On hubris and climate change.

On hubris and climate change.

Recently, a local science teacher sent me an essay written by a climate change skeptic.

Well, okay. I figured that I could skim the essay, look over the data, and briefly explain what the author’s errors were. After all, it’s really important to help teachers understand this topic, because they’re training our next generation of citizens.

And I thought to myself, how hard can this be? After all, I’m a scientist. I felt unconcerned that I’ve never read research papers about climate science before, and that it’s been years since I’ve worked through the sort of differential equations you need for even basic fluid mechanics calculations, and that I’ve never run any simulations on oceanic heat transfer or glacier melting.


Since then, I’ve read a fair bit about climate science. I’ll be honest: I didn’t go through the math. All I did was read the papers and look over the processed data.

This is lazy, I know. I’m sorry. But my kids are at home. At the moment, this is the best I’ve got.


Prominent climate change skeptic Richard Lindzen, an emeritus professor of meteorology, recently delivered a lecture to the Global Warming Policy Foundation. I wholeheartedly agreed with Lindzen when he stressed that the science behind climate change is really, really complicated.

Former senator and Secretary of State John F. Kerry is typical when he stated, with reference to greenhouse warming, ‘I know sometimes I can remember from when I was in high school and college, some aspects of chemistry or physics can be tough. But this is not tough. This is simple. Kids at the earliest age can understand this.’

As you have seen, the greenhouse effect is not all that simple. Only remarkably brilliant kids would understand it. Given Kerry’s subsequent description of climate and its underlying physics, it was clear that he was not up to the task.


Climate science is tricky. In a moment, I’ll try to explain why it’s so tricky.

When people make predictions about what’s going to happen if the average global temperature rises by half a degree – or one degree, or two – their predictions are probably incorrect.

My assumption that I could skim through somebody’s essay and breezily explain away the errors was incredibly arrogant. I was a fool, I tell you! A fool!

But my arrogance pales in comparison to the hubris of climate change skeptics. Once I started learning about climate science, I realized how maddeningly difficult it is.

Lindzen, who should know better, has instead made brash claims:

So there you have it. An implausible conjecture backed by false evidence and repeated incessantly has become politically correct ‘knowledge,’ and is used to promote the overturn of industrial civilization. What we will be leaving our grandchildren is not a planet damaged by industrial progress, but a record of unfathomable silliness as well as a landscape degraded by rusting wind farms and decaying solar panel arrays.

There is at least one positive aspect to the present situation. None of the proposed policies will have much impact on greenhouse gases. Thus we will continue to benefit from the one thing that can be clearly attributed to elevated carbon dioxide: namely, its effective role as a plant fertilizer, and reducer of the drought vulnerability of plants.

Meanwhile, the IPCC is claiming that we need to prevent another 0.5ºC of warming, although the 1ºC that has occurred so far has been accompanied by the greatest increase in human welfare in history.


So. What aspects of climate science can we understand, and what’s too hard?

Let’s start with the easy stuff. Our planet gets energy from the sun. The sun is a giant ball of thermonuclear fire, spewing electromagnetic radiation. When these photons reach Earth, they’re relatively high energy – with wavelengths mostly in the visible spectrum – and they’re all traveling in the same direction.

What we do – “we” here referring to all the inhabitants of our planet, including the rocks and plants and other animals and us – is absorb a small number of well-organized, high-energy photons, and then release a larger number of ill-organized, low-energy photons. This is favorable according to the Second Law of Thermodynamics. We’re making chaos.

And here’s the greenhouse effect: if the high-energy photons from the sun can pass through our atmosphere, but then the low-energy photons that we release get absorbed, we (as a planet) will retain more of the sun’s energy. Our planet heats up.


And, in defense of former senator John Kerry, this is something that a kid can understand. My children are four and six, and this summer we’re going to build a solar oven out of a pane of glass and a cardboard box. (After all, we need stuff to do while all the camps are closed.)

If we fill our air with more carbon dioxide, which lets the sun’s high-energy photons in but then won’t let our low-energy photons out, the planet should heat up, right? What’s the hard part?

Well, the problem – the reason why climate science is too difficult for humans to predict, even with the most powerful computers at our command – is that there are many feedback loops involved.

