Re: Solar powered lasers in space

On 24 Sep, 22:43, Willie.Moo...@xxxxxxxxx wrote:


Actually ballistic flight may not be the best solution.

Why not? Postulating that industrial humanity gets on a path that
cuts the cost of energy by half every 5 to 7 years - as was that case
from 1850 through 1970 - then ballistic transport is a very efficient
solution. Orbital velocity is 7 km/sec. Escape velocity is 11 km/sec
- twice orbital velocity - 14 km/sec - would produce 1 gee outward
force to maintain altitude - these represent energies of

E = 1/2 m V^2 = 24.5 MJ per kg - orbital - $0.74/kg
49.0 MJ per kg - escape - $1.48/kg
98.0 MJ per kg - 2x orbital - $2.96/kg

The costs are calculated on the basis that a gallon of gasoline costs
$3.60 and contains 120 MJ. So to transport 500 kg ballistically would
cost $370, $740, and $1,480 per trip - respectively.

At the moment energy costs are on an upward spiral.

Assuming energy costs were on a downward cost trajectory, being cut in
half every 5 years - (13% reduction every year compounded), far less
agressive than say the advances in the consumer electronics industry,
then in 10, 20 and 30 years we'd have per trip costs of;

10 years $92.50 $185.00 $370.00
20 years $23.12 $46.25 $92.50
30 years $5.78 $11.56 $23.12
40 years $1.44 $2.89 $5.78

Yes but the consumer electronics industry is taking advantage of the
fact that o0ne can put progressively smaller and smaller components
onto a chip. In terms of energy to get a downward spiral you need new
technology. OK there are ways in which that can be provided.

We can see that in 50 years, the cost of travelling from one side of
the world to the other, would not only be accomplished in 45 to 22
minutes, but would also cost the same as it now costs to drive across
town in 20 to 45 minutes.

There are also environmental factors. At present helicopters make a
lot of noise, but because they are only available to the very rich and
public services, they are allowed to fly fairly freely. Give everyone
a helicopter or VTOL aircraft and the main driving force will be
environmental. With the emergency services being exempted there would
be draconian restrictions on where you could and could not fly. All
flying below 1000m in towns would be banned. This being so it seems
foolish to talk about VTOL. If you have to go outside city limits
anyway you might as well have a runway and be done with it.

The solution
may well be to have evacuated tunnels and electromagnetic
acceleration.

The solution to what? I'm having trouble tracking your thought
process.

Suppose you have a straight evacuated tunnel. The tunnel is evacuated
so that there is no air resistance. A linear induction motor gives a
constant comfortable acceleration up to half way. At the half way
point the acceleration is reversed. Most of the energy involved in the
acceleration is then reversed.

Excavating the tunnels will be a major piece of engineering.

Robert Goddard suggested that in 1910. The tunnels, if the Chunnel is
representative, would be very capital intensive and of lmited
utility. Getting on and off the tunnel, and then driving to and from
the tunnel entrances become huge bottlenecks. This cannot compare to
an automated aerial taxi service that transports you anywhere on Earth
in minutes in response to a cell phone call.

Yes but so would an energy system. What is needed for BOTH in fact is
cheap methods of construction. Cheap ways of moving material whether
on an asteroid or on Earth is what is needed. If you have our VN
machine you can use it to excavate tunnels.

Distance travelled at 1 gee - acceleration to halfway point - 1 gee
deceleration to destination from halfway point;

1 mile 26 seconds 285 mph top speed
2 mile 36 seconds 395 mph top speed
5 mile 58 seconds 635 mph top speed
10 mile 81 seconds 900 mph top speed
20 mile 2 minutes 1,275 mph top speed
50 mile 3 minutes 2,015 mph top speed
100 mile 4 minutes 2,850 mph top speed
200 mile 6 minutes 4,030 mph top speed
500 mile 10 minutes 6,590 mph top speed

The Channel Tunnel is simply a tunnel to take you through a geographic
barrier. What I have in mind would be as complete network. The
technology required for massive excavations will not be so different


I don't think so. There are a great many conspiracies but this is not
one of them.

