IMPOSSIBLE! Preposterous! These words are often thrown about when people declare certain things to be scientifically ridiculous.
Aliens cannot reach the Earth in spaceships, they proclaim, because the distance between stars is too great. Telepathy is impossible since the brain does not emit or receive messages. And it's impossible to instantaneously transport an object from A to B because you cannot know the location and momentum of all its atoms -- teleportation would violate the Heisenberg uncertainty principle.
Yet if you carefully analyse these examples, you realise that they are merely impossible today or in the near future. The real question is, are they impossible with technologies that lie decades, centuries or even millennia beyond ours? Perhaps these "impossibilities" are merely very difficult engineering problems.
So says Michio Kaku, the renowned physicist who was one of the developers of string field theory, in a New Scientist article titled "Impossible physics: Never say never." Kaku then reminds us of Arthur C. Clarke's famous admonition that "any sufficiently advanced technology is indistinguishable from magic."
An accompanying article by Michael Marshall lists ten things "that were once thought scientifically impossible," including heavier-than-air flight, harnessing nuclear energy, space flight, black holes, and many more.
A couple of months ago on this blog, we wrote about a new three-part BBC TV special in which "Michio Kaku explores the cutting edge science of today, tomorrow, and beyond."
In Part 3 of that series, Kaku asserts that we are "on the brink of a revolution which will give us control -- exquisite control -- of our physical world." He says:
Today we can manipulate individual atoms, but this is just the beginning of a journey -- a journey which will ultimately give us the power to manipulate the very stuff of our universe: matter itself.
Impossible? Preposterous? Scientifically ridiculous?
These words were often thrown about just a few years ago by people denying the claims of those who had spent many years studying the physics, chemistry, and engineering concepts behind advanced nanotechnology and molecular manufacturing.
But perceptions can change quickly when science advances rapidly.
And today, what was declared impossible not long ago is starting to enter the mainstream of scientific thought. Broad public acceptance may not be far away. Soon after that, we hope, serious discussions of the many implications of this transformative new technology will take place at the highest levels of governance and at the grassroots as well.