Rainbows

There is something magical about a Rainbow.  

I have never known of anyone taking a rainbow for granted.  People comment on their size, brilliance, whether they saw a double or not.  "...did you see the rainbow at the kids' soccer game last week?  or the one over the left field fence?  or on the way to work this morning?"

There have probably been as many pictures taken of rainbows as of any other single event.  So what IS a rainbow and why is it so fascinating?  Sometimes you see one and call home to tell everyone about it, but they can't see it?  How can that be?  You are watching a rainbow and it begins to fade and soon it is gone.  Are there lessons to be learned from rainbows?

Before we get into the physics of why they occur, let's see what else we can learn about rainbows.  In the Bible we read that the rainbow is the token of the covenant God made with man that never again would the Earth be destroyed by flood (Genesis 9: 9-17).  God said in Genesis 9:

     13 I do set my bow in the cloud, and it shall be for a token of a covenant between
     me and the earth.   14 And it shall come to pass, when I bring a cloud over the 
     earth, that the bow shall be seen in the cloud.

Was that the beginning of rainbows?  In Genesis 2, just before God made man He said:
 

       5 ...for the Lord God had not caused it to rain upon the earth, and there 

       was not a ^dman to till the ^eground.

      6 But there went up a ^amist from the earth, and watered the whole face of  

      the ground. 

 

A mist, and God had not caused it to rain.  There is some debate over this, of course, but it sounds like heavy clouds covered the Earth and the sun was hidden from view.  When the rain stopped and the sun came out, there was the rainbow.

Just because we understand HOW something works, doesn't negate that it is miraculous.  Ice floats because it expands when it freezes and is less dense than liquid water, the entire Earth depends on that fact.  It is still miraculous--I mean, can man MAKE something as miraculous as water?  I thought not!

 

So here is how rainbows "work."  Rainbows in clouds occur only when the sun is behind your back and is at approximately a 42 degree angle.  Yes, I am saying that you never see a rainbow in the East in the morning hours or in the West in the evening or at noon at all.  Because the Earth gets in the way, you never see a full circle (except under extreme circumstances), nor can you drive through one or find the end of a rainbow.

That should have your attention.  Here is your chance.  Let the arguments begin.  My email address is listed and I do expect to hear from you.

 

Rainbows in the cloud result when white light from the Sun is split apart (diffracted) into the various components by droplets of water.  As the light passes into the droplet, it is split into RedOrangeYellowGreenBlueIndigoViolet (ROY G BIV).  These colors are reflected off the back of the droplet and back to your eye forming a semicircular display which we call a rainbow.  WOW!  All that just from about a million or two droplets of water.

 

 

So the light comes from behind you, reflects off droplets in front of you and you see the rainbow.  If you draw a line from the Sun through the back your head, you find the "antisolar" point or the center of the arc.

Pretty cool huh?  In case you have been so caught up in the fact that you are understanding the physics of light and have missed the most important point of all, let me point out that each rainbow is in the eye of the beholder.  Yes, a camera can capture the refracted light rays, but there is not actually any tangible bow that you can touch with your hands.  It is for you to see and enjoy then, for that moment, and remember...

~klock