Member Rara Avis
The newest theory (law) in physics that is currently being dispelled is the speed of light. Researches in the US have accelerated light up to 300x its believed set speed of 186, 000 miles per second. This is achieved by directing the light through specially treated Caesium gas. In following this new set standard, it appears that Einstein's theory of relativity is in jeopardy, due to it's assumption of light speed as a set standard.
For those interested, here's the original article in Nature, a very prestigious science journal. The findings are, indeed, very important. But, sadly, the results were entirely blown out of proportion by the media. Hey, we all know the newspapers love snappy headlines.
The experiment involves sending a pulse of light through a chamber filled with a caesium vapor. Think about it. A pulse of light is not a simple object. It is not infinitely short in time, nor in space. The shape of the pulse is the critical part of the experiment. Any light pulse can be thought of as starting with an intensity smoothly rising from zero up to a maximum value and then dropping away again. When you tell me the "burst" of light exited before it had fully entered, you have to also tell me which part of the burst you were measuring. The leading edge? The peak? It makes a difference.
What essentially happens (some think) is that the leading edge is "rebuilt" into a burst of lesser light (dimmer) of exactly the same "shape." If you are measuring the peak of the burst entering, you seem to see the peak leaving more quickly than can be accounted for in relativistic terms. But, in reality, you are seeing the leading edge leave.
The really critical factor, however, is that no information can be transmitted in this manner. If you wish to actually transmit information, you need to measure more of the pulse. When you work out the details, it turns out that you need to measure enough of the pulse to bring the total transmission speed back down below the speed of light in a vacuum.
For a more balanced view of the experiment (something you won't find in many places), here's an article by Chris Colin at Salon.com
I particularly liked your "bump into it" description. That makes more sense to the layman than the traditional "cannot observe without interference."
Einstein did not like quantum theory. One of his more famous quotations was, "I refuse to believe that God plays dice with the Universe." During the 1930's Einstein and Niels Bohr fought tooth and nail over the particulars. And of course, Einstein spent most of the next 25 years, until his death in 1955, trying to unseat quantum mechanics.
I mention this because the "cannot observe without interference" interpretation of HUP was Einstein's. He wanted very much to believe the consequences of HUP were simply a reflection of our own clumsiness. The standard interpretation of quantum physics, known as the Copenhagen Interpretation, was established largely through the efforts of Bohr, who argued that the fuzziness was an intrinsic feature of the quantum world, and that within the limits set by Heisenberg's uncertainty principle an electron itself does not "know" both where it is and where it is going.
(Incidentally, momentum and position are not the only complimentary properties that cannot be measured simultaneously. Spin, for example - or more correctly, angular momentum - can never be measured accurately in more than one axis.)
If you accept Einstein's interpretation, then HUP is simply a consequence of our own limitations. But if you accept the Copenhagen Interpretation, it goes a long way towards explaining some of the paradoxes of modern science. For example, in other threads, we've occasionally mentioned the fact that light (and we're discovering just about everything else, right up to molecules) seems to exist as both a wave and as particles. Some of its characteristics can only be explained as a wave function, others by assuming it is composed of particles. Einstein's own Nobel Prize, by the way, wasn't for Relativity, but rather for showing the particle nature of light (the photon). In one of the most ironic examples of wave-particle duality, the physicist J. J. Thomson received a Nobel Prize for discovering that the electron is a particle, while his son George received a Nobel Prize for proving that the electron is a wave.
This wave-particle duality is linked with the uncertainty principle. "Waviness" is a property associated with momentum - a typical wave is spread out, so it has no definite location in space, but it does have a direction in which it is going. By contrast, a particle can have a precisely defined position. Heisenberg found that the quantum equations imply a strict tradeoff between the two complementary properties. If the position of a quantum entity is precisely defined (for example, when it hits a detector screen), its waviness is suppressed; but if it is allowed to give full expression to its wave nature, the particle aspect vanishes.
Sound confusing? Think of it this way, then. Photons and electrons travel through space as particles. Given their direction, we cannot then tell exactly where they are. But we can predict approximately where they will be through probabilities. And if you graph those probabilities? By golly, it looks just like a wave!