The gap in the image of Molecular Cloud Barnard 68 is not a black hole. It's a dark molecular cloud. The denseness of the dust and molecular gas in this area absorbs almost all of the visible light emitted from the background stars, though it is possible to look straight through the cloud in infrared light. The dark abyss looking cloud are, as could be predicted, one of the coldest and darkest places in the universe. Barnard 68 is located near the constellation Ophiuchus (the Serpent Handler). The size of the absorption gives astronomers the impression that Barnard 68 is about 500 light years away and spans half a light year. It is still unknown how dark molecular clouds form. It is predicted that Barnard 68 will collapse and form a star system.
Monday, January 5, 2015
Friday, December 19, 2014
David Rittenhouse Essay
Amber
Stich
Percival
D.E.
Astronomy
19
December 2014
David Rittenhouse Essay
David, the son of Matthias and
Elizabeth Williams Rittenhouse, was born on a farm in 1732, about 20 miles
north of Philadelphia in the town of Norriton. Of German Mennonite and Welsh
Quaker decent, Rittenhouse belonged to the Presbyterian Church and was given
informal education. Most of Rittenhouse’s education was self-taught.
Rittenhouse married Eleanor Coulston in 1766 and had two daughters. When Eleanor
died, Rittenhouse married Hannah Jacobs in 1772. Rittenhouse was of poor
health, mostly due to his duodenal ulcer. But despite his ailments, Rittenhouse
was a major contributor to both astronomy, and the early United States. Rittenhouse
spent most of his life in Philadelphia.
By
trade, Rittenhouse was a clock and mathematical instrument maker. He was known
for his workmanship. His astronomical clock used a pendulum he himself had designed.
Many of Rittenhouse’s instruments were so well made they were able to be
preserved to this day. His handmade instruments were far superior to any other
in the United States at that time. Some of the instruments Rittenhouse made
were surveyors’ compasses, levels, transits, telescopes, zenith sectors, thermometers,
barometers, a hygrometer, and eyeglasses. Rittenhouse was one of the early
users of spider webs over a telescope’s eyepiece to be used for cross hairs. He
also built a collimating telescope in his observatory. The Vernier compasses
Rittenhouse built were known in America as “Rittenhouse compasses”, and the
stove type he made for Benjamin Franklin’s fireplace were deemed a “Rittenhouse
stove”. Rittenhouse, among his experiments with pendulums, created the concept of
magnetic dipoles. During his diffraction studies, Rittenhouse created plane transmission
gratings, using fine wire across a frame and followed this by stating the law
of governing their displacement.
Though it was often overlooked –David
Rittenhouse played an important part in the development of Pennsylvania. Rittenhouse
was the most celebrated American surveyor; marking Pennsylvania’s borders with
its surrounding states. During the American Revolution, Rittenhouse helped
design the Delaware River defenses and worked on the production of saltpeter
and guns. Rittenhouse also experimented with telescope scopes for rifles and
cannons. Along with this, Rittenhouse participated in the forming of the Pennsylvanian
Constitution of 1776, the Board of War, and the vice-presidency of the Council
of Safety. Occasionally, Rittenhouse held the responsibility of executive
leadership of the state. From 1777-1798, Rittenhouse served as the treasurer of
Pennsylvania. And when Thomas Jefferson was working on his report for weights
and measured, he turned to Rittenhouse as a consultant and named him the first
director of the U.S. Mint in 1792.
Beginning in 1773, Rittenhouse moved
his talents to astronomy. Rittenhouse began supplying almanacs in Pennsylvania,
Maryland, and Virginia with astronomical calculations. Rittenhouse first
success was in his observation of the transit of Venus in 1769. He then
submitted the best American calculation contribution to the worldwide efforts
to establish the sun’s parallax. On his publishing of his initial volume of Transactions, which is where he
published most of his work, Rittenhouse was made the President of the American
Philosophical Society, succeeding Ben Franklin. Rittenhouse built all of the
instruments used by the Norriton observation group. To enable him to keep daily
records and conduct regular observations for his publishing data and
calculations on meteors, comets, Jupiter’s satellites, Mercury, Uranus and
various eclipses- Rittenhouse established the Philadelphia observatory.
