Rocks, smoke, and chipmunks

It's good to be back on some serious trails again. Badger and I hiked up Independence Peak, in Pence Park, South of Bear Creek and Kitteridge, last week. It was more demanding than Panorama Point being a little further, about a hundred feet more elevation gain, and fewer switchbacks. Still, there were a lot of people out and, if you've been reading this blog, you know that I consider that a plus.

If you're on the Eastern Slope of the Rocky Mountains, you might have noticed a more-golden-than-usual sun lately. When I wrote about sky colors, I neglected to mention that some of the most beautiful (and weird) displays are caused by things you don't want in your lungs. If you've ever seen any of the images from Mars, that sky is the opposite of ours - red during the day and bluish at sunrise and sunset. NASA thinks it has to do with Mars dust, which has magnetite (basically rust) in it.

I sorta felt like I was back in the Great Smoky Mountains.

The forest fires causing this is almost 400 kilometers (over 240 miles) away, but the prevailing winds are from west to east here. I've read that much of the topsoil in Brazil is blown across the Atlantic from the Sahara Desert in northern Africa.

I remember a fire in the Okefenokee Swamp in Georgia that made Selma, Alabama look like the woods just outside town were burning.

The Smokies in the Appalachian Mountains were known to be smokey long before Europeans moved in. The valleys and hollows created natural channels that captured and held aerosols from campfires and natural forest fires all over the East. With industrialization, acid rain from nearby Copperhill, Tennessee became a serious problem.

The stars of this trip are these fellas.

Chipmunks were all over the rocks and they seem to have no fear of humans.

How does the wildlife in your area behave around humans? Do wind patterns there collect smoke, dust, or pollution, or do they clear them out? How?

The Rainbow Connection

I guess I've seen a handful of rainbows since I moved to Colorado in 2013. They're not a common occurrence here like they were in the much rainier South. The rain, the sun, and you have to be lined up in a certain way to get a rainbow.

My favorite rainbow memory is from my days as a welder's assistant on a pipeline barge in the Gulf of Mexico. We were installing a riser (the part of the pipeline that connects it to an oil well platform) and it was late on an overcast day. The sky was dark but the horizon was clear and where the sun was setting it was blood red, casting a deep red light across the underside of the clouds. Against that backdrop was a brilliant triple rainbow.

I had to get out our lawn sprinkler to get this one.

Here's how rainbows work. A rainbow is actually a cone. The part you see is where a sheet of rain intersects the cone - it's actually a circle. It looks like a bow because part of it is below the horizon or underground.

The apex of the cone, it's point, is at your anti-solar point. If you draw a line from the sun (don't try this) through your head (right between your eyes) and continue it down into the Earth, that's your solar axis. The anti-solar point is somewhere on the solar axis below you. Now, imagine a cone extending back toward you from that point.

The cone has an angle of 40 (the blue part) to 42 (the red part) degrees - that's the angle at which the light leaves the raindrops). That means that the sun has to have an angle of inclination of 42 degrees or less to see the rainbow. For my rainbow (the sun's angle of inclination is the same as the top of my shadow's angle of declination - only positive.

49.1° ... wait... that's more than 42°.

Hey, okay, notice that my rainbow was formed by a lawn sprinkler and it's below the horizon.

I mentioned that my favorite rainbow was a triple rainbow. If you ever see one of these, pay attention to the order of the colors. In a secondary rainbow, the order is reversed with the blue on top. That's because the light is reflected twice inside the drops. The drops that cause a secondary rainbow are completely different drops and the cone is at 51° to 54° of the anti-solar point.

Triple rainbow? Well, there are a lot of different kinds of rainbows. Some can be formed by light from the sun bouncing off the surface of a lake or the ocean and then hitting rain. If a rainbow is caused by sea mist, salt water has a different index of refraction than fresh water, so the angle of the cone will be different. Also look for rainbows in waterfalls and geysers. And if you're in a plane and see a rainbow in the clouds below you, you may be able to see the whole circle!

Rainbows are special, and rare. If you see one, see if it looks different than the one I described and see if you can figure out what makes it different.

Sunsets and mountains

Suddenly, I'm hiking again. The bug has bitten one of my housemates. We have been to the Lair O'the Bear, between Morrison and Kitteridge, Colorado the last two weekends. At the western end of Bear Creek Canyon, it's a short drive from home and it's near a new favorite restaurant, the Switchback Smokehouse, in Kitteridge (they have an ice cream shop next door!), so it's a great destination for me.

I didn't get many photo-ops the first time. Everything's so big it's hard to get a good picture, but Panorama Point provides some workable views. Here are some of the pictures.

Maidenhair ferns

Penstemon. The main wildflower season is done, but there are still some nice surprises out there. We also saw a lot of anemones but they looked pretty tired.

I don't know why there are things in this tree but it makes an interesting subject. There may have been people rappelling off the Point.

View to the southwest

Kitteridge and, in the distance, Mount Evans

I've also picked up some nice shots from home.

An airplane. We're near Centennial Airport and get a lot of air traffic over our house.

The sunsets have been nice recently.

I'm still working on physics and astronomy excursions and should have something to show for it soon. In the meantime, keep exercising that camera.