![]() ![]() Cosmology deals with the origin and eventual fate of the universe as a whole, which in a funny way means that it wraps back around to the infinitesimally small- at the instant of the Big Bang, the universe was small enough and hot enough that what follows afterwards depends very strongly on the details of particle physics. Then you have astrophysics, which involves whopping huge things, the size of stars, solar systems, and galaxies- thousands of kilometers up through thousands of light-years (one light-year is around 9,500,000,000,000 km).Īnd finally, you have fields like cosmology, whose subject is the entire universe, and beyond- all the way up to billions of light-years, and beyond. Objects with dimensions of several kilometers to thousands of kilometers. Getting to really big things, we have geophysics and planetary science, which studies the physical processes involved in things the size of, well, planets. It's where humans live and work, and central to what those of us in academic physics teach, though, so it plays a big part in physics education research. This is where the science of physics began, though there's not a great deal of active research on the behavior of these sorts of things. If you took physics in high school or college, you probably spent most of your time looking at physics on everyday scales- the motion of macroscopic objects like baseballs and cars, or the behavior of electric circuits and magnets. It's less likely to show up in headlines than other branches, but has the most profound impact on your everyday life. Condensed matter physics is concerned with the behavior of very large numbers of particles bound together in solids or liquids, and is the biggest single subfield within physics, largely because this is the domain of the semiconductor industry, which generates trillions of dollars off the manipulation of the properties of solid chunks of silicon to make tiny little transistors. This is the area I work in, and I could go on at great length (and probably will, later).Ĭondensed matter physics covers a huge range of scales all by itself, from nanometer-sized particles (0.000000001m 10 to the -9) up to macroscopic samples of material with dimensions measured in sizable fractions of a meter. These operate on the scale of whole atoms and molecules, around 0.0000000001 m (10 to the -10), and are concerned with how the electrons arrange themselves around the nucleus of an atom, and how they're shared between atoms in a molecule. The next step up is a big one, to atomic and molecular physics.
0 Comments
Leave a Reply. |