In a 2 row table with text control in row 2

Jim in IA

As an embedded image

Bad news Friday May 24 about this bridge collapse. This from the New York Times.

MOUNT VERNON, Wash. – The partial collapse here on Thursday night of a heavily used river bridge on Interstate 5 caused no deaths, but as the long holiday weekend began it underscored the vulnerability of a transportation system that hinges not just on high-profile water crossings and tunnels, but on thousands of ordinary and unremarked components that travelers mostly take for granted.

A 160-foot section of the 58-year-old four-lane steel truss bridge, which crosses the Skagit River about an hour north of Seattle, crumpled around 7 p.m., apparently after being struck by a truck carrying an oversize load, state officials said. Three people were injured, none of them seriously, when vehicles went into the river.

I live in Iowa. It is mostly a rural state. We have nearly 25,000 bridges spanning at least 20 feet that carry highway traffic. Their average age is 42 years. Nearly 22% are rated structurally deficient by the Federal Highway Administration’s (FHWA) 2010 National Bridge Inventory (NBI).

NBI data is released annually and provides a significant level of detail on the condition of over 700,000 bridges nationwide. Bridges are inspected every two years, unless they’re in “very good” condition (four years) or “structurally deficient” (every year.) This data was released in February 2011.

Click on this map to view the linked online version. There, you can click on your state and see the statistics such as these for Iowa. I find the data disturbing.

Despite billions of dollars in annual federal, state and local funds directed toward the maintenance of existing bridges, 68,842 bridges – 11.5 percent of total highway bridges in the U.S. – are classified as “structurally deficient,” requiring significant maintenance, rehabilitation or replacement as of the publication of this report.

Tell me more…

The week ahead of May 24 -31 promises some wonderful views of a rare event, a triple conjunction of Venus, Mercury, and Jupiter in the evening sky. Look to the west soon after sunset at 8:30 or later. This is the view for May 24th. I hope your skies are clear.

Mercury orbits closest to the Sun, it has a fast orbit. Venus is next closest and less fast. Earth is also moving. Jupiter plods along taking much longer to orbit in it’s huge path. Because of the movement of each planetary body, the view of the conjunction each evening will change a little. Here is May 25th.

Images for the next six evenings are in the rest of the post. So, if your skies are cloudy one evening, don’t fret. This show will be prominent for the entire week. You ought to be able to see it on several of the evenings.

Take me to more of the conjunction.

Earth’s climate is changing. It affects our weather, the oceans, ice, ecosystems, and society. Some of it is natural. But, humans are contributing to climate change in profound ways. Billions of tons of carbon dioxide (CO₂) and other gases that trap heat are released into the atmosphere each year. These greenhouse gases are measured and monitored by several agencies. The level of CO₂ is currently at 400 ppm (parts per million) and continues to rise.

This is not new information. It has been known for the past 50 years that Earth’s CO₂ is trending upward. What is new is this particular number. It is going to be higher in the future. The issue should have been addressed by the global community in a comprehensive way back then and through the decades that followed to the present. My fear is that the story will get some news coverage for a few days, and then fade away like it has in the past. 

Mom lived to be 93 years young. She died May 16, 2005. We all miss her very much. Happy Mother’s Day.

The majority of countries that celebrate Mother’s Day do so on the second Sunday of May. On this day, it is common for Mothers to be lavished with presents and special attention from their families, friends and loved ones. But it wasn’t always this way. Only recently dubbed “Mother’s Day,” the highly traditional practice of honoring Motherhood is rooted in antiquity, and past rites typically had strong symbolic and spiritual overtones; societies tended to celebrate Goddesses and symbols rather than actual Mothers. The maternal objects of adoration ranged from mythological female deities to the Christian Church itself. The personal, human touch to Mother’s Day is a relatively new phenomenon. Only in the past few centuries did celebrations of Motherhood develop a decidedly human focus.

That human focus for me is shown in this photograph. I am the baby in the picture. Two more younger brothers came in the six years after this photo. Our mother was a tireless worker and loved us all with her whole being. Keeping up with the demands of the farm home, the school work, the church going, discipline, and cooking non-stop must have been exhausting. My brother said we had a wringer clothes washer at the time of this picture. Fortunate for her. I remember always having three long clothes lines in the yard, usually drooping under the weight of our clothes. Apparently, the dryer didn’t come until much much later.

In addition to the duties and pleasures of being our mother, she also kept some diary and journal entries for some occasions. I think she could have done many other kinds of productive things in her life. She chose this course and gave it her entire being. Below is a note transcribed from her writing. It clearly expresses the events of the special day in 1947.

The planets Earth and Saturn are currently aligned in the same general direction from the Sun. April 28th was the date of the most direct alignment called opposition. Saturn was in the opposite direction of the Sun as viewed from Earth. Saturn rises in the east each evening at about the same time the Sun sets. By late evening it is positioned high and is a pleasing sight in a telescope.

I am fortunate to have an account with the University of Iowa’s Robotic Telescope called Rigel. It is located at the Winer Observatory near Sonoita in southern AZ. The children of the Rigel director were in my physics classes years ago. He kindly gives me the account for my use. On the night of May 4, the Rigel telescope obtained this image for me of the planet Saturn.

How cool is that? I got to use a telescope over a thousand miles away to get this image. What if I could use a spacecraft actually orbiting Saturn to see images up close and in great detail? I would want to see some of the fine structure details of the rings. Galileo called the rings ‘ears’ when he first saw them in 1610.

