Does Life Exist

[geoschmo]

Originally posted by Loser:
I like the "if there's anybody out there, where the bleep are they!?!" side of the question. Even within the limitations of the speed of light, it would take no more than a couple hundred million years for one race of intelligent life to spread throughout the galaxy, the whole galaxy.

I believe there is a very good chance that there is intelligent life elsewhere in the universe. Possibly a lot of it. There are a LOT of stars out there after all. I consider the Drake equations to be on the conservative side. The Rare Earth guys are down right pessimistic in their assumptions.

However, it may be exceedingly difficult if not impossible for life to spread beyond it's home system. Life that is built to exsist on a certain type of planet with a specific type of circumstances cannot easily pack up in man made, or Phong made for that matter, ships and fly to the next star over.

Technology can only do so much to prepare for the hostile conditions we know exsist in the vacuum between our own planets, much less anticipate and prepare for dangers we don't know about.

We may be hundreds of years from being able to establish semi-permanant facilities on Mars or teh moons of Jupiter. And those will still be heavily dependant on the supply of resources and personell from Earth.

For life to spread to another star system we have to figure out a way to design extremely intricate technological systems, but make them Last the decades or centuries that it would take to reach our destination. We'd need multiple upon multiple redundancies for systems, and some method of repair and replacment of critical parts only with the raw materials and manufacturing capacity that we can carry with us.

Some people equate it to the sailing ship explorers of the enlightenment age on Earth. But that is romantic nonsense. It's much harder then that. To equate it you'd have to have a sailing ship where you can't throw a line over and catch a fish, and you can't stop on an island and gather water, where the trip Lasts so long the ship would rot out from under you, but you have to rebuild it as it does from wood you have stored in the hold.

Not an easy proposition. It may be that intelligent life is abundant, or at least has been abundant over the lifespan of the galaxy. But it may be simply beyond the scope and ability of that life to travel the lifeless void of space between the stars.

At least until we get a Warp Drive.

[ August 08, 2003, 13:34: Message edited by: geoschmo ]

[JurijD]

I don´t think we´re hundreds of years from having self-sustaining colonies on other planets. All the technology that we´d possibly need has long since been invented (say 30 years ago). If they could send a man to the moon in 69 we can most surely send several to mars and have them stay there indefinately... the ony problem is the will to do so. (if you have the will you find the money and the means)

We have the technology to construct self sustainable environments... there are about 200 of them floating uder the worlds oceans (called nuclear submarines) They surface once every 6 months only to resupply on food beause it would be too unpractical to have it produced on-board. Everything else... water, oxygen, heat etc. is produced by the nuclear reactors that turn CO2 to O2 and recycle urine and the vapour in the air to usable water.... In a hypothatical colony we´d only need to bring plants along to produce carbohydrates for us to eat (I admit, it would be a strange diet but one would be able to live off it indefinately) And if we could genetically change certain cells not to grow into animals but just to produce large quantities of proteins we´d have ourselves a meat substitute... we´re not there yet but its completely possible.

sailing off to distant stars is another matter... We simply don´t have the technology to do so in the desired time span (10 years there and back).

One proposal is to use say ion engines to propel enormous ships that carry hundrets of thousands of people in a self-sustaining enovironment with an fusion energy source that would Last for centuries to the nearest stars... they would require 50 years to get there and they would never return... but their offspring would construct a new civilisation on a planet orbiting that distant star and build new ships and send them off to yet other stars.... it has been calculated that it would take several million years but in the end we could colonize the enire galaxy using this principle...

Well I´m still hopefull that physics will save us and discover that travel over and beyond the speed of light is indeed possible... and I´m a firm believer in the saying that anyting is possible.

[Atrocities]

I don´t think we´re hundreds of years from having self-sustaining colonies on other planets. All the technology that we´d possibly need has long since been invented (say 30 years ago). If they could send a man to the moon in 69 we can most surely send several to mars and have them stay there indefinately... the ony problem is the will to do so. (if you have the will you find the money and the means)

You should consider that to send a manned mission to Mars would require far more technology than we currently have. The effects of prolonged weightlessness on the human body, the micro metorites that would pummule a ship to dust, and the enormus calculations needed to get there and back, the cost, etc.

Keep in mind that NASA has stated that ships with rotating sectiosn are not fessable in any degree and the technology to create such a ship is currently not available.

The best we can hope for in the next 200 years is perhaps a small moon base or orbital facility near the moon. Nothing more.

[Suicide Junkie]

Don´t EM transmissions fade at 1/r^3 ?

No, because when you send out a signal pulse, it moves out in a spherical shell. The area of the shell is proportional to r^2. Dividing the signal out along that surface, you get 1/r^2.

For a Cylindrical wave it goes down 1/r (think a long light bulb filament blinking on and off)

Plane waves maintain constant intensity. (1/r^0)

[Ruatha]

Originally posted by Atrocities:

quote:

---

I don´t think we´re hundreds of years from having self-sustaining colonies on other planets. All the technology that we´d possibly need has long since been invented (say 30 years ago). If they could send a man to the moon in 69 we can most surely send several to mars and have them stay there indefinately... the ony problem is the will to do so. (if you have the will you find the money and the means)

You should consider that to send a manned mission to Mars would require far more technology than we currently have. The effects of prolonged weightlessness on the human body, the micro metorites that would pummule a ship to dust, and the enormus calculations needed to get there and back, the cost, etc.

