================================================================
================================================================
X-Sender: S9421793@mail.student.utwente.nl Mime-Version: 1.0
Date: Mon, 10 Jun 1996 12:36:23 +0100
To: KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU
From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
Subject: Re: Energy:momentum ratio

To Steve:

Words as "efficiency" and "convert" are only used to not make sentences
more elaborate than they could be, I had not thought the word "efficiency"
would create that much trouble, since one only needs an unit-conversion
to make things right.
It is this same origin that makes the word "convert" not 100% at its place.
Even now, I can't find a single word would be satisfying, the only solution
would be to use sentences like your:

When you take something that has momentum, and you get energy out of it
by slowing it down, you are getting the extra energy it has to compensate
for its momentum (m^2 = E^2 - p^2). If m is constant, then when p
increases E also increases.

Even then, the words "get energy out of momentum" sounds much like
"convert", "transfer" or "transform" which don't sound very well either. 


The derivation is as follows:

The momentum of a particle with velocity v : p=gamma m v The energy of a
particle with velocity v : E=m c^2 (gamma-1) 

p/E = v gamma / (c^2 (gamma-1))

Simplifying the above gives:

p/E = 1/c {v/(c-Sqrt[c^2-v^2])}

All units are according to S.I.

(When mentioning energy, I only mean kinetic energy) 

TimothyDate: Mon, 10 Jun 1996 07:19:21 -0700
From: Genny Houston <hous0042@maroon.tc.umn.edu> Mime-Version: 1.0
To: kellyst@aol.com
Cc: kgstar@most.fw.hac.com
Subject: [Fwd: Re: Energy:momentum ratio] 

Wow,

Short, to the point, and full of math. I think Tim's a little peeved. 

;)

BTW, I wrote Dave and asked what his intentions are for LIT, I told him
that I already got myself a domain name, and could not justify a virtual
server at this time unless I thought that LIT was going to need space (no
pun intended) I expect to hear back from him today or tommorrow. I really
would like a big hit site like LIT to help generate ad money. I'd have to ask
for about $20.00 from each of the members (as a donation only) to help
with the startup costs, but then I would not everr ask for money again
unless I absolutely had to. As long as URLy-bird makes money (I don't see
how it can't) LIT will always have a home.

Kevin

Timothy van der Linden wrote:

>To Steve:

>Words as "efficiency" and "convert" are only used to not make sentences
more elaborate than they could be, I had not thought the word "efficiency"
would 

<snip>


>The momentum of a particle with velocity v : p=gamma m v The energy of
a particle with velocity v : E=m c^2 (gamma-1) 

>p/E = v gamma / (c^2 (gamma-1))

>Simplifying the above gives:

>p/E = 1/c {v/(c-Sqrt[c^2-v^2])}

>All units are according to S.I.

>(When mentioning energy, I only mean kinetic energy) 

>Timothy

================================================================
================================================================
X-Sender: kgstar@pophost.fw.hac.com
Mime-Version: 1.0
Date: Mon, 10 Jun 1996 09:00:27 -0500
To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) From:
kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Subject: Re:
USING A ELECTROMAGNETIC BEAM TO PROPELL A STARSHIP Cc:
KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU

At 3:20 PM 6/8/96, Timothy van der Linden wrote: 
>>>>Of course if your using my hybrid fuel/sail configuration you want a
havyer sail... ;)

>>>Laser forth and maser back?

>>Doesn't really matter. On the way out it depends on what lithium
reflects best. On the way back probably the same thing, just so you don't
need to build new beaming facilities.



>>>>I worry about EM and secoundary reactions in the plasma. We are after
all talking about hellish amounts of power. Even small percentages could
incinerate the engine and ship. (Even a mile of Lithium might not protect
the crew.)

>>>OK, then we're back on one line...

>>One line?

>Eh, I guess my Dutch translation was a bit to litterally: 

>"We're in line with eachother" or "We're in agreement with each other" 


>Timothy

Ah, like "in sync". Yeah, were together on the basic idea. Now how do you
boost that much stuff!!

Kelly


------------------------------------------------------------------
---- 

Kelly Starks	Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html) 

------------------------------------------------------------------
----

================================================================
Date: Mon, 10 Jun 1996 08:58:49 -0700
From: Steve VanDevender <stevev@efn.org> To:
T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc:
KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU
Subject: Re: Energy:momentum ratio

Timothy van der Linden writes:
>The derivation is as follows:

>The momentum of a particle with velocity v : p=gamma m v The energy of
a particle with velocity v : E=m c^2 (gamma-1) 

That's kinetic energy, not total energy. For many purposes kinetic energy
is not particularly useful. Most importantly, when I say p/E is v, I use E to
mean total energy (m*c^2*gamma in conventional units). 

