Tag Archives: quantum mechanics

Trespassing on Einstein’s Lawn by Amanda Gefter

This book is thought-provoking.

When she was fifteen, Amanda Gefter’s father, while out to dinner at their favorite Chinese restaurant, asked her “How would you define nothing?” Her father had been thinking about the nature of reality and he had come to the conclusion that it was nothing. Or better said, Nothing. This question led Amanda on a journey, both of personal development and to understand the true nature of reality. She delved deep into what physics said about reality. Along the way, in her mind masquerading as a journalist, she interviewed and discussed physics with leading physicists. She delved deep into what the cutting edge of science said about the nature of reality. And, along the way, she discovered her own voice, writing a book detailing her journey.

Gefter’s knowledge and insight about the nature of reality, and the excitement she conveys as she learns it, is simply inspiring. As she tries to uncover what physics says objective reality truly is, she slowly finds, step by step, that nothing is objective. Beginning with relativity that said that time and gravity are relative, and through quantum mechanics, that tells us that even measurements are relative, she examines what we know, what the gaps in our knowledge are, and what that uncompromisingly leads us to conclude about reality. There is no objective reality. Every observer essentially has their own reality, their own definition of the universe.

She jumps into how that means a universe could arise out of literally nothing. As no observer can know everything about the universe, as our views are limited and finite, it puts bounds on the information we can each collect. That bound essentially leads to the formation of the universe, a shadow that arises out of nothingness. I don’t completely understand it, and not sure I buy it all, but the steps by which she gets there are all based on what our science tells us.

In any case, her examination of the science itself is fascinating. I was unaware of what the most recent developments in cosmology, string theory, and quantum mechanics were concluding. Her excitement in discovery each new twist and turn is infectious. And, along the way, she gives great perspectives of the leading thinkers in this area.

This book is humbling.

Gefter has no formal science training. Her father, though a medical doctor, is not a physicist. But, these two delve so deep into questions regarding the nature of reality, it is simply humbling for someone like me who has studied physics. Granted, I went in a different direction, focusing on the properties of atoms and materials, but still, that these two have the curiosity, the drive, and the deep intuition to really delve into these questions is inspiring. I’m inspired to try to delve deeper into my own fields, beyond the every day drivers of doing practical science. We’ll see if I’m able to follow through.

The ideas that Gefter explores, that she describes, are hard concepts  and I admit that I struggle with many of them. Most of them arise from simply considerations, typically from seeming paradoxes where some assumption leads to contradictions about how reality must be. In each case, those assumptions must be abandoned and soon we are left with very few. The chain of reasoning and evidence that leads to the final picture is well described, but they ideas are challenging. To fully grasp them, I know I will need to read further.

This book is touching.

Gefter is set on her quest by her father’s question and his own ruminations on the nature of reality. She is both accompanied and followed by her father on this quest as she makes it her own. But, the way Gefter and her father conspire as this journey unfolds, the way they discuss their most recent insights, the way they work together to delve into these deepest of questions, is, in some sense, maybe what all parents dream of. Gefter’s father inspires his daughter to undertake the quest of a lifetime. And she takes it beyond what he could have ever done on his own. The deep intellectual relationship between the two, the shared vision, is something that I could only dream of passing along to my own daughter.

This book is awesome.

The way Gefter explores the nature of reality, the way she starts on her quest knowing literally nothing about the physics of cosmology, quantum mechanics, and relativity, and reaches into the deepest understanding we have, is a great way to convey what we know about reality. She systematically crosses off elements of what might comprise reality and delves deeper and deeper into the seeming paradoxes that arise as our science progresses. I certainly learned a great deal, and the ideas presented are thought provoking in a way that is rare in such books. As opposed to other books on cosmology and string theory, this one doesn’t necessarily take a side or advocate for a certain perspective. Instead, Gefter is really trying to understand what we know and what science tells us about reality. And, in doing so, she produces one of the most entertaining and educational forays into modern physics I’ve had the pleasure of reading.

The ideas that arise from modern physics are mind bending. They push the limits of our ability to understand the world around us. They are beyond our wildest imagination. Science is often criticized for its lack of creativity, but modern physics has created a view of the world and reality that could never have simply been imagined, never dreamed up.

Genius: The Life and Science of Richard Feynman by James Gleick

These days, celebrities come in the form of musicians, actors, sometimes politicians, and athletes. They draw lots of attention and, in many cases, lots of money. They impact our lives, creating the music and films we listen to and watch, the sporting feats that entertain us, and, in particular, the policies that govern our lives. However, conspicuously missing in this list are scientists. Arguably, scientists make more profound and lasting changes that have greater impact on our lives, providing the fundamental discoveries and insights that become the technologies that transform our world, our way of work, and even how we are entertained. But, they don’t become celebreties. They are not widely recognized in society. Most of us would be hard pressed to name more than a few scientists, and most of them are known more for their advocacy than their actual science. Think Neil deGrasse Tyson. Or Stephen Hawking. How many more can most of us think of?

