little green men... and women

In Brian Aldiss' 1962 masterpiece Hothouse the Sun is in its final phase before going nova. On earth, increased heat means that plants have taken over the earth (hence the title). New, deadly plants have evolved, plants that fly, vines that slash at moving objects, all kinds of variations of the venus flytrap. All this takes place in a seemingly bottomless forest, which has only one kind of tree: a successful tree species has destroyed competitors and taken over the planet as one huge, knotted, labyrinthine organism. It is, effectively a single tree.
High in the branches of this forst/tree live the descendants of modern humans. No longer masters of the world, they are tiny, green, and spend their short lives hiding from predatory plants.
The story centers Gren, a young man who inadvertantly gets a parasite lodged in his brain. This parasite talks to him about his heritage, and sends him on a quest around the world to recover man's forgotten greatness.
The future of mankind described by Aldiss may seem to be pessimistic. After all, it is rather depressing to think that the great works of mankind amount to nothing in the long run. At least, unlike Wells, or some evolutionary theorists, there is no beautiful master race.
Aldiss' story, however, far from depressing, is in fact enlightening and reinforces the value of the lives that we have today, rather than the chimeras of tomorrow. In the course of his journey, Gren learns what is really important: love, and an appreciation of the here and now, rather than the pursuit of ambitious dreams. Such dreams are mirages, receding forever out of reach. In Hothouse, those who chase their dreams of future greatness are represented by a group of people who are trying to escape the world before the sun goes out.
Gren rejects their lofty aspirations, choosing instead to settle down with a mate and live out his life on earth.

life on Mars

As a boy I loved astronomy, and was into anything to do with space. I collected newspaper articles about the Viking expedition to Mars and pasted them in a scrapbook, alongside my own clumsy but fanciful drawings of what might lie on the red planet. The failure of Viking to find life on mars was a devastating blow to a young boy's fertile imagination.
Now, it seems, I was short-changed. The equipment used at the time to search for life would not have found it even even if life was there. Scientists have recently used the same equipment on Earth in places where bacterial life is known to exist. The equipment failed to find microbes even when the scientists knew that microbes were present. It turns out that microbes are too stable to be vaporised and detected in the manner that Viking tried to do.
There were three tests conducted by Viking to detect life. One of the three actually came back "positive" for life, but because the other two were negative, scientists disregarded the positive test. However, the man at NASA who was in charge of that "positive" test, Gil Levin, has always maintained that life exists on Mars. It was not a false positive, he says.
So is there life on Mars? As I have said before, I find the notion that bacteria live not only on Mars but other planets and non-stellar objects throughout the universe highly plausible.
In any case, even if there was not life before humans explored Mars, there is now, if you believe that humans are cyborgs. Two Mars rovers that landed there in 2004 are still roaming around the Martian landscape at the bidding of their human masters. If, as Andy Clark says, machines such as these are really an artificial extension of ourselves rather like a bionic limb, then there is a living human presence on Mars, in the form of two functioning robot explorers.

actual professor is building a time machine

A professor in Connecticut predicts that time travel will be possible this century, and is working towards making it happen. Good luck, professor! I'll take a ride when it's ready.

Nature can reclaim what is lost

According to the New Scientist, the area around Chernobyl has returned to a wilderness state, including roving wolves and bears. There was an intermediate stage where feral dogs, rats and mice were plentiful, followed by reversion to an almost completely pre-human state. This gives us reason to be optimistic about the fate of the world. Nature is robust. Balance is eventually restored, even after a catastrophic environmental event such as the Chernobyl nuclear disaster.

teleportation, approximately

Before a technology is invented, it seems fanciful, even ridiculous, to believe that it could be achieved. Flight, radio, man walking on the moon. After its invention those who doubted it seem quaint and lacking in imagination. The breakthrough joins the realm of the known, the understood, and in some cases (such as television) the banal.
It is unlikely, but perhaps such a future awaits teleportation? The crew of the starship Enterprise travelled from spaceship to planets and back again via this very convenient mode of transportation.
Humans cannot be teleported, but thanks to a team of researchers in Germany, small objects can, at least over small distances. Glenn Reynolds has said that teleportation would disrupt our concept of nationhood, which relies on the idea of "in here" and "out there". He also notes that airline travel is already achieving this. Indeed, air travel is a rough approximation to teleportation.

