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Now particle physics in the United States is struggling to survive the d isaster of the Supercond ucting Supercollid er. The Supercollid er was a gigantic particle accelerator project that was canceled in 1 993 after about 3 billion d ollars had alread y been spent on it. The cancellation was a personal traged y for…
It is common when discussing the Invisible Pink Unicorn to point out that because she is invisible, no one can prove that she does not exist (or indeed that she is not pink). This is a parody of similar theistic claims about God—that God, as creator of the universe, is not subject to its laws and thus not physically…
If, on the other hand, we live in an open universe, infinite in space and time and continuing to expand into a future without end, then life has to face a prospect of slow freezing {111} rather than quick frying. The universe grows constantly colder as it expands, and the supply of free energy is constantly dwindling…
A hundred years ago, Charles Darwin could write books discussing the central problems of biology in language which was scientifically precise and still accessible to the general public. In those days the subject matter of biology was plants and animals. The language of Darwin was intelligible to experts and…
The discoveries of recent decades in particle physics have led us to place great emphasis on the concept of broken symmetry. The development of the universe from its earliest beginnings is regarded as a succession of symmetry-breakings. As it emerges from the moment of creation in the Big Bang, the universe is…
This is our world now... the world of the electron and the switch, the beauty of the baud. We make use of a service already existing without paying for what could be dirt-cheap if it wasn't run by profiteering gluttons, and you call us criminals. We explore... and you call us criminals. We seek after knowledge... and…
In programmable matter, the same cubic meter of machinery can become a wind tunnel at one moment, a polymer soup at the next; it can model a sea of fermions [elementary particles], a genetic pool, or an epidemiology experiment at the flick of a console key. Ten times as large a simulation will simply require ten cubic…
Neutrinos, they are very small. They have no charge and have no mass And do not interact at all. The earth is just a silly ball To them, through which they simply pass. Like dustmaids down a drafty hall Or photons through a sheet of glass. They snub the most exquisite gas, Ignore the most substantial wall, Cold…
Imagine you had to take an art class in which you were taught how to paint a fence or a wall, but you were never shown the paintings of the great masters, and you weren't even told that such paintings existed. Pretty soon you'd be asking, why study art? That's absurd, of course, but it's surprisingly close to the way…
It is called a tokamak—old Soviet shorthand for a more precise and geometrical name, toroidalnaya kamera s aksialnym magnitnym polem, or “toroidal chamber with an axial magnetic field.” Sakharov’s rough sketch depicted a doughnut-shaped vacuum chamber, or torus, ringed with electromagnets, and that is how iter’s core…
In the physical world, the only way to learn tomorrow’s weather in detail is to wait twenty-four hours and see, even if nothing is random at all. The universe is computing tomorrow’s weather as rapidly and as efficiently as possible; any smaller model is inaccurate, and the smallest error is amplified into large…
As the statistician George E. P. Box wrote, “All models are wrong, but some models are useful.”90 What he meant by that is that all models are simplifications of the universe, as they must necessarily be. As another mathematician said, “The best model of a cat is a cat.”91 Everything else is leaving out some sort of…
Daddy,' she says, 'which came first, the chicken or the egg?' Steadfastly, even desperately, we have been refusing to commit ourselves. But our questioner is insistent. The truth alone will satisfy her. Nothing less. At long last we gather up courage and issue our solemn pronouncement on the subject: 'Yes!' So it is…
We called the new [fourth] quark the “charmed quark” because we were pleased, and fascinated by the symmetry it brought to the subnuclear world. “Charm” also means a “a magical device to avert evil,” and in 1970 it was realized that the old three quark theory ran into very serious problems. ... As if by magic the…
Physicists have long pondered the problem and may have an answer. It seems that just before the universe was one millisecond old, matter and antimatter annihilated each other in a sweeping extinction. But a tiny asymmetry was built into the universe so that matter dominated over antimatter by one part out of 100…
In the three-dimensional space in which we live, elementary particles are designated as fermions and bosons, depending on their spin. We associate with each variety of elementary particle a quantum number, which gives the value of its spin. This number can be an integer (0,1, 2,... ) or a half integer (1/2, 3/2…
Protons are more massive than electrons, for example, and electrons are way more massive than neutrinos. Photons have no mass at all. For most us, that's no more than a fun fact (and not all that much fun, really). For physicists, though, it's a mystery that demands a solution. Why are the masses so different — and…
In a thoughtful mood Davy wrote a new kind of metaphysical poem, ‘The Massy Pillars of the Earth. It reflects on the human condition, and suggests that since nothing is ever destroyed in the physical universe, only transformed (the First Law of Thermodynamics), then man himself must be immortal in some spiritual…
Feynman's graphical method provides a way of visualizing each term in the sum over histories. Those pictures, called Feynman diagrams, are one of the most important tools of modern physics. In QED the sum over all possible histories can be represented as a sum over Feynman diagrams like those below, which represent…