Mind Wandering

I recently found myself in a church, the one two blocks from the house I grew up in. The one where my mom sang in the choir. And where I spent many a Sunday bored to tears for about an hour.

While trapped in a pew I would spend time looking around, day dreaming, and wondering about an optical illusion.

This is the alter as it is today, a bit more open and bright than when I was a school kid.

The illusion has to do with the brown arch at the top of the image.

Or is it a white arch?

At either end of the arch is a corner piece. Sometimes it appears brown and concave. And others, white and convex. At least to me. And has since I was in grade school. How does it appear to you?

🕯  🕯  🕯  🕯  🕯

There was another optical puzzle to occupy my time on this visit.

Look at the candle shadows in the image below (bigafy for best results).

The shadows for the right three candles appear "solid" while those for the left three have a dark center with lighter edges. Curious. The key for me to solve the puzzle was the leftmost candle on the right side. It has a shadow lighter than the other two.

That's because it is only one shadow, from a light to its right, whereas the other two are shadows from two lights, on on the left and one on the right, and from two candles. It just so happens that the geometry of the situation, for the candles on the right, is such that the shadows overlap. So for the shadow to the left of the middle candle, it is the shadow of the middle candle from the light source to the left and the shadow of the right most candle from the light source on the right. The leftmost candle on the right side does not have a candle to its left, so the leftmost shadow is from only one candle.

If you look at the base of the candles on the right, you can see the double shadows as the back wall juts out a bit, and the geometry is no longer such that the shadows overlap.

Here is a text based schematic diagram:

                                                  Double

                         Shadow             Shadow

                                \                      /\

                                  \                  /    \

                                    \              /        \

                                      \          /            \

                                        Left              Middle

                                      Candle            Candle

                          

                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                            ^            

                            |    gap between lights and candles

                            v

                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                Left Light                                                Right Light 

                   Source                                                       Source

For the three candles on the left, the lights and candles don't quite line up, so the overlap of the shadows is not complete. Thus the dark center to the shadows, that's the overlap.

Kitchen Optics

Les Cowley, the host of the Atmospheric Optics website, uses the term "Kitchen Optics" for everyday optical phenomena all around us.

And a couple of days ago I experienced some literal Kitchen Optics, as evidenced by these images of my kitchen sink.

As I was starting up the coffee maker that morning, I noticed the colors in the sink. The water in the wine glass was acting as a prism, or in this case multiple prisms, resulting in the colors in the sink. Or at least that is what I think is happening.

Les and I are kindred spirits, in that we find these phenomena fascinating. I suspect most people wouldn't even notice, or give them a second glance. I know that at least some readers have become interested as well. And that is cool. And if you haven't, that's ok too. Hopefully you'll enjoy the next post. :-)

I've sent these to Les, and I hope he enjoys them as well. And that they cheer him up. You see, when I sent him my Halo images from last month, to see if it really was a 9° Halo, I received an email stating that Les was recovering from major surgery. Not a response I was expecting nor wanted.

Get well soon Les, get well soon.

Solar Halos?

This past Saturday while sitting on the deck taking a break from yard work, (installing a deer fence around the other half plus of our yard), I looked up (I know, right?). And I saw a ring around the sun. So I took some pictures. As I didn't think it was all that spectacular a display, I used my iPhone, and didn't bother to go get a 'real' camera. Too lazy and too dirty to go inside.

The bright outer ring is the plain old 22° Halo, seen on this blog on multiple occasions.

It is the ring closer to the Sun that has me wishing I had gone and gotten my 'real' camera. It is a 9° Halo? Is it an artifact of the iPhone optical system?

The display lasted for quite a while. I took this image more than two and a half hours after the first (I did some yard work in-between, I'm not that lazy!). And while the 22° Halo is still quite prominent, the inner ring is barely there if it is at all (there are camera artifacts though). This actually makes me more confident the 9° Halo is real.

Next time I'm gonna get up off my lazy *** and get a camera more suited to this subject.

Until then, keep looking up!

Spectrum

The other day I blogged about an optical phenomena I could not fully explain.

I have no problem explaining this one. Again this is in my home office. But this time the cause is obvious. A prism sitting one of a pair of desktop speakers.

