Forms of Energy


The energy used by your computer to download this post, your screen to display it, and your brain to read it are all fundamentally the same. Energy can take many forms, and there is nothing particularly special about the kind that runs humans. Life is complex, but it always obeys chemical and physical laws. People used to believe in an "animus", a special form of energy that creates life but this idea has long since been debunked. For fun, let's take a look at what it really takes to give a person the ability to perform a seemingly mundane task, pressing a key on a computer keyboard.

This story started a very long time ago. Though the very earliest moments are poorly understood, it is generally accepted that our universe underwent a very rapid period of inflation about 14 billion years ago, transforming from an unimaginably dense, high-energy, homogeneous state to a plasma of quarks and gluons. Today quarks are invariably found locked up as the constituent components of hadrons like protons and neutrons so having a state of free quarks is very "strange". As quarks make up mass, gluons are carriers of energy. Specifically, they carry a fundamental force called the strong nuclear force which generally binds quarks together to form hadrons, in addition to gluing protons and neutrons together to form the nucleus of an atom. However, at this incredibly high level of energy both were free and continually colliding near relativistic speeds, creating and annihilating matter – antimatter pairs. At some point, for some reason, an important balance called the Baryon number was slightly upset and there ended up being more matter than antimatter, which eventually resulted in a universe made of matter.

The universe continued to expand and cool and eventually the other three fundamental forces, weak nuclear, electromagnetism, and gravity, separated and various other elementary particles began to take shape. Quarks began to settle in to their baryons, forming protons and neutrons, as well as their antimatter counterparts, but when temperatures dropped too low to create new matter – antimatter pairs, they mostly annihilated each other, leaving only the slightly offset balance of regular matter from before. A similar process then happened for electrons and positrons (anti-electrons), leaving the energy of the universe dominated by photons and neutrinos, which are the pure-energy products of these annihilations. This all happened in less than a second.

Some of the free protons and neutrons combined to form Helium, bound by the strong nuclear force, but most protons remained free and eventually combined with electrons to form the Hydrogen that makes up the vast majority of the atoms in the universe and our bodies today. As mass came to dominate the universe regions of slightly higher density eventually coalesced via the gravitational force, attracting ever more mass and increasing in density to form gas clouds, some of which reached high enough levels of density and heat to catalyze a nuclear fusion reaction. Hydrogen atoms normally repel each other due to the electrostatic force, but if the surrounding energy is high enough, a percentage can get close enough together for the strong nuclear force to cause their nuclei to fuse, since it is stronger than electrostatic forces at very close distances. This nuclear fusion releases the overcome electrostatic energy as a positron and neutrino, and forms Deuterium, which may then fuse with another atom of Hydrogen, forming Helium-3 and releasing a Gamma Ray, a very high energy photon.

The Sun is a huge nearly perfect sphere of plasma consisting mostly of Hydrogen and Helium, reacting in the core in the aforementioned way. However, since fusion happens only within the core, and the sun is very dense, the gamma rays are continually absorbed and re-emitted by the surrounding mass, taking tens of thousands of years to eventually reach the surface. At this point, each gamma ray is split in to millions of photons of lower energy, visible light. About 8.5 minutes later, some of these photons strike the surface of the earth.

All life takes energy. Without the intake of energy from the environment, an ordered system such as an organism quickly succumbs to entropy and death. Some forms of life have evolved to use the energy produced by the sun in the form of photons. Chlorophyll, for example, appears green because it absorbs mostly blue light, which is shorter wavelength and thus higher energy. The energy from a photon strips an electron from a suitable molecule, such as water, via the photoelectic effect. This ionizes and separates the hydrogen from water. The oxygen is then discarded and the ionized, or charged hydrogen and free electron are transferred to a substance such as NADP+, which becomes NADPH and is later consumed to generate ATP, via the Calvin cycle.

