Violating General Relativity

Physics today is hard and incredibly head-spinningly confusing. That does not mean, however, that it cannot still be fun and presented in a way that makes us think deeply about the nature of the universe while still enjoying the science of how our universe exists and behaves. Amanda Gefter did not set out to be a science journalist, but she parachuted into a career as a science journalist and has a real skill for combining difficult scientific principles and relatable, real life jokes, puns, situations, and experiences. In doing so, Gefter is able to make physics and science engaging, which is a real and important skill for scientists, technocrats, and skilled professionals to develop. Learning to be engaging, even with the boring and the difficult, is what our society needs in order to convey the importance of the dull and often times drudgery of difficult thought work.

 

And that brings me to Gefter’s writing about General Relativity, the scientific principle laid out by Einstein that has been reinforced by recent discoveries such as gravitational wave experiments. In our universe, there are certain things we can’t measure simultaneously. We can know one item with certainty but in making a measurement or observation we suddenly are unable to identify or know another related aspect with certainty. Tied together in this type of relationship are time and total universal energy. We seem to be able to potentially measure one or the other, and we must eliminate one when trying to make predictions or models of the universe based on an understanding of the other. Describing this relationship, Gefter writes:

 

“When you think about it, it ought to have been obvious from the start that there’s no possible way to have both general covariance and a universe that evolves in time—the two ideas are mutually exclusive, because for the universe as a whole to evolve in time, it must be evolving relative to a frame of reference that is outside the universe. That frame is now a preferred frame, and you’ve violated general relativity. It’s one or the other—you can’t have an evolving universe and eat it, too.”

 

There are two things I want to pick out of the quote above. I am not scientifically literate (within the physics world) to fully pull apart the ideas about general relativity, general covariance, and how the universe changes in time, but I do understand Gefter’s point about a preferred reference frame. Relativity tells us that the universe is observer dependent, meaning that how you observe the universe shapes the reality that you experience. The experiments you do, what you can see, feel, measure, and interact with has an impact on the physics of the universe around you. This does not seem to apply only to conscious observers, but other types of observers such as stars emitting light rays, giant space rocks traveling to our solar system from other solar systems, and even quantum particles popping in and out of existence along the horizon line of a black hole. Everything in the universe is in the universe and therefore every action impacts the universe. We are never perfectly outside the universe in a true world or perfect perspective from which we can point back and say “that, right there, is the universe as it actually truly exists.”

 

Second, physics does not have to be all technical and serious. In complex writing we often want to display how smart we are and how well we understand the subject by using the language and writing style of smart academics. A recent podcast from the Naked Scientists highlighted work from researchers that show that journal articles are getting harder to read, and that means science is becoming less accessible. However, if you put the ego aside you can write about science without having the need to prove to others that you are smart and can write in complex styles. In the quote above Gefter manages this, and even includes a fun variation on a popular idiom. Finding ways to do this in science is important because it shows others that you can be a real human being and an ordinary person and still be interested enough to learn a little about cutting edge science.
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Spacetime as a Wave Function

Amanda Gefter dives into complex physics in her book Trespassing on Einstein’s Lawn, and helps us better understand the challenges of modern physics research today. When we look out into space we see stars and planets and if we look really closely with telescopes we see asteroids, galaxies, and lots of dust floating through space. What physics tells us exists within the empty space between those objects (and indeed within all space) is spacetime. Spacetime is a thing. It bends and is warped by matter and it can ripple through the universe and change the physical matter that we can see and feel.

 

Gefter describes our complex understanding of spacetime as a wave function, describing probabilities of our observations. She writes, “When it comes to spacetime, though, there’s no such thing as spacetime at an instant, because spacetime contains all instants. And you can’t have spacetime evolve in time, because it is time. The only way forward seemed to be this: break four-dimensional spacetime into three dimensions of space and one of time, then describe the spatial portion as a wave function that can evolve relative to the dimension you called ‘time’.”

 

Gefter’s quote is how we as humans experience spacetime. We do not experience all instances of space and time at one exact moment, but instead we experience space and our movement through space over time. Here on earth, where things operate on scales that seem constant and continuous to us, this works. But once we start operating on different scales in different parts of the universe with different masses, different speeds, and different energies, the experience of three dimensional space and one dimensional time break down. Gefter continues:

 

“Different observers can slice up spacetime in different ways. So when we decide to quantize only the three dimensions of space, we have to choose certain coordinates to call ‘space’ and others to call ‘time.’ But whose space? Whose time? Making any kind of choice would suggest that one observer had a truer view of reality than all others. But that can’t be so. That was Einstein’s whole point: the laws of physics must be the same for everyone.”

