pwn physics 365: physics history, vocabulary, and resources every day of the year

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 21 February 1953- Watson and Crick arrived at the conclusion that the DNA was a double helix structure using X-Ray crystallography. Word of the day- Potential Energy is the ability for an object to do work. The most common example of this is gravitational potential energy. Remember from yesterday that an object can have kinetic energy by moving a certain velocity. Well, if you drop an object from a specific height, it will change velocity, how is this possible if we don't push it? Well, gravity is what is converting all that potential energy into kinetic energy. It is possible to calculate this potential energy by multiplying the mass, times the acceleration due to gravity (g or 9.81m/s^2) times the height above the ground. This is how much work can be converted into potential energy by gravity. Quote of the Day: "I try to show the public that chemistry, biology, physics, astrophysics is life. It is not some separate subject that you have to be pulled into a corner to be taught about." -Neil Degrasse Tyson Keywords: Potential, Energy, Height, Gravity, Mass

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 20 February 1844- Happy Birthday to Ludwig Boltzmann, who would have turned 172 today. He is the Boltzmann of the Boltzmann constant, Boltzmann equation, Boltzmann distribution, Stefan-Boltzmann constant, Stefan-Boltzmann Law, to name a bit. Word of the day- Kinetic Energy is the amount of energy that an object in motion has. This is not the same as momentum, but in some ways similar, because kinetic energy is dependent on both the mass and velocity, and can be calculated as .5*m*v^2. This is the amount of work required to get a mass m to the velocity v. Once at this velocity, the mass will continue to maintain this amount of kinetic energy until the speed changes, i.e. work of some sort is done on the object, whether it be friction, air resistance, or another active force, like a car putting on the brakes.  Quote of the Day: "In string theory, all particles are vibrations on a tiny rubber band; physics is the harmonies on the string; chemistry is the melodies we play on vibrating strings; the universe is a symphony of strings, and the 'Mind of God' is cosmic music resonating in 11-dimensional hyperspace." -Michio KakuKeywords: Boltzmann, Kinetic, Energy, Velocity

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 19 February 1473- Happy Birthday to Nicholas Copernicus, astronomer extraordinaire who was certainly not the first to discover, but quite probably the impetus for the scientific revolution triggered by his publication which posited that the earth was not the center of the universe, but rather than the Earth orbits the sun. He published it while on his death bed, so that he would not be threatened for "heresy" during his lifetime. Word of the day- Blueshift- Is a type of doppler shift which occurs with cosmic light. Like yesterday's word of the day, the same idea applies with light moving towards an observer. When light moves away from the observer, the wavelength gets longer, or shifts to the red side of the spectrum. When light moves closer, the wavelength gets shorter, this shifting towards the blue end of the spectrum. It does not necessarily indicate that blue light is emitted. Quote of the Day: "The brain is like a muscle. When it is in use we feel very good. Understanding is joyous." -Carl SaganKeywords: Blueshift, Light, Doppler, Shift, Relativity

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 18 February 1745- Happy Birthday to Alessandro Giuseppe Antonio Anastasio Volta, who turns 271 today. The inventor of the "voltaic pile" which was an early version of the battery. He invention pretty much started the entire field of electrochemistry.Word of the day- Redshift- Is a type of doppler shift which occurs with cosmic light. Like yesterday's word of the day, the same idi applies with light. When light moves away from the observer, the wavelength gets longer, or shifts to the red side of the spectrum. It is possible to analyze the light from galaxies, if the light is redshifted, astronomers can decipher whether or not galaxies are moving away from us or not. When analyzing starlight, it is possible to identify critical frequencies which we know to be emitted from different elements. If the wavelength of the light is, for example, several nanometers longer than potassium, we know that potassium exists in the star and that it is moving away from us.  Quote of the Day: "If you want to make an apple pie from scratch, you must first create the universe." -Carl SaganKeywords: Redshift, Light, Doppler, Shift, Relativity

Dig Deeper at pwnphysics.blogspot.comOn this day in physics: 17 February 1888- Happy Birthday to Otto Stern, the Physicist with the most Nobel Prize nominations of all time, with 87 total nominations between 1925 and 1945, and actually sealing the deal in 1943 for the infamous Stern-Gerlach experiment. Word of the day- Doppler Effect- Continuing on waves, this is a special sort of relativistic wave phenomenon. Imagine a wave such as a sound wave, such as a horn, is being emitted from a moving vehicle at constant frequency. If the car is driving towards you, because of the velocity of the car, the emitted wave will pick up a little extra speed and have a higher pitch. As it drives past you, and moves away from you, the velocity away from you will "slow the wave down a bit" and give it a little lower frequency. This is known as the doppler effect. Quote of the Day: "Somewhere, something incredible is waiting to be known." -Carl SaganKeywords: Doppler Effect, Wave, Velocity, Direction

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 16 February 1948- Uranus's moon, Miranda, was photographed for the first time. Word of the day- Wavelength- Its pretty much what it sounds like. It's the length of the wave for one oscillation. The easiest way to measure it is to measure from crest to crest or trough to trough. The length of the wave is related to the speed of the wave divided by the frequency.Quote of the Day: "All matter originates only by virtue of a force...We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter." -Max Planck Keywords: Wavelength, Wave, Crest, Trough

