The generation that took us to the Moon…

I’m cross-listing this here, from my personal blog, because I think it has some relevance to the discussion of training the “next generation of scientists and engineers”.

The generation that took us to the Moon…

Global Energy Growth, the Drake Equation, and Fermi’s Paradox

A friend and colleague of mine, Tom Murphy, has started a new blog about climate change, peak oil, future energy consumption, and other stuff related to what some have coined “The Long Emergency”. His blog, called “Do the Math”, is unique in that he takes a physics approach to calculate from first principles many aspects of the problems that face us.

I strongly suggest taking a look if you have ever worried about the future of civilization and don’t just want to wring your hands about it, but look at the problems from a physics perspective…the one that says ‘hey, I’m a physicist, how hard could the problem be?’

Turns out, pretty hard. But I like Tom’s approach. Many of his analyses have that Fermi Problem approach that are used in my field of astrobiology to either predict that aliens are everywhere (Drake Equation) or to wonder why they aren’t seen anywhere (Fermi’s Paradox).

One my favorite posts of Tom’s is this one.  In it he extrapolates our current growth rate of energy usage (2.3%) and looks at potential energy sources for future humans.  The punch line is pretty dramatic.  According to Tom, a civilization like ours should be harnessing (and re-emitting) all of the energy incident on the surface of the Earth in a mere 400 years from now at the current rate of growth.   Of course, he is assuming in 400 years we have learned how to harness that energy and dissapate it into space without concern to the state of the climate or the habitability of the planet, but perhaps that is the topic of another post.

Rather than reflected light, the vast majority of this will be emitted in infrared wavelengths as waste heat.  Based on some quick internet research, a typical CCD camera has a dynamic range of about 90 dB, which gives a power ratio of 1 billion.  If the star and the planet differ in total power output by this much, in principle we should be able to see it, provided we can resolve the components on the sky.  Hubble has an angular resolution to see a object in an Earth-like orbit around a Sun-like star out to about 60 light years, provided that object is bright enough.  Since most of that power would be radiating in the infrared rather than visible light, it is likely such an object would be observable with current technology or the next generation of space telescopes.  Looking at the graph, the moment we start using all of the incident radiation on the Earth (the 100% Earth Solar point, at 400 years) we are using (an re-emitting) roughly 1 billionth the total power of the Sun.  Thus, in 400 years, the waste energy of our civilization is observable from space from a distant of about 60 light years using current or near-future technology.

It occurs to me that Tom may have unintentionally answered one of the greatest questions in astrobiology by putting a hard limit on the maximum value of L in the Drake Equation.  Regardless of the other parameters in the Drake Equation (which multiplied together are of order 1 regardless of your pessimism or optimism) L  in large part determines the number of potential civilizations in the galaxy.  Large L predicts lots of civilizations whereas a small L ensures we are alone in the Universe.  According to Tom’s calculations, L = 500 years (our current run of 100 years plus another 400 years).

Inadvertently, Tom may have also linked the Hubbard Peak  to the solution of Fermi’s Paradox, since it is very likely that the end of fossil fuels will preclude us from building the solar arrays necessary to be visible from deep space.

So, in addition to solving the world’s problems through physics, he is pinch hitting for astrobiology and clearing up a few pressing details.  Nice work, Tom!

sustainability

by Adam Johnston

When I hear “sustainability” and its root, I think of the sustain pedal on my piano; I think of sustenance; and, especially lately, I think about and worry about the sustaining of programs and people.  I consider what I can sustain on a few hours of sleep. But it’s not really about me, or even a program, no matter how big and important. I know this is really about a bigger sustainability, sustaining, sustenance.

Lately I’ve been wrecking our sustainability by driving an extra car instead of riding the bus or my bike.  I’ve wondered if I could, maybe just to alleviate my guilt, save the world by driving my girls to dance lessons. If I drive them to dance or violin, will they learn something that will make up for the refined fossil that I’ve just exhausted into the air they’re breathing. It’s a good question. I justify it. If they learn dance they’ll learn spatial skills and have a better understanding of calculus later. Maybe. If they learn violin they’ll learn patience and have a better sense of perseverance in graduate school. Perhaps. Or maybe they’ll just learn movement and music. Those are the hard questions, the ones that don’t have the coveted analytic solution.

