Cooling Through Sweat

Cooling Through Sweat

The physics of how sweat cools us down is pretty interesting. I can’t remember the specific physics formula that calculates the cooling effect of evaporation, but as water molecules leave the skin, they take some heat energy with them, leaving the body slightly cooler. But how well this system works is also dependent on the weather and air conditions that the sweat would potentially evaporate away into.
In Gulp, Mary Roach describes some of the important factors for this process. “When the air around you is saturated with moisture, your sweat – most of it, anyway – has no where to evaporate to. It beads on your skin and beads down your face and back. More to the point, it doesn’t cool you.” The water in your sweat has to evaporate away for cooling to take place. When the air is too humid for the water to evaporate away into (an over simplification of the physics I’m sure) then you can’t take advantage of the cooling potential of sweat.
Roach continues, “It’s the humidity, but it’s also the heat. When the air is cooler than 92 degrees Fahrenheit, the body can cool itself by radiating heat into the cooler air. Over 92 – no go.” Hot air rises through convection, allowing cooler air to replace the hotter air, cooling you off as slightly cooler air replaces the hotter air around you. At a certain point however, there is no cooler air moving in to replace the hot air coming from your body. Roach also writes, “a breeze cools you by blowing away the penumbra of swampy air created by your body. If the air that moves in to take its place is cooler and drier, so, then, are you.”
Sweating is an incredible ability that helps keep us cool, but its efficiency is dependent on the weather outside our body. We can sweat all we want, but if the air that is around us isn’t cooler and drier than we are, we won’t enjoy the benefits of sweating. We won’t dry off in the air, we won’t cool down, and we will be gross and swampy.
People Eat Physics - Gulp - Mary Roach - Joe Abittan

People Eat Physics

In the book Gulp, Mary Roach explores what it is that makes us like certain foods. She investigates different qualities of different foods in an attempt to discern what food attributes make us like different things. There are the obvious taste and texture qualities, but she investigates further, and finds that there is a lot of physics involved in which foods we like and which foods we don’t like.
Roach quotes researcher Tony Van Vliet in her book writing, “People eat physics. You eat physical properties with a little bit of taste and aroma. And if the physics is not good, then you don’t eat it.” This quote followed the explanation of an experiment regarding potato chips. Researchers found that manipulating sound waves, to eliminate the crunch sounds of the chips, made people think they were eating old, stale chips, when in fact they were eating fresh chips. Eating, an activity dominated by taste and the mouth, it turns out is also greatly impacted by the ears.
“Crispness and crunch are the body’s shorthand for healthy,” Roach continues. When we eat, our noses play a big role, the touch receptors in our mouth play a huge role, and it turns out even our ears play a huge role. Without realizing it, we are using a huge amount of our senses to determine whether food is healthy, safe to eat, and nutritious. When the physics don’t align for any given physical property of the food, we will experience it differently. Add red coloring to white wine and people won’t experience it as a white wine. Mute the crunch on chips and people will think they are old and stale. People eat physics just as much as they eat food.

Social Constructionism in Physics and … Everything!

I just finished a semester at the University of Nevada focusing on Public Policy as part of my Masters in Public Administration. Throughout the semester we focused on rational models of public policy and decision-making, but we constantly returned to the ways in which those models break down and cannot completely inform and shape the public policy making process. We select our goals via political processes and at best develop rational means for reaching those political ends. There is no way to take a policy or its administration out of the hands and minds of humans to have an objective and rational process free of the differences which arise when we all have different perspectives on an issue.

 

Surprisingly, this is also what we see when we look at physics, and it is one of the big stumbling blocks as physicists try to understand quantum mechanics within the framework of physics laid out by Einstein and relativity. Throughout her book, Trespassing on Einstein’s Lawn, Amanda Gefter introduces us to the biggest concepts and challenges within the world of physics and how she and her dad attempted to make sense of those concepts within their own physics studies. A major influencer on the world of physics, and consequently on the adventure that Gefter took, was John Wheeler, who seemed to bring this idea of social construction to the rational and scientific world of physics. Wheeler described the idea of the self observing universe, to say that we are matter, observing other matter, creating our reality as we observe it. This idea is exactly the idea of social construction that I touched on in the opening note, but Gefter quotes a note in one of wheeler’s notebooks, “Add ‘Participant’ to ‘Undecidable Propositions’ to Arrive at Physics,” which sounds a bit like social construction to me as someone who studies public policy.