Some of these are “negative feedback loops” – although atmospheric carbon dioxide causes us to absorb more energy from the sun, various mechanisms can buffer us from a rise in temperature. For example, warm air can hold more water vapor, leading to more cloud formation, which will reflect more sunlight back into space. If the sun’s high-energy photons can’t reach us, the warming stops.

And some are “positive feedback loops” – as we absorb extra energy from the sun, which causes the planet to heat up a little, various mechanisms can cause us to absorb even more energy in the future, and then the planet will heat up a lot. This may be what happened on Venus. The planet Venus may have been habitable, a long long time ago, but then runaway climate change led to the formation of a thick layer of smog, and now it’s broiling, with sulfuric acid drizzling from the sky.

On Earth, an example of a positive feedback loop would be the melting of polar ice caps. As polar ice melts, it reflects less light, so our planet absorbs more of the sun’s energy. Heat made the ice melt in the first place, but then, once the ice has melted, we heat up even more.

And it turns out that there are a huge number of different positive and negative feedback loops. After all, our planet is really big!

For instance, the essay I was sent included graphs of ice core data suggesting that, in the ancient past, changes in average global temperatures may have preceded changes in the concentration of atmospheric carbon dioxide.

Frank Brown Cloud holding demo ice core.
Holding a demo ice core like my spouse uses in her classroom. The real ones drilled from glaciers are several miles long! I haven’t spent enough time at the gym to lift those.

But this is just another feedback loop. In the past, there was no mechanism for carbon dioxide to pour into our atmosphere before temperatures rose – dinosaurs didn’t invent internal combustion engines. This is the first time on Earth when carbon dioxide levels could rise before temperatures, and we don’t know yet what the effect will be.

Extra carbon dioxide will probably cause an increase in temperature, but a planet’s climate is really complicated. We have huge quantities of poorly mixed water (otherwise known as oceans). Our topography is jagged, interspersed with valleys and mountains. There are huge forests (only some of which are on fire). The air is turbulent.

We might find that temperatures are buffered more than we thought. The ocean might act like a giant heat sink.

Or then again, the ocean might warm up, accelerate polar ice loss by lapping at the undersides of glaciers, and magnify the changes.

The mathematics underlying fluid mechanics and heat transfer within an enormous, inhomogeneous system are so complex that it’s almost impossible to say. Nobody knows how much detail you’d need to put into a simulation to get accurate results – all we know for sure is that we can’t simulate the world with as much detail as actually exists. All our models are approximations. Some of them contradict each other.

With my admittedly limited understanding, I don’t think anybody knows enough to assert with confidence whether our climate will exhibit either buffered or switch-like behavior. Maybe we can muck about without hurting much. Or we might bring about our own doom with a tiny mistake.


Our planet’s climate is so complex that you could make a similar argument – we really don’t know whether we’re going to be buffered from future changes, or whether we’re at the precipice of doom – no matter what evidence we obtain.

Maybe sea levels start rising – well, perhaps that will somehow reduce the further heating of our planet. Maybe we get more horrible tropical storms – well, perhaps they’re linked to a greater density of sunlight-reflecting clouds.

Maybe things seem to be changing fast for a little while, but then we enter another stable state.

Or, insidiously, maybe it will seem like we’re in a well-buffered system – pumping large amounts of carbon dioxide and methane into the atmosphere without seeing much harm – until, suddenly, we tip over the edge. We often see that sort of behavior from positive feedback loops. Nothing seems to happen, for a while, then everything changes at once. That’s how cooperative binding of oxygen to hemoglobin works in your body.

Another problem is that climate change will probably happen on a very different rhythm from our lives. Weather happens on timescales that we can understand. A decade of droughts. Two years of tropical storms. A few hard winters, or hot summers. But climate happens over hundreds or thousands of years. Most of the time, it changes more slowly than we’d notice.

A two degree shift in average global temperatures, spread out over a few decades? That’s bad, but it’s boring. Which was the main focus of Jonathan Safran Foer’s We Are the Weather.

History not only makes a good story in retrospect; good stories become history. With regard to the fate of our planet – which is also the fate of our species – that is a profound problem. As the marine biologist and filmmaker Randy Olson put it, “Climate is quite possibly the most boring subject the science world has ever had to present to the public.”

Climate science doesn’t fit our culture. Especially not now, when the pressures of surveillance capitalism have forced even the New York Times to run like an advertising company. They earn more from news that gets clicks. Stories need to be sensational. Yes, they run stories about climate change. For these, the polar bears need to be dying, now, and there needs to be an evil villain like Exon lurking in the shadows.

