Fire and Ice

Warm Morning Sky

Some say the world will end in fire,
Some say in ice.
From what I’ve tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To know that for destruction ice
Is also great
And would suffice.

Robert Frost  (From Harper’s Magazine, December 1920.)







We know, sounds made by a moving objects will sound lower if the object is moving away from us and the same sound will sound higher if the object is moving towards us.  We've all experienced the distinctive change in frequency as something making noise rapidly gets closer and then passes by.   The change in frequency based on whether an object is moving toward or away from you is called Doppler shift.  Amazingly, a similar shifting happens with light.  Objects traveling towards us appear bluer, and objects moving away appear redder.  From astronomy, we know stars within our galaxy are both shifted red and blue.  Meaning some are stars are getting closer while others are moving further away.  But.... from the study of light from other galaxies in the universe, they are all red shifted, meaning all other galaxies are moving away from each other.  Probably since the "Big Bang".  If this process continues, eventually everything in our universe will spread out, stars will burn out and we be left with a cold, dark and boring place.

    This is the way the world ends
    Not with a bang but a whimper.

    The Hollow Men (1925) a poem by T. S. Eliot 

Not emotionally appealing: frozen, dark, and lifeless. Yuck...

Frozen Back Yard

However, it is also the possibility the universe's expansion will eventually come halt, (red shift become blue shifts) and the universe will begin to contract and eventually collapse into a single point.  It will be hot and there will be fireworks.  In "The Big Crunch", the universe will end fire, followed by perhaps, another "Big Bang",

This is a more reassuring ending, because, it is conceivable, this could result in an exact carbon copy of the universe being reborn.  And, if that were the case, we could meet again and you could be reading this again a couple billion years from now!