Knocking on Heaven's Door Read Online Free PDF Page A

Nobel Prize—winning pioneer of quantum mechanics Niels Bohr noted, “If you are not completely confused by quantum mechanics, you do not understand it.” Here’s another secret (at least as well protected as those in a bestselling book): quantum mechanics is notoriously misunderstood. Our language and intuition derive from classical reasoning , which doesn’t take quantum mechanics into account. But this doesn’t mean that any bizarre phenomenon is possible with quantum logic. Even without a more fundamental, deeper understanding, we know how to use quantum mechanics to make predictions. Quantum mechanics will certainly never account for Byrne’s “secret” about the so-called principle of attraction between people and distant things or phenomena. At those large distances, quantum mechanics doesn’t play this kind of role. Quantum mechanics has nothing to do with many of the tantalizing ideas people often attribute to it. I cannot affect an experiment by staring at it, quantum mechanics does not mean there are no reliable predictions, and most measurements are constrained by practical limitations and not by the uncertainty principle.
    Such fallacies were the chief topic in a surprising conversation I had with Mark Vicente, the director of the movie What the Bleep Do We Know!? —a ?lm that is the bane of scientists—in which people claim that human influence matters for experiments. I wasn’t sure where this conversation would lead, but I had time to spare since I was sitting on the tarmac at the Dallas/Fort Worth airport for several hours waiting for mechanics to repair a dent in the wing (which first was described as too small to matter—but then was “measured by technology” before the plane could depart, as one crewmember helpfully informed us).
    Even with the delay, I realized if I was going to talk to Mark at any length, I had to know where he stood on his film—which I was familiar with from the numerous people at my lectures who asked me off-the-wall questions based on what they had seen in it. Mark’s answer caught me by surprise. He had made a rather striking about-face. He confided that he had initially approached science with preconceived notions that he didn’t sufficiently question, but that he now viewed his previous thinking as more religious in nature. Mark ultimately concluded that what he had presented in his film was not science. Placing quantum mechanical phenomena at a human level was perhaps superficially satisfying to many of his film’s viewers, but that didn’t make it right.
    Even if new theories require radically different assumptions—as was certainly the case with quantum mechanics—valid scientific arguments and experiments ultimately determined that they were true. It wasn’t magic. The scientific method, along with data and searches for economy and consistency, had told scientists how to extend their knowledge beyond what is intuitive at immediately accessible scales to very different ideas that apply to phenomena that are not.
    The next section tells more about how the notion of scale systematically bridges different theoretical concepts and allows us to incorporate them into a coherent whole.
    EFFECTIVE THEORIES
    Our size happens to fall pretty much randomly close to the middle in terms of powers of ten when placed on a scale between the smallest imaginable length and the enormity of the universe. 6 We are very big compared to the internal structure of matter and its minuscule components, while we are extremely tiny compared to stars, galaxies, and the universe’s expanse. The sizes that we most readily comprehend are simply the ones that are most accessible to us—through our five senses and through the most rudimentary measuring tools. We understand more distant scales through observations combined with logical deductions. The range of sizes might seem to involve increasingly abstract and hard-to-keep-track-of quantities as we move further from directly visible