Sci-Fi thoughts
Those of you who know me by now should know that I'm prone to posting random crap about whatever I've been thinking while in the shower...
Well this particular ramble has come about due to the book I'm currently reading. It's something of an expansion on a previous ramble from months ago. By the way, I will review the book properly when I've finished it.
Thoughts on interstellar travel.
The Hitch-Hiker's Guide to the Galaxy is a truely remarkable book. The introduction starts like this: "Space", it says, "is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space. Listen..." And so on. - Douglas Adams.
Even light, which travels so fast that most people don't even realise it travels at all, takes years to go from one star to another. (I think I'm misquoting Adams again there, but I can't remember the reference).
So, for humans to get from one star to another there are serious problems.
Most sci-fi writers solve these by inventing some sort of "Faster-Than-Light" (FTL) travel. Warp drive, Hyperspace drive, Jump drive, Star drive, I've even come across one called the "sponge space drive". What ever you want to call it, however it's supposed to work, the practical upshot is the same: a space ship is moved from one place in our universe to another place in our universe in a lot less time that it takes light to travel there.
There is also the "worm-hole" method of getting from place to place, where a stable hole is opened in the fabric of space-time between two places. This gives rise to the possibility of moving between stars without a space-ship in the manner of "Stargate SG1".
The Sci-Fi world is divided on exactly how much subjective time it takes to get from one star to another. Most science fiction has some sort of non-relativistic time-line, whereby the time spent in a jump between two stars as perceived by those making the jump is exactly the same as the time taken to jump from one star to another as percieved by the people at those stars. In other words, someone travels from earth to Sirius and back, and to them it takes two weeks. When they arrive home again, two weeks have passed on Earth, too.
Of course, the actual chances of this being the case (should some sort of FTL ever be invented) are very remote!
Other sci-fi has the transition taking place instantly. You don't spend time in hyperspace, you simply move directly from one point to another. Mostly, this sort of FTL travel has no time passing in the real world either, although some times a period of time passes based upon how far one has travelled - a jump of one light-year results in a year of time passing. Again, I've encountered the oposite effect... A jump of one light-year results in the traveler going back in time one year.
Star Trek famously uses the principles of interstallar travel to allow time-travel. This is not so far-fetched as one might imagine. Think on it: if I've travelled ten light-years and arrived at my destination at the same relative time I left, I have in effect travelled back in time ten years, because the light I'm seeing from my start-point originated ten years before I left. Got that? Ok, now for the next bit: If I travel ten light-years in a circle, so my start point and end point are the same, when do I arrive?
The answer depends on the definition of FTL in use. If transits are instantaneous and the apparent time is equal to the actual time, then a transit of ten light-years involves a trip back in time of ten years (in theory) and so I should arrive ten years before I left.
Yeah, I know, it's like trying to nail jelly to the ceiling... The point is, it's not physics, it's fictional physics, which means you can do what you want with it... Scotty's famouse line "Ye cannae change th' laws o' physics, Cap'n", is so ammusing for that very reason - changing the laws of physics is exactly what Gene Roddenberry did!
However, not all Sci-Fi uses FTL, and even some that do still have a great deal of time required to get from one star to another. This presents the author with an interesting scenario. Relativistic effects mean that people moving at significant fractions of the speed of light (c-fractional speeds) live a significantly longer time than people moving slower. So, when you return home, everyone you knew is much older than you, if they are even still alive. Also, the enormous amounts of time taken to get from one star to another even at c-fractional speeds mean that the ships' crews and passengers will be old or dead by the time they reach their destination.
Again, there are a number of solutions to this problem.
Firstly and most obviously (asside from using FTL), is cold storage. The passengers are deep-frozen in some manner and then revived once the ship nears its destination. The second option is the generation ship. In this scenario, the entire family of the crew are on board the ship and as the children grow up they take the places of family members who die. This is commonly used even with FTL, simply because it creates an interesting social structure. The ships crew tend to be very protective of their own, and at the same time very promiscuous once in port, in order to expand their gene pool.
(Hmmm... Idea for short story... *saves for later*)
The final option, which in my experience is very rarely used, is probably the most elegant and may even be the most likely. It involves not an advance in transportation technology so much as an advance in medical technology. Simply put: cure old age!
If people don't get old and die, then they can spend three hundred years travelling from one star to another without worrying about it. If they don't get old and die, then when they get back, the people they left behind will still be alive. Admittedly any children will be grown up, but that is supposed to happen...
"What about the population?" I hear someone cry. "If people don't die, it will rise exponentially". Well, maybe. Maybe not. If the medical process that prolongs life also reduces firtility, so that a woman only ovulates once every ten years, the birth rate would drop dramatically and the population would stabalize very quickly. Or of course you have the other option. With infinite reaches of space to explore and infinite time to get there in, you just pack the excess population off to another world!
Anyway, that's quite a ramble. If you've had the patience to wade through that and have actually understood it, I'd welcome any comments...
Today, my first lead wasn't until 5:30pm, I was told to try it at 5:00pm. She just phoned to cancel while I was typing the above and I now have a 6:00pm that I am to try at 5:30...
So, to pass the time I'm going to compile a little quiz, that I shall post here. The rules will be very simple. I'll post a list of song lyrics and you have to tell me the artist and song for each one. I'll screen all comments on the quiz (not on this post) so that you can't cheat. Then I'll give the answers in a couple of days...
