Phil Cook wrote:
> And lo on Wed, 16 Jan 2008 02:49:42 -0000, Chambers 
> <ben### [at] pacificwebguycom> did spake, saying:
>> Air resistance might not apply, but manueverability does.  Applying a 
>> force to different parts of the ship will stress different sections in 
>> different ways.  That's a whole lot of differences there!
> 
> Yes except what might be deemed 'travel' ships shouldn't be engaged in 
> high stress producing maneuvers; those are reserved for the 
> fighters/escorts/shuttles, which I agree need to be smaller.
> 
>> Besides which, weight is out, but mass is in.  So smaller is still 
>> better.
> 
> No because a) although you need more oomph to get the ship 
> moving/stopping that's a one-off cost

It's a four-off cost.
1) Cost of materials to build a larger room
2) More fuel needed to accelerate the additional mass
3) More fuel needed to decelerate (brake)
4) More fuel needed to carry the additional fuel for 2) and 3) above.

> and b) volume doesn't directly 
> equal mass; if I increase the height of a room the only mass increase is 
> in the walls and 'air'.

While volume != mass, as your rooms grow in volume, the mass needed to 
enclose them also grows.  It's not a linear relationship, but it is there.

> Create a 7 unit cubic room with walls massing 1kg per square unit (all 
> the same thickness). You're pumping it full of a gas that masses 0.1kg 
> per cubic unit. So the mass of the initial room is 328.3kg. Now increase 
> the height of the room by 1 unit and you get 361.2kg a ~10% increase in 
> mass for a ~14% gain in volume. Make it all 8*8*8 and you get a ~49% 
> volume increase for a ~32% mass increase.

But what is that 32% mass increase is not feasible?  What if an 
additional 10% isn't feasible?  This is a government funded project, 
remember, and their budget is spread over many things - not just the rec 
room for the astronauts.

> Not that I'm saying 'Hey why not make all the rooms 300ft square' at 
> some point you hit overkill, what I am saying is make the rooms the size 
> they need to be for everyone to use them comfortably. So no ducking 

And the point was that it's not reasonable to just make it as big as you 
want; due to the (assumed) constraints, this is the ship that was 
created.  A bit cramped, yes, but it gets the job done.

-- 
...Ben Chambers
www.pacificwebguy.com

Post a reply to this message

And lo on Thu, 17 Jan 2008 04:35:39 -0000, Chambers  

<ben### [at] pacificwebguycom> did spake, saying:

> Phil Cook wrote:
>> And lo on Wed, 16 Jan 2008 02:49:42 -0000, Chambers  

>> <ben### [at] pacificwebguycom> did spake, saying:
>>> Air resistance might not apply, but manueverability does.  Applying 
a  

>>> force to different parts of the ship will stress different sections 
in  

>>> different ways.  That's a whole lot of differences there!
>>  Yes except what might be deemed 'travel' ships shouldn't be engaged 
in  

>> high stress producing maneuvers; those are reserved for the  

>> fighters/escorts/shuttles, which I agree need to be smaller.
>>
>>> Besides which, weight is out, but mass is in.  So smaller is still  

>>> better.
>>  No because a) although you need more oomph to get the ship  

>> moving/stopping that's a one-off cost
>
> It's a four-off cost.
> 1) Cost of materials to build a larger room

But like mass/volume the cost is not necessarily proportional to the vol
ume

> 2) More fuel needed to accelerate the additional mass
> 3) More fuel needed to decelerate (brake)
> 4) More fuel needed to carry the additional fuel for 2) and 3) above.

Except by default the mass of the fuel has to be less then the mass that
  

fuel can move and as I've already shown mass and volume are not  

proportionate.

>> and b) volume doesn't directly equal mass; if I increase the height o
f  

>> a room the only mass increase is in the walls and 'air'.
>
> While volume != mass, as your rooms grow in volume, the mass needed 
to  

> enclose them also grows.

No not really if you break it down to the simplest situation which is ju
st  

the one room, simply expand the room and section it. Okay the external  

walls may be thicker then the internal ones, but the principal stilll  

holds.

