A Michelson Interferometer is a device used to measure the speed of light in precise optical measurements. It does this by splitting light into two or more beams that recombine and interfere with each other causing the interference fringes. The interferometer basically consists of a light source, a beamsplitter, and two (or more) mirrors to reflect the light.
The interference pattern for a Michelson interferometer is circular-- that is, it produces concentric circles of light and dark "fringes". When one mirror on the interferometer is moving, the path difference between the two split beams of light changes, and the interference pattern is seen
Interference is a phenomenon that occurs when two photons of light interact with each other in such a way that their waves sum to either increase or decrease their total amplitude. Complete constructive interference occurs when two electromagnetic waves are of the same frequency and in phase; destructive interference occurs when two electromagnetic waves of the same frequency have a phase difference of one-half wavelength. When complete destructive interference occurs, no light can be detected. Similarly, complete constructive interference results in intensity quadrupling (intensity is proportional to the square of amplitude). The following picture demonstrates these effects.
Originally, the inventors of the interferometer produced it to measure the speed of light so they could determine the existence of ether. Since then it has been important in measuring the wavelengths of light, using the wavelengths of light to measure very small distances (up to 0.5 microns), to measure extremely small times (up to 1x10-15 seconds), and to study optical media.
Albert A. Michelson (1852-1931)
The Michelson interferometer was invented by American Physicist Albert A. Michelson in 1887. Michelson was born in Strzelno (Poland) in 1852 and moved to American in 1855. When he was 17, he joined the United States Naval Academy in Anapolis, Maryland where he excelled in science subjects. Michelson later became a science instructor at the academy, but moved on to become a professor of physics at several universities. During the years of 1923-1927, he was president of the National Academy of Sciences. In 1907, he was the first American to be awarded the Physics Nobel Prize for his many efforts in optics.
Michelson began experimenting with the interferometer in April of 1887. He came up with a system of mirrors and semi-transparent mirrors (or beamsplitters) for merging separated beams of light, which are coming from the same source. The system was set up so that the beam of light was split in two, sending each split perpendicular to each other, and then merging back so they “interfered” with each other.
Ewald Georg von Kleist is a German scientist who created the capacitor in November of 1745. Regrettably, Kleist did not have the proper paper work to claim in the records that the design of the capacitor was his idea. Many months later, a Dutch professor named Pieter van Musschenbroek created the Leyden jar, the world’s first capacitor (on record). It was a simple jar that was half filled with water and metal above it. A metal wire was connected to it and that wire released charges. Benjamin Franklin created his own version of the Leyden jar, the flat capacitor. This was the same experiment for the more part, but it had a flat piece of glass inside of the jar. Michael Faraday was the first scientist to apply this concept to transport electric power over a large distance. Faraday created the unit of measurement for a capacitor, called Farad.
and quality of the light, by arranging its angle and coverage.” (Millerson, pg. 16, 2013). As for the
Discovered that certain chemicals glowed when exposed to cathode rays. These chemicals were special because they weren’t deflected by the magnetic field produced in the cathode ray tube (which was built by Sir William Crookes in 1870).
This process is used in forensics because it is so precise, fast, and reliable. The process includes creating a high-temperature plasma induced by a laser, which allows the user to remove a small amount of mass from the subject, known as laser ablation. This ablated mass is then further manipulated to form a high energy plasma containing free electrons and energized ions. Once the laser is turned off, the plasma will begin cooling, which will let the ions return to their natural state. When this happens, they will give off a certain spectra that will allow the user to be able to tell what exactly was in the species they experimented on (appliedspectra.com). This could be useful in determining such substances like what glass is composed of or what type of glass was
As said above, both light and sound waves have to do with interference. In sound, interference affects both the loudness and amplitude. When two waves’ crests overlap, the amplitude increases. The same is true with the troughs of the waves, which decrease the amplitude.
Although telescopes has been around for several hundreds of years, there has been great discrepancy as to who invented it first. Here is one authors opinion. Lippershey was a Dutch spectacle marker during the early 17th century (approximately 1600). He was one of the first who created the "looker" (now called telescope) by placing two pieces of lenses together. The discovery that placing lenses together can magnify images were made by children who took Lippershey's spectacles and looked at a distant church tower.
Stemming from the first years of the 20th century, quantum mechanics has had a monumental influence on modern science. First explored by Max Planck in the 1900s, Einstein modified and applied much of the research in this field. This begs the question, “how did Einstein contribute to the development and research of quantum mechanics?” Before studying how Einstein’s research contributed to the development of quantum mechanics, it is important to examine the origins of the science itself. Einstein took much of Planck’s experimental “quantum theory” research and applied it in usable ways to existing science. He also greatly contributed to the establishment of the base for quantum mechanics research today. Along with establishing base research in the field, Einstein’s discoveries have been modified and updated to apply to our more advanced understanding of this science today. Einstein greatly contributed to the foundation of quantum mechanics through his research, and his theories and discoveries remain relevant to science even today.
People are familiar with measuring things in the macroscopic world around them. Someone pulls out a tape measure and determines the length of a table. A state trooper aims his radar gun at a car and knows what direction the car is traveling, as well as how fast. They get the information they want and don't worry whether the measurement itself has changed what they were measuring. After all, what would be the sense in determining that a table is 80 cm long if the very act of measuring it changed its length!
...d signal prior to detection. Another special feature that COS contains is its maximised efficiency, which means every bounce of a light beam along its path leads to a loss in signal strength. COS has a single bounce when the beam is fed into the appropriate channel.
Throughout different experiments, scientists have discovered that light behaves as both a wave and a particle in different circumstances. The only way that all of the properties of light can be explained is through the idea of a wave-particle duality.
An oscilloscope is an electronic test instrument that is used to observe an electronic signal, typically voltage, as a function of time. In other words, it is a voltage versus time plotter. Oscilloscopes come in two basic types, analogue or digital, and support various features and functions useful for measuring and testing electronic circuits. An oscilloscope is a key piece of test equipment for any electronics designer.
The index of refraction is defined as the speed of light in vacuum divided by the speed of light in the medium. In this experiment, the index of refraction for the perspex is 1.50. Snell's Law relates the indices of refraction of the two media to the directions of propagation in terms of the angles to the normal. It refers to the relationship between the different angles of light as it passes from one transparent medium to another. When light passes from one transparent medium to another, it bends according to Snell's law which states: [IMAGE] where: n1 is the refractive index of the medium the light is leaving, n2 is the refractive index of the medium the light is entering, sin 2 is the is the incident angle between the light ray and the normal to the medium to medium interface, sin 1 is the refractive angle between the light ray and the normal to the medium to medium interface.
Unlike water waves for example, Feynman emphasised that when electrons are fired through the slits one at a time, an interference pattern would be produced. He then famously said that this phenomenon “has in it the heart of quantum physics [but] in reality, it contains the only mystery.”
Spectroscopy is measured using a spectrophotometer. A beam of light is first pointed towards the spectrophotometer. The beam of light then strikes a part of the spectrophotometer called the diffraction grating. The diffraction grating works similar to the prism shown above. It separates the light into its component wavelengths by rotating so that only a specific wavelength will reach a part of the spectrophotometer called the exit slit. On the other end of the exit slit there is a sample located in a test tube as well as a detector. After the wavelength passes through the sample, the detector measures the transmittance and absorption of the sample. The transmittance is the amount of light that was able to pass through the sample and reach the detector, and the absorption is the amount of light that was absorbed by the sample. The detector converts the measure of transmittance into s digital display, such as a graph.