using induction so there is no physical contact

Date sent: Sun, 03 Aug 2003 21:21:57 -0000
Send reply to: ssi_list@...

>
> > Every once in a while I like to watch 2001: A Space Odyssey to see
> > what our life in cislunar space could have been like :)
>
> Or still could be. :)
>
> > So I'm watching the movie last night, and on board the Discovery,
> > in the rotating section there are a number of control stations and
> > other equipment which monitors the rest of the vessel.
>
> Wish NASA would take note of this, and drop the "we need medical
> breakthroughs to allow people to go to Mars w/o getting brittle
> bones" stuff. Just send two ships and cable them together! GGGRRR!!!
>
> > If there is hard wiring, rather than radio connection, between the
> > control stations and the equipment on the rest of the ship, my
> > question is how do they make the hard wire connection when the
> > control station is rotating with respect to the stationary
> > equipment on the Discovery?
> >
> > Anyone care to explain this to me?
>
> My first reaction is to say, "The same way Taco Bell can have a
> rotating, light-up sign." But then I realized that I'm not sure how
> Taco Bell does that, and now I am curious too.
>
> Xenophile (eating his tostada)
>

danst@...
The horse, the original in 4x4 off road recreation.

--- In ssi_list@... "Dan St. Sauveur"
>
> That is accomplished one of a few ways.
> 1. Conductive rings meet each other at the point of rotation, in
direct contact
> 2. A ring on one side, and brushes on the other the drag around
the ring keeping
> contact (used in old generators and amusement part rides)
> 3. Same concept as rings, but using induction so there is no
physical contact

Are you referring to Xenophile's TacoBell example or my U.S.S.
Discovery example.

I could see how electrical current could work, but how would you
differentiate between a multitude of control signals and HAL
computer neural pathways, etc that would transit between the
rotating section and the remainder of the Discovery.

Also, an afterthought. Wouldn't the Discovery have to have two
counter-rotating sections to neutralize angular momentum?

TangoMan

my guess is that they have a ring that rotates with a bit (ferod?) that is
pressed against it to make contact, the entire ring being conductive it
doesn't matter which portion of it is currently in contact. Basically the
same way an electric motor works.
Certainly messy for a giant space station, especially because it would need
lubrication which would be extremely troublesome I guess...
What's wrong with microwaves? Or lasers? would seem a much cleaner approach,
and no need to replace the parts periodically as they get consumed by
attrition...

I'm sure someone more technically minded can suggest better solutions
anyway...

cheers,

Claudio

PS: sorry no much time to reply to everything these days... :)

> I could see how electrical current could work, but how would you
> differentiate between a multitude of control signals and HAL
> computer neural pathways, etc that would transit between the
> rotating section and the remainder of the Discovery.

This is commonly done - and readily available. The devices are called "slip
rings". For example, every radar antenna has to have one. The quantity of
data is no problem. Fiber optic slip rings exist for this purpose.

Here's a link to a power+signal slip ring.

http://www.army-technology.com/contractors/motion/northrop/

Cheers
Dale

>
> > I could see how electrical current could work, but how would you
> > differentiate between a multitude of control signals and HAL
> > computer neural pathways, etc that would transit between the
> > rotating section and the remainder of the Discovery.
>
> This is commonly done - and readily available. The devices are
called "slip
> rings". For example, every radar antenna has to have one. The
quantity of
> data is no problem. Fiber optic slip rings exist for this purpose.
>
> Here's a link to a power+signal slip ring.
>
> http://www.army-technology.com/contractors/motion/northrop/
>
> Cheers
> Dale

Thanks for the link. It definitely helped clear up the concept for
me.

Now my questioning evolves to limits of data transmission.

Consider that a point to point connection in a non-rotating
environment will involve just a wire to make the connection. Thus,
you can have a control center, or a command bridge, where all
control functions are centralized and are hard wired to the rest of
the ship.

