Flying Feats

Look closely at the winged creatures around us and you’ll see many have extraordinarily athletic abilities, some of which we are trying very hard to copy with the latest mechanical drones.  Did you see the amazing formation flying, amid the regular fireworks, of lights carried by perhaps more than a hundred drones at President-Elect Biden’s victory speech on Nov 7?

 

Last season’s Eagle nest, nearly ½ mile away to the North on Audubon Island, is gone.  It was good for at least two years and two sets of young birds, but now it is nowhere to be seen.  We last saw it on May 1st when the leaves opened and hid it, with the two young ones who were almost ready to fly, from our view:


The tree is bare now in November and with the summer leaves fallen we can see that the nest has gone without a trace.

To our great good luck the parents seem to have decided to give Garden Island, just 150 yards away, another try. An effort there 2 or 3 years ago failed miserably.
This time, in just one month, they’ve built a nest up from nothing.  Seems that one (the male?) collects a branch in less than 5 mins and brings it back. The other (the female?) then repositions it, while he’s gone looking for another stick.  (Everyone know that men can’t properly load a dishwasher!).

The eagle prefers branches directly from a tree. (A few years ago I temptingly laid out a dozen good branches on the river bank and none were taken by any nest builders.)  Occasionally the bird clasps a tree branch which won’t break off and he is left dangling precariously, upside-down.  I was lucky enough to have the camera (iPhone) running when he came to the walnut tree right outside.  Look carefully and you’ll see the eagle first snaps off a twig.  Could it have been testing the wood to see if it was brittle enough to break easily?  If so, then the answer was ‘yes’ – he jumped onto and grasped the branch which broke under his 10 to 14 lb. weight, dropped, spread his wings and flew back to the nest.
The new nest is holding up well even though there was a 37 mph wind this week:

 

Other very fine fliers are the Big Brown Bats.  Twice this summer they crept into the house through a very small hole under the balcony screen door.  Alice and Pinot quickly tell us we have an early morning visitor:

I close all doors but one, leaving a rectangular loop for their flight: down the corridor, through the bedroom, and into the other end of the corridor.  At one end of corridor the balcony door is open, but at that point they are turning on their circuit.  No combination of indoor and outdoor lights on and off will induce them to turn the other way and leave.

Alice watches it fly round and round, never bumping into me or the walls, until we are all exhausted and a bat finally lands on a wall.

At that point you can easily pick them up in a towel and take them out before Pinot closes in.  I know: I should wear gloves and a bee suit, but it is 3:00 am.  The good news is I can see no sign of the ‘white nose syndrome’ which is badly hurting so many bat species.

 

A beautiful late summer sight is the vertical flight of a bunch (sometimes hundreds) of miniscule gnats who swarm on a warm evening, presumably in a wild mating dance?  Also hard to photograph, but watch carefully and you’ll see individuals rising and falling.  Even a gust of wind only temporarily disturbs the flying formation.  How do they navigate?  Pheromones may be attracting them back to the spot, even though wind must surely carry away any scent.  How do they navigate in 3D?  I never see them bump into each other.

 

One day on the Portage River we found a 2D version of the 3D gnat swarm.  These magnificent water striding bugs were having their pre-start maneuvers to a regatta like no other.  Turning and swerving, hardly making a dent on mirror smooth water, they somehow gain traction for accelerating and braking without penetrating the surface tension skin of the river.  I switched the movie to slow-motion but can hardly see a ripple in the water from their feet.  What is their rhyme or reason?  Perhaps they’re just having fun?

 

 

Thoughts from Totality or Seeing the Only Star We Can Truly ‘See’

The Solar Eclipse of 21 August 2017

Starting at 5:00 a.m. we drove South: 415 miles in 8 hours. Two days before Google Maps had said it could have been done in 6 ½ hrs. (without the Eclipse traffic).  We used Google Maps to tell us how bad the traffic jams were, and Weather.gov to watch the developing Infra-Red and visible satellite view of the sky so we could attempt to avoid clouds at our destination.

– there was disturbed weather (colored areas on the map above) to the West of our path but we found a lovely little public park in Bowling Green KY, just 6 miles inside the totality path and just short of the Tennessee border (a white X marks the spot in the map above). They were having a very friendly eclipse party there and happily had room for us on the grass and under the trees.  That was fortunate because the highway police were making great efforts to prevent people from stopping on the hard shoulders of the interstates.

The eclipsing moon was just starting its path across the sun when we arrived under clear blue skies.  As during the annular eclipse I’d seen decades ago in Toledo, I once again felt slightly uneasy as an ever increasing greyness of the sunlight became more apparent.  It was like someone very slowly sliding a dimmer switch to our prime source of light (and life), but with a steadily increasing speed.  The change in light quality is very different from that in our daily sunsets.  The typical evening setting sun has a warmth to its reducing light.  During the eclipse there was a coldness to the illumination as it dimmed – I tried rubbing my eyes to fix it.