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 15 February 1786 - The Cat's Eye Nebula was discovered in 1786 by Astronomer William Herschel.Word of the day- Amplitude- On a wave, the amplitude is the distance from the center of the wave to the highest point, known as the crest. The lowest point of the wave is known as the trough. So the amplitude is twice the distance from the crest to the trough. Think of a water wave on the beach, the crest of the wave is the highest point, which when it comes close to shore usually causes the wave to collapse, to the delight of beachgoers and surfers everywhere. The higher the amplitude, the larger the wave, and the more energy that it transfers, this is true of all waves. In radio signals, AM radio is referred to as amplitude modulation. In order to send your car radio the signal, the radio station varies the amplitude of the wave at a certain frequency in order to send the signal. As sort of a redaction to yesterday's FM explanation, the way the frequency modulation delivers the carrier signal is that the antenna is sensitive to changes in frequency to deliver the signal to your radio. (Sorry guys!) Think of amplitude modulation kind of delivering what you'd know as a longitudinal wave, changing the amplitude and keeping the same frequency, and frequency modulation as like a transverse wave of a spring, looking at the same amplitude, and of course modulating the frequency. There is a seriously excellent graphic illustrating this on the wikipedia entry for Frequency Modulation, so you can check that out here if you're so inclined.Quote of the Day: "Arc, amplitude, and curvature sustain a similar relation to each other as time, motion, and velocity, or as volume, mass, and density." - Carl Frederich GaussKeywords: Cat's Eye, Nebula, Amplitude, Wave, Crest, Trough

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On this day in physics: 14 February 1874 - The IOP, or Institute of Physics was founded. It's a 50,000 strong charity which furthers education and scientific research, as well as publishing many journals in the field of physics.     

Word of the day- Frequency is the amount of repetitions something, most usually a wave, undergo in a certain period of time. Frequency is measured in Hertz, the unit of which is 1/s, or "stuff per time". In a wave, it is the amount of oscillations per unit of time. In waves, the frequency multiplied by the wavelength is equal to the velocity. This means the shorter the wave, the higher the frequency. The longer the wave, the lower the frequency. Radio waves are waves broadcast at very specific frequencies, and when you change your radio dial, you actually tune your radio to check for information at a different frequency of radio wave. F.M. stands for frequency modulation, meaning that in this type of radio wave, the frequency is tuned in order to change the stations. 

Quote of the Day: "Physics isn't the most important thing. Love is." -Richard P. Feynman 

Keywords: Wave, Frequency, Love, Valentine's Day, Institute, Physics

Dig deeper at pwnphysics.blogspot.comOn this day in physics: 13 February 1912 - Robert Millikan began his famous Millikan Oil Drop experiment. The experiment consisted of dropping small droplets of oil between two plates which generated an electric field. The field was varied until the oil droplets were suspended in midair, this the force of the electric field counteracted that of gravity. It was then possible to calculate the charge of an electron knowing the voltage between the plates and the size/weight of the oil droplets. Millikan was able to calculate the charge of an electron to within 1% of our current value, 1.602e-19 C.

Word of the day- Wave- A wave is an oscillation which transmits energy, but very infrequently mass. The idea is to distinguish a wave from a traveling object. Waves can propagate in several ways. The first is called a longitudinal wave. Think of yourself holding the end of a string with the other end fastened, and shaking it periodically. This is known as a longitudinal wave because the oscillation is perpendicular to the motion of the wave. Another type of wave is a transverse wave, where the oscillation is in the same direction as the motion of the spring. Think of a spring, or slinky, hanging from the ceiling and being pulled straight down, the motion of the wave would be up and down, as would the motion of the wave. Both the example with the string and the spring are what are referred to as mechanical waves, because they involve physical systems through which the wave propagates. There is still another type of wave, the electromagnetic wave, which does not rely on the motion of matter, rather, the wave propagates through a "field", which affects matter in the vicinity of the field, but does not involve matter itself.

Quote of the Day: "If you want to understand the secrets of the universe, think in terms of energy, frequency, and vibration." -Nikola Tesla 

Keywords: Wave, Physics, Millikan, Oil, Electron

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On this day in physics: 12 February 1804- Happy Birthday to Heinrich Lenz, a physicist who made contributions to the field of electrodynamics, and the namesake of Lenz's Law.

Word of the Day: Lenz's Law- I want to go back to the idea of induction. Remember 2 days ago we were talking about the change of a magnetic field aka a flux, there will be an induced current, which is a flow of electrons through the wire. But which direction does the current flow in the wire? That's where Lenz comes in?  

Lenz's Law states: "If an induced current flows, its direction is always such that it will oppose the change which produced it." So Lenz's law gives us the direction. In Faraday's law of induction, it is the minus sign in the equation, because it shows the direction of the induced current. 

Quote of the Day: "In science there is only physics, the rest is stamp collecting." -Lord Kelvin

Keywords: Faraday, Lenz, Induction, Current