How do you know?

I do not think there is any conspiracy in fundamental
science/mathematics.

Not conspiracy - policy.

You Americans make one basic error and that is to assume that nobody
outside the US knows anything. The fact of the matter is that keeping
things secret merely means that someone else will discover them,
publish them openly and gain all the credit. It may well be the policy
of the CIA to fall on their swords in this way.

I don't know I don't know their psychology. I am going to tackle the
issue of encryption from a theoretical stand point.

http://www.it-director.com/technology/content.php?cid=7475
http://www.claymath.org/millennium/Riemann_Hypothesis/Official_Problem_Description.pdf

Mathematicians generally believe that a proof of the Riemann
hypothesis could enable factorizations of large composite numbers and
enable diferent types of unbreakable code.

We can see this quite simply. We multiply together two large primes.
If the RH is proved cryptology would then (I presume) take prime
modular functions and use those. The Riemann hypothesis can only be
proved using some type of modular field, I am not really an expert in
this. We could, with a proof, understand how theoretically
unbreakable trap door ciphers could be constructed.

http://www.fas.org/sgp/othergov/doe/rdd-7.html

Check out section B-1 - Mathematics is included dude. And this is
just for nuclear physics. I'm sure there are similar classifications
in place for methods involving the production and decryption of codes
and other stuff as well.

Here is what was declassified! haha.. Which means it WAS classified
at one point.

B. MATHEMATICS
Methods of applied mathematics and computation if illustrated on
declassified subjects. (46-1) Examples:

Shock hydrodynamics. (46-1)
Integration of partial differential equations. (46-1)
You can buy packages for this.
General diffusion theory. (46-1)
Ditto
Theoretical methods for determining equations of state. (46-1)
People outside the US are working openly on this. The US will fall
behind with classification.
Chemical kinetics including application to ordinary explosives.
(46-1)
Theoretical methods for calculating opacities. (46-1)
Ditto
General theory of blast. (46-1)
Methods of applied mathematics if illustrated on declassified
subjects. (47-1)
Pure and applied mathematics including computational methods, provided
it does not reveal information classified for other reasons. (48-1)

Suppose I go to India or China and get the full works?

I think that the VN machine has not been built
because in the time of Von Neumann computers just weren't powerful
enough. A similar situation held with regard to language.

You don't need sophistcated computers. VonNeuman had a shoebox filled
with hand carved wood pieces that when shaken self-assembled. He also
had a tiny dried clay pieces that when you put the concave and convex
(female/male coupling) together the void was identical to the
parents. So, you could take a *** of clay and make other identical
pieces out of them.

You do and you don't. That might seem an odd thing to say. The basic
concept of self reproduction is indeed simple. To do something useful
is a little different. People talk about VN machines in the context of
nanotechnology. I feel this is a mistake. You require not only the
ability to reproduce, you also require the ability to perform general
construction. You need an O'Neill space habitation, you need lasers,
you need a power station in space. Build them! To me only a CAD/CAM
based VN machine (strictly speaking one should talk about a VN swarm,
not a single machine). Chlorella is a VN machine, it can reproduce
itself, but is not useful in the way a CAD/CAM system is.

As I've said, this was reported in the press back in the 40s - and
NOTHING has been done to build on these rather simple approaches. And
the pieces and shoebox have disappeared, and computer records don't go
that far back, and its only the memories of old farts like me that
recall it at all.

You cannot compare ProEngineer with JLINK with anything that has gone
before. I agree with you, we are lacking in imagination. With JLINK
you can simulate anything. You can build a robot and give it a
complete workout, before you start to bend metal. YOU have to write a
program in - well JLINK assumes Java and you feed your Java program
into you robot when you have bent the metal. The code is tested
without.

