by eric_b » Thu 15 Jun 2006, 20:56:03
$this->bbcode_second_pass_quote('EnergyUnlimited', '')$this->bbcode_second_pass_quote('grabby', 'W')ould you send even one person to alpha centauri not knowing if it is habitable, and knowing there is no return?
To consider such an adventure you would have to be reasonable confident that there is a good chance of finding habitable planet at destination (unless you have warp drive at disposal - but even I DO NOT BELIEVE IN THAT).
Therefore structurised effort is necessary to achieve that goal.
This would look as below:
1.
(SNIP)
Hawking's doesn't know what he's talking about in
this case.
All this talk about colonising space as things now
stand amounts to the delirious babbling of an
energy junky with a fat stash. It's a holdover
from the scientism in the US during the 1960's
when few things seemed impossible.
I see we're on the same page as far as the warp
drive... good.
First you should realize that fusion may be a pipe
dream. In fact, it may be impossible from a technical
point of view to build a working fusion reactor -
something to keep in mind. As far as getting more
energy out then in. As things stand the only fusion
devices on earth that get more energy out than
in are thermonuclear weapons, and they require a
fission bomb to start the reaction. Not a very
controlled reaction. If true then stars are the only
viable fusion reactors, and fission is the most
energy dense stuff for 'sapient beings'
Keep this in mind, as without a working fusion
reactor it may simply not be possible to ever develop
a propulsion system that would allow one to reach
the stars in a reasonable time frame.
Interstellar distances are so vast they are hard
to imagine. The nearest start, proxima centuri,
is around 4 light years away. The fastest manmade
object currently out there is the voyager 1 probe,
which is travelling around 39,000 mph. At this
speed it would take this probe over 70,000 years
to reach this star -- our closest neighbor!
In order to reach any star within a reasonable
time propulsion systems that currently don't exist
would have to be built.
An ideal manned craft, or 'space ark', would have
the ability to accelerate at 1G for long periods
of time. People need some sort of artificial gravity
to survive long periods in space. They fall apart
physically without it. It would take enormous amounts
of energy to sustain a 1G acceleration for any length
of time, but it would create the necessary gravity.
But let's assume such a craft could be built. In
this case it would be possible to reach the nearest
star to us, centauri, in about 5.5 years time. You'd
accelerate at 1G to the midpoint, then decelerate at
1G to the star. If the crew made it it would take
another 4.2 years for them to radio back success.
A more reasonable assumption would be a craft that
would travel around 15% the speed of light. In this
case it would take around ~40-50 years to reach just
the very nearest stars.
In theory if you could accelerate at 1G for about
a year you would reach relativistic speeds which would
allow you to cross the galaxy in a few years (from
the crews point of view)... but back on Earth thousands
of years would have past. Such are the paradoxes involved
with relativistic travel. In essence it would mean
anyone on such a voyage would be forever isolated
from Earth.
But there are many other problems. Once you reach these
incredible velocities you don't want to hit anything
much larger than a hydrogen atom. Hitting a grain of
sand near the speed of light would probably destroy
the ship - it would impact with the kinetic energy
of an atomic bomb. You'd need mad shielding from the radiation
of space, and from anything you might hit.
We have no idea how to go about creating an enclosed
ecosystem that lasts. You'd need something like this
for any long (or permanent) voyages into space in
your spaceark (see quote below).
Fact is, any colonisation of space would be an
evolutionary process. It would likely start with
a (real) space station, or a colony on the moon or
mars. We are no where even close to this.
Look at our priorities. There's no vision to do this.
In the US most of our money is squandered on 'defense'
and the military (actually at this point we are squadering
other peoples money on our 'defense'

). If we were to
spend this money on space exploration we might be able
to do something, but it's not going to happen. We are on
the cusp of implosion, not explosion into space.
Bottom line is unless we can get our ducks in a row
here on Earth, and not destroy our 'home world', no
splinter of humanity is ever going to make to another
star. It's a complete pipe-dream
Below is a quote from one of my earlier posts trying
to show how difficult, costly, and expensive it was
for us to reach the moon. Reaching the stars would
be orders and orders of magnitude more complex than
this... it's not going to happen, sorry.
