APOD 4.1

A Horizon Rainbow in Paris

    Although the rainbow which appears above Paris in this image looks rather unusual, it is actually just as ordinary rainbow.  The Sun is very high in the sky at the time of this photo, causing it to appear horizontal to the ground.  According to the physics laws governing the creation of rainbows, the center of a rainbow must be exactly opposite the sun.  A rainbow is created by the light reflecting off of water drops in the atmosphere.  "Primary Rainbows show red towards the outside and violet on the inside towards the ground.  Secondary rainbows appear just the opposite.  This image depicts a primary rainbow.  The reason this rainbow appears flat is that only the upper portion of the arc is visible.  The usual "sides" of the rainbow are below the horizon in this case.  This feature was only visible from a certain angle and lasted a few minutes.

Observation 4

Ep. 267 Infinities

   The concept of infinity and zero are both relatively new concepts.  Infinity began to be discussed around 400 BC.  Zeno developed the concept of potential infinities and finite infinities.  Enumerable things are able to be counted and innumerable things are uncountable but are still limited.  Some examples would be the number of grains of sand on the beach.  Other things are not finite such as the expansiveness of a mathematical plane.  Another concept then developed of different quantities making up infinities.  The set of numbers is infinite as is the set of even numbers but the set of even numbers is less than the set of integers.  Countable infinities include all sets of integers.  Uncountable infinities include the list of all real numbers, including the numbers between each integer.  

    The infinity sign has debatable origins but most likely it was developed in 1655 by John Willis, a mathematician.  Some say it is based on Omega from the Greek alphabet which is the last letter.  The infinitesimal accompanies the concept of infinity and, like infinities, has different types.  

    The hotel or Hilbert's paradox states that a hotel with a finite number of guests, an infinity of new guests come in.  A countable infinity comes in as you add rooms and guests.  

    Applied to astronomy, an issue comes up when thinking about infinities and space.  If the universe in infinite in size and age, then whatever direction we look we should see a star.  This obviously does not occur in nature implying that the universe is either finite in age, size, or both.  The universe is most likely 13.7 billion years.  A multiverse is a theory that there are many universes similar to ours. 

Observation 3

Ep. 269 Mass

        Mass and energy can be connected through the equation e=mc^2.  Mass is defined as the property which causes acceleration to be less effective when force is applied.  (F=M(acceleration)).  Acceleration is a change in speed, direction, or both simultaneously.  In contrast, weight is the force something exerts on something else it is resting on.  Weight is actually measured in Newtons because kilograms represent mass and not weight.  Mass does not change depending on which planet something is on, but weight does.  The masses of planets and the Sun can be calculated using equations involving the orbiting planets or moons.  This measures the gravitational force between two objects, eventually giving you the mass of the object in question.  

    Einstein's famous equation not only connects mass and energy but also explains why stars do not burn out quickly.  If enough energy is present, like in particle accelerators, the kinetic energy is released and condenses into particles.  Some theories say that the universe could eventually end due to proton decay.  This would cause energy to spread out and eventually not be able to condense into particles.  

    Higgs-Bosons are present near every atom.  Atoms are made up of many particles with mass and Higgs-Bosons "fly around" and adhere you to the scaler field which is ever present in the universe.  The graviton is an example of a boson particle although it is not detectable because it has no mass.  

Observation 2: Astronomy Cast

Ep. 285 How the World Will Really End

    The most current theory of how the world will end is regarding a rogue planet which is said to be coming near the Earth which will change the magnetic fields of the Earth and have catastrophic effects.  This theory is "backed up" by a painting by the Mayans which contains an extra planet.  This is called the "rogue planet theory."  The flaws in this theory include the fact that if an object the size of Earth were somewhere close enough in space to be approaching Earth in the near future, it would be able to be seen with binoculars or even the naked eye.  It also would have most likely moved the moon if it were coming very soon and was in close proximity to the Earth.  

