Archive for the ‘Quantum Mechanics’ Category

Quantum Leap: The Standard Model, part 2

Friday, March 5th, 2010

Guest author, Thomas Kennedy, features a twice-monthly series, Quantum Leap, wherein he guides readers through the fascinating world of quantum mechanics. This is issue 009.
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So the question is, “what is Elemental?” In 1661, Robert Boyle determined that something that can’t be broken-down by a chemical reaction is an element, a notion, according to Wiki, that held for almost 300 years and a definition I still recall from high school chemistry class. This was a major moment in the process of understanding what the underlying building blocks of life are. Now, for the first time, man had a tool and a way to codify his approach to answering the questions of what is fundamental.

By 1869, a total of 63 elements had been discovered. As the number of known elements grew, scientists began to recognize patterns in properties and began to develop classification schemes. Attempting to understand this pattern and how to best organize it led to the development of the Periodic Table of Elements.

There has been some disagreement about who deserves credit for being the “father” of the periodic table – the German, Lothar Meyer, or the Russian, Dmitri Mendeleev. Both chemists produced remarkably similar results at the same time, working independently of one another. Meyer’s 1864 textbook included a rather abbreviated version of a periodic table used to classify the elements. This consisted of about half of the known elements listed in order of their atomic weight and demonstrated periodic valence charges as a function of atomic weight. In 1868, Meyer constructed an extended table which he gave to a colleague for evaluation. Unfortunately for Meyer, Mendeleev’s table became available to the scientific community via publication (1869) before Meyer’s appeared (1870).*

Mendeleev created a card for each of the 63 known elements. Each card contained the element’s symbol, atomic weight, and its characteristic chemical and physical properties. When Mendeleev arranged the cards on a table, in order of ascending atomic weight grouping elements of similar properties together, (in a manner not unlike the card arrangement in his favorite solitaire card game, patience,) the periodic table was formed. From this table, Mendeleev developed his statement of the periodic law and published his work On the Relationship of the Properties of the Elements to their Atomic Weights, in 1869. The advantage of Mendeleev’s table, over previous attempts, was that it exhibited similarities not only in small units such as the triads, but showed similarities in an entire network of vertical, horizontal, and diagonal relationships. In 1906, Mendeleev came within one vote of being awarded the Nobel Prize for his work.*

For the next installment, “Charge!”

Watch for Issue #10 of Thomas’ “Quantum Leap”, here on A Sky Full of Stars, on March 19, 2010.

*Western Oregon University citation

Quantum Leap: The Standard Model

Friday, February 19th, 2010

Guest author, Thomas Kennedy, features a twice-monthly series, Quantum Leap, wherein he guides readers through the fascinating world of quantum mechanics. This is issue 008.

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With all of the unverified hypotheses regarding black holes, dark matter, and dark energy permeating the general discussions regarding particle physics, I thought it might be good to step back and take a look at what is actually known and tested in the world of quantum mechanics.  To do this, we need to take a look at The Standard Model.

When we seek to understand what is fundamental to life around us, it is a question of what exactly is the essence of our physical world.  If you break matter and energy down to the smallest component what is it that we are dealing with?

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Quantum Leap: Blackholes Don’t Exist

Saturday, February 6th, 2010

Guest author, Thomas Kennedy, features a twice-monthly series, Quantum Leap, wherein he guides readers through the fascinating world of quantum mechanics. This is issue 007.

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Despite the regular pronouncements in the popular press, there is a growing debate among physicists that, in fact, the mathematical models that at one time purported to clearly substantiate the existence of such, black holes are proving out to be false.

Black holes have provided “simple”  answers to, for example, the questions of angular momentum for galaxy formation.  Why is it that galaxies don’t fly apart, given the energy and resulting motions that are readily evident?  Well, the theory goes, if you have a sufficiently strong gravitational force at the center of a galaxy, that provides the stickiness needed to keep galactic material from devolving into chaos.

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