A VN machine in the context of space assumes a cetain degree of sensor
ability. You go to an asteroid, build a copy of yoursel[f][ves]. This
involves a sophisticated sensor system. Not around in the time of v
Neumann. Around now. I think that we NOW have a failure in
imagination.
http://groups.google.co.uk/group/sci.physics.research/browse_frm/thre...

When we are considering assembling flat packs we are in the situation
of "We can build it if we want to and if we have the imagination".

Correct. VonNeuman built examples of what he was talking about - and
then nothing.

As
far as codes are concerned we already know a lot.

Look at a vonNeuman machine. It reads and writes a string of 1s and
0s. - advances, reverses.. that's it. It doesn't take much from
there.

We know about the
RSA code the beauty of which is that you can establish it without ever
having to transmit anything in plain text. We know too that with any
generating function we have a code, but we need RSA to set our
generating function up.

RSA codes are based on the ASSUMPTION that there is no way to factor
numbers quickly. This assumption has never been proved. So, that's
its achilles heel. Sorting numbers is a computationally difficult
task. But when numbers are each concieved as the length of an
uncooked spaghetti noodle, all you've got to do to sort them is hold
them in your hand, drop them onto a table top, and they're
automatically sorted in an instant.

No one has yet proved the Riemann hypothesis.

You have a certain conception based on the popularizations of these
ideas, and that puts your mind into a certain mode. You don't really
understand these things deeply. You appreciate the potential,
certainly, but you don't appreciate the details and just how easily
these things could be built with the right people working on it.

I agree that we suffer from a failure in imagination. Perhaps this is
because of Moore's law and the fact that we have reached present day
computer powers too quickly


I don't think it has to be ballistic.

What is this problem you have with the world 'ballistic'?

You understnad what I mean by ballistic don't you?

It means it follows a ballistic trjectory.

Jesus. you were talking elsewhere about travel between the planets.
Well, that's lots faster and lots more energetic than mere ballistic
transport from point to point on Earth.

Not entirely. If you gather energy from the Sun and blast something
off to Alpha Centauri you are using up energy that was otherwise going
to waste. On Earth you have to be carefukl about general heating.

It takes about 84 minutes for a minimum energy object to orbit the
Earth. It takes no more than half that time for a sub-orbital payload
to follow a ballistic trajectory to the anti-podes (halfway around the
Earth)

http://www.cs.utah.edu/~zachary/isp/applets/Cannon/Cannon.html

Yes but you are making far more trips.

So, since we were talking freely about people flying constant gee
spaceships from planet to planet - there is no trouble whatever
imagining people flying suborbital spaceships ballistically from point
to point ON a planet. And the first planet we'll do that with - is
planet Earth.

Like I said, 42 minutes gets you on the other side of the Earth. With
a constant gee spaceship like I was discussing, you can accelerate to
twice orbital velocity, and boost outward to maintain altitude -
trajectory - and arrive to the antipodes in 21 minutes - and anywhere
else in less time!!




You can meet people in New York easier than you can meet them
elsewhere. OK perhaps not New York, but you do need a settlement.

Wait a minute... please appreciate what we're talking about here. On
the one hand we're talking about interstellar homesteading. The
technology and energy needed to achieve that. Everyone owns their own
space ranch with laser light wings attached - tapping the energy of
the stars themselves to boost through interstellar space at large
fractions of the speed of light.

Now we're talking about communities. Collections of folks. Having
access to this type of technology and this level of energy per
person.

Imagine a time when all the stars have hovering above them man made
fog of laser powersats that beam energy in response to signal lasers
that each starship carries. The ship is booste at 1 gee across the
cosmos until its halfway to its destination. Then, it signals its
destinatoin - and is slowed at 1 gee until it arrives. And the
spaceship is the size of an ONeil colony. I computed that stars the
size of the sun could support 20 million or so of these colonies
arriving and departing every second!!! In a year the entire human
race could circulate out of the solar system.

