Tuesday, March 20, 2007

It's Spring!
Time to get a 911-only phone for your pool

If I look out my window, I see white snow, not green grass. It looks and feels like winter, but scientists say that Spring starts TODAY.

Even here in snow-covered New England, Spring means it's time to think about swimming. If you have a pool, it's important to have an emergency phone (and the phone may be required by law). If you want to keep people from using the phone to order pizza when someone might have to call for an ambulance, consider a phone that calls 911 only. (Well, actually, it can call 119, or 991 or 1199 or 111999 or 99999991111111999999991111111, or any combination of 9 and 1, but it won't reach Domino's or Pizza Hut.)

Several models are available, including a basic 911 phone, and a customizable model that can be upgraded with an armored cord and other enhancements. Guaranteed for five years or more. Made in USA. Outdoor weatherproof housings are also available, and phones that dial 911 without having to tap buttons. CLICK for RedHotPhones.com

Why did Spring start sooner than expected?

While it’s true that we’ve traditionally celebrated the beginning of spring on March 21, astronomers and calendar manufacturers alike now say that the spring season starts one day earlier, March 20, in all time zones in North America. Actually, during the 20th century, March 21 was actually the exception rather than the rule.

The vernal equinox landed on March 21 only 36 out of 100 years. And from 1981 to 2102, Americans will celebrate the first day of spring no later than March 20.

In the years 2008 and 2012, those living in Alaska, Hawaii and the Pacific, Mountain and Central time zones will see spring begin even earlier, on March 19. And in 2016, it will start on March 19 for the entire United States.

There are a few reasons why seasonal dates can vary from year to year.

A year is not an even number of days, and neither are the seasons. To achieve a value as close as possible to the exact length of the year, our Gregorian calendar was constructed to give a close approximation to the tropical year, which is the actual length of time it takes for Earth to complete one orbit around the sun. It eliminates leap days in century years not evenly divisible by 400, such 1700, 1800 and 2100, and millennium years that are divisible by 4,000, such as 8000 and 12000.

Another reason is that Earth’s elliptical orbit is changing its orientation relative to the sun (it skews), which causes Earth’s axis to point progressively in a different direction — a phenomenon called precession. Since the seasons are defined as beginning at strict 90-degree intervals, these positional changes affect the time Earth reaches each 90-degree location in its orbit around the sun.

The pull of gravity from the other planets also affects Earth's location in its orbit.

The current seasonal lengths for the Northern Hemisphere are:

Winter 88.994 days
Spring 92.758 days
Summer 93.651 days
Autumn 89.842 days

As you can see, the warm seasons, spring and summer, combined are 7.573 days longer than the colder seasons, fall and winter (good news for swimmers, not so good for skiers).

However, spring is currently being reduced by approximately one minute per year and winter by about one-half minute per year. Summer is gaining the minute lost from spring, and autumn is gaining the half-minute lost from winter. Winter is the shortest astronomical season, and with its seasonal duration continuing to decrease, it is expected to attain its minimum value — 88.71 days — by about the year 3500.

Another complication revolving around the vernal equinox concerns the length of day versus night. We have been taught that on the first days of spring and autumn, the day and night are equal to exactly 12 hours all over the world.

Yet, if you check the calculations made by the U.S. Naval Observatory or the sunrise/sunset tables in any reputable almanac, you will find that this is not so. In fact, on the days of the spring and fall equinox the length of daylight is actually longer than darkness by several minutes. (info from MSNBC)

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