Evolutionary theorist agrees with HG Wells

Oliver Curry, a theorist at the renowned London School of Economics gave an interview with cable channel "Bravo" in which he predicted that in 100,000 years, mankind would have evolved into two distinct species, a tall, noble, upper class species, and a brutish, short, unintelligent lower class species. This future has more than a passing similarity to the vision of the future portrayed by HG Wells in The Time Machine. It also has overtones of Huxley's Brave New World. In fact, a cynic could claim that it is little more than an indirect expression of a narrow upper class English view of the world as it currently is.
However, since this is expressed as a scientific theory, an expression of what the human race will become, it should be addressed as such.
One of the drivers of species diversification is geographical separation. This was an insight gained by Darwin as he marvelled at the animals on Galapagos Island. Workers and aristocrats, by contrast, do not live on separate continents, but in the same society. Granted, globalisation means that entire countries can specialise in amassing armies of workers for another country's consumers. However, these arrangements are fluid and short-lived. Furthermore globalisation through international travel means that geographical distances play less of a role in separating humans than they once did.
Curry believes that the classes will breed separately, resulting in a new race of intelligent, beautiful people. However,breeding separation between the classes is not unprecedented. Through much of Europe's history this has been practiced in one form or another, the most striking product of which is inbreeding resulting in rare diseases such as haemophilia.
Curry is pessimistic about many aspects of humanities future. For example he predicts that humanity will reduce its ability to resist disease due to modern medicine. This shows a fundamental misunderstanding of the interaction between medicine and mankind.
Medicine is part of mankind, just as anthills are part of ants. If medicine suddenly disappeared from society, human health would deteriorate. Similarly, if you take away an anthill, you're going to mess up the ants. If you want to argue that humans are too reliant on medicine, then perhaps you should also argue that ants have become too reliant on anthills. The metaphor is sound. Both are structures created on a group level that enhance the well-being of the individuals. Ants have the benefit that ant-hill making is genetically wired in. Therefore, in contrast to anthills, it is conceivable that medicine could be lost yet the species (humans) remain. However, the circumstances under which medicine would be lost completely are highly unlikely. This would require a total, global breakdown of society.
For paying the price of dependence on something other than their own bodies, organisms get the benefits from a structure that no single member could build on its own. Medicine is an anthill.

Underpopulation can be a real killer

The population of America has passed the 300 million mark and the Australian birthrate climbs (the newspapers term of "booming" is over the top- it's still below replacement level). Meanwhile, Russia's population is imploding due to AIDS, tuberculosis, alcoholism, poverty, and, well, just not having babies. This will have increasing repercussions worldwide. For example, Russia will have fewer and fewer working age people to support its elderly, to enlist in the military, and to generally run the country. Whereas booming populations have the danger of consuming more resources, falling populations create unstable states. This in turn can cause economic woe, collapsing infrastructure, famine, war, and anarchy. In all our worrying about overpopulation, we fail to realise that its evil twin can also be very destructive.

