Have you ever considered what life would be like without that very thin, fragile band of concentrated gases (concentrated in relation to what lays beyond it anyway) that we call our planetary atmosphere? How about that tenuous (meaning barely noticeable) magnetic field that reaches out into space to protect us from cosmic plasma and radiation? Not to mention together dealing moderately effectively with more solid cosmic detritus ranging from specks of dust, through huge kilometres wide chunks of rock to the very occasional fully formed planetary sized objects?
Well, there wouldn’t be any life on Earth at all, would there? No. Absolutely.
But, just imagine for a moment if you could look up to the sky, well, not the actual sky because there wouldn’t be one, but to the openness of space without the interruption of atmosphere or magnetic field. Sort of like driving a car without a windscreen.
How fast do you think you would be traveling?
I can tell you, or at least give you some idea.
Consider that the Earth travels through space (the universe), not in a straight line (though it could be considered a straight line from our puny viewpoint) but in rotational motion (circular).
First of all, the Earth is spinning on its own axis with a surface speed at the equator of 1600Kph or 1000mph (enough to make your eyes water?), gradually reducing in speed past the latitude where you are standing or sitting, until if you were standing at either of the Earth’s poles you would simply (well, not quite that simple) be rotating completely once a day while standing still, without moving.
Then, the Earth is itself rotating around the Sun at an average speed of 100,000Kph or 66,000mph (getting blown away yet?). Just how fast is that? Well, consider how far you would have traveled (are actually traveling right now) between say, now …and …now. Well, in that approximately one second of time you have actually moved through the universe more than 27 kilometres or 18 miles. Mind-blowing stuff, eh?
Now, imagine this (it is not imaginary, but actually real), our Sun also has both rotational and directional movement as part of the galaxy that it belongs to (what we call ‘The Milky Way’). We have already dealt with the rotational aspect in the preceding paragraph but the Milky Way’s directional movement as it travels through space, causing our Sun to move in an even straighter line (though it is really a huge circle around the galaxy) is another thing entirely. See if you can find out that piece of information for yourself (why should I do all the work?). This would add a considerable new dimension to your speed of travel as you gaze upwards beyond the sky.
But, there’s more. The galaxy itself has both rotational (which we have just dealt with) and directional movement through space, in relation to other galaxies and as part of the expansion of the universe. Too mind boggling to consider in this particular forum.
What can we gather from all this? Well, at least a couple of things.
One. We are never, never ever, between any two moments of time, living out our lives at the same place in the universe. Never standing still. Consider that.
Two. If we are ever going to bump into anything at all solid in nature and of appreciable size, with or without our protective screens (oh, by the way, you can stop imagining there is no sky now), it is going to make quite a huge mess. Consider that too.
Disclaimer: The figures used in this piece have been rounded to make understanding easier. No corrections or precision is necessary for the conclusions drawn from the facts as given, though comment is welcomed. I make no claim to being a cosmological expert, so you take my point of view here at your own risk. I could be making all of this up. Trust no-one. Question everything.