    Another theory regards the sun and says that the Sun will become very highly active and will "roast" the Earth.  The Sun has been observed in the past to have gone through periods of various activity levels and, obviously, the Earth has not been destroyed.  Solar flares could change the magnetic field and knock out power.  Also, some solar flares have "killed" satellites, disrupting telecommunications.  The only thing which is likely to be affected on Earth is electricity.  

    Planets are rumored to be "lining up" in the near future over the pyramids.  The power of gravity is believed by some to be able to affect the Earth.  In 1999, this lining up did occur but the gravitational pull is not nearly strong enough to affect anything on Earth.  

    During December, the Sun is "lined up" with the center of the galaxy as it is in the constellation Sagittarius.  This does not have large gravitational effects as some claim it would.  Another common worry is about tiny black holes which could be formed and "eat" the Earth.  This will not occur in a short amount of time because even if a tiny black hole was at the center of the Earth, it would not destroy the planet in a reasonable amount of time (other methods will most likely destroy the world first).

    The most likely way the Earth would end is a comet collision.  Again, this would be seen in advance and many people would know about it before it occurred.

Observation 1: Astronomy Cast

Ep. 281 Explosions in Space

    A common mistake in science fiction is how films display explosions which occur in space.  In reality, explosions in space would not be extremely loud and dramatic as they are often portrayed.  

    Explosions require both a fuel and an oxidizer to occur.  In space, there is no oxygen so anything which explodes would have to have its own oxidizer present.  There is also no pressure which would moderate an explosion, drawing it out in length.  An explosion in space would last an extremely short amount of time and would expand outward in a perfectly spherical manner, assuming the explosive device is round.  Explosives such as bullets and dynamite do have their own oxidizers contained in them, so the explosion could occur in space.  In early space travel, it was discovered that if there is too much oxygen combined with the burning fuel in a spacecraft, the spacecraft will explode and be destroyed.  

    Sound from explosions is not heard as it would be on Earth.  The energy reaching you will go down by a factor of 4 in space each time you double your distance from the exploding object, according to the "one over R squared" law.  This is because the shock wave expands in a circular manner in all directions.  Even if you were very close to an explosion in space, you would hear minimal noise.  Energy very quickly dissipates because there is no atmosphere to take in the energy.  A nuclear reaction in space would not be seen because it would become literally a flash of energy.  There is no atmosphere to show the fluorescence of it.  

    Natural explosions in space are much more visible than synthetic ones would be.  Many reactions will occur consecutively.  Expanding gas can show more of a "flame thrower" effect.  Coronal mass ejections are energy releases and are, on our sun, basically magnetic loops.  These can be seen and have been photographed and recorded.  Supernovas are another example of a natural explosion in space.  They are collapsing stars in which atoms are compressed until they break apart.  These explosions are very violent.    

APOD 3.8

The Heart Nebula March 4 2013

    This emission nebula IC 1805, also called the heart nebula is in the Perseus Arm of the Galaxy.  It requires a telescope for viewing and is also called the Running Dog nebula.  It is composed of glowing interstellar gas and dark dust clouds.  It is 7,500 light years away and this image shows that it is 200 light years across.  Near the center of the nebula is the star cluster called Melotte 15 which is very young at only 1.5 million years of age.  It is is the constellation Cassiopeia and this image has the span of about four times the diameter of the moon.  I found this image interesting because we have been studying the formation of stars and this nebula is the perfect example of a young star cluster forming from the matter in the nebula.

Maria Mitchell Biography

Maria Mitchell was born to William Mitchell and Lydia Coleman on August 1^st, 1818. She was the third of ten children born to her parents and her family was a part of the Society of Friends, or Quakers, who had moved from England to America. Her parents both had strong passions for learning as her mother had worked in a library for two years for the sole purpose of reading all the books it contained. Her father provided for the family by rating chronometers of ships' captains. A chronometer is a very precise clock which was used by captains to determine their exact longitude. They used this information to navigate by means of the stars. On the side, her father was an amateur astronomer who inspired Maria's love for the heavens. As a child, she helped her father with his work and through this process, learned about both mathematics and astronomy.

