Cumberland-Times Sky Columns
October 2005

October 2 - Looking Deep
October 9 - How Cell Phones Work
October 16 - Atoms Galore
October 23 - Return to Moon in 2018?
October 30 - Latest New Worlds

October 2 - Looking Deep

How far can you see? Most of the time, this question refers to the Earth's surface. Long ago when the air was cleaner, it wasn't unusual to see mountains as far as 25 miles away in in the Mid Atlantic States. In the deserts of New Mexico and Arizona with less humid air, 40 miles was possible. Now with air pollution, especially during the warmer months, 10 miles is good locally. As you drive along Interstate 68, note how far you can see ahead. I like to watch for the Sidling Hill Cut as I pass the Little Orleans exit driving East on I-68.
In our atmosphere, the contrails of a jet plane (where water vapor condeses to ice crystals) can be seen from a distance of 20 or 30 miles. On any clear night, you may see a meteor, the incineration of pea sized comet piece of comet grit 50 to 100 miles above the Earth's surface. Cruising at 218 miles above the Earth's surface is the International Space Station (ISS), which can be seen up to a thousand miles away at dawn or at dusk. Times to see the ISS can be found at www.heavens-above.com which provides a local forecast for the next 10 days. The geosynchronous satellites used by satellite television providers are 100 times farther out, much smaller than the ISS and not visible to the eye. The next most distant object is our moon, a two thousand mile ball of rock that is about 240,000 miles away. The farthest planet we can just barely see is Uranus, now shining in front of the stars of Aquarius at a distance of 1.8 billion miles. (To identify Uranus, you need its celestial coordinates and a good star atlas such as the Cambridge Star Atlas reviewed in last week's column.)

The night stars are vastly farther away. We use the light year as our distance unit. A light year is how far light can travel in one year. Since light travels at 186,300 miles per second and there are about 31,560,000 seconds in a year, then a light year is about 5.9 trillion miles! (A trillion is a million times a million. The U.S. Government spends about 2.5 trillion dollars each year.) The nearest star we can see at night is Sirius, the Dog Star, at a distance of 8.7 light years. Sirius is seen in the cold weather months as a brilliant sparkling star low in the South below and to the left of Orion. The farthest bright star we can see is Deneb, the top star of the Northern Cross. Deneb is now high in the northwestern sky, above and the left of Vega, now the brightest evening star on view. Deneb's light takes 3000 years to reach the Earth. The light just reaching us from Deneb tonight left about the time of King David of the Hebrews, whose lineage led to Jesus.

The farthest object we can see with our eyes is the Andromeda Galaxy, a star kingdom slightly larger than our own galaxy. On dark, moonless nights in early fall, you can make out a starry baseball diamond in the eastern sky in the early evening. Find the star for third base and go to the left. There you will see a chain of stars. The second star from third base star is in the middle of the chain. Go two stars up from this second star and there you will see a dim blur of light. This is the Andromeda Galaxy, a starry congregation of several hundred billion suns. This galaxy is at a distance of 2.5 million light years, or 14.7 million trillion miles.

October 9 - How Cell Phones Work

Recently, the number of cellular phones in Maryland passed the number of standard phones (land lines). Cell phones have quickly become the most used technological device in our society, with compact MP3 players (such as I Pods) also rapidly gaining in popularity. While many are very conversant with the competing plans offered by the different cell phone providers, few cell phone users really know how these devices actually work. In the next few paragraphs, I'll provide a quick overview of these complex devices.

Cell phones are radio receivers/transmitters using very low amounts of power (less wattage than a typical night light). Cell phones send a signal at one frequency and receive at a different frequency so you can have an ordinary conversation in contrast to walkie-talkies and the old CB radios. (These devices are called half duplex in contrast to full duplex devices such as a cell phone.)

A typical cell phone can communicate over 1664 channels in contrast to one channel for a walk-talkie or the 40 channels of a CB (citizen band) radio. Walkie-talkies can transmit up to 1 mile while the more powerful CB's can reach out 5 miles. But cell phones with their low power can be used anywhere as long as they are in sight of a cell phone tower that can process their signal.

