Localized weather phenomenon

Tuesday, June 16, 2009, 14:00 EDT, Accokeek, Maryland

Today a slow moving very localized tropical downpour sat over the Bryans Point Road and Accokeek Creek area of Accokeek. That happens to be centered over my house. Flash flooding occurred all over the local area, but 2000 feet away, there was hardly any rain. I risked life and treasure to cross our causeway. The fast moving stream could have easily swept away the car with Scot and me in it. Accokeek Creek, now a swift river, had stopped up the Apple Valley Road culvert and the water rose almost to the height of the road. I thought the road would be totally washed out. As it was, damage was done to our drive way and to nearby parts of Apple Valley.

Arctic ice cover

A graph of ice cover in the arctic during the month of May for a range of years is available. The data and graph are from the National Snow and Ice Data Center. Whether the recent upward trend will continue is unknown. By fall we should have a better idea.

Wobble Pin

Here is something all aspiring engineers should know. When you want to design a mechanism to give fine precise control to a moved object, use a wobble pin to match between the moving screw and the object to be moved. A wobble pin is needed because a screw is never precisely centered or precisely directed, nor, is the object to be moved. In particular, the tip of a screw will always be off-center by a small amount no matter how precisely it is made.

In the illustration is shown, in green, an object to be moved. In this case it happens to be a lever attached to a pinion. A screw shown in orange, is intended to impart fine motion to the lever. The wobble pin is shown in blue and it fits into hollow cones at the end of the screw and on the lever to be moved. If the screw is off-center, and, it always will be, the wobble pin will wobble with it while the other end remains stationary on the lever to be moved. When required, a spring can be used to keep the object moved firmly located against the wobble pin.



In practice, the cones can be a simple hole drilled with a drill. Some set screws already come with a cone on the end. The wobble pin can be either machined, or, more simply, can be two spherical bearing balls glued to the two ends of a hollow tube. More crudely, the wobble pin can use conical ends itself and simply fit into dimples created with a pin punch. In a more refined version, the cones can be replaced with roller thrust bearings. All these things are refinements and variations. The important thing is to keep in mind the basic concept of a wobble pin. Failure to use it, and instead drive directly with the screw, will result in scoring and friction on the object moved.

Horology 101

Last month I bought a 400 day torsion pendulum clock at an antique store. They are more commonly known as an "anniversary clock." After setting it up at home, it would not tick more than a few times. After a bit of investigation on horology web sites, I measured the timing of the ticks on either side of neutral point when it is doing nothing. It turned out that the swing on one side was much greater than on the other side. Making the swing equal is known as setting the beat, and, is essential for making the clock to run accurately or even to run at all.

It turns out that none of the web sites show how to set the beat. Finally I figured out that the thing from which the pendulum torsion wire is suspended can be made to rotate by first loosening an adjacent screw. I turned it until the tick swing was about equal to the tock swing. Now it runs and now you know how to get an anniversary clock running.

Sometimes someone starts an anniversary clock with too much swing and this kinks the torsion wire. In a case like that the wire must be replaced, and that is expensive. My clock did not require a wire replacement and all it needed was to set the beat. It now runs fine, and, I am now in the process of adjusting its timing.

Setting the beat on a swing pendulum clock is similar to setting the beat on the torsion pendulum. Make the tick equal to the tock by tilting the clock. Then adjust the setting so it will do that while level. Move the setting toward the high side of the tilted clock.

Pirates!!!

How Climate affects Energy which affects National Security

Although some people have disputed the reality of climate change it is a certainty that minimizing CO2 emissions will have the very desirable effect of encouraging greater energy efficiency and resort to alternative energy sources. Indeed, one could reasonably suspect this is the hidden motivation behind concern about the climate.

We really need improved energy efficiency and alternative sources. It is the nature of industrial change that it takes a long long time to implement for the simple reason that it takes a long time for existing infrastructure to become too worn for use. Typically this means a lifetime for infrastructure of around 20 to 40 years. Thus the sooner we start the better. Wind and solar both have the potential to supply a lot of energy, but is will be too late if we wait until an emergency. Quite simply, the security of the nation depends upon starting energy change as soon as possible.

We are lucky that the 1973 oil crisis has already had some good effect on conservation. More is needed. Most critically, that change is needed in the personal transportation sector. Basically that means resort to electrical propulsion. Here is a link to a recent bill in Congress that establishes CO2 emission goals.

Greenbelt Farmer's Market - Opening Day!