            Her Quaker family believed that equal importance should be given to the education for both boys and girls. They lived in an area which was full of natural phenomena which helped to inspire Maria's love for nature and science. She went to a private elementary school and then later to a school which her father ran. His school focused mostly on observations of nature. She then attended the Cyrus Peirce's school for young ladies where the headmaster saw her unique abilities in math and science and encouraged her to pursue her education with a passion. She was described as being “born of only ordinary capacity, but of extraordinary persistency.” She also worked as a librarian for twenty years and continued her own study while employed. She was fluent in French and studied science textbooks in that language. Because of her passion for education, she started her own school in 1835. She was an unconventional instructor who began school before sunrise for the purpose of watching birds with students in the morning and also stayed late into the night to view the stars. Throughout her life, she earned an honorary degree from Hanover College in 1853, Columbia University in 1887, and an honorary doctorate from Rutgers Female College a few years later.

Because she had been so passionate about education and in particular astronomy, Maria was frequently seen making observations at night. During her childhood, she was a helper to her father and together they made thousands of observations which were used for the U.S. Coast Survey. During her life, she also was a computer for the American Ephemeris and Nautical Almanac, working there for 19 years. All of the observations were regarding accurate time and latitude. In 1847, she discovered a new comet which was named after her and brought her worldwide fame. She first viewed it while at her father's observatory, using only a two inch telescope. The King of Denmark gave her a gold medal for her discovery and after that, she became a well known astronomer in both the United States and Europe. She is considered to be the first well known woman astronomer. In 1848 she was the first woman to be elected into the American Academy of Arts and Sciences, her membership being proposed by the very well known geologist Louis Agassiz. She joined the American Association for the Advancement of Science in 1850. In 1857, Maria became the chaperone for the daughter of a prominent Chicago business man and traveled with her to Europe. She visited many observatories during her trip and even met one of her idols, the astronomer Mary Somerville. Soon after, Maria was asked to be a professor of astronomy and the director of the observatory for Vassar College. She encouraged small classes made up of conversation rather than lecturing. Because she felt such a passion for granting other women the opportunities she was given as a child in terms of education, she decided at this point in her life to devote her Maria Mitchell was born to William Mitchell and Lydia Coleman on August 1^st, 1818. She was the third of ten children born to her parents and her family was a part of the Society of Friends, or Quakers, who had moved from England to America. Her parents both had strong passions for learning as her mother had worked in a library for two years for the sole purpose of reading all the books it contained. Her father provided for the family by rating chronometers of ships' captains. A chronometer is a very precise clock which was used by captains to determine their exact longitude. They used this information to navigate by means of the stars. On the side, her father was an amateur astronomer who inspired Maria's love for the heavens. As a child, she helped her father with his work and through this process, learned about both mathematics and astronomy.

Her Quaker family believed that equal importance should be given to the education for both boys and girls. They lived in an area which was full of natural phenomena which helped to inspire Maria's love for nature and science. She went to a private elementary school and then later to a school which her father ran. His school focused mostly on observations of nature. She then attended the Cyrus Peirce's school for young ladies where the headmaster saw her unique abilities in math and science and encouraged her to pursue her education with a passion. She was described as being “born of only ordinary capacity, but of extraordinary persistency.” She also worked as a librarian for twenty years and continued her own study while employed. She was fluent in French and studied science textbooks in that language. Because of her passion for education, she started her own school in 1835. She was an unconventional instructor who began school before sunrise for the purpose of watching birds with students in the morning and also stayed late into the night to view the stars. Throughout her life, she earned an honorary degree from Hanover College in 1853, Columbia University in 1887, and an honorary doctorate from Rutgers Female College a few years later.