In the context of this massive amount of energy entire planets will
seem as small psychologically, as a cozy neighborhood. We wouldn't
want to mess up a planet with big tunnels and huge collections of
buildings. Why do we need them? Imagine millions or perhaps billions
of colonies in leisurely orbit around Earth and Mars and so forth.
Like the rings of Saturn. And small high gee spacecraft dart out of
each habitat and fly in minutes or even seconds to another. In 20
minutes a person could dart from wherever they were in Earth orbit to
wherever else they wanted to be in the ring, or on the surface. This
would BE a city larger than New York ever could be. Phone calls and
telepresence allow people to communicate instantly. Constant gee
spaceships allow them to hop from one side of the planet to the other
in minutes. The entire planet has become one vast city.


Not completely (see above) Von Neumann lived in the era of valves and
it was hard to execute his devices.

Yet he built a machine with a shoebox and a penknife that self-
assembled, and he built a small set of dried clay devices that could
automatically mold daughter devices that also could mold daughter
devices... to illustrate the ease with which is concepts could be
implemented. Have you even read the source material? The orirginal
writings on this subject?? Or have you just read the popularizations
of it?

The thing I feel now

But what is the real solid basis of your feeling? You can see that
machines that can make copies of themselves can end the Malthusian
delimma - but is that because you've been told that or because you've
figured it out on your own? And now what? What do you really thing
based on what you really and truly know? How much of what you're
saying here is just repeatition of what you've already read from
someone who was a journalist or popularizer?

We are all dependent on other people to take us our views. How much of
my thoughts are dependent on journalists/popularizers? IOn technical
issues very little. On mathematics I have read quite a bit about
modular functions, elliptic functions and prime moduli. My views are
based to a degree on my experience with ProEngineer.

A VN swarm - it really should be called that can be described in the
form of a graph. This graph is a graph of processes and objects. If we
can get a graph of processes such that the only net inputs are
sunlight and asteroid rock we have done it. A VN swarm will in fact
map onto a graph.

On the more political issues my views are really worth very little. I
do not speak Arabic which is absolutely vital to carry any weight - at
least academically. I simply know that other people are talking even
more bunkum than I am.

is that we
have computers of fantastic power, in comparison. Somehow though we
have lost a certain amount of vision.

Because no one does the hard work to figure stuff out on their own.
To really think about a topic and thoroughly understand it. You
switch from starships and talk like someone who lived in a ONeill
sized starship couldn't possibly afford a ballistic transport!
haha.. You have no idea what's going on, and so you have no idea how
the pieces might go together.

Newton claimed to be standing on the shoulders of giants. We can only
do a very little bit ourselves.


You don't need ballistic transport - all you need is a decent system
of telepresence.

What the hell do you have against ballistic transport? ITS THE WORD
ISN;T IT? You don't know what the word really means so you're afraid
of it- you have it associated in your head with 'hes gone ballistic'
and 'destruction by ballistic bombardment' haha.. you lunatic. Jesus
learn what the hell you're saying before you say it.

This is achievable in the very near term.

We already have ballistic missiles. And we already have telephones,
we had vidphones 40 years ago - and have teleconference,today and
we're working on telerobotics - so yeah. But in the context of what
we're talking - ballistic transport could be 3 to 5 years away. It
would change everything.

Have you looked at the environmental impact. .


Yes I do. Werner v Braun - like v Neumann in some respects had a
vision that could not be realized at the time.

Yes it could. What do you think Apollo was all about? Project
Horizon 1959 (not to be confused with New Horizons study 1948),
Project Lunex 1961 - he actually built rockets as far back as the
1930s. Tsiolkovski had a vision that couldn't be built in his time in
the 1890s. vonNeuman built a lot of *** - as I pointed out.
VonNeuman and vonBraun BOTH were hands on engineers that built
stuff.

You cannot consider
space colonies without a drastic reduction in cost.

