Physics-Related Articles

Note: Some of the following articles will be difficult to understand at the high school or freshman level. That is ok, many articles that physicists read are hard for them to understand, and there are always new articles appearing that no one except the author understands well, at least initially (and sometimes even the author doesn't fully understand what he or she is writing about).

So just try to do your best to enjoy these articles. Reading the abstract, first paragraph, and closing paragraph is usually a quick and practical way to get a sense of what are the key ideas and implications.

  • There's Plenty of Room at the Bottom by Richard Feynman, the 1965 Physics Nobel prize winner. This is a famous and nontechnical article from 1959 about the many opportunities to develop an engineering capability at the molecular level, foreshadowing the modern field of nanoscience.

    The article ends with Feynman offering two personal rewards of $1,000 (a lot of money in 1959) to the first person to store a page of information on an area that was 1/25,000 the size of a book page, and to the first person to create an electric motor that can operate in a cube of size of 1/64 in. This latter challenge turned out not to be so hard with 1950's technology, and Feynman had to pay the motor prize off just a year later, in 1960. The first prize had to wait until 1985 and was paid to a Stanford graduate student who used electron beam lithography to reproduce the first page of Dicken's novel A Tale of Two Cities on a page measuring 1/160 mm on a side.

  • Ultimate physical limits to computation, by Seth Lloyd. This paper describes how fundamental laws of nature associated with quantum mechanics, thermodynamics, and general relativity (Einstein's theory of gravity) allow one to deduce the ultimate limits that a kilogram of matter can compute. Not only are brains and current computers far from achieving the limits, the ultimate computer requires the extremes of crushing the computer until it is just about to turn into a black hole and simultaneously heating the computer until it becomes a super-hot plasma of about 109 K. This paper is a nice example of how order-of-magnitude estimates can produce interesting insights about a practical issue like computing.

  • The Unreasonable Effectiveness Of Mathematics In The Natural Sciences by Eugene Wigner (1963 Physics Nobel prize Sciences winner). Professor Wigner addresses a deep mystery, which is why is it that mathematics, a human invention, turns out to be so effective in understanding the universe.

  • Fast light, slow light, and optical precursors ... What does it all mean? by Professor Gauthier (here at Duke) and Professor Boyd. This paper describes how a pulse of light propagates through a dispersive optical material whose refractive index varies with the frequency of the light. All materials are dispersive, so the physics is quite general.

    Roughly speaking, the speed of a pulse of light propagating through a dispersive material is described by the group velocity, which depends both on the index of refraction as well on as the derivative of the index of refraction with respect to frequency. When the refractive index of the material is a decreasing function of frequency, the group velocity can take on values that are greater than the speed of light in vacuum or even be negative. Gauthier's and Boyd's research groups have undertaken experiments that demonstrate this unusual behavior. Also, Gauthier's group has done experiments to show how such behavior is consistent with the special theory of relativity. The key is to understand how information is encoded on an optical waveform - the special theory places a speed limit on the speed at which information travels, not on the speed of a pulse. For additional resources, see this tutorial.

  • Is the moon there when nobody looks? Reality and quantum theory by N. David Mermin. This article is an accessible and not-too-technical introduction to one of the strangest features of quantum mechanics, the idea of entangled particles, and to the implications of entanglement for understanding "reality".

    Briefly, it is possible to arrange two particles, say two photons arising from the annihilation of a positronium atom, to be entangled which means that these particles have behaviors that are correlated in a way that makes no sense from a classical (non-quantum) point of view: measurements on one particle of an entangled pair must produce results that are correlated with measurements carried out on the other particle of the entangled pair, even if the two particles are separated by a great distance (say a light year) and even if the measurements are simultaneously carried out on the two particles, more quickly than light can travel between the two experiments. Read the Mermin article to get a better understanding.