I often find that the only way to truly fathom just how vast the universe is, or to successfully communicate the insane enormity of it to other people, is to illustrate just how small humanity is. After all, everything we ever do, say, or experience is measured against the yardstick of human endeavor. It’s great to say that the universe is 14 billion years old, or that Voyager 1 is now flying towards one of the nearest habitable planets, but it’s only when we put things in human terms do we truly appreciate the scale of the universe.
In the image above (click here for a larger version), the blue dot represents the bubble of humanity’s influence in the Milky Way. The bubble is roughly 200 light years across, representing the farthest distance that our earliest radio transmissions will have reached. While broadcast radio as we know it is generally considered to have begun with Tesla and Marconi’s experiments at the end of the 1800s, humans have been toying around with electricity — and thus pumping electromagnetic radiation into the atmosphere — for at least 200 years.
To read more, click here.