The problem with time travel

I've always loved second hand bookshops, particularly the science fiction/fantasy section. These shops are often as well-stocked and have as many quality titles as a regular bookshop. In the past though, I've tended to avoid time-travel titles. Look I can buy giant three headed ogres, faster than light travel, and mental telepathy. But time travel never gets past the suspension of disbelief hurdle for me. I guess that part of the problem is that standard views of time travel violate my understanding of both how the past works, and how the future works. What I have only recently realized is that, firstly, I can suspend disblief on the time travel front, and secondly, much science fiction is more sophisticated in its treatment of time than I realized.
Standard 'hollywood' time travel is often of the back-to-the-future variety: the protagonist travels backward to change a key event in the past. In the case of Back to the Future, Marty McFly (played by Michael J Fox) visits an eccentric professor, accidentally travels back in time, and stops his parents from meeting each other. With the professor's help, he must travel back again and undo the mistake, or he will cease to exist.
In The Terminator, the bad guys travel back, and they travel back from the future to the present, but the concept is the same. We learn that there is a war in the future between humans and robots. The leader of the human resistance is a man called John Connor. The robots send a robot assassin - a "terminator" - back in time to kill Connor's mother, Sarah, before she can give birth to the future leader (the terminator robot was played by Arnold Schwarzenegger). The humans also send a man, Kyle Reese, back in time, to stop the terminator. Thus the stage is set for a thrilling damsel in distress story, with Sarah relentlessly pursued by an indestructible robot, saved at every turn in the nick of time by the resourceful Reese. There were two sequels, each with exactly the same plot.
Back to the Future is light-hearted fun, while The Terminator is a tense thriller. Both rely on exactly the same time travel concept: travelling back into the past to change the present in one's favor. Of course, this opens a hornet's nest of questions, such as "what will happen if I meet myself?", "if I cause someone to not exist, is there a parallel universe where they still exist?" and so forth. Back to the Future, and it's sequels (yes it has two as well) actually explores these and other questions in some detail. It solves many problems by creating a parallel time-line every time the past is changed. This actually leads to some rather convoluted plots in the sequels as the heroes jump back and forth through a maze of timelines that they have created.
The "go into the past to change the present" concept was also employed in at least two Star Trek movies (Star Trek IV: The Voyage Home and Star Trek: First Contact), and has made numerous other appearances on the large and small screen. It was boredom with this conceit that put me off time travel science fiction. However, when I started reading time travel books, written by classic authors such as Clifford Simak, Brian Aldiss, and others, I discovered that the treatment of time travel is much more diverse in the written sci-fi literature than the ubiquity of the go-back-to-save-the-present plotline lead me to believe.
For instance, in Cryptozoic, by Aldiss, humans can go back in time, but only as observers. They can see events unfold around them but they cannot alter them. They can also see and interact with other time travellers. The book is about an artist who has travelled back to the cryptozoic era for inspiration, but has spent so much time in time travel that he is going mad. There is also a sinister sub-plot about him being chased by agents of a shadowy organization (or is that just his brain-addled fantasy?).
In Simak's Tomorrow's people, portals open from the future and people start walking out in the thousands. They are escaping from an apocalyptic confrontation with aliens that are all-powerful and bent on wiping out humanity. There is no hope, so they escape into the past... literally. They stop by in the present on their way back to a distant past millions of years ago, long before the advent of humans.
Phillip K Dick's Now Wait for Last Year involves a drug that can allow you to travel backwards and forwards through time. However the drug is very addictive, and may send you insane. Now wait for last year explores numerous permutations of time-travel problems, from meeting oneself, through to changing the past and the future, and encountering numerous paradoxes.
For me, the problem is with plots that involve travelling into the future, starting right back with Wells' The Time Machine. For the very concept of visiting the future demonstrates a lack of understanding of what the future is: it is that which has not yet been created. Not having been created, it therefore does not exist. There is no future to visit. Visiting the future uses a defunct model of time and space: strict determinism. Once, learned people, scientists, philosophers, theologans and such, believed that the future was fixed and immutable. The principles of cause and effect made it so. If we understood the laws of physics well enough, and we knew everything about the present down to the tiniest detail, then we would be able to predict the future as easily as a professional snooker player can predict which pocket the ball will fall into. Physicists aimed to predict the weather and other mysterious events. Theologans talked of predestination. Philosophers talked of free will and its absense in a deterministic universe.
That concept of the future died with quantum mechanics. Even if you know everything there is to know, any event is still probabilistic. Those uncertainties add up over lots of events, so that in the end, all that is ahead is unknown. Schroedinger's cat is both alive and dead.
Similarly, visiting the past and talking to people in the past shows a lack of understanding of what the past is. The past is fixed, the future fluid. Science fiction that acknowledges this, such as Aldiss' Cryptozoic, can actually be more surprising and thought-provoking than stories that do not, such as Now Wait for Last Year, The Terminator, or Back to The Future. Ignore these fundamental truths about time and you end up with contradictions, paradoxes, and hopelessly messy plots. Such stories may be fun, but they are unconvincing, and therefore, ultimately, unsatisfying.