Besides ATP, the chief currency of energy for all cells, the Calvin cycle produces something very important for humans: sugar. Let's take corn for example. Humans have brilliantly optimized the growth of corn by introducing extra nitrogen in to the soil. This means we can cheaply convert the sun's energy in to sugar, or glucose, and then consume it for energy ourselves. After a human consumes this glucose, the small intestine diffuses it in to the bloodstream and a complex mechanism triggers the release of insulin, a protein whose job it is to transport the molecules of glucose to the cells that require them. The Krebs cycle essentially does the opposite of the Calvin cycle, using the glucose to produce ATP, the same molecule used by the plant cells for energy.

The brain, which also uses glucose for energy, "fires" a neuron, changing the electric potential along a pathway travelling down the top of the spinal column, down the arm, to a group of skeletal muscle cells in the forearm called the "lumbrical muscle". As our nerves make for poor electrical conductors, the signal must activate sodium channels on the way to the muscle in order to propagate. Eventually the signal reaches the junction between nerve and muscle, and activates an influx of calcium ions, which in turn releases the neurotransmitter acetylcholine, opening a channel for sodium and potassium ions, forming yet another electric action potential. This potential spreads throughout the muscle, releasing more calcium which binds to muscle fiber regions called Troponin.

This reaction changes the Troponin, which was previously blocking binding sites on the muscle filaments for Myosin, which in turn acts as a binding site for ATP. The ATP binds the the Myosin, causing it to release Actin, a protein serving as a microfilament to stabilize it, and the Myosin extracts energy from the ATP molecule via hydrolysis. Hydrolysis releases chemical energy by breaking the relatively weak phosphate bonds in ATP. These bonds are easy to break, but contain high energy electrons, which is how they introduce extra energy in to a system. This process causes the muscle to contract about 10-12nm, and is repeated as long as the muscle is signaled and there is sufficient ATP and Calcium to drive the reaction. The average key press distance on a keyboard is 3.81mm so it takes about 381,000 iterations per muscle fiber to perform this action.


What triggered the brain to fire the neurons? Information is also form of energy.

  • Kyle

    Establishing credentials, are we?

    Somewhat elegant. I enjoyed reading it. Thanks for writing it. I could read an expanded version of this with explanatory footnotes for a good long while.

    • rob

      Credentials? Hardly, I just wanted to think about something more interesting than food for a time. I’m glad you enjoyed it.

  • Matt Pennig

    Biochemistry blows my fucking mind, every time.

  • Peter


    Interesting stuff. I know of the ATP process because of your soylent writings.

  • stuf

    Hey Rob, i love your project but I have two small comments to this post. First off the baryon number, which is the ratio between normal and anti matter was already offset at the big bang. And secondly hydrogen do as you say repel each other to some extend due to the electromagnetic force but hydrog also held together with other hydrogen in pairs in coveilent bonds, which are also ultimately electromagnetic in nature.anyway I know I might be nitpicking, but coulndt help it :)

    • rob

      How was the Baryon number offset? I still don’t understand the conditions in which this law is not conserved.

  • blast

    ATP is consumed (along with NADPH), not produced, during Calvin cycle. I am also afraid that the calculation of molecular inteactions in the muscle is wrong, since your muscles are not made of single fibres aligned, but rather by multiple fibers aligned and stacked. I recommend caution in writing about biology and doing calculations without the adequate preparation.

    • buster

      Agreed, within reason. At very least, this info needs to be qualified first. Something like, Audience, I'm just spitballing here, and biologists, jump in when I mess up: 

  • Ben Tremblay

    "Information is also form of energy."

    Not really, no. If there are 9 checkers, 3 black, 3 white, 3 red, they could signify dashes and dots spelling out SOS. But that's different from energy.

    "Information is a difference that matters" … so maybe talk about gradients … like potential.

    • Ben Tremblay

      typo: 3 black, 3 white, 3 black

      • stuf

        Someone spend energy arranging those checkers though. There is a whole field of study called information theory dealing with this and it seems it is impossible to store or convey information without spending energy

        • Randomini

          Energy-mass equivalence. End of story.