If that bridge is in a rotating structure, each connection would
have to have a slip ring. Each slip ring would occupy an area around
the cental axis, and the circumference of each successive slip ring
would grow as they are stacked on top of each other.

Do I have this right?

Wouldn't the physical limit of the area of the rotating axis quickly
limit the number of connections that could be made?

If I've got this right, then ISTM that a bridge should be located in
a non-rotating area of the ship.

The rotating area should be limited to functions that don't require
many features to bridge the non-rotating - rotating junction. This
could be sleep, recreation, exercise, or discrete function areas
that are self contained as possible.

Is my thinking on this making sense?

TangoMan

I'd think an hardwired solution as you seem to envisage would be hopefully
inadequate, not to mention the complexity and amount of maintenance
required...
A much better solution already with available technology would be using
lasers to transfer the data stream, in a single relatively thin disc you
could have a central prism shaped so that regardless from which point of the
circumference the beam hits it would be reflected to a perpendicular sensor.
Any emitter rotating around would remain constantly focused on the sensor at
any time.
I'd imagine this is probably similar to how the fiber optic slip ring works
BTW...
So I doubt you'd need lots of slip rings, just a bigger one.
Incidentally where additional rings should be required (and I would imagine
at least a couple of extra backups for such a vital connection would be in
order) they would be positioned next to each other, not around each other.
The main advantage of course would be the elimination of any need for
physical contact.
It would also seem very likely to me that several independent different
system will be used, first because it would be more efficient to have
specialized systems, and also because if a condition should occur that
affect the functioning of one system the others would be able to temporarily
work as emergency backup, much like you can use the power cable of your
house to send a computer data stream.
I stress I'm not an engineer, but I'd guess an optical system would be best
for data streams, while an induction ring (again no physical contact
required) would be preferable for power supply.
Speaking more generally however I think technology will tend toward
unification and standardization of systems. Today we see a proliferation of
separate channels each specific to a particular system, we have telephone
lines, computer networks, cable tv, power lines, intruder alarms, CCTV
cables, and so on... this is a result of a chaotic evolutionary process, but
things are already changing rapidly with the informatics revolution...
eventually I'd imagine we will see the emergence of much more flexible and
powerful system, and speaking in the contest of an habitat I'd imagine there
will be a single data network running through the entire installation like a
nervous system, carrying all types of signal required, rather than a
multitude of pipes, possibly a layer of liquid crystals, or something along
those lines, sandwiched and built-in into every structural component. A
fluid system which would be including nanotech size components that rely the
data and are powered through the fluid medium, which can also include
maintenance, updating, reprogramming, and self-repairing components. When
more of a kind of signal would be needed than another the system will
automatically adequate the proportion of the required nanocomponents in the
fluid. In the same way when a new type of data will be required it would be
enough add the nanocomponents that support it to upgrade the entire system,
without need to replace a single wire.
Processing units and any other equipment only need to have a single standard
connection to be able to communicate with any other system plugged in using
any of all the signals carrier available.
Thinking of copper cables wiring for a self-supporting space station
advanced and efficient enough for supporting traditional farming in its
interior is a bit like Victorian engineers thinking of supersonic flying
machines made of wood and canvas IMO... :) New technologies will be in
place, today's latest toys like fiber optics and microprocessors will be as
obsolete as vacuum valves and VHS tapes today much before habitats will be
technically feasible... I know, mainstream SF programs have got yourself
used to things like pressing a button for jumping in hyperspace, but what a
nonsense if you think about it! A technology so advanced as to allow for
feats beyond our understanding of what is possible within the physical laws
of our universe can hardly be still using something so primitive like a
button! Is like thinking of driving an automobile with a whip... :) You are
much more likely to have to nod your head to a 3d projection of your
favourite pop star... Think with your head, don't follow stereotypes, what's
the point telling Mr. Sulu to accelerate to warp 5, and him to press buttons
on a consol, when you could have asked directly the "computer" to do it?
Apart that is entertaining to watch I mean... ;)
Space habitats may be a lot closer to us than teletransporters, but still
very unlikely to have many buttons left to press IMHO. Much more likely to
be voice operated as a standard, and that for the very small percentage of
tasks that won't be completely automated anyway, which won't even require
that. AI will probably take care of 99% of what needs to be done...

