- Included in the Claudia de Rham Posts List.
- Claudia de Rham’s book, The Beauty of Falling / A Life in Pursuit of Gravity was published just this year and is an engaging read from cover to cover.
Martin Winfree
December 27, 2024 ·
Shared with Public
(Part I)
One of my best friends from grade school onward, George Konstantinow has been following my posts about Stephen Hawking’s books and videos, among others. Recently, he referred me to several videos by experts in high-level theoretical physics; I keep telling myself that I could follow those lectures to some extent, but I am not yet convinced of that.
Then he sent me a book by one of those physicists, Claudia de Rham, called The Beauty of Falling / A Life in Pursuit of Gravity; and I like that better than the talks, as enlightening as they are. The book was published just this year and is an engaging read from cover to cover. She is not kidding about pursuing gravity: Claudia de Rham is a licensed pilot and also a scuba diver.
Additionally, she went through the grueling selection process to become an astronaut – twice! – and was among the final group the second time, until her dream was shattered when she tested positive for a dormant form of tuberculosis. Claudia de Rham never had the disease, but that positive result was enough to disqualify her as an astronaut.
Undaunted, she moved forward with her studies and is now a professor of theoretical physics at Imperial College London. Claudia de Rham has become a leading researcher in her field and has recently developed a new theory of gravity with a group of other scientists that might help explain the conundrum of “dark energy”. So far, her theory is holding strong as best I can tell.
As I have posted about previously, among the major unanswered mysteries in cosmology and physics as a whole are dark matter and dark energy. Exactly what dark matter is has yet to be determined, but its presence in the Universe is basically undisputed. Essentially, there is not enough ordinary matter in typical galaxies to explain their motion through space – either the orbits of the constituent stars in the individual galaxies, or the interactions between nearby galaxies. Something else is providing additional gravity to hold everything together.
Dark energy is another matter. The questions concerning dark matter date back well over a century; Henri Poincaré used the term “dark matter” in 1906 to discuss some of its early findings. The notion of dark energy though comes from the discovery in the late 1990‘s that the expansion of the Universe is neither slowing nor unchanging; it is actually increasing.
Since gravity is the only known force that operates on the Universe in a large-scale manner, the term “dark energy” was coined by theoretical cosmologist Michael S. Turner less than 30 years ago as more of a concept than anything else. As things stand, scientists believe that most of the Universe is made up of dark energy (68%), most of the rest is made up of dark matter (27%), and ordinary matter that we can see and measure is just 5% of the total. And as we all know from Albert Einstein’s famous equation – e = mc2 – energy and matter are basically the same thing at a fundamental level. So, that is everything.
It must stick in the craw of scientists everywhere that more than two-thirds of the Universe is utterly unknown. Thus, many theoretical physicists like Claudia de Rham have been seeking some other explanation that might allow cosmologists to sidestep the notion of dark energy altogether. Many new theories and explanations have been percolating through my Internet feeds this year.
In her book, Claudia de Rham interweaves her fascinating personal history with an overview of scientific giants who have studied and analyzed gravity, among them Isaac Newton and Albert Einstein. She is a native of Switzerland and has lived all over the world, including eight years in Madagascar. Probably for this reason, the accent in her speaking voice is hard to pin down. She is a great speaker but also an amazing writer. Claudia de Rham talks about what it is like as a woman, trying to break into two fields dominated heavily by men – astronauts and theoretical physicists – though she does not dwell on it.
We think of gravity as only affecting heavenly bodies like the Sun, the Earth, and the Moon. Claudia de Rham demonstrates clearly in her book that gravity is everywhere, and gravity interacts with everything. She states flatly that electrons are attracted by gravity. Electrons are of course major components of any atom, but they are much smaller than the protons and neutrons that make up the nucleus of an atom. Here is a number that I recall from high school physics: A proton is 1,836 times the size of an electron in terms of mass. If gravity can affect something that minuscule, there is nothing beyond the reach of gravity.
Speaking of the Sun, the Earth, and the Moon, I have known about the “three-body problem” for many years. I had thought that the gravitational equations work fine for two bodies like the Earth and the Moon, but the addition of a third body quickly leads to a chaotic system, requiring approximations and assumptions.
As it turns out, it is not that simple for a “two-body problem” either. For a relatively simple system like two stars of comparable size orbiting each other – a common occurrence throughout the Universe – Claudia de Rham states: “In fact, Einstein‘s equations are not just difficult to solve – they are, in fact, impossible to solve exactly in all generality!” Even in that seemingly straightforward situation, approximations and simplifications are necessary to arrive at a meaningful answer.
What really made gravity come alive for me is a thought experiment that Claudia de Rham outlines: Imagine two astronauts are in outer space far away from any heavenly body having a large gravitational pull. If they are separated by one meter, or around three feet, Newton’s laws of gravitation indicate that they would initially move toward each other at about the speed of a garden snail. But the gravitational force increases quickly, varying with the shrinking distance between them, squared; and within four hours, the two astronauts would be close enough to embrace each other. Simply from the force of gravity between the two of them. I have never before heard an explanation about gravity like that, and I have been marveling about it ever since.