The easiest watching tool was my bird spotting scope on a tripod.  A science school teacher from Illinois took over focusing and tracking the moving image on a white screen, while I worked on mirrors and cameras:

My straw hat made more pinhole images on my collar and on the telescope screen when I looked down on it:

The ‘pinhole mirror’ was a 3 inch (75 mm) square sample of one quarter inch (6 mm) thick front surface mirror: 80% reflection Pilkington Mirropane™. It has incredible float glass optical flatness.  Taping over half the sample provided a bright reflection light to allow easy steering of the mirror, while the exposed 1/16 inch (1.5 mm) top left corner of the taped half, provided a ‘pinhole mirror’ image alongside – all it needed was a screen.

The smaller the pinhole – the sharper the image, but also the fainter.  The further back the mirror is from a white projection screen – the larger the image, but the harder it is to hold the mirror steady.
(Next time I should put the mirror on a pan/tilt head on a tripod, and incorporate an operating iris diaphragm, if I can find one).

Both images attracted lots of attention as the light inexorably dimmed.

Meanwhile John Muggenborg in Brooklyn (see Muggphoto on Instagram) had amazing results with his similar front surface mirror, just under one inch square.  He had the great idea of fixing the mirror 200 feet (50 meters) away and shifting his screen to track the moving image.  His screen was a beautifully effective open box, dark on 4 sides and white at the back:

Susan spotted Venus brightly shining even though the sun was only about 90% covered at the time (near the top right corner in the photo below):

And in the lobby of his Vancouver apartment, Keith projected an image from his small front surface mirror sample, with a hole in a piece of paper over it to reduce the aperture, onto a screen to delight the residents and guests.

Then with an alarming suddenness, and no sound from the sky (apart from people’s cries in the park), the sun went out!

The Corona was too dim to see through the very dark eclipse glasses, and yet it felt too bright to try my binoculars to search for corona details.  Rushing with camera and iPhone camera in manual overdrive to try to get an appropriate exposure at full 20 x zoom using new add-on lenses, while dripping sweat on the equipment, I did get the following with full zoom on a Canon G-10.

The corona was too bright to see details.  It looks much better in digitally enhanced images as in the APOD site: https://apod.nasa.gov/apod/ap170813.html

In the excitement I forgot to look through polaroid filters but doubt they would have shown anything.

One minute, 10 seconds later into the darkness, a diamond ring burst into view with a startling brilliance – it was the way kids might think that diamonds should appear if all the advertisements were true – the ‘stone’ in the ring was bright as an arc welders spot.  You could not look at it even if you tried.

My iPhone could only get:

I don’t seem to have burnt out any receptors in the iPhone but it must have been close!

Then 90 minutes of slow and steady return to the sky we once knew.

 

So we clearly saw that the overhead sun, and the moon, are truly circular and most probably spherical.  Our sun is the only star we can truly ‘see’, meaning whose shape we can ‘discern’ or ‘discriminate’.  All the other stars in the sky are so far away that their images, even through the best telescope, do not even cover ONE pixel in a camera.

The popular images of star fields seem to show big, medium and small size stars, but those images are ‘false news’.

The big, bright white circles are simply relatively close stars (more than 30,000,000,000,000 miles (5 light years) away).  The reason we see them ‘big’ in the camera is that their light is so incredibly bright that even though it is only shining on part of one pixel receptor, it reflects off it and overexposes many pixels around it.  (And, of course, the horizontal and vertical ‘spikes’ coming off the brighter stars are telescope reflections/refraction side effects and don’t really exist!)

So we cannot say for sure, from observation at least, that stars (other than our sun) are not square ﬦ , triangular Δ, or even star shaped   ҉ . . But now we have seen our overhead sun to be circular ⃝    and from some elementary astrophysics we can now safely assume that most stars really are spherical!

 

Spare a thought for the exoplanet hunters. They use this eclipsing method we just saw, along with others, to find planets around distant stars.  But the geometry never allows for ‘totality’ to be seen from distant earth, so those astronomers must work with only a very faint effect of partial eclipsing.

Perhaps my biggest surprise was that before the occulting moon had fully moved out of alignment with the sun, the very friendly eclipse watchers in the park packed up and drifted off – like leaving a great movie before the credits have even played.

We waited for the credits to roll, or the bloopers to play (none did), ate the strangest BLT ever for dinner and then joined the crowd for the drive home.

Well, if the traffic was heavy as people converged over 2 days on the 100 mile or so band of totality across the country, when the show was over, they ALL went home at once.  Google Maps traffic showed a wonderful screen of a network of red lines (choked roads) heading North and South away from the East-West path of totality.  Sadly we were too emotional to think of taking a screen-shot but Leslie and Glen, watching their syzgy just a little South of us in Tennessee did get one of the ‘eclipcalyptic’ traffic (Thank you):The drive home took 9 hours, but we’ve already started making plans to watch the next one!