Nobody wants to click on a story explaining that we, collectively, have made and are making a whole lot of small shabby decisions that will cause grizzly bears and polar bears to re-mix and de-speciate.

I got bored even typing that sentence.


Life is incredibly robust.

Our planet has swung through many extremes of temperature. At times, it’s been much hotter than it is now. At times, it was much colder. And life has marched on.

The human species is much less robust than life itself, though. Our kind has flourished for only a brief twinkling of time, during which our climate has been quite stable and mild. A small change could drive us to extinction. An even smaller change could cause our nations to collapse.

Disrupt our food supply – which could happen with just a few years of bad weather, let alone climate change – and there will be war.


So. I tried to learn about climate change, focusing on the work of skeptics. And in the end, I partly agreed with the skeptics:

I agree that climate science is too complicated for anyone to understand.

I appreciate that people are trying. I had fun learning about ice cores, atmospheric modeling, energy absorption, and the like. Well, sometimes I was having fun. I also gave myself several headaches along the way. But also, my kids were being wild. They’ve been home from school for three months now! I was probably on the precipice of headaches before I even began.

Here’s where I disagree with the skeptics, though: given that climate science is too complicated for us to understand – and given that we know that small changes in average temperature can make the world a much worse place to live – why would be blithely continue to perturb our climate in an unprecedented way?

Maybe things will be fine. Yay buffers! Or maybe we’ll reduce the carrying capacity of the planet Earth from a few billion humans to a few million, dooming most of our kind.

I know, I know – eventually our universe will dwindle into heat death, so our species is terminal anyway. We will go extinct. It’s guaranteed.

I still think it would be neat if our great-great-grandchilden were out there among the stars. At least for a little while.

Or even, if they stay here on Earth, it’s nice to imagine them living on a comfortable planet with lots of beautiful trees, and interesting animals to see.


Also, I’m biased.

After all, what are the things that you’re supposed to do if you want to reduce your carbon emissions?

Eat fewer animal products. Live in a smaller home. Drive less. Fly less. Buy less stuff.

Those are all things that I’d recommend to most Americans, for ethical and philosophical reasons, even if we weren’t concerned about climate change. So for me, personally, I don’t need to see much proof that we’ll ruin our climate unless we do these things. I think we should be doing them anyway.

Instead, I think the burden of proof should fall to the people hawking Big Macs. I’d want them to show that a world full of CAFO-raised cows won’t cause climate change, won’t propagate antibiotic resistant bacteria, won’t condemn billions of conscious beings to a torturous existence.

The world is complex. We’re going to err.

I’d rather err on the side of kindness.

On meditation and the birth of the universe.

On meditation and the birth of the universe.

This is part of a series of essays prepared to discuss in jail.

Our bodies are chaos engines. 

In our nearby environment, we produce order.  We form new memories.  We build things.  We might have sex and create new life.  From chaos, structure.

As we create local order, though, we radiate disorder into the universe. 

The laws of physics work equally well whether time is moving forward or backward.  The only reason we experience time as flowing forward is that the universe is progressing from order into chaos.

In the beginning, everything was homogeneous.  The same stuff was present everywhere.  Now, some regions of the universe are different from others.  One location contains our star; another location, our planet.  Each of our bodies is very different from the space around us.

This current arrangement is more disorderly than the early universe, but less so than what our universe will one day become.  Life is only possible during this intermediate time, when we are able to eat structure and excrete chaos. 

Hubble peers into a stellar nursery. Image courtesy of NASA Marshall Space Flight on Flickr.

Sunlight shines on our planet – a steady stream of high-energy photons all pointed in the same direction.  Sunshine is orderly.  But then plants eat sunshine and carbon dioxide to grow.  Animals eat the plants.  As we live, we radiate heat – low-energy photons that spill from our bodies in all directions.

The planet Earth, with all its life, acts like one big chaos engine.  We absorb photons from the sun, lower their energy, increase their number, and scatter them.

We’ll continue until we can’t.


Our universe is mostly filled with empty space. 

But empty space does not stay empty.  Einstein’s famous equation, E equals M C squared, describes the chance that stuff will suddenly pop into existence.  This happens whenever a region of space gathers too much energy.