Just my 2p before going to bed anyway... :O)

Cheers,

Claudio

>Wouldn't the physical limit of the area of the rotating axis quickly
>limit the number of connections that could be made?
>
No. You can use multiplexers to minimise the number of slip rings required.

>TangoMan
>

-Ian

"If you want to build a ship, don't drum up the workers to gather wood,
divide the work, and give orders. Instead, teach them to yearn for the
vast and endless sea." -Antoine de Saint-Exupery

> I'd think an hardwired solution as you seem to envisage would be
hopefully
> inadequate, not to mention the complexity and amount of maintenance
> required...
> A much better solution already with available technology would be
using
> lasers to transfer the data stream,

I consider a laser control system to be a hardwired system by the
criteria of requiring mechanisms to channel and guide the laser
beams to required collectors.

A radio system, OTH, could have transmitters and receivers in
various places rather than at a nexus such as the slip ring.

> BTW...
> So I doubt you'd need lots of slip rings, just a bigger one.

Why? How does one big one handle different transmission standards?
How does it address conflicting signals? Does the necessity of
having one slip ring require that every control station must be
designed as part of a whole system.

> Incidentally where additional rings should be required (and I
would imagine
> at least a couple of extra backups for such a vital connection
would be in
> order) they would be positioned next to each other, not around
each other.

Isn't the entire circumference of the slip ring used to transmit the
data because the rotation prohibits localized transmission points
within the slip ring circumference?

If you design it as you advocate, then you'd have a series of slip
rings clustered together (next to each other), and they'd be out of
synchroniztion with their counterparts on the other surface as they
rotated around their axis.

Am I understanding your vision correctly?

I don't see how this could work.

> A technology so advanced as to allow for
> feats beyond our understanding of what is possible within the
physical laws
> of our universe can hardly be still using something so primitive
like a
> button!

You're creating a whole strawman scenario and then arguing against
it.

I don't think the control systems of a space station and their
junction through a rotating ring are "A technology so advanced as to
allow for feats beyond our understanding of what is possible within
the physical laws of our universe."

> Is like thinking of driving an automobile with a whip... :) You are
> much more likely to have to nod your head to a 3d projection of
> your favourite pop star... Think with your head, don't follow
> stereotypes,

Thanks for the advice, but I'm quite happy with my thought processes.

Have you ever heard of the acronym of KISS? Keep It Simple, Stupid.

Why introduce more complexity and room for error and
misinterpretation when a simple binary solution will suffice. A
button is either on or it's off. You make a decision to activate it
or not. Simple.

Why create a computer program that has to control this process for
you? What if the computer glitches, or doesn't function at the
instant that you need to execute a command. Now you have no option
because you've removed a button from the activation process.

Computer and automated systems have their place, but mindless
implementation should be left out of the design criteria.

If it's simpler to install a switch, then that should be the route
to go.

Have you considered that your thought process is more a stereotype
of future mumbo-jumbo, rather than one based on engineering
fundamentals?

TangoMan

--- In ssi_list@... Ian Woollard

> >Wouldn't the physical limit of the area of the rotating axis
quickly
> >limit the number of connections that could be made?
> >
> No. You can use multiplexers to minimise the number of slip rings
required.

Good point. What would be the typical limits that multiplexers face?

TangoMan

--- In ssi_list@... Ian Woollard Wouldn't the physical limit of the area of the rotating axis quickly limit the number of connections that could be made? No. You can use multiplexers to minimise the number of slip rings required. Good point. What would be the typical limits that multiplexers face? None really.