> It's not a linear relationship, but it is there.
>
>> Create a 7 unit cubic room with walls massing 1kg per square unit (al
l  

>> the same thickness). You're pumping it full of a gas that masses 0.1k
g  

>> per cubic unit. So the mass of the initial room is 328.3kg. Now  

>> increase the height of the room by 1 unit and you get 361.2kg a ~10% 
 

>> increase in mass for a ~14% gain in volume. Make it all 8*8*8 and you
  

>> get a ~49% volume increase for a ~32% mass increase.
>
> But what is that 32% mass increase is not feasible?  What if an  

> additional 10% isn't feasible?  This is a government funded project,  

> remember, and their budget is spread over many things - not just the r
ec  

> room for the astronauts.

No you're conflating feasible with cost, the budget that has been set is
  

simply someone's guess. If you look at almost any government project fin
al  

cost is always greater then initial budget, yet amazingly they've manage
d  

to locate the additional funds.

Now if you were saying "But we need to make these on Earth then transpor
t  

them up into space" then I'd agree that volume and mass are important.  

Before anyone mentions raw materials we're discussing 2001:ASO and if  

they're sending a manned spacehip out to Jupiter I'm betting they're  

mining asteroids.

>> Not that I'm saying 'Hey why not make all the rooms 300ft square' at 
 

>> some point you hit overkill, what I am saying is make the rooms the  

>> size they need to be for everyone to use them comfortably. So no duck
ing
>
> And the point was that it's not reasonable to just make it as big as y
ou  

> want; due to the (assumed) constraints, this is the ship that was  

> created.  A bit cramped, yes, but it gets the job done.

Except what I'm saying is there was no need for it to be "a bit cramped"
  

at all. Having a 300ft square bedroom is overkill, having a 7.5 cube  

instead of a 7 cube isn't.

-- 

Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

Post a reply to this message

Phil Cook nous apporta ses lumieres en ce 2008/01/16 09:28:

> Not that I'm saying 'Hey why not make all the rooms 300ft square' at 
> some point you hit overkill, what I am saying is make the rooms the size 
> they need to be for everyone to use them comfortably. So no ducking 
> through doors or having a shared up/down ladder. It serves no purpose 
> other then being able to use those surplus navy submarine doors.
> 
The small doors do have a purpose: They need to be airtight when closed.
In that case, the key factor is the length of the perimeter. You need it to be 
as short as possible, while still be usable as a door. Surface is also a big 
factor if you may, even remotely, need to close it toward the high presure area.

-- 
Alain
-------------------------------------------------
WARNING: The consumption of alcohol may lead you to think people are laughing 
WITH you.

Post a reply to this message

Phil Cook wrote:
> No you're conflating feasible with cost, the budget that has been set is 
> simply someone's guess. If you look at almost any government project 
> final cost is always greater then initial budget, yet amazingly they've 
> managed to locate the additional funds.

Only when nobody stops you from using guns or fiat money to get 
additional funds. Lots of state-level programs fail in the US for lack 
of budgetted funds.

-- 
   Darren New / San Diego, CA, USA (PST)
     It's not feature creep if you put it
     at the end and adjust the release date.

Post a reply to this message

Phil Cook wrote:
> And lo on Thu, 17 Jan 2008 04:35:39 -0000, Chambers 
> <ben### [at] pacificwebguycom> did spake, saying:
>> While volume != mass, as your rooms grow in volume, the mass needed to 
>> enclose them also grows.
> 
> No not really if you break it down to the simplest situation which is 
> just the one room, simply expand the room and section it. Okay the 
> external walls may be thicker then the internal ones, but the principal 
> stilll holds.

?

This is like saying, "You're right, but you're still wrong." :)

Tim said, "Space is at a premium in just about any vehicle.  You use as 
little as possible. "

My reasoning is that addition volume means additional materials to 
enclose it, and additional fuel needed to propel it.  I never stated 
that the relationship between volume and mass was a linear one.  In fact...

>> It's not a linear relationship, but it is there.