The secret of cell phones is their use of cell regions (about 10 square miles in area) where their low power transmitters can contact a base station (at base of cell phone tower). As soon as a cell phone passes out of a cell region, its signal is passed onto another base station (at another cell phone tower).

In our area, with its ups and downs, you can be cut off from a tower and may have to move a bit to get in contact. Also when you are deep inside a building with much metal in its walls, you may have to shift to a less obstructed area or even go outside to get use your cell phone.

The frequencies used by digital cell phones are about 800 Million cycles per second and 1900 Million cycles per second. (In 'techie' language these frequencies are 800 Megahertz and 1900 Megahertz.) Frequency means the number of waves per second in your signal. Using the speed of radiation of 186,300 miles per second (also known as speed of light), the waves used have wavelengths (from crest to crest) of about 14.8 inches and .52 feet. These short waves allow a very small antenna to pick up the signals.

An article that provides much more information about the working of cell phones can be found at http://electronics.howstuffworks/cell-phone.htm.

Cell phones are appropriately used by many (allowing parents to keep track of their children) and for medical staff, firepeople, policepeople, sanitation workers, etc. But it seems that the overwhelming use of cell phones is by regular folks driving their cars, shopping at a store (shopping lists are passe) and as they walk away from meetings. It seems as if some people must in constant audio linkage with others, lest they be alone. Solitary thinking on one's own seems to be uncomfortable to many!

October 16 - Atoms Galore

The acceptance of atoms by the scientific community dates back about two centuries. Atoms were first proposed by Democritus of Abdera in 5th century BC Greece. The idea of atoms were strongly opposed by Aristotle, who championed his five elements (air, fire, water, earth and quintessence) to explain many properties of material objects. During medieval times, atoms were opposed by the Church as excluding God. The Church had also adopted Aristotle's ideas as they were in line with the Bible's emphasis of the Earth as God's key focus in creation. In the early 1800's, scientists such as Dalton (a deeply religious Quaker) showed that the known laws of Chemistry could be explained using atoms. In 1905 Albert Einstein explained Brownian motion (jiggling of pollen grains in water) as being due to atomic/molecular collisions. Einstein's explanation led to an estimate of the size of atoms (typically 10 to- 10 meters (0.0000000001 meters)or four billionths of a inch). A typical atom is about 5,000 smaller than the wavelengths of light, making them impossible to see with an optical microscope. But for decades, atoms have been imaged by scanning tunnel microscopes using tiny electrical currents. So even through no one has ever seen an atom, scientists accept their existence as so many phenomena are explained by atoms.

How many atoms are in your body? Let's start with mass, the quantity of matter in a body. The weight of a body is the pull of gravity on a body. These two quantities are often confused. Your weight in pounds on Earth is 2.2 times your mass in kilograms. (A typical cantaloupe in a grocery store has a mass of a kilogram while a nickel has a mass of 1/200th of a kilogram (or 5 grams).)

Now to start to answer the number of atoms in your body, we need to state the atomic mass unit, which is 1.66 x 10 to - 27th kilograms (1.66 thousandth trillionth trillionth kilograms). This is roughly the mass of a proton or a neutron, key particles in an atomic nucleus or center. (A trillion is a million times a million with 12 zeroes. As noted in last week's column, in a little less than 5 months, the U.S. Government spends a trillion dollars.)

By weight, biologists have determined that your body is 65% oxygen, 19% carbon, 10% hydrogen, 3% nitrogen, 1.5% calcium, 1% phosphorus, 0.4% potassium, 0.3% sulfur, both sodium and chlorine at 0.2% and magnesium at 0.1%.

Using the periodic table of elements and above percentages, one can show that the average atom in your body has an atomic mass of 14.4 atomic mass units. This means that an average atom in your body has a mass of 14.4 x 1.66 x 10 to the -27 kilograms or 2.39 x 10 to the -26 kilogram. This mass corresponds to 5.26 x 10 to the -26 pounds. So each pound of your body averages 1.9 x 10 to 25th atoms! In plain english, this last number is 19 trillion trillion atoms! I weigh 153 pounds. That means that I have 153 x 19 trillion trillion atoms or 2,907 trillion trillion atoms. So any interested readers can get an idea of how many body atoms they have. (As one gets older, the percentage of body water drops, changing somewhat the average atomic weight and the number of atoms per pound.)

