What a night- Fremont Peak, near San Juan Bautista. The Milky Way from horizon to horizon. Even though I wander through life in the fog and dark, this was the darkest dark I’ve experienced for some time. The familiar constellations were obscured by the appearance of thousands of stars invisible from my back yard. We looked up for 4 hours after which I couldn’t look down, literally.
With my telescope, a scarf and veteran astronomer Alan Zaza, and his, (OK, bigger) telescope, I spent a glorious night looking up in space and back in time. The most magnificent object we observed was The Veil Nebula. This gossamer object, 50 light-years across, is the remnant of a supernova explosion. Imagine. An object 300,000,000,000,000,000 miles across imaged on my little ‘ole retina. Goodness! The number itself barely fits.
In order to see this ghost of an object, it is necessary to block out all the light behind and in front of it. We used an OIII filter, which lets through only light resulting from a very improbable event- the forbidden* downward energy transition of doubly ionized oxygen (Naughty, naughty atom!). For many years, the origin of this light was thought to be evidence of a new element, Nebulium. The actual origin was ruled out because of its statistical improbability. But in 1927, a guy named I.S. Bowen said, “Hey, in space, ANYTHING can happen” And so it does and so right he was. I mean, I’ve heard of thinking outside the box, but this was RIDICULOUS! What a great thinker.
Unbelievable, no? We are seeing forbidden light from an atom trillions and trillions of miles away. As we encounter so many times in astronomy and cosmology, the very large, the very small and the very improbable are evident at once. The Veil Nebula is thought to be about 1,500 light-years away. When those oxygen atoms made their impudent transitions, King Arthur was looking for the Holy Grail. Think about that. And when you’re through, think about something else, like who you’re going to vote for in November.
I re-read this piece and I see words like ‘forbidden’, ‘improbable’, and lots and lots of zeros. And that’s astronomy for ya’. So much of it is difficult to imagine. Astronomy reminds us how restricted our “born-with” senses are and how infinite, in comparison, is the intellect which has enabled us to perceive so far beyond the limitations of vision, hearing, touch, smell and taste. Clever, us Earthlings.
* For ‘forbidden’ read ‘highly improbable’. Scientists are always exaggerating for dramatic effect.