 

Social Constructionism is a theory from the social sciences. It is used to describe the ways in which a society or group comes to understand the problems it faces: who is at fault for the problem, who receives a benefit from our solution, who has the right to complain about a problem, and in what order should we attempt to solve our problems? These are all serious questions to which there is no perfect answer. We cannot identify a perfectly rational answer that will satisfy everyone. Our individual preferences will always be at play and our interactions in the decision-making process will shape the outcomes we decide we want and the solutions we decide to implement to reach those outcomes. In a sense, these large political questions are like the undecidable propositions in physics described by Wheeler. Politics is the outcome we arrive at when you add participants to undecidable propositions in society, and physics is what you arrive at when you add participants with limited knowledge and limited perspectives to the observation and understanding of major questions such as how gravity works.

 

We use questions of social science to inform the way we think about our interactions with other people and how we form societies. Social Constructionism reminds us that what seems clear and obvious to us, may seem different to someone else with different experiences, different backgrounds, different needs, and different expectations. Keeping this theory in mind helps us better connect with other people and helps us see the world in new ways. Similarly, physics informs the way we understand the universe to be ordered and how matter and energy interact within the universe. Recognizing that our perspectives matter, when it comes to politics, science, and even physics, helps us to consider our own biases and prior conceptions which may influence exactly how we choose to model, study, and experiment with our lives and the universe.

Social Constructionism in Physics and … Everything!

I just finished a semester at the University of Nevada focusing on Public Policy as part of a Masters in Public Administration. Throughout the semester we focused on rational models of public policy and decision-making, but we constantly returned to the ways in which those models break down and cannot completely inform ad shape the public policy making process. We select our goals via political processes and develop rational means for reaching those political ends. There is no way to take a policy or its administration out of the hands and minds of humans to have an objective and rational process free of the differences which arise when we all have different perspectives on an issue.

 

Surprisingly, this is also what we see when we look at physics, and it is one of the big stumbling blocks preventing us from linking Einstein’s theory of relativity with quantum mechanics. Throughout her book Trespassing on Einstein’s Lawn, Amanda Gefter introduces us to the biggest concepts and challenges within the world of physics and how she and her dad attempted to make sense of those concepts on their own. A major influencer on the world of physics, and consequently on the adventure that Gefter took, was John Wheeler, who seemed to bring an idea of social construction to the rational and scientific world of physics. Wheeler described the idea of the self observing universe, to say that we are matter, observing other matter, creating our reality as we observe it. This idea exactly the idea of social construction in politics and governance that I touched on in the opening note. Gefter quotes a note in one of Wheeler’s notebooks, “Add ‘Participant’ to ‘Undecidable Propositions’ to Arrive at Physics.”

 

Social Constructionism is a theory from  the social sciences. It is used to describe the ways in which a society or group comes to understand the problems it faces: who is at fault for the problem, who receives a benefit from our problem solution, who has the right to complain about a problem, and in what order should we attempt to solve our problems? These are all serious questions to which there is no perfect answer. We cannot identify a perfectly rational answer that will satisfy everyone. Our individual preferences will always be at play and our interactions in the decision-making process will shape the outcomes we decide we want and the solutions we decide to implement to reach those outcomes. In a sense, these large political questions are like the undecidable propositions described by Wheeler. Politics is the outcome we arrive at when you add participants to undecidable propositions in society, and physics is what you arrive at when you add participants with limited knowledge and limited perspectives to the observation and understanding of major questions about the workings of the universe.

 

We use questions of social science to inform the way we think about our interactions with other people and how we form societies. Social Constructionism reminds us that what seems clear and obvious to us, may seem different to someone else with different experiences, different backgrounds, different needs, and different expectations. Keeping this theory in mind helps us better connect with other people and helps us see the world in new ways. Similarly, physics informs how we understand the universe to be ordered and how matter and energy interact within the universe. Recognizing that our perspective matters, when it comes to science and physics, helps us to consider our own biases and prior conceptions which may influence exactly how we choose to study and experiment with the universe. Keeping social constructionism in mind also helps us understand why we choose to study certain aspects of science and why we present our findings in the ways that we do. We may never be able to get to a purely rational place in either science or politics (though science is certainly much closer), but understanding and knowing where social construction plays a part will help us be more observant and honest about what we say, study, believe, and discover.

