Do you beleive in aliens?????

[koshea]

haha, yeah she is muslum, however i dont see how that quote answers a question presented in this thread

[Don Dimitri]

... they are under the North and South poles..

[ermitonto]

... they are under the North and South poles..

And they're hanging out with the Nazis too.

[NextGen]

I don't think the people who believe that we have been visited by members of a civilization from a distant star have a sufficient grasp of the sheer scale of the problems involved with interstellar space travel. The nearest star is about 4.3 light years from us, which means at the speed of light, a journey would take 4.3 years, one way. The problem with this, is that the speed of light is is impossible to actually reach. Einstein realized that when he wrote his theory of Special relativity, wherein he introduces the famous equation, e = mc^2. It was known since Newton's time that moving objects had energy, and that this energy could be calculated with E-sub-k = 1/2mv^2. Einstein went one step further, and realized that since mass and energy were equivalent, that moving objects not only gain energy, but mass, as well. And this mass could be calculated with a rearrangement of e = mc^2: m=e/c^2. He could then plug this into his equation and see that as the the velocity, approaches the speed of light, the kinetic energy, and therefore the mass, would increase exponentially towards infinity. As a result, it becomes a practical impossibility to drive a ship much faster than about 9% of c, or so. We know there are no planets of significant size around Alpha Centauri because we have not detected any gravitational effects, and, in fact the nearest known extrasolar planet is about 15 light years away.

Another problem is a technological one. We have difficulty manufacturing complex systems which can operate continuously for very long periods of time without extensive maintenance and availability of replacement parts. There needs to be a huge exostructure in place to supply parts and labor to keep something even only as complex as a Boeing 737 operating over a period of years. In average service, such a plane needs millions of man-hours of maintenance, several engine overhauls and a few complete engine changes, as well as tens of thousands of replacement parts for all the subsystems necessary to keep the plane flying. On a space ship, you can have none of this. Eventually, you reach a point where so much of your fuel is being used to merely move the store of replacement parts or support an army of maintenance personnel that it becomes practically impossible to take the journey. Very advanced civilizations may be able to partially overcome some of these obstacles, but not by much. The laws of physics apply equally everywhere. Parts don't wear out because they aren't made well, they wear out because of inherent physical limitations. Moving parts undergo friction - it is unavoidable. Microelectronics suffer thermal breakdown over time, because there is no such thing as a static atom or molecule. They move and bounce off each other, breaking some bonds and forming entirely new ones. These things are true for all real-world materials. Even ones we can't imagine yet

A third problem is life support. There are essentially two ways to make such a journey. One is to keep the crew fed and supplied with water (or suitable intake chemistry). This again means more mass and more energy consumed. The more people, the worse the problem becomes. Compounding this issue is the law of entropy. Entropy says essentially that the amount of disorder in the universe will always increase, on average. This becomes even worse in closed systems. Free energy proposals all violate this principle. If you remember the failure of the Biosphere experiment, you'll have a good grasp of the nature of the problem. Again, a sufficiently advanced civilization may be able to extend this beyond our current capabilities, but not by all that much. The law of diminishing returns applies here, too.

The other way is to freeze everyone, or induce some other sort of "suspended animation". This seems to me to be the most likely method to work for journeys to nearby stars, but it's not without its technical challenges. The problem of technology failure over time I mentioned earlier still applies, and the amount of energy needed to accomplish it may even exceed the energy requirements to keep a crew awake and alive - I haven't worked out any numbers. In short, I think a sufficiently-advanced race of intelligent beings might be able to make a 15-20 light year journey successfully, but going significantly further will become increasingly problematic.

I could write a book, but I'll just end it there.

I see your points and understand everything quite well. Very nice beeble

Ok my head is thinking right now.
Think small sleek and very very very powerfull. Like a bullet from a gun but much faster and big enough to hold 1 person. Can we do this? We'll shoot them from outerspace so we get no gravity lag. Make it so the guy wont fry. Think it's possible? I'd say he'd get pretty far.