In fact, the most likely multiplexer technique you would use would be based on the Internet Protocol (it's actually time division multiplexed if you think about it), and just have computer modules scattered across the vehicle/station monitoring and controlling stuff. The slip ring may even be a wireless link. Doing this cuts down on the amount of control wire you need to lay (if any- wireless protocols are getting pretty popular), and you just need to distribute power around.
TangoMan --
-Ian "If you want to build a ship, don't drum up the workers to gather wood, divide the work, and give orders. Instead, teach them to yearn for the vast and endless sea." -Antoine de Saint-Exupery

> I consider a laser control system to be a hardwired system by the
> criteria of requiring mechanisms to channel and guide the laser
> beams to required collectors.

What make you think that there would be any need for such things?
And even if there should be the hardware can easily be all on one side or
another, only the data stream pass across.

> A radio system, OTH, could have transmitters and receivers in
> various places rather than at a nexus such as the slip ring.

Sure. That's why I suggested that in the first message. But since someone
was stuck with his obsolete models, I've then replied "even a laser system
would be better than that".

> > BTW...
> > So I doubt you'd need lots of slip rings, just a bigger one.
>
> Why? How does one big one handle different transmission standards?
> How does it address conflicting signals? Does the necessity of
> having one slip ring require that every control station must be
> designed as part of a whole system.
>
> Isn't the entire circumference of the slip ring used to transmit the
> data because the rotation prohibits localized transmission points
> within the slip ring circumference?
>
> If you design it as you advocate, then you'd have a series of slip
> rings clustered together (next to each other), and they'd be out of
> synchroniztion with their counterparts on the other surface as they
> rotated around their axis.
>

> Am I understanding your vision correctly?
>
> I don't see how this could work.
>

Since you now seem to agree that a radio system would be preferable all the
above is totally redundant anyway.

> > A technology so advanced as to allow for
> > feats beyond our understanding of what is possible within the
> physical laws
> > of our universe can hardly be still using something so primitive
> like a
> > button!
>
> You're creating a whole strawman scenario and then arguing against
> it.
>
> I don't think the control systems of a space station and their
> junction through a rotating ring are "A technology so advanced as to
> allow for feats beyond our understanding of what is possible within
> the physical laws of our universe."

Me too. I guess that's why the line "Space habitats may be a lot closer to
us than teletransporters" was there...

> > Is like thinking of driving an automobile with a whip... :) You are
> > much more likely to have to nod your head to a 3d projection of
> > your favourite pop star... Think with your head, don't follow
> > stereotypes,
>
> Thanks for the advice, but I'm quite happy with my thought processes.

I've noticed that.
Shame really, arrogance is not going to help you learn anything I'm
afraid...

> Have you ever heard of the acronym of KISS? Keep It Simple, Stupid.
>
> Why introduce more complexity and room for error and
> misinterpretation when a simple binary solution will suffice. A
> button is either on or it's off. You make a decision to activate it
> or not. Simple.
>
> Why create a computer program that has to control this process for
> you? What if the computer glitches, or doesn't function at the
> instant that you need to execute a command. Now you have no option
> because you've removed a button from the activation process.

Are you seriously suggesting you can manually control something of the
complexity of an Habitat?
Actually clicking buttons?
You'll be busy...

> Computer and automated systems have their place, but mindless
> implementation should be left out of the design criteria.

Thanks for this gem of patronizing nonsense, ROTFL!!!!
I think you should tell that to NASA, I'm sure they'll see you wisdom and
stop wasting taxpayers money on automated systems immediately...

> If it's simpler to install a switch, then that should be the route
> to go.

Absolutely. As a matter of fact if it's simpler not to install anything that
would be even better. Pity space station are rather complex systems
really...

> Have you considered that your thought process is more a stereotype
> of future mumbo-jumbo, rather than one based on engineering
> fundamentals?