$this->bbcode_second_pass_quote('', '
')Sigh. OK, I'll bite. I'll attempt to educate you.
I'm assuming we're talking about colonizing space. Now. With
our current technology. And I'm assuming whatever space
colony we establish will be self-sufficient. If it weren't,
what's the point? If things were to fall apart on Earth, the
colony would not survive either. Are we on the same page?
Good.
First, we have no idea how to go about creating an enclosed
environment which is sustainable. Remember Biosphere 2?
If not, check out this link:
http://www.thespacereview.com/article/305/1They attempted to design an enclosed environment with
plants, animals and people to see if it was possible. As
a precurser to space exploration. A small group of people locked
themselves into what was essentially a large sealed greenhouse.
The experiment was a complete failure. Read the above page.
We have no heavy lift capability (at least in the US). The Saturn
V rocket used for the Apollo space program was a marvel:
over 350 feet tall, it weighed well over 6 million pounds fully
fueled and could launch over a quarter million pounds into Earth
orbit. One man, Wernher von Braun, was the mad scientist (though
he was a genius) and glue behind the entire development of this
rocket. At this point the US couldn't build another rocket this
size if it wanted, at least not without starting the project from
scratch. Why? The original plans and blueprints for this extraordinarily
complex craft have been largely lost, as well as the engineering
expertise. In todays dollars it would cost several billion dollars
for each launch of a rocket this size, not including the payload.
Where do you think the money is going to come from? And how
many launches would be required to get the necessary material
into space to construct the first colony/space station?
What part of space are you going to colonize first? It would
probably have to be some sort of craft in Earth orbit. Outside
of the Earth's orbit and magnetosphere you need protection
from the suns particulate radiation -- solar flares (common) are lethal
without heavy shielding. This was a concern during some of the
Apollo missions, because while on the way to the Moon there was
a chance the crew could have been killed by such an event. The
only other option is the moon. Not too likely for a first colony step.
Also, you'd need some sort of artificial gravity. It's become clear
the human body does not hold up well without gravity. Some of
the early cosmonauts whom spent months to years in space
(mir?) had their bodies waste away, and could hardly stand on
returning to Earth. This despite excersising vigorously while
in space. They experienced psychological and nervous problems
too:
http://english.pravda.ru/science/19/94/ ... space.htmlSo this means they would have to build a very large rotating
space station of some sort to create artificial gravity. Something
which, while possible in theory has never been done before.
And how much do you think this would all cost? Hmm? With
an exploding population and declining resources on Earth
do you think this is going to happen anytime soon? Hell, there
have been increasing shortages of basic raw materials (cement,
steel) this last year, partially due to demand from China.
The Apollo space program took years of effort, enormous cost,
and the blessing of the entire US to succeed. It was deemed
necessary to win the space race against Russia. The country
was not as divided then. Everyone pulled very hard. And
for all that time and effort they managed to get a few people to
the moon, briefly. Imagine how much more difficult it would
be to establish any kind of permanent colony in space.
Is space colonization within the realm of possibility? Of course.
Is it likely to happen anytime soon? No way.
I was born in 1968. It was not long ago, but it was a different era.
Scientism was at its height. Scientists and engineers were held
in much higher regard than they are now. Right after WWII the US
was the undisputed king of the world. We'd developed atomic weapons,
split the atom. We created the first jet airplanes. We were sending
unmaned rockets into space. Computers and computer science were
just getting started. There seemed to be few horizons, few things
we couldn't do. People were talking about creating computers more
intelligent than people within a decade. Some people thought everyone
would be flying around jetson's style by the new millennia. There
were plans to create a colony on the moon. I grew up reading science
fiction and watching the original startrek. I lapped that stuff up.
But none of it came to pass. Most of those ideas remain the realm of
Science Fiction.
Oh yeah. I almost forgot. Assuming that somehow a space colony
were to be built, would you want to live the rest of your life in
a glorified tin-can? Never to feel the wind in your hair? Never to
smell another spring day again? Never to walk barefoot on the
beach again? Never to listen to thunder again? To damn any of your
possible descendants to life in such a sterile environment?
Think about the aesthetic costs.
Space colonization anytime soon? Get real.