Ok, radiation shielding is necessary *anywhere*

--- In spacesettlers@egroups.com, "Dr. Omni" wrote:
> From: "Darren Brown"
> To:
> Sent: Thursday, October 19, 2000 3:07 AM
> Subject: [spacesettlers] Re: Ok, radiation shielding is necessary
*anywhere*

Hello again Lucio,

You are very correct about the ordering of English (in truth a very
illogical and badly structured language, this is the result of
borrowing - stealing - words from so many other languages. I had the
advantage - hmmm .. maybe disadvantage - of being born into an
English speaking culture - my hat's off to anybody who learns it as a
second, third language), I only mention this in order to
conform
with the wording found in site dealing with space weather but Mass
Coronal Ejection and Coronal Mass Ejection do mean the same. As I
said a very minor point.

[.]
>> minor point but I really don't like to pass on faulty data.
>>
>
>Seems the same to me (order of adjectives in English always seemed
>irrelevant to me, but maybe that's just because I'm not a native
speaker);
>anyway, ok, lets use CME from this point on.

You are doing better than me, let me see Brazil, that would be
Portuguese plus English, that gives you at lest one more than me. I
regret not doing a second language at school and now I find myself
too
pressed for time, my daughter however currently learning Spanish.

[.]
>> It seems that you and I are the only active people in here, how
>> disappointing.
>
>Indeed. Well, I received a message from another guy, nicknamed
"Seagull",
>but he never posted anything more again. The case is that this group
is
>somewhat recent and I made no effort to advertise it. Hummmmmm...
Perhaps if
>I put it in my signature, though that perhaps would not be *that*
useful: I
>am also a member of a science list and a skeptics list - for
Brazilians -
>and I would have to catch the attention of someone who at the same
time
>likes the subject of space colonization and also feels comfortable
writing
>in English - not a much frequent combination. By the way, do you
participate
>on any other lists/newsgroups with interests intersecting space
>colonization? Maybe it would be easier for you to find more potential
>members for our list.

Alas no other list relating space colonisation but several that
related to computer security and electronic forensics (my
profession),
I currently average around 200-250 emails a day if I added too many
lists I would drown in mail as it is I spend 4-6 hours a day reading
and responding to mail, add to that the 15 or so journals and all the
memos, new product adverts and miscellaneous correspondence and I am
already having trouble getting through everything. Still we all need
a few interests in life and so I am looking around at things like
this
list.

[.]
>> from that you are mostly interested in the human settlement aspect
of
>> space exploration?
>Indeed. With a special emphasis in space settlements/habitats. I'm
kind of
>skeptical about terraformation projects, for example, though I try
to
keep
>myself open minded to them.

Terraforming is an interesting concept but I really think it has
limited potential here. Consider, there are really only two planets
that could be used, Venus and Mars, both have problems. Venus has a
rotation rate that is much too slow, so even if you managed to fix
the
atmosphere you would still have major problems, given the length of
the day and the amount of sunlight you would be getting the daytime
temperature would most likely be a bit high for comfort and it might
just get a little cool at night, all in all an uncomfortable
situation. This doesn't even begin to address the possible problems
of high UV flux and the human physiological complications that arise
from the extended day/night length. Venus does however have nice
gravity. Moving on to Mars the situation is better but I can see the
need to constantly replenish the atmosphere as the weaker gravity
allows it to bleed off into space. There is also the potential for
difficulties from the weaker surface gravity and what it might do the
long term human development. Lots of possible trouble plus very long
time lines. It sounds good but I'm not convinced that it will work
or
if it does it may be far too expensive or complex (complex systems
have a tendency to fail at the worst time). I once had an augment
with a couple (married) who thought that it was irresponsible and
immoral to be using radio-isotopes in space-craft power systems, they
thought that we were polluting space with radioactive waste. I tried
to tell them that space was itself was full of radiation and that
even
if we vaporised the entire Earth we would only succeed if causing a
very slight local and temporary amount of pollution that wouldn't
even
begin to compare to what was spewed out of a single star. They had
no
idea of comparative volume and mass. If we assume no native life on
a
planet or moon (indigenous life would of course change everything)
then changing the environment to allow people to live on the surface
would force a limit on activities on those planets, after going to
the
trouble and expense of setting up a habitable biosphere you can be
certain they wouldn't want you polluting it and making it
uninhabitable again. There are a lot of activities (mining and
industry just to name two) that we could do on the surface of the
moons and planets as they are now that wouldn't really upset anything
(of course the two people I mentioned before seem to me to be the
type
to object for irrational reasons to everything). Just think if you
had a really dangerous process that you needed to do in a high
gravity
- 1G -, without the side effects to would get on a spinning habitat,
just go to Venus. Some people look at a planet/moon and see a
possible home, I look and see a large mass that nature has
conveniently put in one place. We can live on Earth or a habitat but
the rest are resources that we can use.