My dear Tango, have you got the slightest idea of the number of electronic
switches there are inside your mobile phone? Do you really think replacing
any one of them with a button would improve the design, or that doing
something like that would be "based on engineering principles"?
There are too many good reason for automating every single one of the
million billion processes that will be required by an habitat at every
second to even bother list them all really... There may be a handful system
that can benefit from having a manual overdrive, as a third or fourth backup
system that is. Everything else will have to be automated.
Look in front of you: do you have a button on your keyboard with "delete
message" written on it? Or do you have a generic input device with which you
click a simulated button on your generic display system? A display system
that can simulate any number of controls all of which you can directly
control with the same input device?
You can seriously think even for a moment that you would be better off with
a "delete message" button on the keyboard? That it would be better than
"create a computer program that has to control this process for you"
according to your statement above? If that's the case I'd respectfully
suggest you to investigate the present a little further before building too
many details in your vision of the future... :)

Good luck to you.

Cheers,

Claudio

> > A radio system, OTH, could have transmitters and receivers in
> > various places rather than at a nexus such as the slip ring.
>
> Sure. That's why I suggested that in the first message. But since
someone
> was stuck with his obsolete models, I've then replied "even a
laser system
> would be better than that".

Perhaps I should step aside and let you argue with yourself. You
continually make a claim and then proceed to refute it. I'm not
involved in this process at all.

In my original post I wrote "If there is hard wiring, rather than
radio connection, between the control stations and the equipment on
the rest of the ship, my question is how do they make the hard wire
connection when the control station is rotating with respect to the
stationary equipment on the Discovery?"

How is it that you now take credit for introducing the concept of
radio into the discusion?

If I'm seeking information on how hard wiring will function through
a rotating interface, how does that make me "someone was stuck with
his obsolete models."

>
> > > BTW...
> > > So I doubt you'd need lots of slip rings, just a bigger one.
> >
> > Why? How does one big one handle different transmission
standards?
> > How does it address conflicting signals? Does the necessity of
> > having one slip ring require that every control station must be
> > designed as part of a whole system.
> >
> > Isn't the entire circumference of the slip ring used to transmit
the
> > data because the rotation prohibits localized transmission points
> > within the slip ring circumference?
> >
> > If you design it as you advocate, then you'd have a series of
slip
> > rings clustered together (next to each other), and they'd be out
of
> > synchroniztion with their counterparts on the other surface as
they
> > rotated around their axis.
> >
> > Am I understanding your vision correctly?
> >
> > I don't see how this could work.
> >
> Since you now seem to agree that a radio system would be
> preferable all the above is totally redundant anyway.

It was never a question of which method is preferable; I wanted to
know how it could be done with hard wiring. (see original post
again.)

You proposed a solution by clustering slip rings and I'm not at all
clear how this could work. So I don't think it's redundant at all
because it addresses the original question. Would you care to
address the questions I've asked about your proposal?

> > >... Think with your head, don't follow stereotypes,
> >
> > Thanks for the advice, but I'm quite happy with my thought
processes.
>
> I've noticed that.
> Shame really, arrogance is not going to help you learn anything I'm
> afraid...

You may also have noticed that an intelligent and courteous response
will be returned in kind (see EVERY other message in this thread,
except yours), while a baiting and insulting tone will get similar
back.

It's not arrogance, it's just me utterly dismissing your method of
argument as a model to emulate.

First you presume to ascribe to me what I'm thinking, then you make
an argument against it, and you conclude by insulting me by implying
that I don't think but rely on stereotypes.

As I've already written, you're creating your own arguments. Need
proof? Here's a quote:

BEGIN QUOTE

"Thinking of copper cables wiring

(I never wrote anything about them)

for a self-supporting space station advanced and efficient enough
for supporting traditional farming in its interior

(I didn't bring this up - I wrote about the Discovery in the movie
2001)

is a bit like Victorian engineers thinking of supersonic flying
machines made of wood and canvas IMO... :)

(Nice rebuttal, but unfortunately you're rebutting your own point.)

New technologies will be in place, today's latest toys like fiber
optics and microprocessors will be as obsolete as vacuum valves and
VHS tapes today much before habitats will be technically feasible...

(Nice rebuttal, but unfortunately you're rebutting your own point.)