  • Courtney


  • Martin Garrod

    Nicely written, thank you. However, a couple of small points. "The ATP binds the the Myosin…" deserves an edit. And "into" is a word you don't seem to be too familiar with. It is a preposition indicating, usually, movement towards the inside of a place, usually a noun. Whereas "in to" is the adverb "in" followed by the preposition "to" used to express movement (via the verb) towards the relationship defined by the preposition. "He handed his paper in to the teacher". All of your uses of "in to" are incorrect in this sense.


    • Eyeroll Jones

      I appreciate your knowledge, but you should develop some tact. No one cares about what assbags have to say, even if they are correct. All of your advice is useless in this sense.

      • buster

        I'm going to go with Martin Garrod on this one. There's an important message here and syntax critique is viable. 

      • Martin Garrod

        I like the way you demonstrated your own point by being totally tactful and polite in making your point. That must work well for you and is something I really should learn to emulate. Thank you.

  • SantiMonse

    Amazing, I enjoyed reading it! I wonder how the information is stored in the brain. As a sequence of monomers of a polymer?

    Regards from Argentina!

  • Pingback: Miscellaneous | Annotary()

  • Brad

    I learned more in this post than I have in the sum of the rest of my life. Thank you Rob. 

  • http://yahoo matt wallace

    Thanks for all your study and time that you put into this!

  • Dorag

    I'm amazed by what I've seen so far BUT, of all the things I've seen I have one thing I worry about.

    If this rockets sky high off of kickstarter and people start buying their batches, there are simply so many ingridients needed to be extracted in exact amount into what I will be digesting, which is great by the way.

    HOW can I know , how can we all know for sure that there wouldn't be a mix-up in the ingridients?

    All it takes is someone accidentally switching between the 70ug of Selenium and 3.4g of Chloride and you'll have a big fuck up on your hands, how are you planning to prevent this?


    • James

      Same way companies that produce multivitamins keep from switching the wrong amounts for their (potentially toxic) micronutrients.

  • buster

    The corn-to-ATP journey is way more complex than what is described here. I understand the potential of the rhetoric, and I also understand the confusion caused by its wake. For rhetorical purposes, the term sugar is probably viable. If a dad says to his kids, Stay off the sugar kids, that's probably decent advice. Though, to use pop terms like sugar in proximity to science terms like ATP and glucose, that doesn't cut it. There are two forms of corn sugar present in most American's lives: ethanol and HFCS. Ethanol is alcohol, rhetorically a super sugar, and HFCS is a nearly equal pairing of fructose and glucose. Insofar as crebs is concerned, consume any of this S*** and cells are going to get ATP, but that's clearly not the whole picture. As we all know, cells react to these sources of energy differently. It's also limiting to imply brain cells only run on glucose. These are politicized areas of "science" and they're extremely confusing. 

  • Martin

    I love the knowledge and discussion, thanks Rob for this. My input is that we are seeing this as if we were totally understood macro mechanical beings. I believe we are much more fine tuned that we know off or want to accept. Don't get me wrong I'm not getting religious here, which I'm not, but I do believe that there are things that escape our ability to measure or experience/observe. I'm in for scientific certainty, but we should still respect the fact that we know very little.

    Reading about nutrition I got to know that the electric charge of what we eat is important too. For example Hemoglobin needs to be charged under a certain range so that they repel each other or they clot. By this they maintain their ability to pass through the most narrow capilaries and correctly carry iron to our different cells. 

    Many people take a blood sample and see a correct hemoglobin count and think they are ok, but if those cells are clot they ain't passing through the capilaries and getting the job done.

    • zenith



      So then you can perform some tests on the molecualr weight components in that sample (after fractionation) and see if any are multiples of the Mw of hemoglobin. Or perform some clotting tests, of which there are many. Or go further, and do xray crystallography, hNMR, etc.

      Don't make the mistake of thinking that if you can't understand it or don't know about it, that it cannot in principle be known or is known.


  • M@

    If you haven't read Erwin Schrödinger's "What Is Life", I think you should.  It is very relevant to this post.

  • Саша

    Boring. What's the point of it and how is it related to the main goal of the project?