I confess no special interest in relativity or physics, nor even dogs. And then I opened the book to find that the dog’s name is Emmy – the same name as that fascist little spaniel at Pearson airport ... “What did you find Emmy? Huh? What did you find? Oh, good girl.” I can hear it yet. I am also not a regular science fiction reader so neither did the book attract me as a source of concepts for other mind-bending reading.

Why then did I feel compelled to read it? Perhaps it’s partly that we live in the orbit of the Perimeter Institute, with Stephen Hawking showing up now and then and with various educational programs filtering through to our consciousness regularly. I took every kid I knew to their Einstein-fest. And besides, physicists turn out to be good fun at parties, what with talk of fecund universes, loop quantum gravity, and great rants on how string theory is sucking resources, the way sexy new things do until they settle back into a more realistic framework that leaves room for following up on yet other theories, which, I now know, is where loop quantum gravity comes in.  

Mostly though it was a feeling of obligation to keep up with at least the biggest developments going on around us, things that alter the way we look at our world – and ourselves. Kids learn about cloud computing in an instant if it means they can have access to music and videos everywhere they go and on all their devices. But will it motivate them to look to the clouds for other things? And since I was going to be travelling, I thought it might be an opportunity to tackle something outside my comfort zone. 

How to Teach Relativity to Your Dog turns out not to be intimidating at all. What first hits me about the Introduction and Chapter One is how quickly I can read them. So far, so good. I can even imagine reading this aloud to a kid. Orzel provides a clear framework, reminding us regularly what the highlights of the story are – and it is indeed an interesting story – and how they fit together.

Although Einstein is most often associated with the “discovery” of relativity, Orzel gives enough background to make it clear that invention is a social act, with the actions of many others creating the environment for Einstein’s work. This in itself is an important contribution to our understanding of how the world works.

The idea of relativity was probably introduced by Galileo Galilei (1632) who provided the first major challenge to Aristotle’s view of gravity by showing that all objects fall at the same rate, regardless of their weight. This was demonstrated more recently on the Apollo 15 mission when commander Dave Scott dropped a hammer and a feather to show that with less gravity and hence less air resistance, everything falls at the same rate regardless of mass.

It seems fitting to read this book, sitting on the edge of Campo de’ Fiori in Rome. Even in the warm spring sun, surrounded by mountains of fresh produce and buckets of flowers, with a glass of Barbaresco in the other hand, it’s sobering to gaze on the statue of Giordano Bruno who was burned to death here in 1600. It’s a bit too simple to say that his crime was positing that other stars were like our sun, and that they could each support planets teeming with life. That was probably just the proverbial straw. But he did advance the views of Copernicus (Polish: 1473-1543) and others who said the earth revolved around the sun. There is evidence that this was being said as early as the third Century BCE, but Aristotle (384-322 BCE)–who made his own significant contributions in the century before–was adopted where it suited by the growing Christian church. The threat this heliocentric proposal provided to their views meant that advances in this area stagnated for over 1800 years.

My train of thought helps me decide where I will wander next: the Basilica di Santa Maria sopra Minerva. Not only is it Rome’s only Gothic church, containing Michaelangelo’s marble sculpture (1521), the Risen Christ – so accessible you could touch it if you were so inclined and rarely is anyone around to watch you do it – it’s also where Galileo Galilei’s Inquisition trial was held. I imagine him here, in front of this statue, recanting so as not to share Bruno’s fate of three decades previous. Of course, Galileo would have stood in front of the unaltered statue. Right now it is in one of its “bronze loin cloth” modes. Not Michaelangelo’s idea, the loin cloth goes off and comes back on, as one art critic points out, depending on the health or insecurity, respectively, of Christianity. I mutter a little "Eppur si muove" (And yet it moves.) to myself, helping to keep alive the legend that this is what Galileo uttered as he left the trial. Imagine what he would have thought if anyone predicted that a spacecraft would be named after him and launched in 1989 to study Jupiter and its moons. Amazingly, it took yet 3 more years before the Vatican formally apologised to him. Bruno is still waiting for his.

Even Galileo was improving on the work of others before him, specifically on the "Dutch perspective glass” he had learned about a few years earlier. He is credited with the invention of the telescope but really it was more that his version, with its significant increase in magnification, was first to be given the name of “telescope” (1611). Newton (1642-1727)–the first to establish physics as a mathematical science, setting out three laws of motion that govern the behaviour of moving objects and form the core of classical physics–summed up the culture of his time by rephrasing a saying that had been around for centuries: “If I have seen a little further it is by standing on the shoulders of Giants.” Orzel’s story makes it clear that this culture remains in place, so no matter how much we like to tell stories of heros, no one person works alone to make his or her discoveries.

