- Included in the Claudia de Rham Posts List.
- Claudia de Rham discusses the nature of light in her book The Beauty of Falling; as strange as light often is, scientists have a pretty good handle on it.
Martin Winfree
December 27, 2024 ·
Shared with Public
(Part II)
Claudia de Rham thoroughly discusses the nature of light in her book The Beauty of Falling; as strange as light often is, scientists have a pretty good handle on it. “Light” of course covers not just what we can see; it is the entire electromagnetic spectrum: infrared, ultraviolet, radio waves, microwaves, x-rays, gamma rays, all of it. But light is a good catch-all term.
Scientists struggled for decades if not centuries to determine whether light is a wave or a particle. As it turns out, light is both a wave AND a particle. There is for example the famous two-slit experiment; anyone can set up a simplified version of it. However, depending upon exactly how scientists proceed, light will manifest as a wave, or light will manifest as a particle, with the results looking completely different – and in the same experiment. I have seen videos demonstrating this, and I really can’t believe what I am seeing.
Also, consider the speed of light – about 186,000 miles per second. Light always travels that fast, at least in a vacuum, and nothing can travel any faster. The speed of light is a part of our everyday lives, but Claudia de Rham explains that the implications of the unvarying speed of light are among the insights that led Albert Einstein to his special theory of relativity.
While too recent to be included in her book, I have recently seen a photograph of an individual photon, the fundamental particle of light. It looks like a yellow blob, about what you might expect I guess. I have to say, that is a pretty good trick to get a picture of something like that!
Gravity is not nearly so well understood as light. Isaac Newton developed the basic concepts and equations to describe gravity that still work in most situations to this day. Einstein’s general theory of relativity covers how gravity works – an object with a large gravitational field actually warps the fabric of space-time itself. After more than a century, relativity has withstood the challenges that have been brought to bear on it. But Claudia de Rham states in her book that scientific theories eventually fail, including hers.
I had thought that the search for the graviton, the elusive particle that is believed to carry the force of gravity, is no longer necessary; but I was mistaken about that. As with light, gravity evidently can manifest as a particle or as a wave. While no one has seen or measured a graviton as yet, Claudia de Rham is hopeful that this will happen in the near future.
But gravitational waves have recently been seen and measured, and you might have heard about that. Einstein’s general theory of relativity predicted their existence, and it took about a century to prove him right on that score. While gravitational waves within the solar system are much too weak to be noticed or measured, truly titanic events in the Universe, such as the merger of two neutron stars or of two black holes, generate much larger gravitational waves that can be detected from Earth as they expand across the Universe.
The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two massive observatories, one in Washington State and the other in Louisiana. LIGO first detected gravitational waves in outer space in February 2016. I remember thinking when I heard about it that we were lucky that LIGO was up and running just in time to measure that first event. Actually, gravitational waves have been measured multiple times since then, often enough that the signatures of neutron star mergers and black hole mergers can be distinguished. LIGO has also been coordinating with other gravitational wave observatories, Virgo in Italy and KAGRA in Japan.
Claudia de Rham has audaciously invented a term “glight”, basically viewing gravitational waves in the same way that we view light. Plus, she doesn’t have to keep saying “gravitational waves” all the time!