Today was the opening day for the 2009 Greenbelt Farmer's Market.  It is in its second year, and is bigger and better then last years, dispite today's soggy weather.  In addition to fruits and veggies, vendors were selling honey, jelly, bread, plants, soap, ice cream, cheese, meats, eggs, coffee and crafts.   Everything is produced within 100 miles of Greenbelt, Maryland.  The Farmer's market is located in the Roosevelt Center parking lot and is open from 10am-2pm on Sundays, except for Labor Day weekend.

Our Somewhat inactive Sun

Sunspots have finally returned to the Sun after a long absence. There had been concern that the recent prolonged absence might mean the start of centuries long inactivity such as the Maunder minimum of the past that was associated with severely cold weather.

Even with the return of spots, the now commenced Sunspot Cycle 24 is predicted to be weak with relatively fewer spots. That might mean some cooling influence, or, maybe not. If there is any cooling influence it is unclear at the present time whether that will offset the warming influence of increased CO2.

Climate predictions are difficult due to the complexity of the many effects from physical, astrophysical, geomagnetic, solar, biological aerosols, clouds, particulates, biological and soil surface reflections, and anthropogenic pollutant influences. Climate modelers try their best to take it all into account, but the biological influences on the climate are near impossible to model, in part, because the climate influences the biology ! As someone who has done his share of computer modeling, I don't have a lot of confidence in it. As one British scientist put it, it is time to abandon a consensus prediction on the climate. We don't know.

If you would like to keep track of space weather, including sunspots see this link to space weather.

to all mothers

Happy Mother's Day!

GangangGrandma Jo
Luella (Jo's mom) and her sisters

Olga (Grandma Carlson)

(I could upload even more photos but I figured I should probably stop here or you all might get bored)

A cure for obesity ?

Since the Ohio trip I have been feeling great. Even better, I've lost 10 pounds and expect to continue losing. I don't know the cause of all this, but one possibility is that the road vibration from the long trip was vibrating all my fat and reset the metabolism. I have heard of such things. I feel too good to suspect cancer as a cause for weight loss.

After arriving in Ohio, someone asked if my new Honda Fit had a lot of road vibration. I had not previously noticed it, but, on the trip back paid attention, and yes, perhaps there is a little bit more rumble than average, but nothing obnoxious to my personal sensibilities. Anyway, if the vibration hypothesis is true, buy a Honda Fit if you want to loose weight. It is probably the best car I have ever owned. I love it and recommend it to anyone. The new engine loosened up on the trip, and now it gets over 37 mpg with further increases expected.

Excerpts from France

It is evident that Jon is not the typical tourist. He speaks French and also has close contacts with the aborigines. Here are a few excerpts from an email:

we went to the ghost village of perrillios out in the desert not
far away: fairly well preserved tiny village with its own church:
restoration under slow way and things are locked unlike last time when
i visited church: little graveyard and wonderful view over over
valleys to mountains and far distance: the last time i played guitar
under a fig tree for the last nights operation of La Lizard bistro

Apparently life is pretty good there:

lourant and i played into the night after dining on
medeteranian muscles and crab:::::: life is tough but someone must
do it

And so it goes in France. I haven't heard much about what Jake is doing.

Y2K bug strikes 9 years later

It seems that some of the alleged global warming can be attributed to a Y2K bug in software of sensors that gathered data circa 2000. Here is a link to this bizarre basis for a multi-trillion dollar policy decision based on a computer programming bug.

This is not to say there might not be other data that support global warming. It might exist.

The bugs are attracted to purple

Purple Traps for Emerald Ash Borer Survey Being Hung in Trees Along Western Maryland Roads

Lanterns cont.....

I managed to capture a picture of the newest purple lantern at high speeds. It appeared to have some kind of home office printed label on it.

In other news, there was a lone Canada goose in my donkey field this morning calling to my other geese. He was either trying to persuade them to fly north with him or to let him into their gaggle.

Jon and Jake hit the mountains and party life

Herewith is a (sanitized) part of Jon's email to me from France:

these party animals had me out till
3:::::::::up in the mountains at another ancient home,
pictureslllllllstill cant find the keyboard period::::::::::::it was a
goat trail to get therellllllllwild dogs, wild pigs; the man needs a
rifle, has nonelllllllllthe wind power here is well developed, many
massive units to be seen, like war of the worlds things on the
horizon:::::::::::::::i was told that since carolina has a license to
practice in england that since its all now the eu that would be much
easier for her to work here::::::::::::fresh oysters and muscles
yesterday from saltwater farm:::::::::::not cheap; but the muscles
were especially good:::::::::::::were drinking wild thyme tea to ward
off the flu::::::::::::abnormal amounts of rain; but welcomed in this
climate:::::::::i seem to be the only party surviver; only one up at
10 morning::

He must have been posting on a sub-mini netbook that the old guy could barely see or type upon. I wonder what ::::: and lllll mean on that computer ?