Out of scores of books on the origins and machinations of the universe, it’s rare to find one that offers something new. But kudos to Ersilia Vaudo, the author of her newly translated book: “The Story of Astrophysics in Five Revolutions.”
Replete with dozens of ‘inside baseball’-type revelations about the history of astronomy and astrophysics, the Italian, Paris-based author and astronomy communicator and her translator Vanessa Di Stefano have put together a book that is in parts both breezy and profound.
Made up of five long chapters, “The Story of Astrophysics” details different revolutionary aspects of humankind’s understanding of cosmic history. Here are a tiny few of the book’s more interesting tidbits.
The Question Of The Speed Of Light
In a 1638 experiment, Galilei Galileo used two lanterns covered by dark cloths placed on two small hills about a mile apart. Galileo uncovered his lantern first and when a student about a mile away saw the light from Galileo’s lantern, he reciprocated. But the time elapsed between the two events was much too short for Galileo to calculate.
Yet Sir Isaac Newton made great progress in our understanding of light speed by successfully calculating the time it takes for light to travel from the Sun to Earth. As noted in his 1704 “Opticks” treatise, Newton found a value of between 7 and 8 minutes which is incredibly close to the actual value of 8 minutes and 20 seconds.
A century and a half later, Vaudo notes, the speed of light, c, makes its appearance in the late 19th equations formulated by Scottish physicist and mathematician James Clerk Maxwell.
Maxwell used his math to describe the propagation of electromagnetic waves which travel at the same speed as light, Vaudo notes. This suggested that light is a form of electromagnetic radiation, a theoretical conclusion later confirmed by German physicist Heinrich Hertz, she writes.
We now know that light in a vacuum travels at the incredible constant speed of 299,792,458 meters per second.
Understanding that light has a finite speed and linking it to the larger realm of electromagnetism helped secure the spacetime distance scale that is a foundation of contemporary cosmology. Accessing the full electromagnetic spectrum for observations also gave astronomers a multifaceted observational window onto the universe.
That’s because almost everything cosmologists know about the universe comes from observations of electromagnetic radiation in the form of visible light, as well as wavelengths that run the gamut — from the far infrared to the highest energy gamma rays.
Beyond The Electromagnetic Spectrum
Lately, however, astronomers are even searching for and detecting high-energy cosmic ray particles, neutrino particles, and gravitational radiation — none of which are part of the electromagnetic spectrum. Who can say what new methods of observing the cosmos might exist in the medium and far future?
But we wouldn’t be here at all if not for a seeming fluke of nature that allowed matter to persist in a way that antimatter never could.
What’s The Deal With Antimatter?
In the beginning, the Universe was very dense and hot, and particles of matter and antimatter interacted, annihilating each other, notes Vaudo. But there was an imbalance allowing one of the two to survive, even though today, this tiny imbalance is not enough to explain the structure of the cosmos, she writes.
And the ultimate cause of this imbalance is still not understood.
Could There Be Antigalaxies?
If there were “antigalaxies, we would see bright flashes in the sky due to the mutual annihilation between matter and antimatter but, thus far, that has never been observed, Vaudo notes.
Small amounts of antimatter are also produced by lightning during a thunderstorm but they are almost instantly annihilated by matter, Vaudo notes. Even so, she writes that one day it may be possible to use annihilating antiprotons to destroy cancerous tumors.
But until then the cosmos is appreciated for its scientific and philosophical value.
An Artistic Case In Point
Painted in Rome in 1609, Adam Elsheimer’s “The Flight into Egypt” depicts a nighttime sky which highlights three sources of light. As Vaudo notes, they include Joseph walking with a torch in hand behind Mary and the Child on a donkey; a flickering fire around which some shepherds are warming themselves; and the reflection of a full Moon on a still lake.
But above all, there’s a beautiful, star-filled nighttime sky which, for the first time in the history of art, the Milky Way appears in a painting, depicted with remarkable accuracy, Vaudo notes. The author speculates that Elsheimer must have scrutinized the scattered positions of the stars a thousand times to achieve such precision.
Only a hundred years ago, we still believed that the Milky Way was the whole Universe, Vaudo writes. In less than a century, we have understood that our universe is undergoing an accelerating expansion and is neither immutable nor eternal, she notes. Galaxies will gradually become more and more distant from each other and in billions of years’ time, even with the most powerful telescopes, we will not be able to see anything but darkness beyond our Milky Way, she writes.
But that remains beyond anyone’s imagining.
The Bottom Line?
The book is a compelling primer on the history of almost everything we know about astrophysics and why it’s relevant to our existence. As the author notes in closing: French mathematician and philosopher Blaise Pascal sums up a powerful feeling triggered by looking up at the skies: “The eternal silence of these infinite spaces terrifies me.”
Indeed, a clear night-sky is uniquely humbling; that’s just a small part of the inherent attraction and ultimate mystery that is our cosmos.