Standing on the shoulder of a giant as it were, Sir Issac Newton, we understand how light is refracted by wavelength. The really cool thing about spectra is that it can be used to determine the chemical make up  as well as the speed of objects in the universe.  Sir Issac would surely be amazed but probably not surprised.

If you look closely the writing on the prism stand reads, "Edmund Scientific Barrington, N.J." I bought it on my first and only visit to this legendary optics supplier. Alas, I visited during the store closing sale. So while I missed it's heyday I have a bit of it on my desk, still functioning after all these years.

Another Optical Puzzle

 One morning, and it was only one morning, I saw these colors on my home office window.

The photos came out darker than it really appeared, the sun was up.

I snapped some quick images before it disappeared. I planned to investigate further in subsequent days, but the phenomena did not recur. 

These phenomena are ephemeral. And need to be studied when they occur. I lesson I need to heed.

When Given Lemons ...

... write a blog post.

This past Saturday there was a report of a Lapland Longspur at the PPA, just a few miles from our place. This would be a life bird for our other friend Terry (seen with the binoculars in this post). And as good friends we went to help her find it, hidden, as it were, amongst five hundred or so Horned Lark and a large but smaller number of Snow Bunting, with a few Meadowlark sprinkled in (at any other time we'd be quite happy to see those birds, but today they were just a distraction, and in the way). 

Spoiler Alert: We did not find it.

But that's not what this post is about.

Nope it is about Thin Film Interference.

You see, my bins had fogged up. On the inside. At the center of the objective lens. Highly non-optimal for birding.

So while our small group was standing in a cold windy field scanning for a small bird in a large expanse, I was admiring the curious color pattern preventing me from joining in the fun.

After an hour and a half we gave up and headed home. And once there my bins promptly cleared up. A good thing as they would be needed later in the day.

As far as I know, Terry is still out there looking ...

~~~~~~~~~~

Update: We went back Sunday morning. Terry was there. Patty spotted the bird, after an hour and a half or so of scanning the field. Alas they flew before Terry could get a look.

I'm sure she'll be back.

And my bins fogged up again. Thankfully, they cleared before we left.

Desk Optics

Long time readers of this blog know I'm fascinated by optical phenomena, especially those which exhibit color effects. Because of this interest I tend to notice things that many (most) folks would ignore.

And I label these posts under "Things that Probably Only Interest Me" for no doubt good reason. But It's my blog, so here we go!

Like many people my age, I grew up listening to LP records. Unlike many (so I surmise) I still have a turntable. Although it may be obvious that it doesn't get much use these days.

Clearly I'm not one of those vinyl hipsters.

But what caught my attention one morning as I was sitting down to start my work day was how colorful my previously black turntable had become.

I wonder if the box of (physics) books sitting on it stresses the plastic, resulting in the colors.

~~~~~~~~~~

I have a clear plastic holder for small square note paper. And one morning a few months ago I noticed just a hint of color on my desk.

Moving the holder did not significantly enhance the colors. So I tried putting a piece of plain white paper down on the desk.

