Observations 2

Ep. 247: The Ages of Things
This episode focused on how scientists determine the ages of things that are so much older than humans. It turns out that the primary method for doing this is radioisotope dating that is found in the sedimentary layer. The ability of supernovae to create radioactive isotopes allow scientists to determine the timeline of something through calculations of half-lives. Half-lives are the amount of time it takes for an isotope to decay to half of its mass. The amount of mass decreases the greatest at first but eventually slows down to the point that the original parent substance is considered depleted. The exponential decay function mathematically displays this phenomenon. The only viable element to use for things that are really old is carbon. More recent dating can be found through the use of other elements. Carbon-14 has trouble being dated past 60,00 years however. Uranium-235's half life is 80,00 years, which allows for a much larger range of study. Finding out how old the earth was is a process that was determined through looking for older and older rocks beneath the surface. Rocks are found to be millions or billions of years old through the elements of samarium and neodymium. The use of radioactive elements can be used to determine the age of astronomical objects and earth itself.

Ep. 252: Heisenberg Uncertainty Principle
The conversation began with Fraser and Pamela talking about how particles and atoms are not just pieces of matter but waves that interacts with their surroundings. The realization that particles were waves caused a mathematical deilemna and a problem with the understanding of space and time. The production of waves such as tsunamis travel through the ocean and merit the question of where and with what speed. Similarly atoms and particle in space exhibit these same values. Particles such as electrons can be described as many waves interfering and focusing on the position of the electron. The viewing of particles in this way makes momentum impossible to find. The description of particles as waves and vice versa creates problems mathematically. The quantum mechanics of not being able to describe the position or velocity at the same time is the Heisenberg Uncertainty Principle. This theorem explains how energy and time are mutually exclusive values. Position of a particle is found using devices that examine the deflection of a particle. This type of microscope allows for position to be determined, but for velocity to be determined, this must be invalidated. Position and velocity are exclusively known by the Heisenberg Uncertainty Principle.

APOD 3.8

 

This is a picture of NGC 1579: Trifid of the North. This nebula is found in the constellation Perseus and is very similar to a more well known nebula, the Trifid. The nebula is about 2100 light years away and 3 light years across, and expresses an interesting color scheme. Similar to Trifid, the nebula displays a red light, however the light source is different from that of Trifid. Instead of hydrogen emitting red light when excited by ultraviolet light, a star inside the nebula creates the energy to produce the colored light. The blue reflection nebula is created the same as Trifid however, from reflection of starlight by dust. 

Hertzsprung sources

http://www.rundetaarn.dk/engelsk/observatorium/hertz.html http://www.nndb.com/people/225/000169715/
http://www.britannica.com/EBchecked/topic/263944/Ejnar-Hertzsprung

ejnar hertzsprung biography

Ejnar Hertzsprung was born in Copenhagen, Denmark in 1873. Hertzsprung grew up in an environment where astronomy was fostered, because his father was had studied astronomy, but could not find a position. His father got a job as an insurance director and supported Hertzsprung through his early years that way. Hertzsprung attended grade school in Copenhagen, before moving on the Copenhagen Polytechnics to study chemistry. During the turn of the century, Hertzsprung was working with with acetylene-lightning in St. Petersburg Russia. Hertzsprung began to have success in his field during this time. He studied chemistry at Leziping for a short while, but decided to move back home after the tragic death of his brother. Living back in Copenhagen with his mother and sister, he started his own scientific research. The family was able to support him due to previous financial gains. Hertzsprung began to develop research in the field of stereo-photography and spectrophotometry. He was still not recognized in the astronomy field. After 1902, Hertzsprung decided to continue his career at the University of Copenhagen's Obersvatory. During 1905, Hertzsprung compiled his research and he published "Zur Strahlung der Sterne" in "Zeitschrift für Wissenschaftliche Photographie". He was able to discover that stars in the late spectral classes are divided into multiple series. The luminous red stars he found, were the largest. He was the first to understand the connection between luminosity and the spectrum of light that was emitted. He published his work in a different book, and went on to meet Russell, an american scientist. The two had the same results, and thus the diagram that was created to plot luminosity and spectra was named the Hertzsprung-Russel diagram. The diagram shows wavelength of light, visual and absolute magnitude. Hertzsprung recieved Gold Medal for the Royal Astronomical Society in 1929 and the Bruce Medal in 1937 for his work concerning the Hertzpsrung-Russel diagram and estimating the distance to the Small Magelliac Cloud using parallax. He also discovered two asteroids, one of which was named Amor asteroid 1627 Ivar. Hertzsprung passed away with much scientific and astronomical accomplishment in October of 1967 at age 94.

APOD 3.7

This is a picture of the comet Garradd with both of its tails being visible. Comets have ice and dust trails, as well as ion tails. The ice and dust comes from the comet itself, while the ion trails are created from the solar wind ejected by the sun. The two are usually both visible, but are not facing in opposite directions. This view is possible because of earth's current intermediate viewing angle. This special angle with the comet allows viewers to see the comet with opposing tails, and notice the subtle hues surrounding both tails. The grains of the ice and dust trail seems yellow because it reflects sunlight achromatically, while the ion trail appears blue from efficient reflection of light by carbon monoxide.