Cutting Through

The truly great thing about physics is that it is universal. Literally. What we discover about physics here in the United States is true in South Africa, and what is discovered in South Africa can be learned just as well in Vietnam, and it all holds true on Jupiter or in the Andromeda Galexy. Physics is based in mathematics and repeatable experiments and it can be understood anywhere. It takes our perceptions and it boils them down into their most simplistic forms, tests them, repeats the test, and then determines what is real and what is unsupported. This means that physics has the ability to help us understand things in incredible new ways. We can better understand the universe and how it is held together, but only if we can study the physics and step beyond ourselves to understand what the tests, experiments, and math are trying to explain to us.

For Amanda Gefter, this is one of the best parts of physics. It takes our expectations, our assumptions, and what we want to be true, and completely ignores it. A good scientist, during their search for what is real and what is not, is able to cut through the noise of our expectations, beliefs, and desires to see the science underneath, holding things together.

Gefter writes, “That was what I loved about physics—that moment of pure surprise when you suddenly realize that what you had thought was one thing is really something else, or that two things that seemed so different are really two ways of looking at the very same thing. It was the perennial comfort that comes from discovering that the world is not remotely what it seems.”

By cutting through the noise of humanity, physics helps us to see the world more thoroughly. The world and the universe are not the way they simply appears to us from our perspective on Earth. Much of how we interpret and understand the universe is through what we see, but so much of the universe does not emit electromagnetic radiation or react with light in any way. How we perceive the universe depends on our point of view, and of our experience as human beings living on our planet. What physics does, is move beyond our experience of the universe to tell us how things are at any point in the universe, not just on planet Earth today. If we accept the world as it appears to us, then we somehow cease to move forward, and we begin to live in a story that never completely captures the reality we experience around us. We begin to live in ways that don’t add up, that put us at the center and don’t allow for the types of evolution and adaptation that we need to live in this universe responsibly. Physics takes the stories that we tell and re-writes them, adjusting the language to be the language of mathematics, giving us a new perspective from which to tell our story.

Creating History

Physics often times does not align with what we expect. But really, there is no reason that the physics we experience here on our planet with our limited senses should lead us to perfectly predict how physics and reality play out across the universe. Trespassing on Einstein’s Lawn is an excellent physics book because it takes readers with little scientific background through the complex paradoxes and challenges of physics to explore the furthest reaches of our scientific thought. Author Amanda Gefter herself is not a physicist, and learned to understand physics first as a hobby, and later (as detailed in her book) as a bit of an obsessive search for the universe’s ultimate building block.

Along her journey, Gefter introduces us to John Wheeler, a physicist who wrote with an almost poetic style when describing the complex science that he worked on. Wheeler helps us understand that one of the things within human experience that is so fundamental to how we view reality, is not quite as solid as we would expect. He is quoted  by Gefter writing, “We used to think that the world exists ‘out there’ independent of us.” When we study physics we are actually adjusting and changing the past. We are not looking at an independent system that existed before us a certain way. When we measure and observe the past, we actually can change it from the present. This is explained by Gefter with further help from Wheeler by describing experiments with photons to measure how sub-atomic particles travel. Light is made of photons, but it acts as a wave, with probabilities based on the wave function determining where the photons of the light will be. Once, however, we make an observation of a single photon, the probabilistic wave function ceases to exist, and the photon acts as a particle, and not as a wave. Up until we make our measurement however, the photon is a series of probabilities and behaves as a wave, the same way a wave behaves in the open ocean, and not as a particle on a direct path.

Gefter writes, “Delayed-choice experiments have been carried out in laboratories, and each time they’ve worked just as wheeler suggested. It’s an established scientific fact: measurements in the present can rewrite history. No, not rewrite. Just write. Prior to observation, there is no history, just a haze of possibility, a past waiting to be born. ‘There is no more remarkable feature of this quantum world than the strange coupling it brings about between future and past,’ Wheeler wrote. If observations we make today can create a billion-year-old past, so, too, can observations made in the future help build the universe we see today.”

In the quote above Gefter is describing the same experiments with photons, but looking at photos billions of light years away from us that had to travel across the universe and split on one side or another of a black hole, universe, or other star to reach one of our telescopes. The path taken by a given photon is best described by the probabilistic wave function with all the features, such as frequency and amplitude, of physical waves that we can observe on earth. But once we make an observation in a telescope to measure the path the photon took around a galaxy, black hole, or star, the wave function no longer describes the photon, and the photon has to have followed a set pathway, a pathway that was not determined until it reached our planet, billions of years after it was emitted from its original source.