I have done just that. I gathered several beautiful pictures for you of the rings up close and personal. Would you like to see?

Sound great. Let’s go see them.

The planets Earth and Saturn are currently aligned in the same general direction from the Sun. April 28th was the date of the most direct alignment called opposition. Saturn was in the opposite direction of the Sun as viewed from Earth. Saturn rises in the east each evening at about the same time the Sun sets. By late evening it is positioned high and is a pleasing sight in a telescope.

I am fortunate to have an account with the University of Iowa’s Robotic Telescope called Rigel. It is located at the Winer Observatory near Sonoita in southern AZ.

The Iowa River is one of several southeastern flowing rivers that drain the eastern half of Iowa to join the Mississippi River along the state’s eastern boundary. Record floods that swept the nation in the early 1930’s prompted Congress to establish the Flood Control Act of 1938. In an attempt to reduce flooding on the Mississippi River, the U.S. Army Corps of Engineers was authorized to construct several dams on tributary rivers, including the Iowa River. In addition to moderating flows on the Iowa River, Coralville Lake’s less evident, but equally important, role is part of the comprehensive flood control system for the Mississippi River. Construction of the dam started in 1949, but was delayed by the Korean Conflict.

The focus of this story is on the effects of two flooding episodes in 1993 and again in 2008. Both times water breeched the concrete spillway and revealed a layer of bedrock from the ancient Devonian seafloor which existed in this region 375 million years ago.

The area in the lower right corner of the previous image is labeled with the dam and spillway for the lake. Zooming into the Google Earth map to the dam gives the image below. Some key points are labeled A thru F where I have photographs or video for illustration. At point A, there is a tower to control the release gates to regulate the flow out of the lake. Three gates can be opened independently.

During drought, the minimum flow rate of 150 cubic feet per second provides a sufficient flow to meet downstream domestic and industrial water needs. During time of flood, the outflow can be increased to about 20,000 cfs via a 23 foot diameter flow pipe through the dam. Inflow to the lake can exceed 40,000 cfs during rainy flood episodes. The lake level rises and potentially goes over the spillway to the right of point B.

If I have your interest, join me for the rest of the story.

The first tiny House Wrens of the season returned last week. They have just started their singing. It will seem non-stop for the next six months.

Gerry DeWaghe 2006

There’s more…

What is a Supernova?

Stars which are several times more massive than our Sun end their lives in a spectacular explosion called a Supernova. The explosion occurs when the fuel for the fusion process in the core is depleted. This lack of outward pressure, which combats the inward gravitational pull, allows the star to collapse. As it shrinks, the core grows hotter and denser. New nuclear reactions begin and temporarily halt the collapse of the core. When the remaining core nuclear is basically just iron, nothing is left to fuse. Fusion in the core ends. Very quickly, the star begins its final gravitational collapse. The core temperature rises to many billions of degrees. The iron atoms are crushed together. The force of gravity is greater than the repulsive force between the nuclei of iron. The core then recoils. The energy of the recoil produces a shock wave through the star envelope. The envelope material is heated and fuses to form new and heavier elements and radioactive isotopes. The material is exploded away from the star core and is known as a supernova remnant. Many of these are seen. Here are examples.

The smaller supernovae leave behind a spinning neutron core only a few tens of miles across. Larger supernovae exert such tremendous inward shock forces that even the neutron core collapses into a black hole. It is so small and dense, that light is not fast enough to escape.

Turn Up Your Volume before you watch this video. It is an audio rendition of supernovae events in a small part of the sky. How it was done is explained below.

1. First, search for Supernovae over a long time interval.

From April, 2003 until August, 2006, the Canada-France-Hawaii Telescope (CFHT) watched four parts of the sky as often as possible. Armed with the largest digital camera in the known universe, CFHT monitored these four fields for a special type of Supernova (called Type Ia) which are created by the thermonuclear detonation of white-dwarf stars. These four fields covered roughly 16 times the area of the full Moon on the sky, or roughly 1/10,000 of the entire sky. Even though such a small fraction of the sky was monitored, 241 Type Ia Supernovae were seen during the period of observation.

The positions of all the Supernova are illustrated as time progresses. The animation is rendered at 15 frames per second, and each frame corresponds to just under a single day (1 sec of video = 2 wks of real time).

2. Assign each Supernova a note to play.

Distance to each Supernova determines the volume of the note. Closer is louder. Each Supernova follows a similar pattern of brightening and then fading. But they each also have some variations.

The pitch of the notes used was determined by the Supernova’s “stretch,” a property of how the Supernova brightens and fades. Higher stretch values played higher notes. The pitches were drawn from a Phrygian dominant scale for those who understand music theory.

3. Assign the instruments to be played.

Only two instruments were used. Notes of Supernovae in more massive galaxies were played by upright bass. Those in less massive galaxies were played by piano.

Creators of this Work – Alex H. Parker (University of Victoria) and Melissa L. Graham (University of California Santa Barbara / LCOGT).

We are stardust.

If it weren’t for Supernovae, the heaviest elements would be iron. That is the top rung of the fusion process in star cores. Because of the tremendous shock waves of supernovae, fusions of  nucleii of elements heavier that iron are possible, giving us the much wider range of naturally occurring elements. Many of the elements in the rocks and minerals and our bodies came from a Supernova in our vicinity of space.