Thinking About Numbers

‘Numbers’ is a challenging word.  Especially for people who don’t like to deal with them.  Numbers can live up to the meaning of the root word, and be numbing.  I like numbers.  Let’s see if I can make numbers interesting to those of you who are ‘numerically challenged.’

Let’s start with the age of the earth:  Four or five billion years, according to geologists.   Some Christian believers would say around six thousand years.  That difference of opinion is a factor of almost a million!  Astronomers look out through their telescopes at distant galaxies, and deduce that those galaxies are five billion light years away.  Think about that.  The photons of light that they see through the telescope started traveling toward the earth about the time that the earth was condensing from the disk of debris and gas circling the young, yellow dwarf star we call the sun.  Unless you believe that God created all of this six thousand years ago, and then gave us the intelligence to build telescopes and deduce the distance to those galaxies, just to deceive us.

How far is a light year?  Light travels 186,000 miles per second.  That’s about six trillion miles in a year.  In five billion years, the light from those distant galaxies has traveled 30 trillion billion miles! That’s a three followed by 22 zeroes!  The Cosmos is a pretty big place…unless you are a member of the International Flat Earth Society.  They believe that the “dome of heaven” and all the stars and planets are only about four thousand miles away.  They also believe that the Apollo moon missions were a massive hoax perpetrated by NASA, and that the Space Shuttle has never orbited the earth.  You can’t orbit a flat earth, they say.

Astronomers say that our sun resides in the Milky Way, a spiral galaxy.  Spiral galaxies are disk-shaped, with a dense nucleus of stars, dust and gas clouds, surrounding a Black Hole at the center.   Stretching out from that chaotic nucleus are spiral “arms” of similar, but less-dense material.  Our galaxy contains about two hundred billion stars, and is about one hundred thousand light years in diameter and a thousand light years thick.  The closest star, Proxima Centauri, is about four light years from our sun.  Some day, we might figure out a way to travel to Proxima Centauri.  The round trip would take at least eight years, though.  According to Einstein’s Special Theory of Relativity, nothing can travel faster than light.  So, exploration of even the more distant stars in our galaxy will never be possible, given the short human lifespan. Think of all those other galaxies full of quintillions of stars out there that we can never know about.  Recent findings indicate that many stars have planets circling them.  Some of those planets may have life.  How insignificant our little earth is, circling a very ordinary little middle-aged yellow dwarf star, in an outer spiral arm of a relatively large, but otherwise unexceptional galaxy…just one of the many galaxies in the Local Group, a small cluster of galaxies that is part of the Local Supercluster.   It, in turn may be part of a larger-scale structure like the Great Wall, a filament-like sheet of superclusters that is 500 million light years long, 200 million wide, but “only” 15 million thick.  The word “vast” is vastly overworked in trying to describe the scale of these things.  Isn’t it a ridiculous, egotistical self-delusion that we view ourselves as special beings, chosen exclusively by God in the grand scheme of this magnificent, mysterious, unknowable Cosmos? 

Now, let’s go from the incredibly large to the incredibly small.  How many cells does the human body contain?  Opinions on this differ, but the consensus is somewhere between ten trillion and a hundred trillion.  That’s a 1 followed by 13 or 14 zeroes.  Consider that number in relation to the stem cell controversy.  The blastocysts that scientists grow to harvest stem cells contain 100 to 150 cells…about one trillionth the size of a human body.  Does a blastocyst grown in a Petrie Dish have a soul?  Some Christians think so.

Cells, of course, are made up of molecules, which are made up of atoms.  Atoms contain protons, neutrons and electrons, but these can be further broken down into leptons, quarks and bosons.  Physicists keep finding more and smaller bits that everything is made of.  How big is a molecule?  A chemist in the nineteenth century came up with a number.  His name was Amadeo Avogadro, and this number has his name on it:  Avogadro’s Number.  It’s 6.022 times ten to the twenty-third power.  Or 6022 followed by 20 zeroes.  Eighteen grams of water, slightly more than half an ounce, contain that number of water molecules.  Molecules are pretty small.

Here’s a more down-to-earth number:  There are around seven billion humans living on our planet at the moment.  That is far more than there were a hundred years ago.  How fast is the population growing?  Here are a few milestones:

              Year      Estimated World Population (millions)

  • 1000        300
  • 1300        400
  • 1500        500
  • 1700        650
  • 1800        1000
  • 1900        1600
  • 1950        2500
  • 2000        6000
  • 2011        7000
  • 2024        8000  (projected)

 What is clear from the above is that something happened in the 20th century that caused the growth in human population to accelerate, and it continues to accelerate in the 21st.  Before that, growth had been steady, but more-or-less linear.  What happened was that the industrial revolution, and in particular the mechanization of agriculture and commercial fishing made it possible to produce a lot more food.  Also, improvements in medical science stretched life expectancies and reduced infant mortality rates.

Many scientists feel that the current population is far above a sustainable level, and that we are currently in an “overshoot” period.  The return to a long-term sustainable level may not be pleasant, resulting in the deaths of billions of people through famines, epidemics, natural disasters and, of course, wars.

I’ll quit on that cheery note, hoping that you are no longer numbed by numbers.

3 thoughts on “Thinking About Numbers

  1. This was fun reading, Bert!
    It’s always exciting and overwhelming to read about the size of our entire universe. Not really comprehensible to most of us, but exhilarating to imagine.
    I guess many or most people think whichever religious group one belongs to is unique in the universe, but I do know that many Christians accept the fact that we are not the only inhabitants of the solar system that may have been saved. Also an idea that opens one’s mind to exciting possibilties.

    Thanks, Gerry

    1. You could say that we humans live in the middle…infinitesimally tiny compared to the Cosmos, but incredibly huge compared to a molecule.
      The numbers are so large that they defy our imagination. Ten to the twenty-third power? How many is that? Nothing in our worldly experience gives us an example or a clue.

Leave a Reply

Your email address will not be published. Required fields are marked *