There are easier problems. Call it the first law of thermodynamics or conservation of energy, but either way it’s the rule I think that determines our existence, actions, and limits more than any other natural law. With this, you can figure out exactly how fast you could possibly go when skiing down a mountain, and exactly how much gasoline I’ll use to pick up a daughter from any given class or lesson. In some ways, it reduces physics to accounting, but that’s not the image I like to portray too much. It’s accounting with sex appeal, because it’s more than just numbers on a page. It’s actions and potentials for action, and even if they’re hiding in a gallon of gasoline or in the nucleus of an atom, nature is keeping track, effortlessly and elegantly.

This first law of thermodynamics gives me hope. It is, in its very essence, sustainability writ large. It is the big constant of the universe, and with it a certain consciousness in an unconscious system. You know that if your planet starts orbiting faster or your star starts burning brighter that something else is making up for it. Everything is paid in full, and all the exchanges are equal and fair. Best of all, you can exchange energy back and forth without penalty. There’s no stockbroker fee or shipping charges.

But there is a catch. I’ll come back to that in a second. Let me interject one other point first. While I liken nature to this meta-accountant of energy, it’s easy to get caught up in the notion that it’s all just a giant ledger or some kind. Galileo’s notion that “mathematics is the language of nature” is nowhere more true, and best of all it’s mostly just simple addition and subtraction. In fact, the concept of energy and energy conservation was first thought up in order to better keep track of natural systems — an invention to help us predict what might happen next. Energy wasn’t an empirical thing, but a construction of quantities that just happened to be conserved in all exchanges. It made the physics easier. Ask any physics student about how much easier the problems get once they’re in chapter 5, where conservation of energy is introduced, and they’ll suddenly have a look of relief. Using this made up system is a great gimmick that gives them a tool to solve problems. It was all invented purely for this purpose.

So, imagine our surprise when it turned out to be a real thing. This struck me particularly hard somewhere around the third year of teaching College Physics. It’s subtle. Somehow I had found myself going full circle, from thinking that energy was real “stuff,” like the caloric of old, to thinking it was just accounting, and back again to thinking it was not “real” stuff but some other something. It was the mathematics that swayed and seduced me, showing me that energy exists in these “fields”. And, too, it’s in mass. Still, everywhere accounted for and, yes, sustained.

Right, but there was that one caveat, the “catch” I was suggesting earlier. That’s the second law of thermodynamics.

If I were to step outside and not be a fully objective scientist (and let’s not kid ourselves — I’ve yet to meet someone who really is all the time) I would be upset, angry, and simply pissed at the second law. Why? Because, first of all, it doesn’t give me, nor even allow for me, everything I want. And second, it’s inelegant. It’s a pain-in-the-ass piece of physics that simply derives from stupid statistics. In class, I try to derive and explain and animate the second law in a variety of ways, but it boils down to the idea that there are far more ways for systems, including the universe in its entirety, to be disorderly than orderly. That is, energy is much more likely to get spread out than it is to get hoarded into useful corners, shelves, or even habitable planets. And that means that, while energy is conserved, we can’t keep it. Your ice cream sundae will still have all its molecules in place, but it’s going to melt. Mountains erode. Gasoline becomes exhaust. The energy is still there, but it mostly, eventually, just contributes to a slightly higher temperature of deep space.

So my driving to dance and violin lessons had better be worth it.

It would be nice to end here with some rebounding lesson, some metaphor from nature that I can apply to life. It’s not there, though. Yes, everything is sustained, and at the same time everything erodes. We could, and should, slow this down. I’ll appreciate this, as my daughters, I hope, will dance and play in a world that might still be livable.

I can get there from here…

Lately, I’ve been thinking a lot about sustainability.  How do I sustain my lifestyle?  How do I sustain my community?  How do I sustain my career?

Today I got “The Letter”.  I am a tenure track professor in the final year of my tenure review, and “The Letter” is the first in a series of documents that, with luck, will validate what I have been doing for the past several years.  “The Letter” is probably the most important one, because it comes from my department.  It is written by the people who I care the most about, by the people who work with me every day.  It is the most important letter because, while an entire process exists to override the content of the letter if the need arises, who would want to?  If my department isn’t behind me, then what difference does it make?

Tenure is a fascinating concept that is, I think, rooted in sustainability. Here is the way it works: you show, through thought and deed, that you can sustain a certain level of performance in your career.  For several years, you do your good work.  You work hard to help your students, you serve your academic community, and you push important projects forward.  You do this because…well, at the time, you’re not quite sure.  It just seems like the right thing to do.  You get a strong feeling that this is just the way things are.  You should sacrifice for your students, you should do more than is asked of you.  You also get to work on some amazing projects with brilliant people.  And, if you are very, very lucky, you wake every morning remembering that this is what you get to do today.