Maybe one of the last great scientists that also captivated the imagination of society as a whole was Richard Feynman. Even so, I didn’t know about him as a kid, even as I got into science and was going down a path that ultimately led to a career in science. In my case, I think my first exposure was Feynman’s role on the panel investigating the destruction of the Challenger space shuttle. But, even then, I didn’t know anything about his science.

It wasn’t until later, when I actually began studying physics in earnest, that I started learning something about Feynman’s science and life. That was through his two semi-autobiographical books: Surely You’re Joking, Mr. Feynman! and What Do You Care What Other People Think?. These are more anecdotes of his life rather than detailed accounts of his science, and as such they contributed greatly to his celebrity. He was one of the most respected scientists in the world, but he was also a character, a man full of life, full of stories that let people see a side that wasn’t just the science, a side they could relate to.

I admit that I still don’t know much about Feynman’s science. I went a different direction in physics and his work always felt over my head. I did take one of the volumes of his Lectures on Physics with me when I lived in Spain for a year, hoping to delve more deeply into my studies, but I got distracted by the bar scene in San Sebastian. Of course, I encountered Feynman again in graduate school, but only briefly as my own studies agin took me in a different path.

That said, reading James Gleick’s biography of Feynman, Genius, let me “connect” with the mystique and science of Feynman in a way I hadn’t done before. Gleick intermixes Feynman’s personal life with the scientific advances he was making, including describing the struggles that any scientist encounters to some degree when they are embarking on pushing the frontiers of what is known. At times, Feynman struggled to find a topic that inspired him and, at others, struggled to push that science forward at the pace he really wanted to. At least later in life, Feynman had the luxury, due to his past success, to take his time to work at his pace and on problems of profound interest to him. He didn’t have to worry about the modern “publish or perish” paradigm that stifles so many. It makes me wonder how Feynman would have done in today’s environment.

Gleick does describe many of the profound contributions Feynman made to science, though admittedly they still go over my head. I would hope that if I had the time to devote to understanding his work, I might be able to, but the way Gleick describes how Feynman was able to make his leaps of insight and how he saw the fundamental nature of the universe, one can’t help but feel that Feynman was simply one of those people who truly is a genius, someone who’s mind works in either a different or faster way that allows him to see things others simply cannot see.

Even for a non-scientist, I think this biography would be an excellent read, one that conveys the excitement of scientific discovery as well as the hard work that is involved. It also captures that spark that we are all born with and we all have as kids — that spark that causes us to ask questions about the world around us, that spark that many of us seem to loose as we grow older. Gleick captures that spark in Feynman and the fact that he never lost it, he never stopped asking those questions.

Feynman also challenged those around him. He would ask provocative questions, such as If all scientific knowledge were lost in a cataclysm, what single statement would preserve the most information for the next generation of creatures? Feynman’s answer to this question was: “All things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.” It is essentially these interactions that form the foundation of my own research, how atoms interact to form materials and how those materials respond when the atoms are disrupted.

The celebrity of Feynman, and of scientists like him, has seemingly diminished. Gleick gives two reasons for this. First, there has been some disillusionment with science since the heyday after World War II, with the advent of nuclear weapons and our ability to essentially self-distruct. Further, the answers science provides in areas such as biology seem less black and white than they used to be, with the recommendations changing with each generation of scientists. This is in part because biology is that much harder than particle physics. Second, with more wide spread access to education and more people becoming scientists, fewer people stand out. As Gleick says, “When there are a dozen Babe Ruths, there are none.”

This book is a fascinating tour of both science in one of its most exciting and dynamic times, when quantum mechanics was being discovered and fleshed out, as well as one of the leading physicists of the time. His personal life was certainly as interesting as his science. A leading scientist at Los Alamos during the development of the first atomic bomb, his sick wife resided in nearby Albuquerque, suffering from tuberculosis, and dying at a very young age. This left Feynman personally adrift, particularly in his relationships with women, even while he contiuned to produce some of the most revolutionary science. All scientists are, at least so far, human, and have their own personal struggles. How these humans develop science is one of the fascinating aspects of this book. The insight into the creative process, the way science progresses, is a story everyone can appreciate. One of Feynman’s insights that resonates with me is that science is a deeply creative endeavor, but, “scientific creativity is imagination in a straightjacket.” As opposed to art, in science “whatever we are allowed to imagine… must be consistent with everything else we know.”

As Feynman described it, science is not an absolute. “The scientist has a lot of experience with ignorance and doubt and uncertainty… we take it for granted that it is perfectly consistent to be unsure — that it is possible to live and not know. But I don’t know whether everyone realizes that this is true.” He contrasted this doubt with the certainty that is often characteristic of religious beliefs. Science doesn’t provide certainty, it provides a framework in which to interrogate the nature of the universe.

In the end, this is a great book about a fascinating man and his remarkable contributions to science. Getting a glimpse of how a very human person who also had one of the greatest scientific minds approached his work and found his way to these great insights is both fascinating and humbling. It certainly wants me to learn more about other great scientists.

 

The Grand Design by Stephen Hawking and Leonard Mlodinow

These are questions as old as humanity itself: why are we here?  where did everything come from? what does it all mean?

