Why Does E=mc2? is in some ways a simple book with a simple aim: we (Jeff Forshaw and myself) wanted to see whether we could actually derive E=mc2 in a way that any interested non-mathematical reader could understand. By derive, I mean follow a series of small steps that are well-motivated and hopefully obvious, or at least plausible, and arrive at the equation itself, assuming no prior knowledge and making the minimum possible number of assumptions. In other words, we behave exactly as we would in our professional life as research scientists, searching for equations that describe nature.
In doing this, we hope to do much more than simply present and describe the equation, however. If the reader follows the argument, we hope that he or she will experience the delight and awe that scientists feel when they explore nature and reveal its underlying simplicity and beauty. One often hears scientists describe equations as "beautiful," and we believe the best way to understand what this means is to actually see how the most iconic and simple equation of all came to be written down. We don't in fact follow Einstein's route to E=mc2, because we believe that 100 years of teaching and understanding has provided a more profound and transparent route to it — we aren't writing a history book.
There is an element of polemic in the book. We very firmly believe that science, which is synonymous with rational thought as far as we are concerned, is the route to a better future. Woolly thinking and superstition are rife, and we should strive to reduce their place in public discourse. By showing how something as useful and, as far as we can tell, correct, as E=mc2 emerges from simple thought processes that we believe are open to every interested reader, we hope to make our case for an increased respect for and use of the scientific method in everyday life.
We also describe what E, m, and c actually are. Why is the speed of light special? What is energy, and what is mass? The question of mass leads us to the Large Hadron Collider at CERN, where we both work. One of the key goals of this machine is to answer this question definitively for the first time. It is remarkable that Einstein could be led to the equation that describes how mass and energy can be interchanged freely, without actually knowing what mass is. Such is the wonder of physics!
What inspires you to sit down and write?
My wife asked me the question, "What has the speed of light got to do with energy and mass?" It's a very good question, and after chatting with Jeff for a while, we decided that we would explain this properly in a book that could be understood by anyone who had an interest!
I would like to twist the answer slightly and say Carl Sagan. I watched Cosmos as an impressionable 12-year-old and knew immediately that I wanted to be a scientist. Science in Sagan's hands is so much more than just useful. It is poetic, beautiful, and moving, and I really hope we have managed to capture some of his enthusiasm in our book. I was absolutely delighted when Anne Druyan, the co-writer of Cosmos, wrote a few lines for the jacket. If we can get anywhere near conveying the wonder of science as Carl Sagan did, we will have succeeded.
Chess or video games?
Chess. Although I do like playing FIFA soccer on the PS3.
What do you do for relaxation?
I had a little baby boy recently, and I find that spending time with him stops me from thinking about physics, books, or anything else, in a delightfully relaxing way!
What was your favorite book as a kid?
When I was very small (five years old) I had a book of cards I collected from packets of tea. It was called "The Race into Space" and described the wonderful things we had done in space in the '50s and '60s, and the great missions to come. Some of those, like Voyager and the Space Shuttle, became a reality. Others, like manned missions to Mars by 1990, sadly didn't. It's a wonderful book because it captures the immediate post-Apollo optimism when anything must have seemed possible. I think, as a civilization, we have been immeasurably diminished as that spirit has ebbed away, and I want to see it return.
What new technology do you think may actually have the potential for making people's lives better?
The enabler for all of our technology is energy. We need electricity to do pretty much everything that makes a real difference, from medical treatment to communication. So I would say that clean energy generation is the Rosetta Stone that will unlock the potential of our civilization and allow it to grow and make everyone's life better. In the medium to long term, that must be nuclear fusion. The question is, when will we be bothered to invest in it?
If you could be reincarnated for one day to live the life of any scientist or writer, who would you choose and why?
Good question! I think Tycho Brahe would be fun. He had a copper nose after losing his real one in a duel, and liked a drink, as well as making astonishingly valuable contributions to early astronomy. What more could one ask?
What was your best subject in high school? Your worst?
Physics was best. French was by far the worst.
What are some of the things you'd like your computer to do that it cannot now do?
Make coffee in the morning.
By the end of your life, where do you think humankind will be in terms of new science and technological advancement?
We can be on Mars, have unlimited energy supplies for every citizen, and banish superstition to the trash can of history. The trick is to choose to do these things!
Which country do you believe currently leads the world in science and technology? In ten years?
The U.S. certainly leads at the moment, by any measure. The frustrating thing for a Brit is that we could choose to overtake the U.S. if we wanted. Our government spends around 0.25% of GDP on scientific R&D at the moment. If we increased that to anywhere near 0.5%, we would overtake you, and the UK would be the best place in the world to do science. That we choose not to bother is one of the great frustrations of my political life!
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Brian Cox is a professor of particle physicist and Royal Society University Research Fellow at the University of Manchester. He divides his time between Manchester in the UK and the CERN laboratory in Geneva, where he heads an international project to upgrade the giant ATLAS and CMS detectors at the Large Hadron Collider. He has received many awards for his work promoting science, including being elected an International Fellow of the Explorers Club in 2002, an organization whose members include Neil Armstrong and Chuck Yeager. He is also a popular presenter on TV and radio, with credits which including a six-part series on Einstein for BBC Radio 4, 3 BBC Horizon programs on Gravity, Time and Nuclear Fusion, and a BBC4 documentary about the LHC at CERN, "The Big Bang Machine." He was the Science Advisor on Danny Boyle's movie, the science-fiction thriller Sunshine. Brian also has an unorthodox background in the music business, having toured the world with various bands and played keyboard with D:REAM, who had several UK Top 10 hits including "Things Can Only Get Better" (re-released and used as Tony Blair's election anthem back in 1997).
Books mentioned in this post
Brian Cox is the author of Why Does E=mc2?: And Why Should We Care?