Keep in mind that NASA has stated that ships with rotating sectiosn are not fessable in any degree and the technology to create such a ship is currently not available.

The best we can hope for in the next 200 years is perhaps a small moon base or orbital facility near the moon. Nothing more.

---

I think you are pretty alone in thinking that it's technology that hinders a manned mission to Mars.
Today it's mostly economics, the cost will be huge.
The problems with micro-meteroids won't be all that much bigger than when we went to the moon i'd belive, just more prolonged but not a major problem, we've sent probes much further than Mars. Yes, they get hit but it's solvable. Even I can solve that one, 1 meter of lead will stop most meteroids (Not the best solution I agree ).
Prolonged zero-g is not a hindrance either, a problem yes but not unsurmountable. The Russians have had people in space for over a year with much less training facilities than would be possible to mount inside a Mars mission.

The huge calculations is not any problem, that could be solved by most nations space agencies, even our small Swedish space agency has resources to calculate trajectories needed, fuel amount, thrust, launch dates etc..

No the problem is cost, it just costs too much and the profit isn't availible in any near future, to justify that cost will be hard.
If the motivation was right we could have had a manned mission to Mars in the 90-ies, heck, even in the early 70-ies if the motivation was STRONG enough to justify the cost in money and lifes.

Remember that it's hard to get funding for the international space station, the most expensive human space project so far, and that is much cheaper than a Mars mission I'd guess.

[ August 08, 2003, 14:52: Message edited by: Ruatha ]

[Ruatha]

Does anyone have any idiea how big an antenna we're talking about to receive a local TV-transmission out through the atmosphere and the magnetic belt of Earth and the magnetic belt of the solar system and then 34 light years away?

Hey, does the magnetic belts even interfere with EM's? I guess not. But there ought to be some EM disturbances from the sun though, or?

[geoschmo]

Originally posted by JurijD:
We have the technology to construct self sustainable environments... there are about 200 of them floating uder the worlds oceans (called nuclear submarines) They surface once every 6 months only to resupply on food beause it would be too unpractical to have it produced on-board. Everything else... water, oxygen, heat etc. is produced by the nuclear reactors that turn CO2 to O2 and recycle urine and the vapour in the air to usable water....

No, you are missing my point. I wasn't talking about renewable recourse like food and water. I know we are very close to or have acchieved teh basic technology needed for these things. I am not even talking about basic energy needs. Nuclear power is a good long term option, and there is some talk about magnetic scoops to pull hydrogen molecules from the surounding space.

I am talking about the huge amount of raw materials and manufacturing capability you would need to be able to build replacment parts for all the myriad pieces of technology on board the ship. It's not simply a matter of scale, or making a larger ship. Because the bigger you build it and the more equipment you have dedicated to these support functions, the more things you have that can break. It's a curve that I am not confident you can ever get ahead of when you consider you are looking at decades long trips at least.

The submarines are not nearly as self-sufficent as you think. 6 months suberged is nothing. They can surface any time they need and head for a repair dock if something breaks. Or a helicopter can bring them a new circuit board in a matter of hours.

[geoschmo]

Originally posted by Ruatha:
I think you are pretty alone in thinking that it's technology that hinders a manned mission to Mars.
Today it's mostly economics, the cost will be huge.

Actually if you read the recent literature most of the scientific community now believes that Mars colonization is out of our current technological reach. It is NOT simply a matter of money. Recent findings are that the radiation levels there are much higher then we previously believed among other things.

I think most agree that eventually we could have colonies on Mars. The question is whether we are capable of having self-sufficent colonies on mars. And I mean TOTALLY self sufficent. Not dependant on regular replenishment shipments from Earth with spare parts, etc.

Only when we can do that can we even think about sending a ship to another star. And that will be more difficult because at least on mars you have access to the planets raw materials.

A good example of what I am talking about is the Int'l Space Station. It is not anywhere near self sufficent. One accident grounds the Shuttle fleet and you hear talk of abandoning it alltogether. Even keeping it operational is tough. Depending on teh Soyuz means only two crew members can remain on the station. And those two are so busy doing station maintenance that they complain they don't have time for research. More money would not make it self sufficent. It might give us better options for replenishment, but wouldn't make the station self suficent.

[ August 08, 2003, 15:33: Message edited by: geoschmo ]

[kalthalior]

Did the Drake equation thing that Slick posted, used pretty pessimistic figures (by my standards, anyway) and arrived at N=3. Interesting. Additionally, went out and found this:
Mars Colonization Plan

Might be a little on the optimistic side, but it does spell out a fairly serious program. Also, I will admit to be a tad biased in favor of Mars colonization -- I'm a member of the Mars Society.

Mars Society webpage

[Ruatha]

I gotta read the Posts better before I reply, sorry.
I missed the first post and replyed to the reply, thought it was about a simple two-way mission to mars, Colonies is something enterely different, I agree on that!

My sincere apologies, it won't happen again, ever, promise