Rittenhouse’s best published work was an original formula for finding the place
of a planet in its orbit. Rittenhouse also figured out logarithm calculations
as a study of the period of a pendulum. Rittenhouse may have independently
developed a system of calculus during his research of the area. Rittenhouse also
published various accounts of lightning, meteorology, geology, and aspects of
natural history.
Rittenhouse, a prominent American
figure of his time, is often overlooked by historians. Rittenhouse was the
power-house of behind-the-scenes work, overshadowed, but not underappreciated,
by public figures. He contributed major advancements in mathematical and astronomical
instruments, which he used himself to contribute valuable data to the scientific
community. Rittenhouse’s poor health was the cause of his death; he died on
June 26th, 1796 of cholera. His legacy was of being one of American’s
“untutored geniuses”.
Monday, December 15, 2014
APOD 2.6
One celestial body that never fails to amaze is the Nebula. The nebula pictured above is the Flame Nebula- about 1,500 light years away. The Nebula is located near the Orion constellation. The glow and dark dust lanes gives the nebula the fire-like appearance. The bright star Alnitak, of the Belt of Orion, shines the energetic light on the nebula. Alnitak does this by knocking electrons away from the hydrogen gas clouds that reside in the nebula -the electrons and ionized hydrogen then recombine. The Flame Nebula (NGC 2024) picture is a mixed composite of both visible and infrared light. The Flame Nebula is part of the Orion Molecular Cloud Complex, a star-forming region that also houses the Horsehead Nebula.
Observation Post (12/15/14)
After watching the Gemini meteor shower a few nights ago, I gained a new appreciation for what I'm learning in astronomy. Things are happening in space that I never knew about before- and now I get to go outside and not only watch them happen- but understand what's happening and why. I have always liked stargazing, but actually being able to identify constellations and stars gives the practice a whole new light. One of my favorite things to do is to stargaze with my boyfriend and compete to see who can find the most satellites in one night. I never before had this appreciation for doing something so simple as just looking up.
Monday, December 8, 2014
D. Rittenhouse (Sources)
David Rittenhouse Biography Sources
Science and Its Times:
"David Rittenhouse." Science and Its Times. Ed. Neil Schlager and Josh Lauer. Vol. 4: 1700 to 1799. Detroit: Gale, 2000. 367. Gale Virtual Reference Library. Web. 8 Dec. 2014.
The Complete Dictionary of Scientific Biography:
"Rittenhouse, David." Complete Dictionary of Scientific Biography. Vol. 11. Detroit: Charles Scribner's Sons, 2008. 471-473. Gale Virtual Reference Library. Web. 8 Dec. 2014.
Encyclopedia of World Biography:
"David Rittenhouse." Encyclopedia of World Biography. 2nd ed. Vol. 13. Detroit: Gale, 2004. 180-181. Gale Virtual Reference Library. Web. 8 Dec. 2014.
Friday, December 5, 2014
APOD 2.5
This pillar of dust makes what looks like to be a 20 light year long seahorse. The dust structure art is provided to courtesy of our neighboring Large Magellanic Cloud. The Large Magellanic Cloud is inside a star forming region near the Tarantula Nebula. The nebula is in the midst of forming a star cluster is referred to as NGC 2074. The center is visible in this image if you look towards the top around where the neck of the seahorse is. This image was taken back in 2008 by the Hubble Space Telescope using its Wide Field Planetary Camera 2 to celebrate Hubble's 100,000th trip around Earth. As these stars form in the cluster, their light and wind will erode the dust structure away over the next million years or so.
Wednesday, December 3, 2014
Observation (12.3)
In all honesty -astronomy is starting to impact my life. The other day while the sky was clear I was too busy identifying constellations such as Ursa Minor to notice the car heading for me. Also, I had to explain to my coach why I was late for a 5 am practice because I was too busy trying to find zodiacal constellations across the ecliptic. This morning was beautifully clear, but as much as I wanted to stop and stare -I knew I coach wouldn't buy my excuse again.
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