Empty space typically has a “vacuum energy” of one billionth of a joule per cubic meter.  An empty void the size of our planet would have about as much energy as a teaspoon of sugar.  Which doesn’t seem like much.  But even a billionth of a joule is thousands of times higher than the energy needed to summon electrons into being.

And there are times when a particular patch of vacuum has even more energy than that.


According to the Heisenberg Uncertainty Principle, time and energy can’t be defined simultaneously.  Precision in time causes energy to spread – the energy becomes both lower and higher than you expected.

In practice, the vacuum energy of a particular region of space will seem to waver.  Energy is blurry, shimmering over time.

There are moments when even the smallest spaces have more than enough energy to create new particles.

Objects usually appear in pairs: a particle and its anti-particle.  Anti-matter is exactly like regular matter except that each particle has an opposite charge.  In our world, protons are positive and electrons are negative, but an anti-proton is negative and an anti-electron is positive.

If a particle and its anti-particle find each other, they explode.

When pairs of particles appear, they suck up energy.  Vacuum energy is stored inside them.  Then the particles waffle through space until they find and destroy each other.  Energy is returned to the void.

This constant exchange is like the universe breathing.  Inhale: the universe dims, a particle and anti-particle appear.  Exhale: they explode.


Our universe is expanding.  Not only are stars and galaxies flying away from each other in space, but also empty space itself is growing.  The larger a patch of nothingness, the faster it will grow.  In a stroke of blandness, astronomers named the force powering this growth “dark energy.”

Long ago, our universe grew even faster than it does today.  Within each small fraction of a second, our universe doubled in size.  Tiny regions of space careened apart billions of times faster than the speed of light.

This sudden growth was extremely improbable.  For this process to begin, the energy of a small space had to be very, very large.  But the Heisenberg Uncertainty Principle claims that – if we wait long enough – energy can take on any possible value.  Before the big bang, our universe had a nearly infinite time to wait.

After that blip, our universe expanded so quickly because the vacuum of space was perched temporarily in a high-energy “metastable” state.  Technically balanced, but warily.  Like a pencil standing on its tip.  Left alone, it might stay there forever, but the smallest breath of air would cause this pencil to teeter and fall.

Similarly, a tiny nudge caused our universe to tumble back to its expected energy.  A truly stable vacuum.  The world we know today was born – still growing, but slowly.


During the time of rapid expansion, empty vacuum had so much energy that particles stampeded into existence.  The world churned with particles, all so hot that they zipped through space at nearly the speed of light. 

For some inexplicable reason, for every billion pairs of matter and anti-matter, one extra particle of matter appeared.  When matter and anti-matter began to find each other and explode, this billionth extra bit remained.

This small surplus formed all of stars in the sky.  The planets.  Ourselves.


Meditation is like blinking.  You close your eyes, time passes, then you open your eyes again.  Meditation is like a blink where more time passes.

But more is different.


Our early universe was filled with the smallest possible particles.  Quarks, electrons, and photons.  Because their energy was so high, they moved too fast to join together.  Their brilliant glow filled the sky, obscuring our view of anything that had happened before.

As our universe expanded, it cooled.  Particles slowed down.  Three quarks and an electron can join to form an atom of hydrogen.  Two hydrogen atoms can join to form hydrogen gas.  And as you combine more and more particles together, your creations can be very different from a hot glowing gas.  You can form molecules, cells, animals, societies.


When a cloud of gas is big enough, its own gravity can pull everything inward.  The cloud becomes more and more dense until nuclear fusion begins, releasing energy just like a nuclear bomb.  These explosions keep the cloud from shrinking further.

The cloud has become a star.

Nuclear fusion occurs because atoms in the center of the cloud are squooshed too close together.  They merge: a few small atoms become one big atom.  If you compared their weights – four hydrogens at the start, one helium at the finish – you’d find that a tiny speck of matter had disappeared.  And so, according to E equals M C squared, it released a blinding burst of energy.

The largest hydrogen bomb detonated on Earth was 50 megatons – the Kuz’kina Mat tested in Russia in October, 1961.  It produced a mushroom cloud ten times the height of Mount Everest.  This test explosion destroyed houses hundreds of miles away.

The fireball of Tsar Bomba, the Kuz’kina Mat.

Every second, our sun produces twenty billion times more energy than this largest Earth-side blast.


