Take a deep breath, clear your mind, ponder a Milky Way moment….
Take a deep breath, clear your mind, ponder a Milky Way moment….
Ever wanted a closer look at our Milky Way? Nick Risinger of ESO (Emerson Digitized Sky Observatory) zooms beyond Earth in the direction of Sagittarius. Beyond Sagittarius the camera switches to infrared, allowing us to see through and beyond cosmic dust clouds to objects orbiting the supermassive black hole at the heart of our galaxy.
This is the perfect week to lay naked eyes on the Milky Way. August 14 heralds a new moon, for the next week a waxing crescent moon sets just after sunset. From a rural location moonless night delivers Milky Ways iconic smudge across our sky. (The same Milky Way thousands of panicked callers reported as a UFO when California lights went out after the Northridge earthquake)
Technology capable of imaging cosmic formations at unattainable distances from Earth, led to pondering light years. Most everyone knows the terminology, understanding at some level the vast, unimaginable scope of our universe. I find myself wondering how many actually comprehend the magnitude of a light year. In the spirit of imagination and wonder – my armchair grasp of light years….
Light reigns as “fastest” in the known universe – 186,000 miles per second to be precise. To put this in perspective, in a single second traveling at the speed of light you would circle the equator 7.5 times. Multiplying the number of seconds in a year by the speed per second, you would have to cover 5.88 trillion miles in a year. Putting close to 6 trillion miles a year in perspective is mind numbing. Try picturing a light minute – it takes about 8 minutes for sunlight to travel 93 million miles to Earth. Visualize 525,600 minutes in a year, ponder 8 of those minutes evaporating in 93 million miles to the Sun.
American astronomer Robert Burnham Jr. published Burnham’s Celestial Handbook in various forms between 1966-1978. Burnham popularized the astronomical unit or AU. One AU = 93 million miles and/or 8 minutes of light speed. Coincidentally the number of AU in a light year and inches in a mile happen to be 63,000. All you have to do now is draw a mile long line in the sand to represent a light year – one inch of that line is the distance to our sun.
Extend that mile long line to slightly over 4 miles, you’ve arrived at Alpha Centauri, the closest star system to our own, 276,000 times the distance from Earth to the Sun. If modern technology attempted the 4 light year road trip to Alpha Centauri – it would take well over 100,000 Earth years.
Ponder 26,000 light years to reach the centre of our Milky Way galaxy, estimated to be over 150,000 light years wide. The Andromeda galaxy is 2 million light years away.
Contemplating light years is heady stuff. The next time you gaze at night’s sky, take a moment to wonder. Ask yourself how long it took for starlight to cross the cosmos.
Super massive black holes are the cement holding galaxies together. Massive is a word fitting extremely large objects – preface it with “super” and you have unimaginable size. Asking anyone to visualize something hundreds of thousands, perhaps millions or billions times larger than our sun is pointless. If a super massive pimple came up in conversation – few in the room would struggle over mental images. Super massive black holes defy common understanding, they elude definable points of reference. Ridiculous vastness aside, black holes are considered fictional science fiction devices rather than concrete science fact.
Princeton physicist John Wheeler came up with “black hole” in 1967. Albert Einstein surmised their existence as part of his theory of relativity – simply put, when a star “dies” it collapses in on itself, resulting in a core of dense mass. Picture New York city instantly compressed onto a pin head and you have “baby steps” towards visualizing just how dense is dense. If the “remnant core” exceeds three times the star’s mass, gravity screams “oh hell no” – a black hole is born.
Galaxies cluster around the extreme gravitational pull of black holes. The Milky Way galaxy boasts a respectable super massive behemoth over four million times the mass of our sun. Indiscriminate cosmic glue, responsible for galactic rotation, orbits, and sealed fates for anything passing the “event horizon” – a gravitational point of no return, the threshold of absorption by forces so powerful, not even light can escape.
Astronomers are buzzing over an opportunity to witness a black hole in action. In 2011 German astronomers noticed a gas cloud oblivious to its ill fated path, speeding up as it neared the event horizon. Recent data indicates part of the cloud has begun “spagettification”, a certified sign of black hole might – gravity elongates as it pulls towards oblivion. The main body of this cloud is expected to succumb by April.
To actually observe an object, to see how it behaves as it vanishes into mystery – how cool is that? Ponder a moment capable of catapulting science fiction into fact.
Image via ESO/MPE/M.Schartmann/L.Calcada
Pondering our place in the universe is difficult – comprehension relies on points of reference. Take our sun – sure it’s a star yet we would never call warmth or light “star light” – stars are something a child wishes upon, they live outside the realm of sunlight. We feel the sun’s warmth, watch it rise and fall, take it for granted as air and water. Our sun is tangible, we see it every day – grasping what lies beyond our little corner, visualizing the universe in all its enormity without blowing a fuse – that’s the tricky part.
“Baby steps” elude when discussion of universal scope enter the ring. That said – I’ll give it a try. On a clear night, away from city lights with a dark sky void of moonlit interference – systematic dedication might result in counting 8 or 9 thousand stars. A friend shows up with respectable binoculars and perhaps 200,000 is possible. A good backyard telescope materializes and upwards of 15 million stars blow your mind. In reality – our Milky Way galaxy is home to over 300 billion stars.
Ours is an average sized galaxy – measuring about 120,000 light years from end to end, ( one light year is approximately 9.5 trillion kilometres). Astronomers estimate over 170 billion galaxies in the “observable” universe – stretching outward from us for 14 billion light years in every direction.
Professor Marshall McCall of York University published a “map” of galaxies within 20 million light years of planet Earth.
View larger. | A diagram showing the brightest galaxies within 20 million light years of the Milky Way, as seen from above. The largest galaxies, here shown in yellow at different points around the dotted line, make up the ‘Council of Giants’. Image credit: Marshall McCall/York University
The universe can’t be defined – exceeding imagination being the only definition I can offer. All I ask is that you “look at the damn sky” and at least try.
I don’t believe we are alone in the universe; it isn’t reasonable to think in all those millions of galaxies some form of life doesn’t exist. The belief our world is only 6000 years old strikes me as pure lunacy; a sentient being did not create the world in less than a week. The 140 million mile wide black hole at the centre of the milky way galaxy is not the stairway to heaven. Cuttlefish can instantly change; not only the colour, but texture of their skin because evolution is a weird and wonderful thing. Not for one second do I think our historical timeline is accurate; history , civilization lost, whatever you want to call it, existed thousands of years before textbook history class. Governments keep us on a “need to know” basis, and money makes the world go round.
This makes me a conspiracy theorist; a person dismissed as “out there”, someone who dines on ancient aliens and buys into any hair brained argument that comes along. It isn’t about religion, science or politics; the tables have turned, I’ve been branded – open my mouth about Gobekli Tepe. Puma Punku, even solar flares and eyes start to roll. The other night I caught about 5 minutes of a TV show called Conspiracy Theory with Jessie Ventura; the subject was time travel. Jessie and his “team” were getting to the bottom of secret time travel conducted by the U.S. government, a whistle-blower claimed time travellers visited American presidents before they were elected, informing them of their destiny. I’m not able to say the how or why because something dawned on me while scrambling to change channels.
The conspiracy conspiracy seemed the only plausible explanation. Take ex pro wrestler, turned former Governor of Minnesota, Jessie Ventura; throw in Oliver Stone’s son as one of his “investigators”, turn them loose on scripted nonsense, pretty soon the mere mention of something unexplained smacks of crazy. Pure and evil genius.