[.]
>> Don't get me wrong, given a magic wand I would
>> spend the worlds military budget on getting us (the human race in
>> general) into a multi-planet/habitat situation. Just consider how
we
>> currently have all our eggs in one basket. All it would take is a
>> single large lump of cosmic flotsam and even with twenty years
notice
>> we still might not be able to do anything. In fact politics,
>> religion, the laws of physics and human nature could effectively
>> undermine any attempt to save ourselves. To that end the more
places
>> we are the lest chance of any single, natural disaster putting a
stop
>> to us.
>
>Yes, yes... It is pretty weird how *everyone* seems to be completely
unaware
>of the fragility of the human race right know. I also have this
sense
of
>urgency regarding space colonization, but I think that it will take
decades
>(or even a couple of centuries) for the first off-Earth human
settlements
>actually exist. I'll be happy if I just see during my lifetime the
raise of
>some cheap way (a few tens of thousands dollars per ticket ;-) to
get
into
>LEO...

A number of possible ways exist and are being looked at. One that I
find intriguing is the light craft. A spinning disk that rides on a
pulsed laser light that has been tested to lift a model about 30
metres in the air so far (the last I read). I think it is possible
that within the next, say 20-30 years we will have affordable travel
to LEO.

>> I was just wondering about your interests, your pseudonym
>> "DrOmni" would indicate a wide ranging interest, it would help to
>> know
>> if I was talking to a specialist or a polymath.
>
>Your guess is right, I'm a generalist. (I prefer that term to
"polymath",
>which seems to imply that I would have enciclopedic amounts of
knowledge
>inside my head...) "Dr. Omni" was a nickname given to me by a friend
at the
>University, because he was used to say that I knew a little bit of
>everything; it stuck, and it is the name that I prefer to use in the
>Internet. Unlike many internet pseudonyms, it is not a "cover" for
hiding my
>real name, Lucio de Souza Coelho - it's just a matter of
preference,
really.

I didn't mean to imply that you were attempting to hide anything,
your
profile can be seen in eGroups. I was just commenting that it seemed
to fit what I had seen of your opinions. A polymath doesn't require
an encyclopedic knowledge, just a very strong and broad base. Still
a
generalist is just as good, a specialist as we know is a person who
knows more and more about less and less, alas at work I'm considered
a
specialist, which just goes to show that most people do not know what
they are talking about.

>> The wonders of the
>> internet, I sit in my office in Australia and try to decide how to
>> answer a post from Brazil, not a simple thing. What to say. well
>> here
>> goes.
>
>;-) I chose to create an *international* mailing list because I was
>surprised to see that there is *no* list at e-groups dealing with
space
>habitats - although there are many lists dealing, for example, with
>terraformation. It seemed that space habitats are not a very popular
>subject - people seem to be too used to living in a planet, and too
>brainwashed by decades of science fiction movies and shows with
characters
>living on planets, to like the idea spacehabs (actually, most of the
people
>that I know does not even know that concept). Therefore, I thought
that I
>would need a big enough human mass to get participants on the group
-
so I
>chose English (the international language) as the official language
for the
>list.