In other words, volume and mass are related (the relationship is there), 
but not in a linear way (it's not a linear relationship).

>>> Create a 7 unit cubic room with walls massing 1kg per square unit 
>>> (all the same thickness). You're pumping it full of a gas that masses 
>>> 0.1kg per cubic unit. So the mass of the initial room is 328.3kg. Now 
>>> increase the height of the room by 1 unit and you get 361.2kg a ~10% 
>>> increase in mass for a ~14% gain in volume. Make it all 8*8*8 and you 
>>> get a ~49% volume increase for a ~32% mass increase.
>>
>> But what is that 32% mass increase is not feasible?  What if an 
>> additional 10% isn't feasible?  This is a government funded project, 
>> remember, and their budget is spread over many things - not just the 
>> rec room for the astronauts.
> 
> No you're conflating feasible with cost, the budget that has been set is 

No, I'm saying "What if".  The point is, you blithely point out that 
additional materials are needed, and then say that the additional cost 
doesn't matter, while I say that the additional cost may make a difference.

> Except what I'm saying is there was no need for it to be "a bit cramped" 
> at all. Having a 300ft square bedroom is overkill, having a 7.5 cube 
> instead of a 7 cube isn't.

But this room isn't the only one in the spaceship; that extra .5 cube 
(?) needs to come from somewhere.

Assuming that the outer hull of the ship is fixed, and cannot be 
enlarged, then it means you have to take .5 cube from another room.

Assuming that the outer hull of the ship CAN be enlarged, then we don't 
need to change the size of the rooms, but we do need additional materials.

Anyway, the point is that making things bigger has a cost.  It's naive 
to say simply, "They should have made that bigger," without at least 
examining the costs.

-- 
...Ben Chambers
www.pacificwebguy.com

Post a reply to this message

And lo on Fri, 18 Jan 2008 03:00:21 -0000, Chambers  
<ben### [at] pacificwebguycom> did spake, saying:

> Phil Cook wrote:
>> And lo on Thu, 17 Jan 2008 04:35:39 -0000, Chambers  
>> <ben### [at] pacificwebguycom> did spake, saying:
>>> While volume != mass, as your rooms grow in volume, the mass needed to  
>>> enclose them also grows.
>>  No not really if you break it down to the simplest situation which is  
>> just the one room, simply expand the room and section it. Okay the  
>> external walls may be thicker then the internal ones, but the principal  
>> stilll holds.
>
> ?
>
> This is like saying, "You're right, but you're still wrong." :)

Yup :-)

> Tim said, "Space is at a premium in just about any vehicle.  You use as  
> little as possible. "
>
> My reasoning is that addition volume means additional materials to  
> enclose it, and additional fuel needed to propel it.  I never stated  
> that the relationship between volume and mass was a linear one.  In  
> fact...
>
>>> It's not a linear relationship, but it is there.
>
> In other words, volume and mass are related (the relationship is there),  
> but not in a linear way (it's not a linear relationship).

Which I first pointed out and subsequently kept agreeing with.

>>>> Create a 7 unit cubic room with walls massing 1kg per square unit  
>>>> (all the same thickness). You're pumping it full of a gas that masses  
>>>> 0.1kg per cubic unit. So the mass of the initial room is 328.3kg. Now  
>>>> increase the height of the room by 1 unit and you get 361.2kg a ~10%  
>>>> increase in mass for a ~14% gain in volume. Make it all 8*8*8 and you  
>>>> get a ~49% volume increase for a ~32% mass increase.
>>>
>>> But what is that 32% mass increase is not feasible?  What if an  
>>> additional 10% isn't feasible?  This is a government funded project,  
>>> remember, and their budget is spread over many things - not just the  
>>> rec room for the astronauts.
>>  No you're conflating feasible with cost, the budget that has been set  
>> is
>
> No, I'm saying "What if".  The point is, you blithely point out that  
> additional materials are needed, and then say that the additional cost  
> doesn't matter, while I say that the additional cost may make a  
> difference.