And after a few years, you realize you are the person who thinks this a good idea.  After a few more, you recognize that you are the person who doesn’t know any other way of doing things.  And after another year, you convince your colleagues this is the case.  After that?  Well, you have to keep it up. You can’t let them down now!

Stages

by Michelle B. Larson

In my youth, I was thought to be invincible.

In my adolescence, immortal.

Oblivious freedom, then
Conscious denial.

In mid-life, a recognized need to take care.

Longevity required reversing past neglect.
Sustaining new behaviors.

I was Earth.

The Sustainability of an Unscientific Society

by Shane L. Larson

Some days, when I’ve been reading too much Edward Gorey and listening to The Cure at the same time, I imagine what it would be like to get a heart transplant.  “If I have to get a heart transplant,” I think to myself, “then the person I definitely want doing it is Fred Hansen, the proprietor and master cabineter of Intermountain Custom Cabinets.  Fred is a master artisan, well schooled in cutting things up and a master of joinery.  If he can put two pieces of oak together so I can’t even tell they are two different pieces, then surely he can do something as simple as stitching my aorta onto a new heart.”

On the surface, this idle daydream seems completely crazy, and it should.  Fred is not qualified to conduct heart transplants, though he knows about hearts and aortas, and has watched many documentaries on heart transplants on the Discovery Channel and seen a variety of Time magazine articles and news clips on CNN about heart transplants.  Fred knows enough to “talk some talk.”  And he knows how to cut and join things.  But in all likelihood, I should probably not put my life in his hands.

The first human to human heart transplant was conducted by Dr. Christiaan Barnard on 3 December 1967 in Cape Town, South Africa.  Barnard was a trained cardiac surgeon, with a deep experience in heart transplants based on a series of 50 previous transplants conducted on animal subjects leading up to the first human trial.  Despite early disillusionment on the part of cardiac surgeons after the invention of the procedure, technology and medicine have improved over the years, and cardiac transplants are now an accepted life-extending practice with some 3500 heart transplants conducted worldwide every year.  The population of cardiac doctors on the planet are a vital resource to the millions of people living their lives under the shadow of heart disease and heart defects.  If the cardiologists all vanished tomorrow, life would be much worse and in all likelihood shorter for millions of people, some of whom each of us know.

Cardiologists are one piece of the great puzzle of endeavours that makes modern society go, and play a role that they are uniquely qualified to hold.  Life on modern Earth churns forward under the auspices of a myriad of roles that single professions are uniquely qualified to hold: lawyers, diesel mechanics, longshoremen, electricians, dentists and cabinet makers.  Just as Fred knows a bit about heart surgery, all of us know some basics about the way our law system works and know not to stick forks in electrical outlets.  Our surface level knowledge of the world does not make us qualified to overhaul the engine in a 3500 HD Chevy Silverado or to install the electrical feeds in a new cell phone tower, though with enough training and study we could.

Where do scientists fit into the vast machine of society?  What unique role do they play, and in what way does science affect the inexorable churning of our civilization from today to tomorrow?  The root of the word “science” in Latin means “knowledge” and the practitioners of science are engaged in the systematic exploration of the natural world, expanding our knowledge and understanding of how Nature works and how all the parts of Nature are interconnected.  Like Fred and his penchant for surgical documentaries, some non-scientists know a lot about science.  Some take notice when the Large Hadron Collider is turned on underneath Switzerland and know that the generation of a quark-gluon plasma on the microscopic scales of the great particle smasher will reveal secrets about the origin of the Cosmos.  Some participate in the scientific enterprise by observing variable stars from their backyard or by letting their computer execute protein folding calculations while they are downstairs watching football.  There are awesome things that scientists do and discover every day, some of which ordinary citizens are very aware of.

But scientists, like cardiologists and teachers and auto-mechanics and insurance adjusters, are professionals who are uniquely qualified to address and solve particular problems by virtue of their training and expertise.  They are serious people who take their profession seriously.  The world collective of scientists has well defined rules by which problems are explored, debated and understood: experiments are conducted and the results reported, in the scientific literature.  The results are interpreted and debated, in the scientific literature.  New predictions are made and experiments built with the results reported, in the scientific literature.  Overwhelming statistical evidence is accumulated, in the scientific literature.  The collective scientific knowledge of humanity is reported and debated by scientists, in the scientific literature.  Results, theories and opinions which do not appear in the scientific literature have not survived the intense scrutiny and validation afforded by the collective mind and expertise of the scientific community.

