We are all (I assume) very comfortable with the tangible, observable facts that surround us. I am sitting in a chair at a desk in front of a computer I assembled a couple of Augusts ago from parts recommended on the www. My desk is cluttered with papers, CDs (some music, some software), a few groupings of office supplies, and some random stuff that I haven’t gathered the courage to toss yet. Oh, and a work glove – I really have no idea what it’s doing here. Beyond the desk, there are a few tables, one for a scanner, one for a printer, one for a reading light next to my recliner (I should call this the Sleepinator™, or perhaps the Napinator™, as I only nap (or “have a kip,” thus the British trademark for the Kipinator™ is born) in it). My cat (her name is Emma) is sleeping on the window seat (a little earlier, she was sleeping in my left armpit as I read in the Napinator™).
A brief paws for a picture of my kitty (it’s a little blurry, but captures her majestic qualities quite well I think; as she spends a lot of time sleeping, this is an “action” shot).
The floor has a nondescript light brown carpet but is covered by a Persian rug. Various electronics lie about with a nice efflorescence of cabling (I prefer LAN lines to WiFi), and too many books in boxes (although tidy boxes, I might add). Beyond the walls and windows, all objects as well, lies the planet at large, with a scattering of trees interspersed liberally with asphalt and concrete, grass and weeds, shrubs and (less obviously) the invisible beds of fungi waiting to fruit a body and exhale a cloud of spores so that more invisible beds of fungi will grow (and let’s not forget their friends, the adventitious bacteria, etc.). There are squirrels and a variety of birds with wonderful voices, a few neighborhood cats and when accompanied by their obedient masters a variety of dogs, usually of the small and yappy kind (see majestic cat above). An unnecessary miscellany of automobiles, some small and energy-efficient (relatively speaking), some comically large, supported on wheels that would do a gargantuan earth mover proud, move around out there, rushing on errands that may or may not be as important as indicated by their speed. And then there is lots of earth and rocks and sky and, eventually, ocean and, down further, mantle and magma and other molten earth essentials, simmering away at 3,000 to 3,500°C (5,432°F to 6,332°F for non-scientists and Americans) and at a pressure of 1,250,000 (1.25 million) times the pressure up here in my writing room.
Above our sky lie other stars, other planets and moons and asteroids and comets and meteors with all of the associated atmospheric heterogeneity imaginable (methane or sulfuric acid or nitrogen or hydrogen sulfide of frozen water or… well, just about anything) and maybe other life forms, other squirrels and cats and dogs and grass and weeds and shrubs and trees and intelligent bipeds (I mean, whom among us really knows at this point in our young, relatively unevolved lives; there are, apparently, in excess of 100,000,000,000 (100 billion) galaxies known to date (with the limits of our present instrumentation) and each of those galaxies is estimated to have 100,000,000,000 (100 billion) stars, each with who knows how many planets and moons and asteroid belts and all the rest). There is a ton (by which I mean way more than a ton) of “stuff” around us, very near and extremely far away and we have some idea of what constitutes it all – molecules (small and large), elements, atoms, electrons, protons, neutrons, subatomic particles, weak and strong attractive forces, electromagnetic particles and waves (energy), gravity, all the subatomic particles you can blast out of nuclear hiding places in the various kinds of accelerators we have designed and built.
But all of it, if gathered into a giant ball in giant and ethereal hands like a ball of dirt, composes about 4% of the substance of the known universe. The rest of the universe is composed of “stuff” called dark matter (26% of the universe) and dark energy (70% of the universe). As what I have just said may be new to your way of thinking (and/or you may have just stopped reading as I may be entirely nuts), this is an excellent time and place to watch the following video by Dr. Patricia Burchat of Stanford University.