True, I must say though a habitat is much more appealing to me. If
we
learn from experience that people do not need a full 1G for normal
health or it is possible to have long periods at less than a full G
then a lot of interesting things are possible. Consider a n extended
family, you could have mother, father and children living at the
lower
level (1G) and grandparents living up the hill at the lower gravity
area (say .5G), where they find it easier to move around and live a
normal life. In fact it might not be just people who need a lower
gravity who live up the hill, maybe a lot of people would like to
live
in a low or even zero G area. Now while a micro-G living space would
not be healthy for permeant living you may be able get around the
problems by living at the top of the hill and working at the bottom.
The point being there is a lot more possible in a habitat, a planet
give you one type of G a habitat gives you all types of G. For my
part, sign me up for the first seat, I'd shovel waste in a sewer to
live in a habitat (not my first choice you understand).

>> Yes, you do seem to like drills, while I think a big hammer is
>> cheaper, not better, just cheaper.
>
>But would the "hammer method" really be that cheap? You would need a
>monstrously big electromagnetic mass driver or other mammoth
propulsion
>system to deflect the orbit of a big asteroid; it is not evident for
me why
>that would be cheaper than a mirror with a monstrously large surface
>(although probably a few micrometers thick).

The main problem with a mirror is keeping it in place but you would
not need a large or expensive propulsion system. You could just go
back to the old Orion concept, take one (or more) fission/fusion bomb
and place at the back of the rock/s and at the right time set it off.
If you do it at the right time you could arrange a slingshot type
orbit (just like we do for most of the long range probes) and drop it
on to your target, repeat as needed. You could also use a low
thrust,
long burn ion drive or a mass driver (mount it on the rock and throw
small bits out the back to act as your propellent, in fact you could
have an iron ion drive - hard to say fast). It might just take a few
years to impact but that is okay, the problem of course is the target
does not have to be Mercury. Who would make sure they were aiming
for
Mercury and not Earth?

>> The gas giants are really big so there is a lot of room to put
power
>> plants but it occurs to me that I read that some of Jupiter's inner
>> moons were in fact inside the magnetosphere. If that is the case
>> then
>> all you need do is cover the surface with wires and sit back.
>
>Yes, Io is deep inside the magnetosphere and in fact some of the
phenomenal
>internal heat of that moon is generated by Joule Effect, caused by
Jupiter's
>magnetic field inducing electric currents through the moon. Maybe
even
>Europa is deep inside the magnetosphere, but I don't know for sure...

There are so many ways to generate power in space that the main
problem is which one to pick. Power is not going to be the limiting
factor. We have a lot of limits here but out there it is raining
riches and all we need do is hold out our hands.

>> The moon is a lot closer that Jupiter or Uranus, a good place to
>> start, in fact the moon is a good place to build a large fusion
>> reactor, if anything went wrong, well there isn't a lot they could
>> damage, is there. But you should have a look at
>> http://antimatter.phys.psu.edu/documents.html . This group have
also
>> been reported on in Science and New Scientist
>> http://www.newscientist.com/home.html and on the NASA site.

>I think that antimatter is perhaps the key to deep space travel, but
it is
>worth to remember that antimatter is not a *source* of energy, it is
an
>extremely efficient *storage means* for energy. But you need to
spend
lots
>of energy to create antimatter, and that energy would have to come
from some
>natural (Sun, electric tethers, etc) or artificial (fusion reactors)
source.

The links I included will take you to a site where they talk about
things they are doing now with anti-matter and the AIMF (Anti-matter
Induced Micro Fusion) project does not use a 100% matter/anti-matter
reaction to give you power but has the anti-matter acting as a
trigger, a few nano-grams of anti-matter will produce a lot more
power
than is consumed in making it (in theory).

>> Yes but I don't know if I would be quick to volunteer, the Chinese
>> satellite program has been threatened with having its insurance
>> revoked due to the number of launch problems, including total
>> destruction of the rocket. Don't know if I'd feel safe enough.
>>
>
>Indeed, the Chinese now are like the Americans in the early 60's,
blowing up
>a rocket after the other. Building a vehicle that works in extreme
>conditions like a space rocket is not an easy task, and is also a
technology
>that is normally kept secret (due to its utility in building
>intercontinental missiles). At least, the Chinese are a bit more
advanced
>than we Brazilians - we have tried already two or three prototype
satellite
>launch vehicles along the last year or so, and all of them failed
for
one
>reason or another.

At lest you have a program, Australia is not even at that point, we
have a few things kicking around but nothing solid. India and Japan
are also pursuing space programs.

Darren Brown