 

What is so concrete and clear in our world and in our experiences as human beings falls apart on scales beyond those that we can observe unaided with our senses. The universe is more complex and more challenging than we often imagine, and the priors that we bring to conversations, thoughts, and observations impact the way we come to understand the universe. There is no absolute time from which we can measure the universe, because as soon as we set a specific reference clock, physics breaks down for another observer somewhere else in the universe at a different scale of mass and energy. Similarly, there is no clock sitting outside the universe ticking away the lifetime of the universe as a whole. Spacetime is relative according to Einstein, and while we may be able to break spacetime into a wave function that predicts probabilities of space throughout time, we have to understand that the way we break space and time apart is specific to our observation and that both space and time change for other observers who separate spacetime differently from ourselves.

 

But why is any of this important? With physics and a deeper understanding we can begin to see that we are not outside the universe and our observations are not at the center of the universe. We are matter arranged in a way that allows us to observe other matter. Our perspectives and views are incomplete and the observations and perspectives we adopt shape the reality we can measure. There is a parallel between physical science and social science in this way. We may not realize it but our brains turn us all into social scientists, walking around with a megacomputer carefully recording observations of human behavior and reality, analyzing patterns, and crunching data to help us understand our position. If we assume that our observations and our reference frame is the one absolute and correct frame, then we miss the fact that the reality we live in is relative to where and when we make observations and how we have chosen to separate different points and parts of that reality. Perhaps not everything in the social sciences is completely relative since we do live in a constrained world, but we should recognize that there are not any absolutes living outside of our universe measuring us or anything else from the outside.

What Reality Ought To Be

The universe is filled with paradoxes, but often times those paradoxes seem to be the result of how our brains and thinking work. Amanda Gefter addresses this in her book, Trespassing on Einstein’s Lawn. In the book Gefter describes how she found her way to a career as a science journalist, something she never set out to do directly, and at many points never believed would be possible for her. Her descriptions of science and physics are as much a description about the progression of human life that we all share, and it is a perfect opportunity to reflect on paradoxes within our personal lives and within areas like science.

 

Gefter describes the challenges of quantum mechanics and the reality that we can measure some parts of the universe one way, but get a different result if we measure them a different way or at a different time. Also, with quantum particles, we seem to be a able to measure with incredible precision a particle’s position or its momentum, but not both. We can accurately look at where a particle is, but in doing so we can’t describe where it is going. Alternatively, we can look at where a particle is going and how it is moving through space, but we can’t actually then pinpoint where in space it is. This measurement paradox is challenging and creates a lot of problems and further questions for scientists. Describing the way we are challenged by measurements and observations and our inability to separate ourselves from the measurements and observations we make, Gefter writes the following:

 

“There’s no normal reality lurking behind the quantum scene, no objective Einsteinian world that sits idly by regardless of who’s looking. There’s just the stuff we measure. The whole thing reeked of paradox, but as Feynman said, ‘The ‘paradox’ is only a conflict between reality and your feeling of what reality ‘ought to be.’”

 

I think this idea extends well beyond physics throughout our lives. A paradox is something that sounds like it would be correct and obvious, but leads to a conclusion or reality that could not possibly exist. Paradoxes are contradictions that break our expectations and are outcomes that run counter to our intentions. With this framework, we can begin to see that Feynman’s description of paradoxes extends beyond the world of science into any aspect of our lives today.

 

The physical universe and the ever confusing and challenging world of particle physics is under no obligation to act in ways that our limited brains and current extent of mathematical and scientific understanding would expect. We make predictions based on observations, but we are never playing with all the data and never have a complete set of all possible observations when we make our predictions. Our ideas of what should and should not be possible are shaped by our experiences and by all the information we can hold in our head, and that information is astoundingly limited compared to the vastness of possibilities within the universe.

 

Looking at our actual day-to-day lives, we can see that this concept translates into the expectations, generalizations, and predictions we make about our futures and desires. I live in Reno, Nevada, and at the moment housing prices in Reno have increased dramatically as the number of homes and quality apartments has remained level while economic development and population growth have occurred. One result of a stronger economy and a lagging housing infrastructure is increased home costs, and fewer living accommodations for those who want to live on their own. I was recently running with a friend of mine who stated that an individual graduating from college should be able to afford a starter home if they are in an introductory position and have a solid and stable job. My friend is not wrong to say this, but his statement is simply a value judgement based on the experiences of his family and expectations that have been shaped by where he has lived and what he has been told he should do to be successful. Whenever we begin talking in terms of how things should be, we need to recognize that we are making value judgements, and that we are expressing only our ideas of what reality ought to be. The conflicts this creates and the paradoxes it leads us to are not paradoxes that actually exist in the universe, they are just situations where the real world does not align with the way that our brains comprehend our experiences.