The blogosphere, primetime television newscasts and Google are not the medium by which science is debated and communicated.  But here at the start of the Twenty-first Century, where science and technology are all around us and penetrate deeply into the fabric of our everyday lives, a large fraction of our society gleans their understanding and opinions about science through the filters of the blogosphere, primetime television newscasts and Google’s “I’m Feeling Lucky” button.  As a consequence, scientists and their profession are increasingly colliding with sectors of our society that find the process and conclusions of science to be disturbing, distressing and at odds with ideological beliefs.  Increasingly, science finds itself at odds with sociological forces which act out of enlightened self-interest and, increasingly, out of ignorance of the scientific process.  This filtering of scientific knowledge through ideological lenses, and the conflicting information that then propagates through common media channels, is a confusing muddle from which it is impossible to extract any truths.  For a huge segment of our society, this filtered muddle is their only exposure to science.  An entire generation of American children, who are already falling behind their peers around the world in math and science ability, spend their lives plugged in and glean enormous amounts of information from the multimedia circus.  The majority of society today is getting their scientific information from non-scientific sources, at a time when our lives increasingly depend on science.

Perhaps the most prominent example of this is the societal debate surrounding the Earth’s climate.  There are many questions about the Earth’s climate that have yet to be fully understood and answered.  If everything about the climate were completely understood, it would be a subject of record, not a subject of intense research.  But on the question of whether the climate is changing, the scientific literature outlines 28,000 independent lines of observational evidence that point toward the fact that the Earth is warming. Even if one line of evidence is uncertain, there are thousands of other indicators that point toward a warming planet.  This simple fact has brought the scientific community to a consensus — an understanding that the overwhelming evidence, presented and debated in the scientific literature, points toward a warming planet.  The idea of “consensus” has been twisted in the public eye to imply that there is uncertainty and wiggle room in the scientific data, an idea which lends itself well to the ideological polarization of our current culture. It has become fashionable to speculate on the veracity of climatological data when that data has been reviewed, vetted and debated in the scientific literature by the world community of professionals who are trained experts in the interpretation and analysis of such data.  Informing yourself on the nature of climatic data from people other than those qualified in the collection, analysis and interpretation of such data is tantamount to getting advice on heart transplants from someone who is not a cardiac surgeon.

Are there scientists who disagree and don’t believe in the consensus of the community?  Absolutely, and they should, because science does not move forward without the debate.  There are many famous examples of dissenting voices throughout the history of science.  Ernst Mach, one of the most renowned scientific minds of the early Twentieth Century, never believed in the existence of atoms, but the field of materials science grew and exists none-the-less, giving us teflon and polymer paints and carbon graphite tennis racquets.  Harold Jeffreys, a Fellow of the Royal Society and the Plumian Professor at Cambridge University in the 1950s, was one of the most distinguished geoscientists of the Twentieth Century.  He never believed in platetechtonics, but today high precision satellite monitoring and laser metrology incontrovertibly prove that the crust of the Earth is made up of plates shifting and sliding against one another, giving rise to earthquakes and volcanoes at the boundaries.  Albert Einstein was never comfortable with the idea of quantum mechanics, but we still have a semiconductor industry that uses quantum mechanics to make computer chips and feed our appetite for smartphones and Playstations and supermarket checkout scanners.  Being a brilliant mind does not mean a scientist is infallible; we are after all, still human.  Sometimes, unpopular views change the course of science and become accepted by virtue of experimental evidence.  But in the face of overwhelming experimental evidence and data, dissenters cannot argue the entire scientific community away from what Nature has revealed to us.  Science relies on the collective mind to insure that every nuance Nature has to offer is explored, investigated and understood.

Which brings us back to the way modern society approaches science.  In the United States in particular, our current culture of polarization has turned scientific data into an issue, something to be debated and argued about rather than something to be acted upon.  This is not a sustainable policy for our society to hold.   A society that does not embrace and encourage science cannot long endure.  If you take away plastics and electricity and modern medicine, life in the world begins to look a lot like the Middle Ages.  If you take away everything we know about the Earth’s climate and ignore the people who know something about the climate, the world begins to look a lot more like a nightmarish vision of Dante Alighieri.  It is a fallacy to believe that science is a matter of policy that can be debated and accepted based on what makes our leaders, almost all of them non-scientists, comfortable.  It is tantamount to asking Fred about doing a heart transplant.  But then again, I’m sure Fred has something to say about what’s happening to the Earth’s climate too.

January Prompt – sustainability

go!