>p/E = v gamma / (c^2 (gamma-1))

>Simplifying the above gives:

>p/E = 1/c {v/(c-Sqrt[c^2-v^2])}

>All units are according to S.I.

>(When mentioning energy, I only mean kinetic energy) 

If you want to use kinetic energy as a quantity in your relativistic
dynamics problems, be prepared for your analysis to get _a lot_ more
complicated.

I think I went into some detail in my original derivation about how I
analyzed the relativistic dynamics of a ship reacting and ejecting a
quantity of fuel. You might want to take a look at it again. 

The most unlikely result of your derivation is your claim that lower
exhaust velocities are better. Does that mean that zero exhaust velocity is
best, or is there instead an optimal velocity that is non-zero?

>Timothy

================================================================
X-Sender: S9421793@mail.student.utwente.nl Mime-Version: 1.0
Date: Tue, 11 Jun 1996 00:06:42 +0100
To: KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU
From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
Subject: Re: Energy:momentum ratio

To Steve,

>If you want to use kinetic energy as a quantity in your relativistic
dynamics problems, be prepared for your analysis to get _a lot_ more
complicated.

Yes, I assume you know that I and Rex independently have done such
analysis's. We both have made documents that include some algebra that
isn't always fun to look at. We also came to the conclusion that every fuel
(combined with a Vend of the starship) has its own optimal Vexhaust.
(More about this optimum in a few sentences) 

>The most unlikely result of your derivation is your claim that lower
exhaust velocities are better. Does that mean that zero exhaust velocity is
best, or is there instead an optimal velocity that is non-zero?

I think you misunderstood the meaning of these formulas. 

In essence these formulas are just showing p/E ratios, they tell little
about how they should be use, indeed for self-powered spaceships their
use it limited (will come back on that in a minute), but for beaming
stations on Earth they may be of direct use (that comes in another couple
of minutes). 

To answer you question about the optimum, "Yes there is an optimum
bigger than zero (and less than c)".

Let me quote a few lines from my HTML-document: 

(Keep in mind that this assumes a certain constant Vend of the starship) 

The minimum exists because on the one hand, the higher Vexh the worse
the energy/momentum ratio of the exhaust mass or because of the
dumping of excess mass.
And on the other hand, for low Vexh more mass is needed to get the same
momentum, this means that unused fuel is used as propellant mass (this
could easely be changed by increasing the fuel-factor). 

The complete document (large) should be here (with Dave): 
http://165.254.130.92/LIT/calc/calc.html 


To add some extra confusion ;) or to make things more complete I like to
make clear why for beaming mass would be cheaper (in terms of energy)
than beaming photons.

For self-powered starships low exhaust velocities mean enormous
amounts of propulsion mass to get the same total momentum. As one could
imagine, part of that mass needs to move with the starship during the
acceleration phase. This isn't handy because it makes everything harder to
acclerate. 

But when one beames from Earth (or another source), it doesn't matter
much how much mass is beamed, since one doesn't have the accelerate-
the-mass-with you-problem (any other terminology?) that I described
above for the starship. 

For constant momentum (the momentum that the starship needs for a
specific Vend), and decreasing Vbeam the energy levels decrease: 

(Vbeam=v=the velocity of the beamed mass) 

E = p c {(c-Sqrt[c^2-v^2])/v}

where {(c-Sqrt[c^2-v^2])/v} decreases for decreasing v 

Of course decreasing v means increasing M (gamma*m*v=fixed) but as long
as the total energy decreases we don't care. (Mass is cheaper than energy
isn't it?)

OK, hope that your not confused by all the increases and decreases (and
that I made no mistake in it).

Now a more practical problem, the beam velocity cannot stay low at all
times, since the starship accelerates and the beamed mass needs to catch
up with the ship. Well actually this is not really a problem, only the p/E
ratio gets worse, but it will always be better than when one uses photons.
(It is only the same when mass moving with Vbeam=c) 


Timothy

================================================================
X-Sender: S9421793@mail.student.utwente.nl Mime-Version: 1.0
Date: Tue, 11 Jun 1996 00:06:50 +0100
To: KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU
From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
Subject: Re: USING A ELECTROMAGNETIC BEAM TO PROPELL A STARSHIP 

>Ah, like "in sync". Yeah, were together on the basic idea. Now how do you
boost that much stuff!!