 

 

 

Winter Holiday Puzzles

I.  The squirrels here love to eat the many fallen walnuts (as well as the roots of my freshly planted native plants!) even though the meat inside is protected by a very hard shell.

Squirrel_8392

But the squirrel has sharp teeth and manages, with great effort, to chew right through.

Gnawed Nuts_5064The puzzler is the many perfectly split walnuts which were lying on the ground near the end of April.  The inside meat has all been eaten without a trace of tooth marks on the shell:

Split Nut 5063I’d never noticed these hemispheres before.  The plane of the north-south split is fairly flat, smooth and almost polished.  How it happens I have no idea.  I took some whole walnuts, soaked them and froze them, and hit them with a hammer –  all to no avail, they refused to be smoothly split.  There is some secret cleaving process at work, and I’m certain the squirrels would love to take advantage of it if they could?
II.  The younger looking of a pair of bald eagles
2Eagles_8602has been putting sticks against this tree on Garden Island out back for a year now without getting one of them to stay in place.  This clip (click the white triangle in the middle of the picture below to play the video)

shows the bird hard at work, but at the very end the stick sadly drops to the ground once again, wasting all the effort.

It would be so beautiful to have an eagle’s aerie right here but the problem for now is how do I get the process to start?  It is not an easy tree for climbing!

III.  This winter’s weather has been so mild that my bees were actually gathering pollen on December 23, when the temperature was 50 F (10 C), who knows where this one found the bright yellow food packed onto her legs?
Pollen_8702I’ve found nothing in bloom anywhere nearby.  Ever tried following the “bee line” as they leave the hive on their way to their hidden food source?  I could not make it work.

It was so unseasonably warm that the Sandhill Cranes, who we haven’t seen for 10 years since Inez was last here from Spain, stopped by for the week of Xmas on their very late migration south.
Cranes 8746This photo was taken through a closed back window yet we could still here their unique chattering, clacking bills: sounded like humans squabbling about climate change.

IV.  Einstein very neatly showed that something with enough mass can visibly bend a ray of light. (Without any math, he simply stated that we could not tell the difference between the force of gravitational attraction and the force of accelerating a mass with inertia. So when a nearly horizontal beam of light from one wall to the other of your room seems to droop, it means either the room is accelerating upwards, or the room is being pulled down by a gravity field, which is also pulling the light beam down).

The sun at a distance of about 550 AU (Astronomical Units – 1 AU is the distance from earth to the sun) is massive enough to act as a “Solar Telescope” to form an image, of what might lie far, far behind it.   The enlarged image of a bright spot behind the sun becomes an arc or a circle.  A Black Hole would have a similar effect as the sun. (Radio waves are similarly bent.  A good receiver at the focus spot could listen to the radio programs from another galaxy, if any planets there happened to be broadcasting!)

APOD (Nasa’s Astronomy Picture of the Day) often shows images magnified by gravitational lenses.

Einstein Rings:  In the image below the gravity of a close luminous red galaxy (LRG) has gravitationally distorted, into a ring, the light from a much more distant blue galaxy which was directly behind the red one. http://apod.nasa.gov/apod/ap111221.html
Einstein RingsMy Puzzle is that I can’t understand how this works, in even the simplest terms:

An ordinary glass imaging lens (convex) works by bending light rays to come together to form a convergent image.
Convex LensMy problem with the gravitational lens is that the light rays are more deflected the closer they pass to the massive gravitational object.  This results in a fanning out or diverging series of light rays and not the convergence of the rays needed to make a visible image.  The rays shown below, from a star, apart from the red one which is swallowed by the BH, have an increasing bend or deflection the closer they pass to the BH.
Black Hole LensThus the massive object acts as a rather strange concave lens.  I know a regular concave lens looks like this:
Concave Lensbut its effect on a bundle of light rays should show a similar, non-imaging, divergence!

A simple point of light, in this case one quasar far beyond the focusing mass of a faint spiral galaxy, is often shown forming an “Einstein Cross” as 4 spots, rather than an arc or a circle.  http://apod.nasa.gov/apod/ap130102.html
Einstein CrossThat too I fail to understand!

Perhaps a clue lies in the gravitational images formed, not by a point mass, but by a cluster of galaxies:  http://apod.nasa.gov/apod/ap990104.html
Gallactic Cluster LensThe cluster CL2244-02 above is composed of many yellow galaxies and is lensing the image of a very distant blue-white background galaxy into a huge arc.
Here the rays of light from a bright spot far behind the cluster mass might come almost straight through the gravitational center of the cluster with little or no deflection.  The next adjacent rays would be somewhat deflected, and the next ones a little more so.   Thus the central area of the galaxy cluster could conceivably act as a converging lens, but further away from the center and outside the cluster, the rays will be deflected away from each other resulting in the concave lens effect sketched above.  So could there possibly be an imaging process, but only in the center of the cluster?

 

Any solutions to any of these puzzles will be gratefully acknowledged.

 

Happy Solstice, Winter Holiday, Xmas and New Year 2016 to all.