October 23 - Return to Moon by 2018?

Right now our nation's space program is hurting with the Shuttle grounded and the International Space Station (ISS) slowly dropping towards the Earth's surface. The Shuttle flight in July didn't boost the ISS much above its current low orbit (218 miles altitude). Russian supply ships and Russian Soyuz rockets are used for crew transfers and for vital supplies. So a few weeks it came as a surprise that NASA will return to the moon in 13 years, using a fleet of redesigned moon rockets. By then the NASA will use a standard capsule vehicle (Crew Exploration Vehicle) in contrast to the Shuttle Space plane with its easily damaged thermal tiles.

Without a clear reason to return to the moon (except to bolster our nation's prestige), NASA should wait longer. It would be far better to focus on the risk to the Earth of asteroid collisions. One such body will be flying by the Earth in 2029 at a distance of 75,000 miles. NASA could follow up its Deep Impact spaceprobe (that collided with a comet on July 4th) with more robust interceptors that could alter the path of any sizeable asteriod to avoid an Earth collision. We don't need to 'nuke' an asteroid, just soft land a hardy semi autonomous device; this would provide a gentle continuous thrust to deflect the asteroid a few feet per second and alter its path. We have used such devices on a spacecraft; they are ion engines, with firing times that can run for weeks. The only problem with this strategy is that we need a lead time of a half dozen years to prepare the vehicle and launch it. NASA should be planning such a vehicle starting today so when it is needed, it can be put into space; this will save the Earth from a horrible disaster that would be far more damaging than any tsunami or hurricane.

October 30 - Latest New Worlds

In my September 4th column, the large object 2003 UB313 was mentioned as a possible tenth planet. Nicknamed "Xena", this icy body is now about 10 billion miles from the sun, about twice as far as Pluto's average distance. Since its reflected light resembles that of Pluto, Xena is likely about 1800 miles wide, compared to Pluto's 1485 miles. This distant world is in an elongated orbit that takes it from 38 to 97 times the Earth-sun distance; Xena takes 560 Earth years to orbit the sun. The big news about Xena is that on September 10th, a moon was discovering orbiting Xena. The unofficial name for Xena's moon is "Gabrielle", appearing about one sixtieth as bright as Xena. Gabrielle may be about 1/10th as far from Xena as the Earth is from the moon; this makes the Xena-Gabrielle distance about 24,000 miles. Once the discovers have good values of Gabrielle's average orbital distance and its period to orbit Xena, they will find Xena's mass, likely sometimes in 2006. (This was done for Pluto when in 1978, its moon Charon was discovered.)

In addition to Xena, the same research team (Brown, Trujillo and Rabinowitz) has discovered two other large bodies with official names of 2003 EL61 and 2005 FY9. Both objects are about 3/4th the size of Pluto, about 1100 miles across. Their orbits are inclined a little less 30 degrees from the plane of the planets. Both of these bodies are now about 4.8 billion miles from the sun. 2003 EL 61 takes 285 of our years to orbit the sun. Like Xena, 2003 EL 61 has a moon. The pair has code names of "Santa" and "Rudolph". Santa is cigar shaped and rotates every 4 hours. Its reflected light matches that of water ice. 2003 EL 61 has a mass about 30% that of Pluto. 2005 FY9 takes 307 Earth years to orbit the sun. This object's reflected light resembles that of Pluto. No moon has yet been found for 2005 FY9.

The big question is when will the official names of the above three objects be decided. The Roman gods and goddess names have been exhausted in the asteroid belt and the moons of the planets. Maybe the discoverers can be honored by naming the worlds, "Brown", "Trujillo" and "Rabinowitz". Another question is whether any of these worlds will be classified as a planet. (There was an effort to demote Pluto in the late 90's.) The odds are slim that the Commission (of the International Astronomical Union) will move in this direction. Pluto can rest easy as the last planet.