And the colors vanished. I do not know what is going on here. We have sunlight streaming through a double pane window, then through a cube shaped plastic paper holder, onto a wooden desk top.

~~~~~~~~~~

Lastly (for this blog post anyway) I spotted these colors on the other side of my desk, in the late afternoon light.

This 'zoomed' out view shows the light source, a windowed door. While hard to see, the door is made of different glass sections, which act as prisms. No mystery as to the source of the color in this case.

🌈  🌈  🌈  🌈  🌈

Another benefit of working from home is I see these things. My desk in the company's office has no nearby windows. And only boring overhead florescent lights. Nothing to challenge my imagination nor spark my wonder.

Look Up in The Sky

And you'll see cool things.

Like this Solar Corona.

Often the Sun is bright enough to overwhelm the subtle colors but this display was visible to the naked eye. 

Hiding the sun behind the house helps keep the camera sensor from overloading.

And soon enough the clouds passed and the show was over. 

As that famous philosopher Ferris Bueller notes, “Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.”

So keep looking up. And Down. And all around.

Look Up In The Sky

And you'll see cool things, like this Lunar Halo.

Even cooler, I spotted it while I was outside listening for owls, and there were three (and maybe four) Barred Owls calling. 

Keep listening!

Shadow Halos at Home

A couple of years ago, back the before times when I actually went somewhere else to work, I noticed some curious halos in the parking lot outside my then office window. And thus the Shadow Halos post.

Halloween morning I looked out my window to see this.

Shadow Halos on my garage.

Although this time it was a bit easier to see what was going on. Cool to see just the same.

Moth Light

To attract those fancy, and the not so fancy, moths to our sheet we have a very bright light.

This light.

And while sitting enjoying some F-ing Good Wine, I decided to take a picture of the very bright light with my iPhone.

And I got some pretty interesting results.

Interesting to me anyway. I suspect these are reflections from the compound lens in the phone. Had I been thinking straight (too much wine?) I would have used both lenses.

Next time ...

Hints ...

... Of other halos.

The 22° Halo is pretty obvious. But much more subtle is the 9° Halo.

Even more subtle is the 18° Halo.

But they may not be real. Oh, those halos are real. But they may be only artifacts in my image. Alas, I didn't have a chance to get more shots. I'll just have to keep looking up.

And I have no idea what the square grid pattern is.

To learn more about these halos visit Les Cowley's excellent Atmospheric Optics site. But you knew that, right?

Dusty Water ...

... plus Physics ...

... equals Colors!

Quételet Scattering.

A Puzzlement

While working in the yard this weekend I cam upon this. A reflection from one of the house windows. I don't know why it is shaped like a kite.

And more interestingly to me, I don't know why it is pink.

You see, from every other angle it is white.

Moving around the reflection nor changing the height of the viewing angle had any effect. If it was white it stayed white. If it was pink it stayed pink. I would have expected it to change colors, through the visible spectrum. But it did not. A puzzlement for sure.

Why Did the Turkeys Cross the Road?

I don't know.

But did they have to do it ...

... on my driveway?

(And check out the reflection in the car hood.)

Benefits

One of the benefits of hosting the Winter Solstice Bonfire Music Jam with Yule log Ceremony is the left over beer. I have friends with eclectic tastes, and I quite enjoy discovering new brews.

Like this one.

A surprisingly tasty beer made with convenience store coffee. Very satisfying after a morning of yard work on a winter's day.

🍺  🍺  🍺

And if you look closely ...

... portrait of the artist in a beer can.

Purple Sunsets

Chance favors the prepared mind, and my mind was prepared to look for the "purple light" at sunset.

And this past Sunday evening I glanced out the window and saw this. So I quick grabbed my camera.

And now you can see it too.

Learn more at the Atmospherics Optics site. Duh.

And keep looking up.

Mirage

Since there were no birds to look at, nor photograph, at Barnegat I spent my time looking at ships.

Ships that really weren't there, where "there" was where I was looking.

Got that?

(That "guy" standing on the horizon on the left wasn't really there either.)

The ships were below, or in some cases mostly below, the horizon.

The air acts like a lens bending light rays as they pass through it. Usually, the rays travel in straight lines. But when there is a strong temperature differential the light bends, as it does when passing through a lens.

At the lens-air boundary the air is refracted, which is a fancy word for "bent". You've no doubt noticed how a straw looks bent in a glass of water. The water-air boundary also refracts the light.

The temperature gradient refracts the rays back downwards. Thus rays that would have normally shot well above my head were bent down to my eyes. My, and your, brain expects light to travel in a straight line. Thus we see the ship where a straight light ray would have come from.

A pretty cool trick if you ask me.

🚢  👁  🚢  👁  🚢

You can learn more about mirages on the Atmospheric Optics site, including my Death Valley lake that isn't OPOD.

Curious Artifacts

In my post about the recent Red-shouldered Hawk visit I noted the "curious artifacts" caused by shooting through the windows at our house. But in the hawk image the artifacts were somewhat subtle.

Hermit Thrush

Here as some images of recent yard birds taken from inside the house, through the dining room window.

American Goldfinch

The artifacts are much more obvious, especially in the first image above, over and behind the bird's neck.

It's nice to see the birds eating the seeds and berries and using the little frog pond for water.

Dark-eyed Junco

I'm guessing that as there are double pane windows what we're seeing are internal reflections. But that's just a guess.

I suppose I'll have to do some experiments.