But the start of this conversation was about the Jupiter mission in  
2001:ASO. A society with a space base and moon bases. So the money is  
there I didn't see them ducking through doors on the moon base so Alain's  
perimeter argument seems only to apply to ships and not stationery objects.

>> Except what I'm saying is there was no need for it to be "a bit  
>> cramped" at all. Having a 300ft square bedroom is overkill, having a  
>> 7.5 cube instead of a 7 cube isn't.
>
> But this room isn't the only one in the spaceship; that extra .5 cube  
> (?) needs to come from somewhere.
>
> Assuming that the outer hull of the ship is fixed, and cannot be  
> enlarged, then it means you have to take .5 cube from another room.
>
> Assuming that the outer hull of the ship CAN be enlarged, then we don't  
> need to change the size of the rooms, but we do need additional  
> materials.
>
> Anyway, the point is that making things bigger has a cost.  It's naive  
> to say simply, "They should have made that bigger," without at least  
> examining the costs.

And again you're correct in the same way I say a 300 ft room is overkill.  



-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

Post a reply to this message

Jim Henderson wrote:
>>> 2^2677009:1 against.
>>>
>>> (Name that number!)
>> Picking up Ford and Arthur in the ship (whose name I can't recall) in
>> Hitchhiker's.... ?
> 
> Close enough; it's the odds of being picked up by a passing spaceship in 
> deep space within the 30 seconds it takes to asphyxiate.

Surely that's an Islington phone number ? ;-)

Post a reply to this message

On Mon, 21 Jan 2008 16:19:42 +0000, Bill Pragnell wrote:

> Jim Henderson wrote:
>>>> 2^2677009:1 against.
>>>>
>>>> (Name that number!)
>>> Picking up Ford and Arthur in the ship (whose name I can't recall) in
>>> Hitchhiker's.... ?
>> 
>> Close enough; it's the odds of being picked up by a passing spaceship
>> in deep space within the 30 seconds it takes to asphyxiate.
> 
> Surely that's an Islington phone number ? ;-)

It is also that, except for in the film, where the odds were changed for 
some bizzare reason.

Jim

Post a reply to this message

Jim Henderson wrote:
> On Mon, 21 Jan 2008 16:19:42 +0000, Bill Pragnell wrote:
> 
>> Jim Henderson wrote:
>>>>> 2^2677009:1 against.
>>>>>
>>>>> (Name that number!)
>>>> Picking up Ford and Arthur in the ship (whose name I can't recall) in
>>>> Hitchhiker's.... ?
>>> Close enough; it's the odds of being picked up by a passing spaceship
>>> in deep space within the 30 seconds it takes to asphyxiate.
>> Surely that's an Islington phone number ? ;-)
> 
> It is also that, except for in the film, where the odds were changed for 
> some bizzare reason.

Not bizarre; the area codes in London have changed several times since 
1979 and the numbers were altered to produce a plausible London phone 
number.

Post a reply to this message

On Tue, 22 Jan 2008 10:24:06 +0000, Bill Pragnell wrote:

> Jim Henderson wrote:
>> On Mon, 21 Jan 2008 16:19:42 +0000, Bill Pragnell wrote:
>> 
>>> Jim Henderson wrote:
>>>>>> 2^2677009:1 against.
>>>>>>
>>>>>> (Name that number!)
>>>>> Picking up Ford and Arthur in the ship (whose name I can't recall)
>>>>> in Hitchhiker's.... ?
>>>> Close enough; it's the odds of being picked up by a passing spaceship
>>>> in deep space within the 30 seconds it takes to asphyxiate.
>>> Surely that's an Islington phone number ? ;-)
>> 
>> It is also that, except for in the film, where the odds were changed
>> for some bizzare reason.
> 
> Not bizarre; the area codes in London have changed several times since
> 1979 and the numbers were altered to produce a plausible London phone
> number.

Sure, that would make sense, except that the odds as given are somewhat 
iconic - there are certain details about H2G2 that shouldn't change IMHO; 
that's one of them.  Other things, like the addition of entire new 
scenes, however, is part of the H2G2 "culture".

Jim

Post a reply to this message