When will we be able to afford space settlement?

John Ordover wrote:

What product will that be, exactly?

Climate modification.

On Earth? Wow, wait for that, you'll wait a very long time.


You may not be correct, John. My BotE calculations suggest
that surprisingly little mass need be moved to the Earth-Sun L1
point to significantly reduce insolation at Earth, if you arrange
the system properly.

The idea I have would be to mine the moon for materials that can
be vaporized near the Earth-Sun L1 point. The atoms and small clusters
in the vapor would scatter sunlight in certain narrow bands by
resonance scattering or fluorescence. The gas would be accelerated
toward Earth by light pressure, doppler broadening the bands (the
higher the acceleration the better.)

An alternate idea would be to fabricate very small dipole scatterers
and releases them near earth-sun L1 (essentially, micron scale solar sails.)
Short carbon nanotubes could work.

Paul

In article ,
william mook wrote:

In the 1950s it was unbelievable that anyone but an international
corporation could make use of a computer. By the 1970s costs had
dropped to the point that we had games on computers. By the 1990s
there were more computers connected to a vast global computer network
known as the internet, than there were TVs in the 1950s.

Anyone in 1950 asking what the world of computing would be like in
2000 would be dumbfounded by the answer - it would appear overly
optimistic by many many times.

I get to read a lot of older SF as part of my job and I have
come across a few stories that knew about Moore's Law, if not by that
name. Unfortunately, they then tended to miss other potentials, like
that Futurism piece that predicted cell phone-like devices in cars,
except that the author thought you'd have to pull over and plug them
in.

I wish I could remember which story it was but the author
nailed the Moore's Law end of things, but completely missed the PC
possibilies. Computation was very cheap but you had to connect to
the Mother of All Computers first.

ObWWW: _A Logic Named Joe_. Better search engine than google,
anyway.
--
"The keywords for tonight are Caution and Flammability."
JFK, _Bubba Ho Tep_

In article ,
Paul F. Dietz wrote:
John Ordover wrote:

What product will that be, exactly?

Climate modification.

On Earth? Wow, wait for that, you'll wait a very long time.


You may not be correct, John. My BotE calculations suggest
that surprisingly little mass need be moved to the Earth-Sun L1
point to significantly reduce insolation at Earth, if you arrange
the system properly.

How little is surprisingly little?

Any guesses as to the best way to arrive at a concensus on
how the climate is to be modified without triggering open violence
by the people whose homeland becomes less habitable as a result?
--
"The keywords for tonight are Caution and Flammability."
JFK, _Bubba Ho Tep_

James Nicoll wrote:

How little is surprisingly little?

Hundreds of tons per day. This might even be affordable if
launched from Earth.

Any guesses as to the best way to arrive at a concensus on
how the climate is to be modified without triggering open violence
by the people whose homeland becomes less habitable as a result?

Some combination of bribery and deterence.

I suspect violence from countries whose port cities (or more) are
being submerged would be more of a problem.

Paul

"Paul F. Dietz" wrote:

John Ordover wrote:

What product will that be, exactly?

Climate modification.

Namely, Solar power satellites, which displace fossil-fuel power
stations.

In article ,
Paul F. Dietz wrote:
James Nicoll wrote:

How little is surprisingly little?

Hundreds of tons per day. This might even be affordable if
launched from Earth.

Huh.

It strikes me that if you are putting in a dimmer switch,
you might also want a way to increase insolation. Any thoughts?

Any guesses as to the best way to arrive at a concensus on
how the climate is to be modified without triggering open violence
by the people whose homeland becomes less habitable as a result?

Some combination of bribery and deterence.

I suspect violence from countries whose port cities (or more) are
being submerged would be more of a problem.

I suppose we'll find out if submerging nations provokes
a violent reaction from their inhabitants over the next century. I
wonder what nation has the worst combination of low national income,
high population and low elevation? Bangladesh?
--
"The keywords for tonight are Caution and Flammability."
JFK, _Bubba Ho Tep_

James Nicoll wrote:

It strikes me that if you are putting in a dimmer switch,
you might also want a way to increase insolation. Any thoughts?

If you release the scatterers not on the direct Earth-Sun line,
but near it, some light will be scattered onto the planet.
(ObSF: some well-known Murray Leinster story.)

There are also some extremely longlived greenhouse gases.
CF4, IIRC, has a halflife of ~50,000 years (the C-F bond is
stronger than the O=O double bond, so UV capable of breaking
the former is only present in the very upper atmosphere.)

But the near term problem is too much warming, so you want to
reduce insolation.

I wonder what nation has the worst combination of low national
income, high population and low elevation? Bangladesh?

That would be my candidate.

Paul

In article ,
Paul F. Dietz wrote:
James Nicoll wrote:

It strikes me that if you are putting in a dimmer switch,
you might also want a way to increase insolation. Any thoughts?

If you release the scatterers not on the direct Earth-Sun line,
but near it, some light will be scattered onto the planet.
(ObSF: some well-known Murray Leinster story.)

It's in _Med Ship_. Just a second as I check my report
on that. "Ribbon in the Sky". Unfortunately, as presented the
idea probably doesn't work because the ribbon is supposed to be
very long lived on human scales and it probably would be cleared
out fairly quickly.

There are also some extremely longlived greenhouse gases.
CF4, IIRC, has a halflife of ~50,000 years (the C-F bond is
stronger than the O=O double bond, so UV capable of breaking
the former is only present in the very upper atmosphere.)

I thought about greenhouses gases but I don't like control
systems with long latency times (Even though I cook with a glass
top electric stove). Dump a megaton of HCFCs into the atmosphere
and you're stuck with it for a long time.
--
"The keywords for tonight are Caution and Flammability."
JFK, _Bubba Ho Tep_

James Nicoll wrote:

Dump a megaton of HCFCs into the atmosphere
and you're stuck with it for a long time.

HCFCs come out fairly quickly, actually(*). CFCs
take an order of magnitude or two longer, and PFCs
even longer.

(*) Except that the degradation product trifluoroacetate
may be persistent in the biosphere.

Paul

the near term problem is too much warming, so you want to
reduce insolation.


No you don't. The world is running out of oil. We need every watt we can
capture from nonoil sources. And with oil getting more expensive, CO2 and its
associated greenhouse effect will become self-terminating.

Now, if you sunshield were in fact a gigantic SPS, you may have a point.