Duh. that's what we're talking about. Reducing the cost of energy and
the cost of materials on orbit. This is related. Beam energy from
near the sun to Earth for industrial use. Beam energy across the
solar system to change the orbits of rich asteroids to bring them to
Earth orbit. Then launch telerobotic systems into Earth orbit or
begin working those rich asteroids into useful stuff. And deorbit
that stuff directly to consumers using GPS and satellite
communications.

This reduction of
cost is so many orders of magnitude below current costs

Nonsense. You talk as if these costs couldn't be reduced. I've
outlined a specific program to produce 300 TW of laser energy at a
cost of $20 billion - that would bring 8 asteroids each 1 km in
diameter into polar orbit around Earth per year - and power space
factories and flights from orbit to surface of finished goods.

True. As far as I see it you can reduce costs in 2 ways. You can use
the resources of space. You can get what amounts to freebies from
asteroids, or you can have a more efficient space transportation
system. The only transportation system that would be orders of
magnitude cheaper would be the laser based "Nerva".

that a lot a
technology has to be developed first.

Like what? You don't know what's going on and you don't know enough
to understand what i've said, so you are say uh uh its complicated and
will take a long time. phhtt. Anything takes a long time if you don't
know what the hell you're doing.

We can have a power station as
an objective, we can have a VN maschine. Colonies, they will be
objectives when the costs are right.

So you ARE familiar with Gerard O'Neill and the L5 society right? You
are familiar with the NASA studies done back in the 70s about space
colonies. These give the basics. Now, reduce the cost of stuff on
orbit by a factor of a million by bringing rich asteroids into Earth
orbit and process them with telerobotic systems. This avoids a moon
base up front and a large manned presence in space up front - but
gives you immediate economic benefits and huge cost reductions.

You say L5. I thought you were also thinking in terms of actually
sending O'Neill colonies to stars and having 1 micron radiation all
the way.


But colonies will still not be an objective.

When you can buy 10 sq km of any environment you want free of any
restrictions - that is mobile - for less cost than a 1/4 ha plot in a
suburb - and when travel to orbit is less costly than travel across
town - people will naturally buy homesteads in space.

The highest price homes are $100 million. Millions of homes are
priced between $10 million and $100 million. There are 9.5 million
millionaires in the world. An ONeill space colony masses about
500,000 tons. So, let's say a starting price of $50 million per
colony is needed to attract a critical mass of buyers. By the way, a
Boeing Business Jet costs over $65 million - and there are dozens of
those. but this is $100 per ton. $0.10 per kg. This is the price
point we have to reach. Today it costs $10,000 per kg - or
1/100,000th the cost.

To reach that your colony will have to be pure asteroid - pretty well,
with perhaps just the odd chip coming from Earth.

Now, I have proposed a system that builds 100 kg systems that get
launched into space by rail gun, and fly to hover over the solar
surface. There they operate in conjunction with one another to create
a 20 km diameter 300 TW beam of laser energy. This beam can bring
trillions of tons of material into Earth orbit. The same rail gun
array that launched the laser sats can also launch advanced versions
of ASIMO - powered by laser energy from the sun - along with toolkits
to allow the remotely controlled robots to process the materials into
useful products.

Coal miners routinely process tens of thousands of tons per day. With
an average cost per worker of $100,000 per year, and a million tons
per year - we're ALREADY at $0.10 per kg.

We need AUTOMATIC mining - Asteroids & Earth. On Earth we need to
excavate under such places as New York.

A reusable system that makes 10,000 flights - and has 1/2% replacement
cost as arecurring cost per flight - a system that is achievable
nearterm - then we have a system that has reduced to cost of GETTING
into orbit to $100 per kg. This is cheap enough for the high net
worth individuals to routinely travel back and forth to their space
homes.

What I'm saying we could do space colonies today with the right
approach.

I would concentrate more on asteroid mining.

- Ian Parker

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