Catch a Wave (or a photon)
by Larry Ketchersid
The headlines in physics today revolve around efforts to determine and define a common model for all things - a provable-through-experimentation unified Theory of Everything. String theory, Garret Lisi’s recent Theory of Everything based on E8 Lie Algebra, and others seek to unify the four different types of forces – the strong and weak nuclear forces, gravity, and electromagnetic forces - into one joint theory. A Theory of Everything would seek to describe with physical laws and mathematics not only those phenomena that we do not normally observe, such as nuclear interactions, or black hole event horizons, with those that we encounter in our everyday lives.
But while the quest for one theory continues, the beauty of physics can be demonstrated in existing, simple solutions. As Richard Feynman put it in The Robb Lectures in 1979: “So much of nature is so accurately described by one theory; an enormous range of phenomena, all the things that you normally see.”
Every day, every minute, people are talking on cell phones, using wi-fi computers, watching analog and digital TV broadcasts, listening to radios, catching a wave or two. All of this data, this information, travels wirelessly in waves, using something called the broadcast spectrum. The broadcast spectrum is a limited number of frequencies that are allocated by governments around the world for the wireless usage of one or two-way communications.
The broadcast spectrum and its uses for business and technical motivations is immense. For example, in January 2008, the U.S. Government will open an auction for the 700MHz broadcast spectrum. The Government is forcing all analog television broadcasters to switch to digital broadcast by 2009. This provides a re-opening of wireless broadcast spectrum known as 700MHz. To consumers, these were channels 52-69 on your television set, what were called “UHF” channels (UHF stands for Ultra-High Frequency). Potential bidders include not only the “big four” U.S. cellular companies (AT&T, T-Mobile, Verizon, Sprint) but also Google, Yahoo and eBay;
In 2007, MIT demonstrated Wi-Tricity, electricity moving without wires to provide power. While currently too inefficient for commercial usage this application runs near the 10MHz frequency band, which might be below government regulation and scrutiny.
The broadcast spectrum is a subset of the electromagnetic spectrum. Classically, the EM spectrum (the range of EM radiations) is divided into categories by wavelength: electrical, radio, microwave, infrared, visible spectrum (light), ultraviolet, X-rays and gamma rays. Electrical EM radiation covers ELF (extremely low frequency, such as that given off by power lines) and VLF (very low frequency, such as computers or other electrical equipment). Radio EM radiation includes not only radio, but television, cell phone, global positioning systems (GPS) and wi-fi communication systems.
The visible spectrum, covering the waves that appear as colors visible to the human eye, is also a part of this same spectrum.
EM radiation is defined by the basic properties of electrical and magnetic fields, i.e., the “waves” for radio, TV and other consumables are created using basic properties of electricity and magnetism. The classical area of physics which describes how these everyday tools and phenomena work is called electromagnetism, as physicists proved that electricity and magnetism are two different aspects of the same interaction. This was further expanded with the understanding and inclusion of quantum mechanics into quantum electrodynamics, abbreviated QED. QED describes the same phenomena as classical electromagnetism with more accuracy and broader coverage. The basis of the theory describes charged particles interacting through the exchange of photons.
QED not only explains the everyday phenomena such as radio and visual spectrum, the look and texture of the items we use, but has also been proven accurate and correct through experimental measurements of electromagnetic fields at the atomic and subatomic level and in high-energy collider experimentation.
In classical theory, the four main interactions that physics uses to describe the world are electromagnetism, strong and weak nuclear force (the forces at atomic and subatomic levels) and gravity. The current theories for these interactions are QED, quantum chromodynamics, electroweak theory and general relativity.
Research for a Theory of Everything seeks to unify these four interactions into one experimentally provable mathematical model that can be mathematically proven with a similar rigor to QED. The basic tenets and admired simplicity of QED helped lead physicists to the quantum mechanical theories of the strong and weak nuclear interaction forces.
Gravity, the other interaction besides QED that we encounter everyday, is the “odd man out” in finding a experimentally provable theory for unifying the forces. Work continues on the search for a Theory of Everything, while some dissenters insist that, if a solution were to present itself, it would be so complex as to fail the simplicity test, it would be non-trivial and therefore incomplete.
As this search gets more complicated, it also gets more expensive: the largest experiment to detect proposed portions of these theories is the Large Haldron Collider (LHC) at CERN in Switzerland and France. At an approximate cost of $6 Billion shared across multiple countries, the LHC is scheduled to go online next year.
Larry Ketchersid is an entrepreneurial technologist and currently the CEO of Media Sourcery, Inc., a security software company. A former executive with Compaq, he has led large technology companies as well as initiated several small startups. He is a martial artist, rugby player, writer, and family man. His first novel is Dusk Before the Dawn.