Eventually, our sun will run out of fuel.  Our sun shines because it turns hydrogen into helium, but it is too light to compress helium into any heavier atoms.  Our sun has burned for about four billion years, and it will probably survive for another five billion more.  Then the steady inferno of nuclear explosions will end.

When a star exhausts its fuel, gravity finally overcomes the resistance of the internal explosions.  The star shrinks.  It might crumple into nothingness, becoming a black hole.  Or it might go supernova – recoiling like a compressed spring that slips from your hand – and scatter its heavy atoms across the universe.

Planets are formed from the stray viscera of early stars.

Supernova remains. Image by NASA’s Chandra X-Ray Observatory and the European Space Agency’s XMM-Newton.


Our universe began with only hydrogen gas.  Every type of heavier atom – carbon, oxygen, iron, plutonium – was made by nuclear explosions inside the early stars.

When a condensing cloud contains both hydrogen gas and particulates of heavy atoms, the heavy atoms create clumps that sweep through the cloud far from its center.  Satellites, orbiting the star.  Planets.

Nothing more complicated than atoms can form inside stars.  It’s too hot – the belly of our sun is over twenty million degrees.  Molecules would be instantly torn apart.  But planets – even broiling, meteor-bombarded planets – are peaceful places compared to stars.

Molecules are long chains of atoms.  Like atoms, molecules are made from combinations of quarks and electrons.  The material is the same – but there’s more of it.

More is different.

Some atoms have an effect on our bodies.  If you inhale high concentrations of oxygen – an atom with eight protons – you’ll feel euphoric and dizzy.  If you drink water laced with lithium – an atom with three protons – your brain might become more stable.

But the physiological effects of atoms are crude compared to molecules.  String fifty-three atoms together in just the right shape – a combination of two oxygens, twenty-one carbons, and thirty hydrogens – and you’ll have tetrahydrocannibol.  String forty-nine atoms together in just the right shape – one oxygen, three nitrogens, twenty carbons, and twenty-five hydrogens – and you’ll have lysergic acid diethylamide.

The effects of these molecules are very different from the effects of their constituent parts.  You’d never predict what THC feels like after inhaling a mix of oxygen, carbon, and hydrogen gas.


An amino acid is comparable in scale to THC or LSD, but our bodies aren’t really made of amino acids.  We’re built from proteins – anywhere from a few dozen to tens of thousands of amino acids linked together.  Proteins are so large that they fold into complex three-dimensional shapes.  THC has its effect because some proteins in your brain are shaped like catcher’s mitts, and the cannibinoid nestles snuggly in the pocket of the glove.

Molecules the size of proteins can make copies of themselves.  The first life-like molecules on Earth were long strands of ribonucleic acid – RNA.  A strand of RNA can replicate as it floats through water.  RNA acts as a catalyst – it speeds up the reactions that form other molecules, including more RNA.

Eventually, some strands of RNA isolated themselves inside bubbles of soap.  Then the RNA could horde – when a particular sequence of RNA catalyzed reactions, no other RNA would benefit from the molecules it made.  The earliest cells were bubbles that could make more bubbles.

Cells can swim.  They eat.  They live and die.  Even single-celled bacteria have sex: they glom together, build small channels linking their insides to each other, and swap DNA.

But with more cells, you can make creatures like us.


Consciousness is an emergent property.  With a sufficient number of neuron cells connected to each other, a brain is able to think and plan and feel.  In humans, 90 billion neuron cells direct the movements of a 30-trillion-cell meat machine.

Humans are such dexterous clever creatures that we were able to discover the origin of our universe.  We’ve dissected ourselves so thoroughly that we’ve seen the workings of cells, molecules, atoms, and subatomic particles.

But a single human animal, in isolation, never could have learned that much.

Individual humans are clever, but to form a culture complex enough to study particle physics, you need more humans.  Grouped together, we are qualitatively different.  The wooden technologies of Robinson Crusoe, trapped on a desert island, bear little resemblance to the vaulted core of a particle accelerator.

English writing uses just 26 letters, but these can be combined to form several hundred thousand different words, and these can be combined to form an infinite number of different ideas.

More is different.  The alphabet alone couldn’t give anyone insight into the story of your life.


Meditation is like a blink where more time passes, but the effect is very different.

Many religions praise the value of meditation, especially in their origin stories.  Before Jesus began his ministry, he meditated for 40 days in the Judaean Desert – his mind’s eye saw all the world’s kingdoms prostrate before him, but he rejected that power in order to spread a philosophy of love and charity. 