Ah yes, "in sync" that is what I was looking for. 

About your question, we know the answers, all we need is the technology
and the money :))


Tim


================================================================

From: David Levine <David@InterWorld.com> To: "KellySt@aol.com"
<KellySt@aol.com>, 
"kgstar@most.fw.hac.com"
	 <kgstar@most.fw.hac.com>,
"stevev@efn.org" <stevev@efn.org>,
"jim@bogie2.bio.purdue.edu" <jim@bogie2.bio.purdue.edu>,
"zkulpa@zmit1.ippt.gov.pl" <zkulpa@zmit1.ippt.gov.pl>,
"hous0042@maroon.tc.umn.edu" <hous0042@maroon.tc.umn.edu> To:
"rddesign@wolfenet.com" <rddesign@wolfenet.com>, 
"lparker@destin.gulfnet.com" <lparker@destin.gulfnet.com>,
"DotarSojat@aol.com" <DotarSojat@aol.com>, "neill@foda.math.usu.edu"
<neill@foda.math.usu.edu>, "101765.2200@compuserve.com"
<101765.2200@compuserve.com>, "MLEN3097@Mercury.GC.PeachNet.EDU"
<MLEN3097@Mercury.GC.PeachNet.EDU> To:
"'T.L.G.vanderLinden@student.utwente.nl'" 	
<T.L.G.vanderLinden@student.utwente.nl> Subject: RE: Energy:momentum
ratio
Date: Mon, 10 Jun 1996 18:20:55 -0400
Mime-Version: 1.0

>----------
>From:
>	T.L.G.vanderLinden@student.utwente.nl[SMTP:T.L.G.vanderLinden@student.utwen te.nl]
>The complete document (large) should be here (with Dave): 
>http://165.254.130.92/LIT/calc/calc.html 



Hi, all.

QUICK NOTE: Had some problems with the virtual server at 165.254.130.92,
so try 165.254.130.90 instead. I think everything will work much better.
URLs are
still the same (http://165.254.130.90/LIT/calc/calc.html for example) 

For those of you FTPing documents, please use 165.254.130.90 now. 

Thanks.

David

(If anyone else wants an FTP account, let me know...)Date: Mon, 10 Jun
1996 21:26:59 -0700

================================================================
X-Sender: kgstar@pophost.fw.hac.com
Mime-Version: 1.0
Date: Tue, 11 Jun 1996 07:47:54 -0500
To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) From:
kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Subject: Re:
USING A ELECTROMAGNETIC BEAM TO PROPELL A STARSHIP Cc:
KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU

At 12:06 AM 6/11/96, Timothy van der Linden wrote: 
>>Ah, like "in sync". Yeah, were together on the basic idea. Now how do you
boost that much stuff!!

>Ah yes, "in sync" that is what I was looking for. 

>About your question, we know the answers, all we need is the technology
and the money :))

>Tim

All in all we've done fairly well. Most people still talk about starships as
being impossible or talking centuries to get anywhere. We've at least
figured out a technically plausible way to do it in a decade or two. <well
about as plausible as anyone elses.>

Kelly


------------------------------------------------------------------
---- 

Kelly Starks	Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html) 

------------------------------------------------------------------
----

From: David Levine <David@InterWorld.com> To: "KellySt@aol.com"
<KellySt@aol.com>, 
"hous0042@maroon.tc.umn.edu"
	 <hous0042@maroon.tc.umn.edu>,
"T.L.G.vanderLinden@student.utwente.nl"
<T.L.G.vanderLinden@student.utwente.nl>, "stevev@efn.org"
<stevev@efn.org>,
"jim@bogie2.bio.purdue.edu" <jim@bogie2.bio.purdue.edu>,
"zkulpa@zmit1.ippt.gov.pl" <zkulpa@zmit1.ippt.gov.pl> To:
"rddesign@wolfenet.com" <rddesign@wolfenet.com>, 
"lparker@destin.gulfnet.com" <lparker@destin.gulfnet.com>,
"DotarSojat@aol.com" <DotarSojat@aol.com>, "sl0c8@cc.usu.edu"
<sl0c8@cc.usu.edu>,
"MLEN3097@Mercury.GC.PeachNet.EDU"
<MLEN3097@Mercury.GC.PeachNet.EDU>, "101765.2200@compuserve.com"
<101765.2200@compuserve.com> To: "'kgstar@most.fw.hac.com'"
<kgstar@most.fw.hac.com> Subject: RE: Opps
Date: Wed, 12 Jun 1996 09:28:33 -0400
Mime-Version: 1.0

>Others.
>The image map TOC's don't work. <AAHHHH!> 

I will take a look at them.

