The Milky Way's Galactic Center in the night sky above Paranal Observatory

So, we thought about how we might travel into the future, if we could break some bonds, but what about traveling into the past?

Tonight, I was sitting outside sipping a cup of tea and looking up into the Milky Way galaxy as many people have done before me.  It has the appearance of a disk-shaped structure that is being viewed from inside. Our Earth is around two-thirds of the way out from the center, on the inner edge of a spiral-shaped concentration of gas and dust called the Orion–Cygnus Arm.

This faint band of light was shown by Galileo Galilei and his telescope to be individual stars. And about four centuries later, Edwin Hubble showed us that the Milky Way was just one of around 200 billion galaxies in the observable universe.

It is pretty awe-inspiring to look at it and know that it is about 13.2 billion years old, nearly as old as the Universe.  It is about 100,000 light-years wide, so light from its more distant stars can take thousands upon thousands of years to reach Earth. When we look at those stars, that light, we are looking back in time. Astronomers measure the cosmic microwave background radiation and they are looking back more than 10 billion years.

But that’s not your idea of time traveling into the past, is it?

Einstein’s theory doesn’t say that we can’t travel into the past, but we smack into a few problems – like the law of causality (cause and effect). One event leads to another in an endless one-way string of events. Cause comes before effect.  The baby isn’t born before its parents meet. That’s reality, so many people dismiss time travel into the past. And some tricky paradoxes.

But maybe, just maybe, we can we can hit warp speed and beat the cosmic state troopers by propelling a bubble of space-time across the universe.

For now, I’ll just have to be content with staring into the Milky Way. Which is pretty nice, and pretty safe.

A panoramic image of the Milky Way arching across the night sky shot from a dark sky location.

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