Before Buddha began his ministry, he meditated for 49 days beneath the Bodhi tree – he saw a path unfurl, a journey that would let travelers escape our world’s cycle of suffering. 

Before Odin began his ministry, he meditated for 9 days while hanging from a branch of Yggdrasil, the world tree – Odin felt that he died, was reborn, and could see the secret language of the universe shimmering beneath him. 

The god Shiva meditated in graveyards, smearing himself with crematory ash.

At its extreme, meditation is purportedly psychedelic.  Meditation can induce brain states that are indistinguishable from LSD trips when visualized by MRI.  Meditation isolates the brain from its surroundings, and isolation can trigger hallucination.

Researchers have found that meditation can boost our moods, attentiveness, cognitive flexibility, and creativity.  Our brains are plastic – changeable.  We can alter the way we experience the world.  Many of our thoughts are the result of habit.  Meditation helps us change those habits.  Any condition that is rooted in our brain – like depression, insomnia, chronic pain, or addiction – can be helped with meditation.

To meditate, we have to sit, close our eyes, and attempt not to think.  This is strikingly difficult.  Our brains want to be engaged.  After a few minutes, most people experience a nagging sense that we’re wasting time.

But meditation gives our minds a chance to re-organize.  To structure ourselves.  And structure is the property that allows more of something to become different.  Squirrels don’t form complex societies – a population of a hundred squirrels will behave similarly to a population of a million or a billion.  Humans form complex webs of social interactions – as our numbers grew through history, societies changed in dramatic ways.

Before there was structure, our entire universe was a hot soup of quarks and electrons, screaming through the sky.  Here on Earth, these same particles can be organized into rocks, or chemicals, or squirrels, or us.  How we compose ourselves is everything.


The easiest form of meditation uses mantras – this is sometimes called “transcendental meditation” by self-appointed gurus who charge people thousands of dollars to participate in retreats.  Each attendee is given a “personalized” mantra, a short word or phrase to intone silently with every breath.  The instructors dole mantras based on a chart, and each is Sanskrit.  They’re meaningless syllables to anyone who doesn’t speak the language.

Any two-syllable word or phrase should work equally well, but you’re best off carving something uplifting into your brain.  “Make peace” or “all one” sound trite but are probably more beneficial than “more hate.”  The Sanskrit phrase “sat nam” is a popular choice, which translates as “truth name” or more colloquially as “to know the true nature of things.”

The particular mantra you choose matters less than the habit – whichever phrase you choose, you should use it for every practice.  Because meditation involves sitting motionless for longer than we’re typically accustomed, most people begin by briefly stretching.  Then sit comfortably.  Close your eyes.  As you breathe in, silently think the first syllable of your chosen phrase.  As you breathe out, think the second.

Repeating a mantra helps to crowd out other thoughts, as well as distractions from your environment.  Your mind might wander – if you catch yourself, just try to get back to repeating your chosen phrase.  No one does it perfectly, but practice makes better.  When a meditation instructor’s students worried that their practice wasn’t good enough, he told them that “even on a shallow dive, you still get wet.”

In a quiet space, you might take a breath every three to six seconds.  In a noisy room, you might need to breathe every second, thinking the mantra faster to block out external sound.  The phrase is a tool to temporarily isolate your mind from the world.

Most scientific studies recommend you meditate for twenty minutes at a time, once or twice a day, each and every day.  It’s not easy to carve out this much time from our daily routines.  Still, some is better than nothing.  Glance at a clock before you close your eyes, and again after you open them.  Eventually, your mind will begin to recognize the passage of time.  After a few weeks of practice, your body might adopt the approximate rhythm of twenty minutes.

Although meditation often feels pointless during the first week of practice, there’s a difference between dabbling and a habit.  Routine meditation leads to benefits that a single experience won’t.

More is different.

On the ethics of eating.

On the ethics of eating.

Every living thing needs energy.  But our world is finite.  Energy has to come from somewhere.

Luckily, there’s a lot of potential energy out there in the universe.  For instance, mass can be converted into energy.  Our sun showers us with energy drawn from the cascade of nuclear explosions that transpire in its core. A tiny difference in mass between merging hydrogen atoms and the resultant helium atom allows our sun to shine.