Because she had been so passionate about education and in particular astronomy, Maria was frequently seen making observations at night. During her childhood, she was a helper to her father and together they made thousands of observations which were used for the U.S. Coast Survey. During her life, she also was a computer for the American Ephemeris and Nautical Almanac, working there for 19 years. All of the observations were regarding accurate time and latitude. In 1847, she discovered a new comet which was named after her and brought her worldwide fame. She first viewed it while at her father's observatory, using only a two inch telescope. The King of Denmark gave her a gold medal for her discovery and after that, she became a well known astronomer in both the United States and Europe. She is considered to be the first well known woman astronomer. In 1848 she was the first woman to be elected into the American Academy of Arts and Sciences, her membership being proposed by the very well known geologist Louis Agassiz. She joined the American Association for the Advancement of Science in 1850. In 1857, Maria became the chaperone for the daughter of a prominent Chicago business man and traveled with her to Europe. She visited many observatories during her trip and even met one of her idols, the astronomer Mary Somerville. Soon after, Maria was asked to be a professor of astronomy and the director of the observatory for Vassar College. She encouraged small classes made up of conversation rather than lecturing. Because she felt such a passion for granting other women the opportunities she was given as a child in terms of education, she decided at this point in her life to devote her work to education rather than practical astronomy. In 1873, she founded the Association for the Advancement of Women and served as president. After her work with this agency advocating for the recognition of women's contributions to science, she was the first woman elected to the American Philosophical Society in 1873. Regarding her job as either a teacher or observer, Maria said, “the scientist should be free to pursue his investigations. He cannot be a scientist and a schoolmaster... It is not all mathematics, nor all logic but is somewhat beauty and poetry.” After her death, Maria had a crater named after her on the moon. Also, the Maria Mitchell Association of Nantucket was formed in her honor, maintaining the Maria Mitchell Observatory. There are now several institutions named after her such as the Boston Public Library and a public school located in Denver, Colorado.work to education rather than practical astronomy. In 1873, she founded the Association for the Advancement of Women and served as president. After her work with this agency advocating for the recognition of women's contributions to science, she was the first woman elected to the American Philosophical Society in 1873. Regarding her job as either a teacher or observer, Maria said, “the scientist should be free to pursue his investigations. He cannot be a scientist and a schoolmaster... It is not all mathematics, nor all logic but is somewhat beauty and poetry.” After her death, Maria had a crater named after her on the moon. Also, the Maria Mitchell Association of Nantucket was formed in her honor, maintaining the Maria Mitchell Observatory. There are now several institutions named after her such as the Boston Public Library and a public school located in Denver, Colorado.   

Sources:

Ragan, Gay A. "Mitchell, Maria." Mathematics. Ed. Barry Max Brandenberger, Jr. Vol. 3. New York:                

Macmillan Reference USA, 2002. 51. Gale Virtual Reference Library. Web. 7 Mar. 2013.

DEROCHE, CELESTE. "Mitchell, Maria." American Women Writers: A Critical Reference Guide from Colonial Times to the Present: A Critical Reference Guide from Colonial Times to the Present. Ed. Taryn Benbow-Pfalzgraf. 2nd ed. Vol. 3. Detroit: St. James Press, 2000. 151-152. Gale Virtual Reference Library. Web. 7 Mar. 2013.

"Maria Mitchell." Encyclopedia of World Biography. 2nd ed. Vol. 11. Detroit: Gale, 2004. 61. Gale Virtual Reference Library. Web. 7 Mar. 2013.

"Mitchell, Maria." Complete Dictionary of Scientific Biography. Vol. 9. Detroit: Charles Scribner's Sons, 2008. 421-422. Gale Virtual Reference Library. Web. 7 Mar. 2013.

APOD 3.7

March 1 2013 Colors of Mercury

    This picture shows Mercury, our solar system's innermost planet.  Mercury has an orbital period of 88 days and can reach 800 degrees Fahrenheit on its surface.  This image was taken using the MESSENGER (MErcury Surface Space ENvironment, GEochemistry, and Ranging) spacecraft which is orbiting Mercury. This photo is enhanced to show color because the human eye would not be able to discern the colorful features visible here.  The colors are real though and reflect the chemicals and minerals present on the surface.   The Caloris basin can be seen in the upper right hand corner.  It was created by an asteroid which struck the planet in the early days of the solar system.  After the impact, lava entered the basin and created the feature which can now be seen.