 

The set of possibilities within the universe is virtually infinite as far as the human mind is concerned, and thinking that we know how things should be is to some extent arrogant and irrational. The world and universe in physical terms and in terms of our social ordering can have many forms, and if we try to force the universe to be the way that makes sense from our perspective, we will simply be frustrated and confused in a spiral of paradox. When we take away our opinion and think through our expectations, we can begin to see the world more clearly and better react to and adjust to the actual realities of our world. When we take away the expectations of how the world ought to be, we can live in the world we actually have and learn and adapt with greater skill.

Measuring the Universe from the Inside

The human mind is an amazing tool, but it does go astray from time to time and some of our logical fallacies trip us up. The world of physics, particularly the physicists who are pushing the edge of physics knowledge, run into a lot of challenges that clash with the way we typically think about and understand the universe. Our physics today shows us where our logical fallacies lie and how we must tread the line of reason and nonsense to understand what is truly taking place in the universe.

 

One of the challenges that modern physics presents us with is the need to abandon the idea of objective observers outside the system. Everything in the universe is within the universe. That sounds obvious enough, but it means that everything that is, all matter, all energy, and any observer is in the universe itself. This is important because it means you cannot step outside the universe and look in to see what is happening to make observations and measurements. From the moment the universe began, it has been all there ever is, and there was never anything outside the universe as best as we can understand it.

 

Amanda Gefter tackles this in her book Trespassing on Einstein’s Lawn where she writes, “Of course, if that was true, you couldn’t have an observer to make the measurement in the first place. The observer’s got to live in some kind of reality. That was the problem with Bohr’s view. If measurement is the arbiter of reality, then the measuring device has to sit outside reality—which even within the bizarro universe of quantum mechanics, is downright impossible.” Gefter wrote this in response to the challenges of describing particles within quantum mechanics. There are some properties of particles that you can’t define very precisely, or at least that you can’t define simultaneously. We also look at particles within the wave function, indicating that particles follow a general probability pathway until we decide to make a measurement and determine where they are and how they behave.

 

But,  because we are inside the universe, when we make an observation we change the system. We shape the reality that we are trying to measure because we are matter and our measurement tools are made of the same building blocks as the things we are trying to measure, so everything interacts and mutually shapes and has an impact on everything else. There is no way to stand outside the universe and there is no way to observe and measure the system without interacting with it, and when you do, you influence the observations you make.

Thinking About Science Writing

Amanda Gefter’s book Trespassing on Einstein’s Lawn is an enjoyable read even if you only have a slight science background because Gefter is able to transform incredibly challenging physics topics into understandable and relatable concepts and ideas. Her use of metaphor throughout the book is funny and inviting, and while I am not an expert in the cutting edge of physics after reading her book, I do have a better basic grasp of the challenges physicists face when observing and making predictions about the universe today.

Early in the book Gefter describes some of her own confusion with topics like general relativity and quantum mechanics, and she provides in depth yet accessible explanations. In addition to describing the ideas themselves, Gefter is able to describe the why the problems and challenges at the edge of science puzzle so many people in a way that is accessible. Regarding quantum gravity she writes,

“I knew that physicists needed a theory of quantum gravity because general relativity and quantum mechanics couldn’t manage to peaceable coexist in a single universe. But what made exactly made them so hopelessly incompatible? Everywhere I looked I found technicalities—the world of relativity is continuous and the quantum world discrete; relativity regards positions in spacetime as well defined, while quantum theory renders them fuzzy. They were obstacles, sure, but they struck me as mere couple’s squabbles, not deep, unbridgeable rifts. It was like relativity preferred chocolate and quantum theory vanilla—not like relativity was a Protestant and quantum theory was a duck.”

I have more or less forgotten any ideas about quantum gravity, but I have managed to retain some general relativity and some quantum mechanics knowledge after reading Gefter’s book. What I enjoy about the passage above is the humor she brings to the science. We don’t often invite people into the science because we become very technical when describing the complexities of cutting edge science. There is a place for the jargon, but when we want to excite people and get them interested in the truly fascinating work taking place, we need to make science more clear and create demonstrations that will encourage people to look further as opposed to confuse people and put them to sleep.