Our sun radiates about 10^26 joules per second (which is 100,000 times more than the combined yearly energy usage from everyone on Earth), but only a fraction of that reaches our planet.  Photons radiate outward from our sun in all directions, so our planet intercepts only a small sliver of the beam.  Everything living here is fueled by those photons.

When living things use the sun’s energy, we create order – a tree converts disordered air into rigid trunk, a mouse converts a pile of seeds into more mouse, a human might convert mud and straw into a house.  As we create order, we give off heat.  Warming the air, we radiate infrared photons.  That’s what night vision goggles are designed to see.  The net effect is that the Earth absorbs high-energy photons that were traveling in a straight beam outward from the sun … and we convert those photons into a larger number of low-energy photons that fly off every which way.

We the living are chaos machines.  We make the universe messier.  Indeed, that’s the only way anything can live.  According to the Second Law of Thermodynamics, the only processes that are sufficiently probable so as to occur are those that make the world more random.

We’re lucky that the universe started out as such a bland, orderly place – otherwise we might not even be able to tell “before” from “later,” let alone extract enough energy to live.


The earliest living things took energy from the sun indirectly – they used heat, and so they were fueled by each photon’s delivery of warmth to the Earth.  (Please allow me this little hedge – although it’s true that the earliest life was fueled only by warmth, that warmth might not have come from the sun.  Even today, some thermophilic bacteria live in deep sea vents and bask in the energy that leaks from our Earth’s molten core.  The earliest life might have lived in similar nooks far from the surface of the Earth.  But early life that resided near the surface of the seas seems more likely. Complicated chemical reactions were necessary to form molecules like RNA.  Nucleic acids were probably first found in shallow, murky pools pulsed with lightning or ultraviolet radiation.)

Over time, life changed.  Organisms create copies of themselves through chemical processes that have imperfect fidelity, after all.  Each copy is slightly different than the original.  Most differences make an organism worse than its forebears, but, sometimes, through sheer chance, an organism might be better at surviving or at creating new copies of itself.

When that happens, the new version will become more common. 

Over many, many generations, this process can make organisms very different from their forebears.  When a genome is copied prior to cell division, sometimes the polymerase will slip up and duplicate a stretch of code.  These duplication events are incredibly important for evolution – usually, the instructions for proteins can’t drift too far because any change might eliminate essential functions for that cell.  If there’s a second copy, though, the duplicate can mutate and eventually gain some new function.

About two billion years ago, some organisms developed a rudimentary form of photosynthesis.  They could turn sunlight into self!  The energy from our sun’s photons was used to combine carbon dioxide and water into sugar. And sugar can be used to store energy, and to build new types of structures.

Photosynthesis also releases oxygen as a biproduct.  From the perspective of the organisms living then, photosynthesis poisoned the entire atmosphere – a sudden rise in our atmosphere’s oxygen concentration caused many species to go extinct.  But we humans never could have come about without all that oxygen.

Perhaps that’s a small consolation, given that major corporations are currently poisoning our atmosphere with carbon dioxide.  Huge numbers of species might go extinct – including, possibly, ourselves – but something else would have a chance to live here after we have passed.

In addition to poisoning the atmosphere, photosynthesis introduced a new form of competition.  Warmth spreads diffusely – on the early Earth, it was often sheer chance whether one organism would have an advantage over any other.  If you can photosynthesize, though, you want to be the highest organism around.  If you’re closer to the sun, you get the first chance to nab incoming photons.

That’s the evolutionary pressure that induced plants to evolve.  Plants combined sugars into rigid structures so that they could grow upwards.  Height helps when your main goal in life is to snatch sunlight.

Animation by At09kg on Wikipedia.

Nothing can live without curtailing the chances of other living things.  Whenever a plant absorbs a photon, it reduces the energy available for other plants growing below.

Plants created the soil by trapping dirt and dust, and soil lets them store water for later use.  But there is only so much desalinated water.  Roots reach outward: “I drink your milkshake!”, each could exclaim.

For a heterotroph, the brutality of our world is even more clear.  Our kind – including amoebas, fungi, and all animals – can only survive by eating others.  We are carbon recyclers.  Sugar and protein refurbishers.  We take the molecular machines made by photosynthesizing organisms … chop them apart … and use the pieces to create ourselves.

Some heterotrophs are saprophages – eaters of the dead.  But most survive only by destroying the lives of others.

