General Clark Advocating Time Travel????, page 2

Is faster-than-light travel possible?

It's worth taking a little time to refer to the belief (often with little maths, physics or astronomy knowledge but a lot of wishful thinking) that we are regularly visited by aliens across such huge distances (often to be seen by one person who demands acceptance of their story, though there are no witnesses). Physics has shown (expanded below) that no material body can travel at faster than the speed of light. Yet the wishful thinkers dismiss this with arguments like 'we once thought we could not break the sound barrier and we did; one day we'll break the light barrier'. It's as though the two concepts were the same. They are not. The serious reader in astronomy and physics will find that the speed of light is 'built-in' to the very nature of everything from atoms to stars. To exceed the speed of light is a bit like saying 'one day I'll be able to jump 100 feet in the air'. Something 'built-in' to our bodies prevents that.

This is not just theory. Every day physicists accelerate tiny particles (electrons, protons etc) in sophisticated (and hugely expensive) circular particle accelerators. As the speeds build up it would appear that just a few times more power will get them past the speed of light. But as they approach the speed of light more and more energy is needed and the speed flattens out, always just below the speed of light. We didn't decide that. The energy available didn't decide that. The nature of the particles and the laws of physics decided it.

Every few days astronomers witness a star in another galaxy exploding as a supernova - producing more energy for a few weeks than all the stars in the galaxy. Yet no material is observed in the explosion moving anywhere near the speed of light. Yet some people dismiss all this (or are not aware of it) and say 'I think it is possible', but can't suggest how we might come up with some form of energy which exceeds that of an exploding star.

We should not be sad, that earthly humans are not destined to physically explore the stars; anymore than an ant does not get upset if it could see other ants on a far distant hill top but accepts that its physical limitations will not enable a visit.

The work of theoretical mathematicians on black holes, is sometimes, perhaps irresponsibly, interpreted that we could dive into a wormhole here and pop out somewhere else. This is then picked up by a certain class of TV shows (enjoyable within these constraints), perhaps showing some amazing device that gets us into the wormhole. There's never any explanation of how we get a similarly amazing device to just where we need it in the Universe, to get us out of the other end of the wormhole. The square root of -1 is also a concept that theoretical mathematics comes up with which is not physically possible. I can't buy the square root of -4 apples for example. Yet much of science and engineering and other technology depends on being able to include such complex numbers in the mathematics involved.

If other life exists on planets orbiting other stars, now frequently being discovered as our instrumentation becomes more sensitive, then the first line of communication will be by radio waves, which, like light (and X-rays, and ultraviolet and infrared) travel at 300,000 km/sec. We are listening out now (the SETI projects - Search for Extraterrestrial Intelligence) but even if we heard from a planet 25,000 light years away (announced January 1999), it would take 25,000 years for our reply to reach 'them'. Not a very fruitful conversation. But it would be the knowledge of the existence of other life that would make the biggest change to Earthly ideologies. The possibility of other life cannot be excluded - the strongest evidence for this proposition being, simply, that we exist.