Less than 100 years ago we thought the Milky Way was the entire Universe—one starry pinwheel floating in empty space, like a lone actor under spotlight, reciting his soliloquy to a dark and empty theater.
But in 1923 astronomer Edwin Hubble spotted distant fuzzy blobs of light through a 100-inch Hooker telescope. He realized they were agglomerations of stars, and his observations proved there were galaxies outside our own.
What Is a Galaxy?
A galaxy is a massive system comprised of stars, interstellar dust and gas, and a component we’ll learn more about momentarily called dark matter. Galaxies are bound by gravitation and usually revolve around a supermassive black hole.
The Milky Way, Our Home
The Milky Way is a spiral galaxy over 100,000 light-years in across. (A light year is a unit of distance determined by how far light travels in one year at 186,282 miles per second.) Our galaxy contains anywhere from 200–400 billion stars. That’s a lot of stars.
Our sun is located about two-thirds of the way out from the center of the galaxy, on the inner edge of what is called the Orion-Cygnus Arm. And around this single sun orbit the planets, including the one we live on.
The Milky Way is estimated to contain hundreds of billions of planets, 10 billion of which could be located in the habitable zone of the stars they revolve around. This lends fairly good odds for the possibility of life on some of those planets or their moons.
Ours Is One of Many Galaxies
We think the Earth is huge. But it’s tiny compared to Jupiter or Saturn.
It would take years to travel to these neighboring planets in a spacecraft. Yet these distances are nothing compared to the distance between stars—or the expanse between galaxies.
Ours is not the only galaxy in the neighborhood. And it’s by no means the largest.
The Adromeda galaxy, the closest to us, is over 200,000 light years in diameter. Messier 87 is larger still, but IC 1011 is six million light years wide—enormous in comparison to ours—and the largest galaxy known.
Galaxies vary in size and can contain anywhere from 10 million to 100 trillion stars. There are more than 170 billion galaxies in the observable Universe.
Galaxies, Clusters, Filaments, and Dark Matter
Galaxies are themselves like stars, sprinkled throughout the Universe. They are collected in clusters, which are grouped in super clusters that make up filaments over a billion light years long. These filaments are networked in a vast cosmic web like the texture of a sponge, a sponge saturated with dark matter.
Dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly seen with telescopes. Dark matter is believed to constitute 83% of the matter in the universe and 23% of the mass-energy. (http://en.wikipedia.org/wiki/Dark_matter)
Dark matter holds galaxies together in groups and combines these groups together in space. There is about six times as much dark matter in the Universe as there is regular matter. The Universe could not exist without this enigmatic substance. It’s what fills the “empty” spaces of the filament sponge.
How Big Is the Universe?
Is this intergalactic sponge the entire Universe? Or is it only a tiny fraction of something even bigger?
Is our Universe the only one? Or is it merely a cell in the greater body of All That Is, like one sun among the trillions in a galaxy?
Contemplating such things can boggle the mind. It seems that space and all it contains goes on forever in ever vaster scales.
The same is true of the small.
The Cellular and the Subatomic
Zoom back in to our Universe, to our galaxy, to our solar system, to our planet, to where you are. Look at your own hand.
Living matter is composed of cells so small you need a microscope to see them. And the matter of this plane is comprised of molecules—combinations of atoms so miniscule that they cannot be seen without the aid of an electron microscope.
We once thought atoms were the smallest unit of matter. Today they seem big as solar systems with the discovery of more and more subatomic particles such as neutrinos and quarks and leptons and gauge bosons.
Particle theory may lead to the discovery of subatomic substances like the conceptual koilon mentioned in “How Spirit Interpenetrates the Physical”.
Where Do You Fit In?
Now they say that no matter how large or how small—or how far apart—each part of the Universe is connected with every other, transcending even time.
All this talk can leave you feeling pretty small. Where do we fall in the grand scheme of things?
In a Universe as colossal and glorious as ours, I see the plan of Infinite Intelligence at work, manifesting both Natural Law and personal care. David wrote,
3When I look at your heavens, the work of your fingers,
the moon and the stars that you have established;
4what are human beings that you are mindful of them,
mortals that you care for them?
5Yet you have made them a little lower than God,
and crowned them with glory and honour.
—Psalm 8:3-5 NRSV
The next time you look at the stars—or your own hand—realize how immense the Universe it, but know that you’re still important and that your presence matters.