For the earliest heterotrophs, to eat was to kill.  But, why worry?  Why, after all, is life special?  Each photosynthesizing organism was already churning through our universe’s finite quantity of order in its attempt to grow.  They took in material from their environment and rearranged it.  So did the heterotrophs – they ingested and rearranged. Like all living things, they consumed order and excreted chaos.

The heterotrophs were extinguishing life, but life is just a pattern that repeats itself.  A living thing is a metabolic machine that self-copies.  From a thermodynamic perspective, only the energetics of the process distinguish life from a crystal.  Both are patterns that grow, but when a crystal grows, it makes matter more stable than its environment – life makes matter less stable as it’s incorporated into the pattern.

Your ability to read this essay is a legacy of the heterotrophs’ more violent descendants.  The earliest multicellular heterotrophs were filter feeders – they passively consumed whatever came near.

But then, between 500 and 600 million years ago, animals began to hunt and kill.  They would actively seek life to extinguish.  To do this, they needed to think – neurons first arose among these hunters.

Not coincidentally, this is also the time that animals first developed hard shells, sharp spines, armored plates – defenses to stop others from eating them.

The rigid molecules that allow plants to grow tall, like cellulose, are hard to digest.  So the earliest hunters probably began by killing other animals.

With every meal, you join the long legacy of animals that survived only by extinguishing the lives of others.  With every thought, you draw upon the legacy of our forebear’s ruthless hunt.

Even if you’re vegan, your meals kill.  Like us, plants have goals.  It’s a matter of controversy whether they can perceive – perhaps they don’t know that they have goals – but plants will constantly strive to grow, to collect sunlight and water while they can, and many will actively resist being eaten.

But it makes no sense to value the world if you don’t value yourself.  Maybe you feel sad that you can’t photosynthesize … maybe you’d search out a patch of barren, rocky ground so that you’d absorb only photons that would otherwise be “wasted” … but, in this lifetime, you have to eat.  Otherwise you’d die.  And I personally think that any moral philosophy that advocates suicide is untenable.  That’s a major flaw with utilitarianism – rigid devotion to the idea of maximizing happiness for all would suggest that you, as another organism that’s taking up space, constantly killing, and sapping our universe’s limited supply of order, simply shouldn’t be here.

At its illogical extreme, utilitarianism suggests that either you conquer the world (if you’re the best at feeling happy) or kill yourself (if you’re not).

We humans are descended from carnivores.  Our ancestors were able to maintain such large brains only by cooking and eating meat.  Our bodies lack an herbivore’s compliment of enzymes that would allow us to convert grass and leaves into the full compliment of proteins that we need.

And we owe the very existence of our brains to the hunts carried out by even more ancient ancestors.  If they hadn’t killed, we couldn’t think.

Just because we were blessed by a legacy of violence, though, doesn’t mean we have to perpetuate that violence.  We can benefit from past harms and resolve to harm less in the present and future.

Writing was first developed by professional scribes.  Scientific progress was the province of wealthy artisans.  None of the progress of our culture would have been possible if huge numbers of people weren’t oppressed – food that those people grew was taken from them and distributed by kings to a small number of privileged scribes, artisans, philosophers, and layabouts. 

When humans lived as hunters and gatherers, their societies were generally equitable.  People might die young from bacterial infections, dehydration, or starvation, but their lives were probably much better than the lives of the earliest farmers.  After we discovered agriculture, our diets became less varied and our lives less interesting.  Plus, it’s easier to oppress a land-bound farmer than a nomadic hunter.  Stationary people paid tribute to self-appointed kings.

This misery befell the vast majority of our world’s population, and persisted for thousands of years.  But the world we have now couldn’t have come about any other way.  It’s horrific, but, for humans to reach our current technologies, we needed oppression.  Food was taken from those who toiled and given to those who hadn’t. 

Mostly those others created nothing of value … but some of them made writing, and mathematics, and rocket ships.

Although the development of writing required oppression, it’s wrong to oppress people now.  It was wrong then, too … but we can’t go back and fix things.

Although the origin of your brain required violence, I likewise think we ought to minimize the violence we enact today.  We can’t help all the animals who were hurt in the long journey that made our world the place it is now.  And we can’t stop killing – there’s no other way for heterotrophs like us to live.

To be vegan, though, is to reckon with those costs.  To feel a sense of wonder at all the world pays for us to be here.  And, in gratitude, to refrain from asking that it pay more than we need.