Humanity has tried to answer these questions in a multitude of ways.  It is, in my opinion, the reason religion started, as one way to answer these questions.  One way, with a nearly never-ending variety of answers.  Philosophers had been the standard bearers of more systematic approaches to understanding and answering these questions, but also with a vast variety of results.  Relatively recently, science has also weighed in.  As science evolves, the insights into these fundamental questions also change, from the clock-work determinism of Newtonian mechanics to the relativistic view of Einstein’s universe to the inherent randomness associated with the Copenhagen interpretation of quantum mechanics.

The Grand Design, by Stephen Hawking and Leonard Mlodinow, is the latest attempt to use modern physics to try to answer some of these questions.  Regardless of what you might think about the authors or their basic premise, the book is both very easy reading and gives some interesting perspective into what modern physics “means”.  I put means in quotes because there are two very different camps about finding meaning in modern physics and, in particular, quantum mechanics and its brethren quantum field theory and quantum chromodynamics.  One view is that the math that underlies these theories is just that, math, and should not be interpreted any more deeply than that.  The words we give different constructs in that math, such as “path” or “particle”, are the consequence of our trying to impose familiar concepts onto physics that are entirely outside our ability to make direct connections to.  The other view is that one can take a more literal interpretation and see where it takes us.  That is the view of Hawking and Mlodinow.

The strangeness of quantum mechanics can be summarized in one simple experiment, the double slit experiment.  As the name implies, the experiment involves a board or paper or some obstacle in which two slits have been cut.  If you imagine throwing particles at it, each particle goes through one or the other slit and the pattern that appears on the detector on the other side consists of two groups where the particles hit the detector.  Imagine throwing tomatoes at the slits.  On the other side, you’d get two stains corresponding to the two slits.  However, when you throw quantum particles at the slits, you get a much more complex pattern, an interference pattern, a pattern that is associated not with particles but with waves.  If a wave passes through the two slits, such as a wave in water, it will go through both at the same time, interfere with itself, and create an interference pattern that consists not of two groups of “stains” on the detector, but many at a given interval.  The amazing thing about quantum mechanics is that you get this interference pattern even if you throw one particle at a time.  What is the particle interfering with?  Itself.

One way to formulate quantum mechanics, developed by Richard Feynman, is that the particle, an electron perhaps, takes all paths from where it starts to where it ends.  That is, you have to integrate over all possible paths.  This is the mathematical construction and is where Hawking and Mlodinow take the next step.  They interpret Feynman’s “path integral” formulation of quantum mechanics as saying that the electron did take all possible paths.  However, in any given universe, clearly it only took one, so there are other universes where the electron took a different path.  This is the so-called Many Worlds Interpretation of quantum mechanics.  In the Copenhagen interpretation, the electron only did one thing, but that thing was random.  In the Many Worlds interpretation, the electron did all things, but in different universes.  Further, Hawking and Mlodinow take the additional step in saying that Feynman’s path integral formulation says that the electron we see could have had one of many histories, so that history is also an indefinite thing.

I have to say that I don’t understand everything they are claiming.  I’ve had a few courses in quantum mechanics, but they were certainly more focused on calculating things than interpretation.  So, here, as in a few other spots, I don’t follow everything they say.

But, if you then apply this interpretation to the universe as a whole, you end up with the conclusion that there are an infinite number of universes and each has its own physics in the sense that the basic physical constants of each universe are a bit different.  We happen to be in one that has the right constants for life to exist.  This is a variant of the weak anthropic principle, which says that the world we live on is one of billions that just happened to have the right conditions.  That there are such planets is not surprising, given the shear number of them.  Applied to the whole universe, this is harder to suggest.  If there is only one universe, it had to be just right, but there were no other random choices, so its a much tighter constraint, called the strong anthropic principle.  However, if you have an infinite number of universes, each with its own constants, then we again are just in the one that of course supports life.  The others don’t.  The strong anthropic principle again becomes weak.

They make further claims, such that at the beginning of the universe, time as a concept breaks down (in the four-dimensional space-time of relativity, time becomes more space like in those first few moments) and there is no beginning.  They suggest it is the same as asking what is south of the South Pole.  Well, nothing, the question is meaningless.  To them, what occurred before the universe was created is the same meaningless question.  This line of reasoning also suggests to them that there is no need to invoke a God as creator of the universe.  The universe comes about naturally as a consequence of the laws of physics.

I don’t feel like I’m giving the book nor Hawking and Mlodinow’s ideas justice.  The book is certainly very interesting with a lot of deep concepts that will take a few readings to absorb more fully.  However, the ideas are presented in a rather logical and straightforward way that I found compelling.  I thought they did a good job of presenting their reasoning.  Along the way, I also learned quite a bit about modern physics that I hadn’t appreciated.

The only complaint I have is that the book is sprinkled with “jokes”, phrases that are meant to be amusing or to connect with the lay reader, but to me they were just jarring and out of place.  I think the book would read much better without those phrases.

Overall, while the book has generated its share of controversy, I would recommend it to anyone interested in these big questions.  You may not agree with them (some reactions, positive and negative, are here), but it will give you a different perspective on what these questions mean and one view towards understanding the universe around us.