Note how completely energized she is by these ideas (I really love to see passionate people talk about their work). Now, when Dr. Burchat and others in her field speak or write about “dark” matter, they are using words in a very imprecise way. They are finding words that are place-markers for the mathematics that they have worked through, math that is perched on the shoulders of other math worked through by other physicists and mathermaticians, reaching back to the Greeks. But you need to be a deeply committed practitioner of those disciplines to understand what really underlies the metaphorical “dark matter” and “dark energy.” I am attempting – as Dr. Burchat does – to expand on these insufficient metaphors.”Dark” matter isn’t dark in color – it’s not black (a color that appears to our eyes and minds when an object has absorbed ALL wavelengths of light in the visible spectrum), it is not dark in a spiritual or theological sense, it is not dark in the way that
“Dark” matter isn’t dark in color – it’s not black (a color that appears to our eyes and minds when an object has absorbed ALL wavelengths of light in the visible spectrum, which is in turn a very tiny sliver of the overall electromagnetic spectrum), it is not dark in a spiritual or theological sense, it is not dark in the way that Scandinavian “black” metal is dark (that compels me to reach for the “stop” button).
Dark matter is only apparent because of its influence in the fabric of the universe, its effect on gravitational forces that, by way of Einstein (and Riemann) permeate that blackness up in the sky at night and hold the shiny bits (including our apparently sky-blue bit) in place. The observation of dark matter is seen in the behavior of galaxies; stars at the edge of galaxies, if only under the influence of gravity, should move more slowly than stars closer to the center. They don’t; the speed of stars rotating around the center of a galaxy move at the same constant rate as the stars towards the middle of the galaxy, so there must be matter that is interacting throughout the galaxy that forces the exterior stars to move at that rate. An oversimplified analogy might be that we do not see air, but we see the effects of wind (but air and winds are composed of atoms of gasses and have mass and energy that we understand very well, so this is a poor, earthbound analogy indeed). The effect of dark matter is seen not only in the circulation of outer stars (and their planets, etc.) around the center of the galaxy but in how galaxies cluster together and how the light from individual galaxies smears due to gravitational lensing. This unseeable matter has enormous effects in our universe, but we are still struggling to find a method of “seeing” (this is a poor word to use here) it. For some stunning computer simulations of how the universe might have evolved in the presence of dark matter and dark energy, watch the “full-size” version of the film at this website (bottom of page).
Now, if all 96% of the remaining “stuff” in the universe was dark matter, solar systems and galaxies and clusters of galaxies would tend to cluster and the universe would not seem to be expanding outwards. Instead, we (well, astrophysicists and their ilk) observe a universe that is expanding. Space itself is spreading apart. The hypothesis is that this occurs due to dark energy, the predominant “ingredient” in the universe, one so powerful (in spite of its unseeable nature) that galaxy clusters and the universe that contains them in a web of gravitational force are expanding away from each other, the opposite of what we would expect to see from the more neighborly, clustery behavior of galaxies and their contents.
This is weird suprahuman stuff, stuff beyond touch and beyond our usual intuition, unless one bathes the brain in a nutrient-rich broth of advanced mathematics, physics, chemistry, astronomy, and similar elixirs. The concepts of dark matter and dark energy are elusive to those of us who crawl the earth looking for groceries and the next mortgage payment, but I am extremely (EXTREMELY!) pleased that some of us are paying attention to how this whole amazing thing fits together.
To close, while I was writing this thing I thought about a great Brian Eno song called “Help Me Somebody” from his amazing collaboration with David Byrne “My Life in the Bush of Ghosts.” The song centers on samples of Reverend Paul Morton letting his congregation know what time it is but is fattened up by funk of the most satisfying kind, delivered by Eno, Byrne, John Cooksey (drums) and Steve Scales (congas, other percussion); I dare anyone to stay still while listening to this track.
The “lyric” (i.e. Rev. Morton’s sermon) includes the following, which I will paraphrase:
“It’s so high you can’t get over
It’s so low you can’t get under
It’s so wide you can’t get around”
I obviously dilute Reverend Morton’s intent here, but the song and lyric popped into my mind and seemed to be telling me that this is the nature of the universe – so high, so low, so wide. That’s the 96%. We live in the 4%.
As in all of these weighty posts, I encourage whatever readers I have to explore the additional materials. Some of them might make your brains hurt or itch or explode or collapse in on themselves. All of those are good! Do more of the things that make these things happen! There is great happiness available to those that feed their minds!