What I think is also important to remember is that it is good for people to hear the answers to the basics, even if we (or they) have heard the basic questions and basic answers multiple times in the past. I listen to a lot of science podcasts, and the question/answer portions of the shows often have pretty strait forward and basic questions. My reaction as a human being when someone asks a question to which I know the answer is to praise myself for being so smart and to criticize the other person for not already knowing the answer to the question. However, I try my best to acknowledge that reaction, and then put it away because it is not helpful. Undoubtedly every time a simple question is answered, the response on a podcast is unique, and my understanding is deepened or even corrected altogether. What we must remember when discussing science, and what Gefter does a great job of in her book, is that everyone in our audience will come to our writing (or podcast discussion) with a different level of understanding and we must write in a way that does not make those with less background think that we are arrogant in our use of language and description of basic concepts.

Energy and Gravity Games

A great challenge within physics today is understanding how the same physics is able to operate at different scales. The geometry of planets and galaxies seems to operate in the same way as the physics of airplanes and softballs, but dive a level deeper and the physics of electrons and photos does not quite seem to follow the same rules. Experiments give us photons that seem to know how we are looking at them, and behave differently depending on what experiment we choose and what method of observation we use. Once we get to the super small world of particle physics, we continue to use the same physics, but the interactions between matter and energy seems to be different. Piecing together exactly what is happening is challenging, and often requires looking at the results of experiments in new and creative ways.

 

In her book Trespassing on Einstein’s Lawn, author Amanda Gefter explores many of these head turning and confusing realities. She looks at the smallest scale we can reach in the universe, the point at which there simply are not more “things” to be discovered by looking for even smaller and smaller particles. At the Plank scale, gravity and energy have interactions that we would not expect based on our understandings of quantum physics. Gefter describes what physicists observe,

 

“But keep zooming in and, strangely, things start to turn around. The laws of quantum mechanics contain a loophole that allows large fluctuations of energy to burst forth from the vacuum, provided they don’t stick around too long. At increasingly shorter time scales, energy blinks in and out of existence in the form of fleeting, or ‘virtual,’ particles. The more localized the virtual particle, the greater its momentum, and the  greater its momentum, the larger its energy. Thanks to E=mc2, more energy means more mass. So as you look at smaller and smaller distances, virtual particles grow increasingly massive until, at the Plank scale, gravity grows as powerful as the other forces An energy in its own right, gravity’s crescendo generates a runaway feedback disaster of the same variety that can collapse a 1032 pound star into a black hole.”

 

Gefter describes the process above as the breaking of spacetime and refers to John Wheeler who said that this process creates “spacetime foam.” Physicists are challenged because all the forces we experience as sentient human beings exist across all scales, but their impact is different based on the mass and energy of the particle or system. Gefter’s quote above shows us that physics does not just go away at a certain point. Instead, the rules remain, but the way the rules play out changes.

Solving a Great Mystery

As a teenager in high school, Amanda Gefter was relatively disengaged from classes and studying. It was not that she wasn’t smart, was not interested in the world around her, or did not want to learn, but that teachers and her school did not manage to grab her attention and excite her with the subjects they taught. In her book Trespassing on Einstein’s Lawn, Gefter explains the interest she took in physics and science outside the classroom, and discusses how interesting science is, yet how little of the mystery of our world was actually conveyed in her classes.

 

She writes, “Einstein said, ‘This huge world stands before us like a great eternal riddle.’ Why couldn’t any of my teachers have told me that? ‘Listen,’ they could have said, ‘no one has any idea what the hell is going on. We wake up in this world and we don’t know why we’re here or how anything works. I mean, look around. Look how bizarre it all is! What the hell is all this stuff? Reality is a huge mystery, and you have a choice to make. You can run from it, you can placate yourself with fairy tales, you can just pretend everything’s normal, or  you can stare that mystery in the eye and try to solve it. If you are one of the brave ones to choose the latter, welcome to science.”

 

We present science in school in a way that allows us to test student knowledge. The knowledge we test is usually just basic facts and information that can be evaluated with multiple choice questions. Science in the real world, however, is not multiple choice. We don’t actually know all the answers and the quest to find them involves creative thinking to design experiments, evaluate the world, observe complex phenomena, and crowdsource knowledge to establish accepted theories of what is taking place. When we reduce this complex web that we call science to basic multiple choice questions, we create an illusion that science is well understood and that we have all the answers figured out. Students become disengaged because we lose the mystery and fail to connect the challenging science to the important developments of the world.

 

To inspire kids with science we need to first obliterate the idea that math is hard. Math is not hard, it is just a different frame for understanding the interactions of the universe. If we tell our kids that math is a secrete code to the universe that they have the power to understand, then they can approach the subject with less apprehension and more intrigue, and they can be more successful. From there we must explain the mysteries of the universe that we are working to better understand, and we must demonstrate to kids the interesting work and knowledge being undertaken and discovered every day. We must create new ways of transmitting knowledge and testing knowledge that don’t involve multiple choice questions and textbooks that present information without connections to real world applications.