-David

Date: Fri, 14 Jun 1996 00:56:36 -0400
From: KellySt@aol.com
To: kgstar@most.fw.hac.com
Subject: Fwd: Re: Sf movies & FX


---------------------

================================================================
X-Sender: S9421793@mail.student.utwente.nl Mime-Version: 1.0
Date: Sat, 15 Jun 1996 00:19:30 +0100
To: KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, 
jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com,
David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com,
neill@foda.math.usu.edu, 101765.2200@compuserve.com,
MLEN3097@Mercury.GC.PeachNet.EDU
From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
Subject: Re: Post singularity society

>>What about the third world? They think we're pretty freaky now. What if
we start to radicaly change. Would they deside we were no longer human? 

>>Just a few thoughts.

>>Kelly

Yes, we touched this earlier, worrying if we could control them, me
suggesting to create a virtual world to keep them in, so that they could
never do us any harm, but us allowing to look inside to see how they
"performed".

One should consider what abilities one would like to have, speaking 20
languages fluently? Being able to compute the most difficult
mathematical problems, figuring out the laws of the universe? Or how to
love, to life in this world among and with others?

I assume most of us are looking for a world that offers freedom (in all
ways), eventually such a world will exist, the only problem then will be: 
What to choose...


Another viewpoint is this:
Today we are wondering, how should we treat nature, our origin and
mother? In a few decades we need to take care of our children, they need
upbringing, are we able to give them that? On the other hand, children can
help to understand oneself better.


Just some other thoughts...

Timothy


=================================================================
Date: Sat, 15 Jun 1996 14:04:34 -0400
From: KellySt@aol.com
To: kgstar@most.fw.hac.com
Subject: ox

From: Shld Wulf

Kelly St: Said:

>I wonder how much space it takes to keep one in oxegen.< 

My figure is @ six liters of algea per person. That could be contained in a
less than 2 meters of clear tubing, wrapp it helicaly around your light and
go for it.

================================================================
X-Sender: S9421793@mail.student.utwente.nl Mime-Version: 1.0
Date: Sun, 16 Jun 1996 02:00:10 +0100
To: KellySt@aol.com, kgstar@most.fw.hac.com From:
T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Subject:

Hi Kelly,

I've made time to read your HTML,

About the "Space Settlement Designer's Corner", I know the numbers there
aren't yours, but 15-20 kg of water as input seems very much. Also peeing
over 7 liters of urine per day seems rather much. Could you explain what
I'm overlooking, or am I just some one who use little water? 

In the "Externally Fueled Fusion Rocket" in the "Laser fuel launchers"
paragraph you write: "If you space the tugs out every 60,000 miles for
100,000,000 kilometers..."
The double metric standard is a bit confusing. A few lines further you
write "... is 100,000 m/s^2, or about 100,000 G's." I assume you mean
10,000 G's (one zero less). You also say that such accelerations are
acceptable, how sure are you about that?

Finally you end with "The major problems with this system are the amount
of reaction mass, and power, necessary to reach the desired maximum
speeds may be prohibitive."
You got me confused, what reaction mass are you talking about, all this
was about lasers.

I still don't see why one want to use a plasma shield instead of a solid
one, could you repeat your latest arguements? 

A general note, a lot of your tables (not all) are cropped up (at least with
the font I am using), for a reason not clear to me, you have added the
WIDTH-tag in the tables, if you would just leave it out, the tables are
automatically scaled.

I suggest a table of contents at the top of several pages, especially the
overview pages like "Mission flight type", "Future tech" and "Mission
purpose", it gives an immediate overview of the page. 

I see you use "&;" instead of "& " in your "Support Ships: SSTO lander /
Hypersonic Cruise Aircraft" page, try "&amp; " the next time :) 

The "aero-lan.gif" image at this same page could be emphasized with the
'blue-border-link' so that people know they can get a better look by
clicking on it.

What I wonder about with these support ships, shouldn't they have a little
bit more overcapacity, for example they should be able to do multiple
landings and takeoffs at a more than 1g planet (at least 2 g). 

About the contents of all pages, it all seems OK, I wouldn't have expected
otherwise, we have discussed everything several times. 


Timothy