To me the world seems to have lost it's mind. Last few days have looked at pictures of gitmo bay and almost threw up. The dehumanizing of people was beyond words. History talked of hitler and auschwitz. Decades later what I saw in those photos of gitmo made me think of images of the the very humiliation that the United states once fought against. Turkey is burning because of fighting back the government turned on it's own people like a mad dog. here in america we finally start getting rights for LBGT . Along comes salvation army saying that it should be a death sentence. Killing people over religion seems to be on the rise. in india women are burning for supposed witchcraft and girls killed being victims of rape . The catholic church is says birth control is wrong . Nuns who argue with church are being excommunicated. In last political race it was debated whether women had a right to their on viginas . People are dying world over because of religion and lack of even basic medical and dental care. there is hope for this world right?
@ Tom Sarbeck;
To even begin with it would be necessary to know where you are going.
I believe the REAL point to getting into space is to use its resources, and to move industry there where it won't pollute earth. We'd end up having to construct artificial habitats either in space itself or on planets or asteroids. We aren't looking for an uninhabited yet perfectly habitable planet at this point, that's absurdly far away and could only work for a tiny handful of people at most.
Of course if your primary concern is carbon emissions, not industrial pollution, you should be pushing for non-carbon burning forms of energy. The kicker is they have to be energy dense to really work in more than niche roles.
After we get to space and start using its resources, mainly asteroids and comets, what is the point of coming back does this gravity well other than tourism. You've seen one mountain you've seen them all. If you like the Spring air and gentle breezes go to that climate area of the ship -- think Babylon 5 and remember no mosquitoes, tornadoes or hurricanes or frozen rivers or droughts.
But don't stop with Bab 5. Stick a fusion engine on it. Get the fuel and reaction mass from comets. Populate the solar system with them letting robots do all the building. Everything to make them from comes from the asteroids. When resources get short here those cities will be in the Oort cloud which is already most of the way to the Oort cloud of other stars.
One of the cities is headed for another star? Ah well, someone had to do it some day.
Dream on. Unless we develop a propulsion system we can only dream about at this time, like nuclear pulse propulsion, getting to the nearest star will take anywhere from 19,000 to 81,000 years. That's 760-3240 human generations (a generation is usually figured at 25 years).
Space is a dangerous place since it's not empty and is subject to occasional pulses of intense and dangerous radiation. Over such a long time scale, SOMETHING is certain to turn the mission into a disaster. And that doesn't even count internal disasters.
After we have lived in space surrounding our star for a few hundred generations what are a few hundred more? And what the distance between Oort clouds not from star to star? I suspect we will soon discover the space between stars is filled with Oort objects to the point where interstellar space can be assigned a density.
Once we have fusion we have unlimited power. We will have no need for being near a stat.
If you let this scenario play out for a hundred million years or so humans will have populated this galaxy with a technology that can't be any more than a couple centuries in our future. That will speciate humans of course.
Once the ethical issues get discussed, the project will never get off the ground.
As for fusion power, it depends upon what you mean by "unlimited." Maybe there's an unlimited supply, but it doesn't follow that the energy available is unlimited. The estimates I've read say that fusion energy can drive a spacecraft perhaps twice as fast as the propulsion sources that currently exist, which are so slow that even doubling them yields impractical results.
Sadly, it will take more than fusion energy to make interstellar travel possible.
You still haven't addressed the risks, though you've inadvertently hinted at one: space isn't empty. There are objects floating around between star systems ranging in size from dust particles to,well, stars.
What happens to your spacecraft going at some major fraction of the speed of light when it hits a boulder the size of an automobile, a rock the size of a baseball or marble, or even a speck of dust? At some speeds, it will make hardly any difference because it will be a disaster.
Then, let's talk about gamma radiation. To go for very long without the entire crew being wiped out by gamma radiation exposure is pretty hard to imagine, and the shielding required to protect them is very impractical to install in a spacecraft.
THINK BABYLON 5.
Space ships as self-contained worlds tens to hundreds of miles long and tens of miles in diameter. Outer walls of iron so thick there is less radiation than we get on earth. As for speed, what is the point of speed when these worlds do not need to be in a hurry? Fusion provides all the power necessary as the number of comet like objects is in the tens of billions. Throw in solar sails if you like. I am just keeping things limited to the perfection of technologies we are working on today.
As I said, two centuries to master all the technology. And it starts just as we are talking about now, mining asteroids. The mining operations get bigger. People start staying in space to operate tourist hotels if nothing else. There becomes little point to going back and forth to the surface of planets and moons with the energy cost.
Notice I am not talking about taking apart moons and planets as the energy cost and the technology to do it is not on our technology horizon.
If the people on these worlds "miss" mountains build one. If they "miss" breezes engineer them. Will people really miss such things? Think New York City with climate control. Without climate control there are millions happy to live their lives there and anxious to get home after visiting elsewhere.
I am suggesting just the opposite of an objective to travel to other stars. The objective would simply be more plentiful comets and asteroids around another star simply because they have not been mined out for 100,000 years as they will be in our solar system.
For these worlds once the distance from the sun is beyond the orbit of Mars there is not much difference from being half way to Alpha Centauri. Nor does it matter if a million years are spent just beyond the orbit of Mars or getting half way to Alpha Centauri. With fusion it is solely a matter of obtaining hydrogen.
And this is not much new save realistic instead of Blish's Cities in Flight. Nice and slow fusion engines instead of spindizzies to move the action along.
At last, a bit of thinking in place of the wild-eyed dreaming! Thanks, U.
Also, rotate the vehicle so radiant energy from our sun won't overheat one side.The short 1960s Moon missions required this.
Even that short trip required mid-course corrections in navigation. These corrections required precise radar readings from both earth and moon.
The dreamers here might turn to sci-fi writing.
The dreamers here might turn to sci-fi writing.
LOL Sounds about right.
Once they are big enough they are rotating anyway for fake gravity. But the farther from the sun the less need for it.
I'm confused - rotating a space ship can create artificial gravity, which I don't discount, but when I suggested speeding up the rotation of Mars, to increase its gravity, someone said that wouldn't do it. Why not?
Not artificial gravity, centrifugal force. The old kid thing of swing a bucket of water over your head and the water no falling out. It has to be very large, I don't think anyone has figured how large yet, else the change in motion/force from head to foot will mess up walking. Definitely in this system things do not fall straight down but "behind" the direction of rotation.
Gravity however is purely a matter of the mass of objects. Their rotational velocity does not change their mass.