Billions and Billions

(Remembering Carl Sagan)

Billions and Billions (remembering Carl Sagan)On a trail near Paradise (truly), Mt. Rainier National Park, Washington, USA. October 1, 2010. © Copyright Richard Mitchell,

Touching Light Photography - all rights reserved.

Billions and Billions (remembering Carl Sagan)

Photos of the Milky Way always keep me humble. Although the nighttime sky often gives the impression of looking out on the universe, in fact nearly all of the stars we see are neighbors of ours within the Milky Way. That's right - those specs of light in the sky are our nearest neighbors, not their distant cousins billions of light years away.

When he was younger, my second son once inquired about UFOs. Not wanting him to be alarmed, I told him that UFOs were nothing to fret about, and in fact aliens surely could not visit earth since even the nearest star was so far away. "What star is the closest, Daddy?" came his next question.

I knew the answer, or I thought I did…"Proxima Centauri" I replied confidently. (Of course, the sun is the NEAREST star…but I knew what he meant).

"How far away is that star, Daddy?" I was in for the long haul now. I knew how curious he was, and I was sure to face an onslaught of questions.

"It's 4.22 light years away, Eric" I answered, hoping this would end the inquisition, and yes, I did know the answer to that question without having to look it up.

"But how far away is 4.2 light years Daddy?". Hmmm…I thought. No way out of this now. I started multiplying in my head, using approximations to simplify the problem. I knew that light traveled at about 186,000 miles per second…times 60 seconds per minute times 60 minutes per hour times 24 hours per day times 365 1/4 days per year times 4.22 years. Tonight as I post this photo, I'm cheating - I just used Excel ... and the answer is - it comes out to 2.477 x 10e13 (10 to the 13th power) miles to the nearest star.

I gave him an answer that approximated that answer… "About 25,000,000,000,000 miles, Eric". (That's about 25 TRILLION miles … to the NEAREST star.)

"But Dad, how far is 25 TRILLION miles???"

I quickly ran some numbers in my head and answered him like this:

"If you were to get into the fastest spaceship any human has ever flown in ... on the first day of your life... and you hurdled through space towards the NEAREST STAR for the REST OF YOUR LIFE until the day you died, the nearest star would not seem any closer on the day you died than it did on the day you were born." (In fact, you'd cover less than 1% of the distance at 25,000 miles per hour in a 100-year lifetime. There are probably faster spaceships now, but that is still a reasonable approximation.)

That answer seemed to satisfy him, and it opened up the vast realm of space to my mind. Suddenly, the universe seemed HUGE. The nearest star - at 4.2 light years - so far away, and yet there are stars 15 billion light years away. One day, when you have the chance, look at the Hubble Deep Field Image of a spec of sky with 1500 GALAXIES in it...it is truly wonderous.

Gazing into the endless emptiness of space above my head on a lonely dark trail in Mt. Rainier National Park, I again really saw the vastness of this amazing universe, the depth of space above me, and wondered about so many things, and the connectedness of all living things, and the good fortune in having friends to share this with.

Technical details: Canon 5D MK II ISO 6400, Canon EF17-40mm f/4L at 17mm, exposure for 30 sec at f/4.0 with high ISO and long-exposure noise reduction ON.

This photograph is not in the public domain and may not be used in electronic, print, or any other form, without advance permission from Richard Mitchell. Richard Mitchell Touching Light Photography

Flickr Twitter Facebook Blog Email