That said, it’s not surprising that when asked to name a scientist, Albert Einstein’s (1879-1955) name comes up most often. (Although Orzel refers to the sad state of affairs shown by a US poll: asked to name a scientist, 23% couldn’t; asked to name a living scientist, 66% couldn’t.) Einstein clearly built on the work of others, but as Orzel’s story of relativity unfolds, it becomes clear that what Einstein did with the information around him is truly remarkable.

One of the ways Einstein improved on Galileo was by challenging the notion that there’s a single, universal time that all observers agree on. It gets even more fascinating at the next step in the story since, perhaps, the most dramatic consequence of relativity is the merging of time and space, something Orzel calls the key to Einstein’s greatest triumph, namely, the theory of general relativity.

It’s hardly possible to simplify the distinction between special and general relativity more than Orzel already has, especially when one is not a physicist. However, as a starting point, let me just say:

• while Newtonian physics does incorporate the principle of relativity of motion, as introduced by Galileo (in other words, rather than saying that something could be stationary or it could move over time, this new advancement posited that all you can say is that you are moving relative to some other object), Einstein extended it from motion to all physics, including light and electromagnetism.

• among other things, Einstein was building on the Michaelson-Morely experiment of the 1880s, often called the most famous failed experiment because Albert Michaelson, assisted by Edward Morley, was unable to detect any difference in the speed of light caused by the motion of the earth through space. It’s a colourful section in the book as Orzel has us imagining them with their gizmo, its 11-metre arms mounted on a two-tonne granite block, floating on a vat of mercury (!) to minimise any vibrations, adjusting it by the width of a hair, literally, at different times of day and throughout the year–and finding nothing. But at least they had the satisfaction of seeing their work acknowledged as fundamental: Michaelson received a Nobel prize (1907). In fact, the gizmo (an interferometer) is still being used: now its arms are 2.5 km long, looking for gravitational waves.

• in 1905, while he was a 26-year-old patent clerk (unable to find a teaching post), Einstein published four revolutionary papers, kicking off the fields of quantum mechanics, atomic theory of matter, and special relativity. It’s called “special” because it deals only with the special case of observers moving at a constant speed.

• Emmy Noether, in 1915, (having just spent 7 years working at a Mathematical Institute without pay because women were not accepted into academic positions) developed the theorem that provided a general framework tying conservation laws to symmetries.

• Einstein again advanced the work that came before him. The symmetry he uses to bring together, convincingly, space and time – adding a forth coordinate to describe an event in a new geometry he called spacetime – is the relativity of inertial observers.

• Einstein, in 1916, published his general theory of relativity covering all possible moving observers and bringing in the effect of gravity, thereby extending the four dimensional spacetime concepts to a curved spacetime. This is considered a monumental accomplishment, one that was followed by others of equal importance, including his paper on the photoelectric effect, for which he was awarded the 1921 Nobel Prize (received it in 1922, actually, but it was the 1921 prize). Orzel devotes a chapter to discussing how general relativity “not only provides exquisitely detailed predictions of current physics phenomena but also provides the framework for describing the origin, evolution, and eventual fate of the entire universe.”

At this point you deserve Orzel’s lucidity and often dramatic examples (why atomic clocks are so accurate; why moving clocks run slow; how GPS works; when parallel lines can actually meet; when the shortest distance between two points isn’t a straight line...etc.). I think you will agree that Orzel’s clear writing, both about the science itself and the political/social contexts in which it developed, is grounds for awe and wonder. For example, it’s amazing to think that these revolutionary developments in physics were primarily published in German (English journals didn’t take over until after WWII) while two world wars were being fought (Karl Schwarzchild offered up the first mathematical description of a black hole while fighting on the Eastern front in WWI), and that great thinkers like the Jewish Einstein and Noether, among others, had to flee to the U.S. after Hilter’s rise to power (1933).

With all this going on, it’s easy to see why the late 19thC was such a heady time. Orzel points out that many physicists believed they were on the verge of a complete description of the universe. But, really, physics was on the verge of two major crises, each requiring a revolutionary new theory to resolve the problem: 1) the nature of matter led to the development of quantum mechanics and 2) the nature of space and time led to the theory of relativity and the subject of this book.

If you are looking for ways to entice the young people around you into interesting conversations, you could do worse than give the book as a gift and introduce it with a few interesting examples. Together, you could even watch the YouTube video of Dave Scott dropping the feather and the hammer. The history of discovery abounds with invention as a social act. And while most of us “little Smatterers in Mathematicks ” are unlikely to do anything remarkable with these ideas, maybe we can at least help influence the brilliant young minds around us to delve into them. After that, there is no telling what might happen.