I know, mainstream SF programs have got yourself used to things like
pressing a button for jumping in hyperspace,

(How would you know?)

but what a nonsense if you think about it! A technology so advanced
as to allow for feats beyond our understanding of what is possible
within the physical laws of our universe can hardly be still using
something so primitive like a button!

(Yeah, I guess that's why the caveman inventions of wheels aren't
used anymore, or clothing to keep us warm. Both are so primitive!)

Is like thinking of driving an automobile with a whip... :) You are
much more likely to have to nod your head to a 3d projection of your
favourite pop star... Think with your head, don't follow stereotypes"

(Talk about sterotypes. Mindless techno-worship for stylistic,
rather than substantive, purposes.)

END QUOTE

>
> > Have you ever heard of the acronym of KISS? Keep It Simple,
Stupid.
> >
> > Why introduce more complexity and room for error and
> > misinterpretation when a simple binary solution will suffice. A
> > button is either on or it's off. You make a decision to activate
it
> > or not. Simple.
> >
> > Why create a computer program that has to control this process
for
> > you? What if the computer glitches, or doesn't function at the
> > instant that you need to execute a command. Now you have no
option
> > because you've removed a button from the activation process.
>
> Are you seriously suggesting you can manually control something of
the
> complexity of an Habitat?
> Actually clicking buttons?
> You'll be busy...

First off, shame on me for taking your bait. From your recent posts
on this message board, I'm learning about your style of
argumentation.

You introduced the whole scenario of button-pushing into a topic
that had nothing to do with buttons.

Then you argue against buttons and invoke techno-mumbo-jumbo.

Now, you're thick-headedly twisting what I wrote and and asking
whether I think a Habitat can be entirely controlled manually. Where
did you get that from? Oh, it's just more of your style of
argumentation. Introduce a point, ascribe it to someone else, and
then refute it.

Then you imply that I do indeed hold this belief but the only
evidence you can muster is the strawman argument you've constructed.

Lastly, you ignore the KISS principle. If it is simpler to have a
human control a particular function, then why introduce more
complexity into the system by automating it?

>
> > Computer and automated systems have their place, but mindless
> > implementation should be left out of the design criteria.
>
> Thanks for this gem of patronizing nonsense, ROTFL!!!!

You're welcome. You deserved it!

> I think you should tell that to NASA, I'm sure they'll see you
wisdom and
> stop wasting taxpayers money on automated systems immediately...

Are you really this dense? Do you not read what other people write?
Do you always make a habit of responding to your own strawmen
arguments?

> > Have you considered that your thought process is more a
stereotype
> > of future mumbo-jumbo, rather than one based on engineering
> > fundamentals?
>
> My dear Tango, have you got the slightest idea of the number of
electronic
> switches there are inside your mobile phone? Do you really think
replacing
> any one of them with a button would improve the design, or that
doing
> something like that would be "based on engineering principles"?

Once again you're supplying both sides of the argument without
acknowledging the point I made.

To make my own point: If it is more efficient and reliable to punch
in the phone number via a keypad on the phone than it is to use a
voice interface, then dispite the gee-whiz factor of the voice
recognition program, and the electronics overhead it requires, I'll
opt for the keypad.

The many processes within the phone don't require human control,
thus they can be automated.

Am I getting through to you?

> There are too many good reason for automating every single one of
the
> million billion processes that will be required by an habitat at
every
> second to even bother list them all really... There may be a
handful system
> that can benefit from having a manual overdrive, as a third or
fourth backup
> system that is. Everything else will have to be automated.

Well, it's a good thing that you've joined this group, because until
now, I'd say most of us didn't know ALL of the systems that'll be
required on a Habitat.

It's reassuring that you know everything there is to know and can
state unequivicably that each system can be fully automated and that
human judgement can be completely removed from the Habitat.

TangoMan

> Am I getting through to you?

yes, sorry now I got it.
I thought you were genuinely interested in the concepts, not the rhetoric.
Will be careful to avoid being dragged into this kind of things again.

Cheers,

Claudio