Cumberland Times-News

Bob Doyle - Astronomy

March 1, 2014

What do these vital measurements mean?

 A while back, I wrote a column on how the U.S. has firmly held onto British units that the British themselves have abandoned (inch, pound, quart).

Today, I’ll take up some other important quantities and their units. My reference is “How Fast Is A Knot?”, a deck of knowledge cards by Don Root, from Pomegranate Communications with ISBN 9780764954535.

 A nautical mile is the distance North or South to change your latitude by 1/60 th of a degree. One nautical mile is 1.15 of our miles. A knot is one nautical mile per hour. Ships would put out a line with a “knot” every nautical mile.

The difficulty in using knots is that this unit is based on a ship’s motion relative to the water, rather than land.

So if a cruise ship moving south is in a current flowing to the north (Gulf Stream), the speed in knots wouldn’t be useful in determining your arrival time at the Caribbean port. (Of course, the ship would have global positioning devices that would tell the deck exactly where the ship was.)

What is a cubit, the unit in which Noah’s ark was described in Genesis? The cubit was the distance from the elbow to the tip of the middle finger. Egyptian measuring sticks show their cubit to be 20.5 inches while the Roman cubit was 17.5 inches.

So if we use the smaller cubit, Noah’s ark of 300 cubits long, 50 cubits wide and 30 cubits high would have dimensions of 437 feet long, 73 feet wide and 45 feet high.

What is a bushel? Originally, a bushel was a measure of volume for agricultural goods equal to 2,150.42 cubic inches. But the bushel has evolved into a weight measurement, that varies for each kind of produce. A bushel of barley now means 42 pounds, according to the USDA (U. S. Department of Agriculture).

There is more to the temperature scales than most books mention. Gabriel Fahrenheit set up his scale in 1724 with water’s freezing at 32 and boiling at 212.

In 1742, Anders Celsius created his scale with water’s boiling temperature at 0 degrees and its freezing at 100 degrees.

Swedish botanist Carolus Linnaeus reversed Celsius’ scale, putting freezing be 0 C and boiling at 100C, the way Celsius temperatures are used worldwide.

 Major earthquakes seem to strike every few years with devastating consequences for those near the quake’s epicenter.

The Richter scale is logarithmic so that every increase in one unit means that earthquake’s energy is 10 times larger.

In 1965, seismologists Richter and Gutenberg determined that an earthquake at 7.0 on the Richter scale would have a total energy equivalent to 475,000 tons of TNT (far larger than the atomic bombs dropped on Japan).

The earthquake with the highest Richter scale struck Southern Chile in late May of 1960 with a reading of 9.5. The energy of this quake was 316 times larger or equivalent to 150 million tons of TNT, with more energy than any hydrogen bomb tested during the Cold War.

 What is an acre? Originally, an acre was defined as the area that an oxen could plow in a day. Today, we define an acre to be 43,560 square feet. A square field that’s 208.7 feet on a side would occupy 1 acre of land. 1 square mile = 640 acres.

In Europe, areas are measured in Hectares, the area of a square field that’s 100 meters (328 feet) on a side = 10,000 square meters. 1 Hectare = 2.469 Acres.

SKY SIGHTS AHEAD: The moon is now growing in lighted width from a slender crescent in the western dusk to half full in the southwestern evening sky March 8.

The very bright planet Jupiter is high in the south as it gets dark. The planet Mars is a bright yellow point of light low in the southeast in the last hour of the evening.

The planet Saturn is best viewed in the southwestern sky at dawn, appearing to the right of the star group Scorpion (resembles a “J” in the South.)

Bob Doyle invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu . He is available as a speaker on his column topics.

1
Text Only
Bob Doyle - Astronomy
  • FSU Planetarium has new outreach program

    Several years ago, the FSU planetarium acquired an iPad. Months later, we purchased an iPad projector with necessary cables. I purchased a number of astronomical apps this year for the iPad. So I’m interested in visiting schools in this county to teach the stars and planets to classes. The astronomical apps allow you to survey the current evening night sky and show the planets, bright stars and star groups. One of the apps shows the planets close up with wonderful surface detail (as if you were cruising by in a spaceship). The apps I’ll be using can be purchased from the iTunes app store for a few dollars.

    July 27, 2014

  • It’s hotter here than in D.C. or Baltimore

    At this time of the year, the weather is a frequent subject of conversation, particularly the temperatures. We are now in the “Dog Days,” usually the hottest days of the year. The term comes from our sun appearing to be near the “Dog Star” (Sirius) and the “Little Dog Star” (Procyon). In reality, the sun is now about 94.5 million miles away while Sirius is 8.6 light years away with Procyon at 11 light years distance. Sunlight takes only 507 seconds to reach us, while the two dog stars’ light takes about a decade to travel to our eyes. So our sun is in the same direction (but not distance) as these two bright winter evening stars.

    July 20, 2014

  • Fronts, highs, lows determine weather

    Weather news on television and internet focus on violent weather, extreme temperatures and flooding.

    July 13, 2014

  • A long and winding road faces our food

    Last week’s column dealt with organs you can do without, our DNA (molecular blueprint for our bodies) and hair. My reference is “Body: Discover What’s Beneath Your Skin,” a Miles Kelly Book, written by John Farndon and Nicki Lampon and published in 2010. This column will consider finger and toe nails, breathing and coughing, saliva, mucus and your food’s long and torturous journey. Most cities and mid sized towns have nail shops where you can have your finger nails and toe nails adorned. Nail painting can be traced back 5,000 years.

    July 6, 2014

  • Here’s a look at what goes on inside you

    In high school, my favorite science course was biology. I can remember Mr. Munley in his wheelchair. Our class went on a field trip to the University of Miami Medical School where we saw the cadavers used by the medical students.

    June 28, 2014

  • Moon-watching easy when you know how

    Long before the first writing (scratches on clay tablets) appeared, our early ancestors noticed that the moon went through a regular cycle of shapes in about 30 days.

    June 21, 2014

  • Here’s how you can tell the stars, planets

    How can one tell one star from another at night? It’s a matter of knowing the sky areas (constellations).

    June 15, 2014

  • Smithsonian guide to stars is a good one

    At a local book store, I yielded to temptation and bought “Stars and Planets,” a Smithsonian Nature Guide written by four authors. Dinwoodie, Gater, Sparrow and Stott. It’s another Dorling Kindersley product with ISBN 978-0-7566-9040-3 and a 2012 copyright. “Stars and Planets” is a trade size paperback that is beautifully illustrated with appealing diagrams. “Stars and Planets” begins with the biggest topic, the Universe. There is a striking visual showing the known universe on the hugest scale, a delicate lacework of superclusters of galaxies with large voids. It resembles a bubble bath!

    June 8, 2014

  • Think a little more and be less frazzled

    Last Sunday’s column dealt with using technology carefully in education. What about technology in everyday life? There is a marvelous book “The Thinking Life,” by P.M. Forni, of The Johns Hopkins University which addresses this issue as well as timeless suggestions for living by Greek and Roman thinkers. “The Thinking Life: How To Thrive in the Age of Distraction” was published by St. Martin’s Press in 2011 with ISBN 978-0-312-62571-9. Dr. Forni also wrote “Choosing Civility” and “The Civility Solution”.

    May 25, 2014

  • Technology helps with learning, but take care

    Since I have been involved in teaching, two different technologies have been applied to learning at the secondary and collegiate level. The first was video (from videocassettes to DVDs) where a student or class might watch a presentation of some historical event, or a set of scientific principles or even a simulated exploration of the human body.

    May 18, 2014

Latest news
Facebook
Must Read
House Ads