Journal 4-8 Max Bardowell 5-26-08

The Elegant Universe

This week we began watching the documentary The Elegant Universe. It is an exploration of the "String Universe Theory", which is a new approach to theoretical physics. While I still don't understand the theory, it does have the potential to unite the two sects of practicing physicists; those who follow Einstein's school of Relativity and those who study Quantum physics, two theories which have previously been irreconcilable. More importantly, it will unify all the theories of the universe, a goal which Einstein stubbornly sought until the time of his death, when, in his old age, he saw drifting dreams of a seamless, harmonized universe from the edge of his deathbed. It now seems that he was not as crazy as some of his contemporaries believed. While his direction might have been flawed, his ultimate goal of smoothing the boundaries of the universe was right on the mark.

Question: Who developed the theory of Quantum physics.

Journal 4-7 Max Bardowell 5-18-08

Einstein's Theory of Relativity

This week we discussed light and sound waves, and, in the course of our discussion, Einstein's Theory of Relativity came up. I have always heard about this theory and its significance to the way the universe is perceived, but it has never been fully explained to me. After some research, I think I have the basic ideas down, however it would take a while to explain them here. For a link to the Theory of Relativity explained in layman's terms, look here: http://www.muppetlabs.com/~breadbox/txt/al.html.

The impact the two theories (special and general relativity) have had on society has been immense. Special relativity is mathematically self-consistent, and it is an organic part of all modern physical theories, most notably quantum field theory, string theory, and general relativity (Wikipedia.com).General relativity has emerged as a highly successful model of gravitation and cosmology, which has so far passed every unambiguous observational and experimental test to which it has been subjected. Still, there are strong indications the theory is incomplete.

The problem of quantum gravity, and the associated question of the reality of spacetime singularities, remain open. Observational data like that for dark energy and dark matter could indicate the need for new physics, and while the so-called Pioneer anomaly might yet admit of a conventional explanation, it, too, could be a harbinger of new physics. Even while staying within the frame of Einstein's theory, general relativity is rich with possibilities for further exploration: mathematical relativists explore the nature of singularities and the fundamental properties Einstein's equations, ever more comprehensive computer simulations of specific spacetimes (such as those describing merging black holes) are run, and the race for the first direct detection of gravitational waves continues apace, with opportunities to test the theory beyond the limited approximations it has been tested so far even in the binary pulsar measurements. More than ninety years after the theory was first published, general relativity remains a highly active area of research (Wikipedia.com).

Journal 4-6 Max Bardowell 5-14-08

Creation of a Light Bulb

First you begin with the raw materials. All incandescent light bulbs have the three basic parts—the filament, the bulb and the base. Although extremely fragile, tungsten filaments can withstand temperatures as high as 4500 degrees Fahrenheit (2480 degrees Celsius) and above. The development of the tungsten filaments is considered the greatest advancement in light bulb technology because these filaments could be produced cheaply and last longer than any of the previous materials.

The bulb itself is made of glass and contains a mixture of gases, usually argon and nitrogen, which increase the life of the filament. Air is pumped out of the bulb and replaced with the gases. A standardized base holds the entire assembly in place. Today, aluminum is used on the outside and glass is used to insulate the inside of the base, producing a stronger base.

Originally produced by hand, light bulb manufacture is now almost entirely automated.

The filament is manufactured through a process known as drawing, in which tungsten is mixed with a binder material and pulled through a die—a shaped orifice—into a fine wire. The coiled filament is attached to the lead-in wires. The lead-in wires have hooks at their ends which are either pressed over the end of the filament or, in larger bulbs, spot-welded.

After heating in a furnace, a continuous ribbon of glass moves along a conveyor belt. Precisely aligned air nozzles blow the glass through holes in the conveyor belt into molds, creating the casings. A ribbon machine moving at top speed can produce more than 50,000 bulbs per hour. After the casings are blown, they are cooled and then cut off of the ribbon machine. Next, the inside of the bulb is coated with silica to remove the glare caused by a glowing, uncovered filament. The company emblem and bulb wattage are then stamped onto the outside top of each casing.

The base of the bulb is also constructed using molds. It is made with indentations in the shape of a screw so that it can easily fit into the socket of a light fixture.

Once the filament, base, and bulb are made, they are fitted together by machines. First, the filament is mounted to the stem assembly, with its ends clamped to the two lead-in wires. Next, the air inside the bulb is removed, and the casing is filled with an argon and nitrogen mixture. These gases ensure a longer-life for the filament. The tungsten will eventually evaporate and break. As it evaporates, it leaves a dark deposit on the bulb known as bulb-wall blackening.

Finally, the base and the bulb are sealed. The base slides onto the end of the glass bulb such that no other material is needed to keep them together. Instead, their conforming shapes allow the two pieces to be held together snugly, with the lead-in wires touching the aluminum base to ensure proper electrical contact. After testing, bulbs are placed in their packages and shipped to consumers.

"Light Bulb." How Products are Made. Ed. Stacey L. Blachford. Gale Group, Inc., 2002. eNotes.com. 2006. 14 May, 2008 <http://www.enotes.com/how-products-encyclopedia/
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Question: How did Edison invent the light bulb?

Journal 4-5 Max Bardowell 5-4-08

Why Do Light Bulbs Burn Out?

Answer to Last Week’s Question: The top manufacturers of wind turbines in the US are the Distributed Energy Systems corp, Green Energies Technologies, and Earth Wind and Power systems.

This week we worked with light bulbs and how to develop a continuous electrical current involving them. During this process, my group, while conducting some unauthorized experimentation with the bulbs, burnt two of them out (sorry Mr. Couillard). After this event, I began to wonder why bulbs burn out and why some bulbs burn out faster than others. I found the answer from Ask Yahoo.

Why do light bulbs burn out?

To summarize: electrical current flows through the bulb’s filament, a long, super thin, double coil wire made of the metal tungsten. This interaction creates extreme heat around 4,000 degrees and starts a process that causes the atoms to release extra energy in the form of light photons.

At such a high temperature, though, some tungsten atoms will fly off and collect on the inside of the bulb's glass. This loss of tungsten is slowed but not prevented by adding inert gases, typically argon. The argon atoms rebuff the tungsten atoms when they collide, so that some tungsten atoms rebound and rejoin the solid filament. But eventually, as more and more atoms are lost, the filament starts to disintegrate.

The filament is further compromised by the rapid heating and cooling of the wire when the bulb is turned on and off. This creates areas of stress almost like in a paper clip that's repeatedly bent. Eventually, this stress, coupled with the loss of tungsten atoms, weakens the filament enough to break.

http://ask.yahoo.com/2004/1228.html

Question: How are light bulbs made?