Well this particular ramble has come about due to the book I'm currently reading. It's something of an expansion on a previous ramble from months ago. By the way, I will review the book properly when I've finished it.
Thoughts on interstellar travel.
The Hitch-Hiker's Guide to the Galaxy is a truely remarkable book. The introduction starts like this: "Space", it says, "is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space. Listen..." And so on. - Douglas Adams.
Even light, which travels so fast that most people don't even realise it travels at all, takes years to go from one star to another. (I think I'm misquoting Adams again there, but I can't remember the reference).
So, for humans to get from one star to another there are serious problems.
Most sci-fi writers solve these by inventing some sort of "Faster-Than-Light" (FTL) travel. Warp drive, Hyperspace drive, Jump drive, Star drive, I've even come across one called the "sponge space drive". What ever you want to call it, however it's supposed to work, the practical upshot is the same: a space ship is moved from one place in our universe to another place in our universe in a lot less time that it takes light to travel there.
There is also the "worm-hole" method of getting from place to place, where a stable hole is opened in the fabric of space-time between two places. This gives rise to the possibility of moving between stars without a space-ship in the manner of "Stargate SG1".
The Sci-Fi world is divided on exactly how much subjective time it takes to get from one star to another. Most science fiction has some sort of non-relativistic time-line, whereby the time spent in a jump between two stars as perceived by those making the jump is exactly the same as the time taken to jump from one star to another as percieved by the people at those stars. In other words, someone travels from earth to Sirius and back, and to them it takes two weeks. When they arrive home again, two weeks have passed on Earth, too.
Of course, the actual chances of this being the case (should some sort of FTL ever be invented) are very remote!
Other sci-fi has the transition taking place instantly. You don't spend time in hyperspace, you simply move directly from one point to another. Mostly, this sort of FTL travel has no time passing in the real world either, although some times a period of time passes based upon how far one has travelled - a jump of one light-year results in a year of time passing. Again, I've encountered the oposite effect... A jump of one light-year results in the traveler going back in time one year.
Star Trek famously uses the principles of interstallar travel to allow time-travel. This is not so far-fetched as one might imagine. Think on it: if I've travelled ten light-years and arrived at my destination at the same relative time I left, I have in effect travelled back in time ten years, because the light I'm seeing from my start-point originated ten years before I left. Got that? Ok, now for the next bit: If I travel ten light-years in a circle, so my start point and end point are the same, when do I arrive?
The answer depends on the definition of FTL in use. If transits are instantaneous and the apparent time is equal to the actual time, then a transit of ten light-years involves a trip back in time of ten years (in theory) and so I should arrive ten years before I left.
Yeah, I know, it's like trying to nail jelly to the ceiling... The point is, it's not physics, it's fictional physics, which means you can do what you want with it... Scotty's famouse line "Ye cannae change th' laws o' physics, Cap'n", is so ammusing for that very reason - changing the laws of physics is exactly what Gene Roddenberry did!
However, not all Sci-Fi uses FTL, and even some that do still have a great deal of time required to get from one star to another. This presents the author with an interesting scenario. Relativistic effects mean that people moving at significant fractions of the speed of light (c-fractional speeds) live a significantly longer time than people moving slower. So, when you return home, everyone you knew is much older than you, if they are even still alive. Also, the enormous amounts of time taken to get from one star to another even at c-fractional speeds mean that the ships' crews and passengers will be old or dead by the time they reach their destination.
Again, there are a number of solutions to this problem.
Firstly and most obviously (asside from using FTL), is cold storage. The passengers are deep-frozen in some manner and then revived once the ship nears its destination. The second option is the generation ship. In this scenario, the entire family of the crew are on board the ship and as the children grow up they take the places of family members who die. This is commonly used even with FTL, simply because it creates an interesting social structure. The ships crew tend to be very protective of their own, and at the same time very promiscuous once in port, in order to expand their gene pool.
(Hmmm... Idea for short story... *saves for later*)
The final option, which in my experience is very rarely used, is probably the most elegant and may even be the most likely. It involves not an advance in transportation technology so much as an advance in medical technology. Simply put: cure old age!
If people don't get old and die, then they can spend three hundred years travelling from one star to another without worrying about it. If they don't get old and die, then when they get back, the people they left behind will still be alive. Admittedly any children will be grown up, but that is supposed to happen...
"What about the population?" I hear someone cry. "If people don't die, it will rise exponentially". Well, maybe. Maybe not. If the medical process that prolongs life also reduces firtility, so that a woman only ovulates once every ten years, the birth rate would drop dramatically and the population would stabalize very quickly. Or of course you have the other option. With infinite reaches of space to explore and infinite time to get there in, you just pack the excess population off to another world!
Anyway, that's quite a ramble. If you've had the patience to wade through that and have actually understood it, I'd welcome any comments...
Today, my first lead wasn't until 5:30pm, I was told to try it at 5:00pm. She just phoned to cancel while I was typing the above and I now have a 6:00pm that I am to try at 5:30...
So, to pass the time I'm going to compile a little quiz, that I shall post here. The rules will be very simple. I'll post a list of song lyrics and you have to tell me the artist and song for each one. I'll screen all comments on the quiz (not on this post) so that you can't cheat. Then I'll give the answers in a couple of days...