[Kramerica]

If the aliens are conservatives, they'd already be here to liberate us...
:P :O

[Beeblebrox.420]

hink small sleek and very very very powerfull. Like a bullet from a gun but much faster and big enough to hold 1 person. Can we do this? We'll shoot them from outerspace so we get no gravity lag. Make it so the guy wont fry. Think it's possible? I'd say he'd get pretty far.

Well. I can poke quite a few holes in that, but I'll settle for three major ones:

First, there's the matter of life support. No matter how much initial energy you impart to your hypothetical craft, you can never get much faster than about 90% of the speed of light. So, we're talking about a minimum of several years of life support. That means bulky equipment and a power source to run it all. This doesn't even address the issue of food stores, and the inability of closed systems to remain stable over significant time.

Second, in order for the voyage to make any sense, the craft must be able to slow itself to orbit around the star and locate locate potential planets to investigate. In order to do that it needs to burn off the same amount of kinetic energy it was given at launch, and that means large fuel stores, engines and support systems.

Thirdly, once you get that complex, you need multiple personell available for maintenance. Or at the very least, a small army of maintenance robots, and some sort of human crew all of which require resources. Which means more space, more power demands, larger food stores and other engineering headaches we can't even begin to imagine.

Getting out there will require a MASSIVE effort. But I think, one day, if we survive long enough, we'll make it. But not in my lifetime.

[OPM]

For all those into the question of aliens:
http://notweird.com/bugsport/

[4252]

What about the improbability drive in the Heart of Gold? If you could brew a really hot, strong cup of tea......

Maybe intelligent life "as we know it" is the limiting factor. It's not so hard to imagine life evolving up to and beyond our current technological level. And I don't think technology is the limiting factor. Someone asked the question of how we developed from rocks and trees to plastics and semi-conductors, and someone else gave a pretty good answer. The first powered flight, at least by the conventional standards, occurred in 1903; today we're sending vehicles to Mars, and farther. That's a lot of advancement for 100 years or so, who can say what progress will happen in the next 100 or more?

Torogs comments made me realize that in beings like ourselves, sheer bloody mindedness and stupidity would hold them back. They may have the technical potential to reach the stars, like we do, but may not survive to make the trip, being bent on self destruction, as we seem to be. An alien society which has overcome the technical and social challenges might not be interested in meeting us; sort of like the way I avoid the noisy, obnoxious neighbors down the street.

42

[4252]

Sorry Torog, when I re-read the above and realized I wanted to edit it, it was too late. I didn't mean to imply that you're bloody minded and stupid, but your point about their thinking as we do set off a process of considering our own weaknesses as a race. Hope that sounds a little better.

42

[NextGen]

Well. I can poke quite a few holes in that, but I'll settle for three major ones:

First, there's the matter of life support. No matter how much initial energy you impart to your hypothetical craft, you can never get much faster than about 90% of the speed of light. So, we're talking about a minimum of several years of life support. That means bulky equipment and a power source to run it all. This doesn't even address the issue of food stores, and the inability of closed systems to remain stable over significant time.

Second, in order for the voyage to make any sense, the craft must be able to slow itself to orbit around the star and locate locate potential planets to investigate. In order to do that it needs to burn off the same amount of kinetic energy it was given at launch, and that means large fuel stores, engines and support systems.

Thirdly, once you get that complex, you need multiple personell available for maintenance. Or at the very least, a small army of maintenance robots, and some sort of human crew all of which require resources. Which means more space, more power demands, larger food stores and other engineering headaches we can't even begin to imagine.

Getting out there will require a MASSIVE effort. But I think, one day, if we survive long enough, we'll make it. But not in my lifetime.

"I'm thinking" of making a-line of space stations and airports to each of the planets at least. Someday when we mine some of these diffrent planets we'll be able to have some quality materials (strong as titamiun light as feather minerals) or something like black matter fuel.

Someday I guess in due time, at least this is a little more realistic we might destroy our own planet too. So who knows if we'll ever get there.