The physics is beyond my ability to describe, but the key point is that we are human and have limited brain space and experiential ability. We can only experience first hand so many sensations and realities. More possibilities exist than we can experience and understand. Thinking that we can ever describe reality in the most comprehensive manner is a great dream for scientists and physicists to work toward, but we will always be limited by the fact that we are human and can only experience the world in so many ways. Things that we take to be so certain, like history and the passage of time, seem to be interconnected with the present and the future in ways that we can’t quite explain right now.

Only Referencing the Inside

The problem of physics and the universe being relative to observers haunts Amanda Gefter in her book Trespassing on Einstein’s Lawn. Throughout the book she writes about the challenge of understanding physics and finding a set, definitive, absolute reality within physics. Motion, matter, electromagnetic waves, particles, and time all seem to change relative to an observer. The observer does not need to be alive, but it just any given point of reference.

 

During her quest to better understand physics and find an objective agreed upon base for reality Gefter spoke with physicist Fotini Markopoulou. Recounting the conversation Gefter writes, “Was there some way to continue talking about the universe while only referring to it from the inside? Markopoulou seemed to think so, but it came at a serious price. It meant tossing aside ordinary Boolean logic and replacing it with a kind of logic that depended on the observer. It meant redefining what we mean by “true.” It meant stripping physics of the ability to make absolute statements about ultimate reality. Propositions were no longer true or false. They were true or false according to some particular observer.”

 

Einstein’s theories of relativity tell us that observers make a big impact on how the universe is measured and understood. Where an observer exists in space, the observer’s scale, and its motion all impact the measurements for the observer.  Gefter was on a quest with her father to understand and determine what it is in the universe that is the absolute reality of the universe. What is the basic constant that forms the simplest building block of all of the universe? Here quest was to find the one thing that was not relative to a reference point and an observer and to find the one thing that everyone and everything in the universe can point to and say “yes, that there is X, and it is always X, and is X for all of us who look at it.”

 

The challenge is that we are all within the universe. We are all matter and each point within the universe is a point of the universe and is itself changing and interacting with other things in the universe. There is no way to stand outside the universe and set a universe clock to a specific time and see everything a specific way. There is no ‘outside’ to the universe, and that means that any point of reference or timeframe is relative to others based on a host of factors. Gefter wanted to find an objective piece of the universe that was not determined relative to another point, but the only way such a point could exist is if it were outside the universe, something we philosophically understand to be impossible.
Tresspassing on einstein's lawn

A View from Nowhere

Physics is all around us, taking place within our coffee mug, within jet airplane engines, and on the roof above our head. Everywhere we go, physics goes, and everywhere we look, we see physics. Across the universe, magnified at the end of an electron microscope, and throughout time, physics connects everything there is. Amanda Gefter in her book, Trespassing on Einstein’s Lawn, describes the importance of viewing physics within a totally inclusive system. Because we are walking physics experiments, we alter the physics of the world around us and have an impact on every system that we study and interact with. In fact, it is not just us but everything that interacts or has the ability to observe a phenomenon in physics that acts upon and changes the system.

 

This is important because it shapes the way we study and understand physics and reality. There is no way for us, or anyone or anything else, to stand outside the universe and look back in at the universe to make an observation independently. If you are observing the universe you are within the universe and you are part of the universe. Describing her efforts to learn and understand what this means for physics, Gefter wrote,

 

“I had already learned that both relativity and quantum mechanics were trying to tell us the same thing: we run into trouble when we try to describe physics from an impossible God’s-eye view, a view from nowhere. We have to specify a reference frame, an observer. But now I finally understood the real tension between the two theories. The whole mess could be summed up with one question: where’s the observer?”

 

General relativity tells us that everything is inside the universe, but when we look at quantum mechanics we are trying to look at incredibly tiny particles that form the building blocks of the universe. A tension arises because we appear to be able to separate ourselves from the system in which our experiments take place, but the reality is that we are making an observation of the system, which means we are interacting with the system. Even when we take the human part away from our experiments and our systems, we still leave behind something to make an observation to somehow detect what is taking place. An observer does not have to be conscious and is better thought of as a frame of reference or something that can be changed and adjusted within the system. The only way we could truly understand pure physics it seems, is to be completely outside the system to look in and observe without changing the system, but this completely violates what we know is possible about how our universe works.

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.

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.