Saturday, February 6, 2016

07 February 2016- Range | PWN Physics 365

On this day in physics: 07 February 1940- Happy Birthday to Toshihide Maskawa who turns 76 today. He is a Nobel Laureate who won one quarter of the prize in 2008 "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."

Word of the Day: Range- Since today is Super Bowl Sunday, I thought we'd take a look at projectile motion, which anyone watching the Super Bowl tonight will see plenty of. As the quarterback throws the football, they will be putting an projectile, namely the football, in the air. It will follow the shape of a parabola as it reaches its (hopefully) destined target somewhere downfield. Now, there are many many different critical words relating to this parabola, but today we will talk about the range. Range is the total horizontal distance traversed by the projectile, in tonight's case, the football. The announcers, coaches, players, and referees will be highly concerned with the range of the projectile, aka a "30 yard pass", et cetera. In sports, they don't care much about the maximum height achieved, or the angle of the throw, but rather just how far it has gone, and where it lands. In physics, this is referred to as the range of the projectile.

Quote of the Day: "Winning can be defined as the science of being totally prepared" -George Allen

Keywords: Kinematics, Range, Football, x-direction

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06 February 2016- Escape Velocity | PWN Physics 365

On this day in physics: 06 February 1802- Happy Birthday to Charles Wheatstone, a physicist who invented a myriad of things including the concertina and the stereoscope. A stereoscope is kind of like a viewfinder that children play with. A card will contain slightly different variations of the same image which when looked through the viewfinder produce a 3D image.

Word of the Day: Escape Velocity- the least velocity required in order to for an object to free itself from the gravitational attraction of a massive object. Objects which are traveling less than the escape velocity in range of a massive object orbit it. Example: The Earth is traveling less than its escape Velocity of the sun, and so the Earth orbits the Sun. Now, the escape velocity is dependent on the mass of the object you're trying to escape, and the distance you are from that object. The equation for the escape velocity is actually sqrt(2GM/r), where G is the gravitational constant G = 6.67×10−11 m^3kg^−1s^−2, M is the mass of the object to be escaped and r is the distance from that mass. Here are some examples of what escape velocities might look like.[Source] From the Sun's surface, you would need to be traveling 618 km/s to escape its gravitational clutches. From Earth, you would need to be traveling 11 km/s to escape Earth's gravity, and 42 km/s to escape the Sun's. At Jupiter, the tables turn. You would need to be traveling only only 18.5 km/s to escape the hold of the Sun, but 60 km/s to slip the grip of Jupiter itself. Lastly, from Neptune, 7.7 km/s to escape the Sun, and 24 km/s to escape Neptune itself. The escape velocity of anything at the event horizon of a black hole is the speed of light. Past the event horizon, there is no escape.

Quote of the Day: "Once someone gets a little escape velocity going, ain't no play in the world that will keep them from leaving." -Junot Diaz, Drowned

Keywords: Escape, Velocity, Mass, Gravity, Distance, Sun, Earth.

05 February 2016- Centripetal Acceleration | PWN Physics 365

On this day in physics: 05 February 1915- We say Happy Birthday to Robert Hofstadter, an American Physicist and winner of the Nobel Prize in 1961. He shared the prize with Rudolf Mössbauer, however they won for separate contributions. According to the Nobel Prize official award, "The Nobel Prize in Physics 1961 was divided equally between Robert Hofstadter "for his pioneering studies of electron scattering in atomic nuclei and for his thereby achieved discoveries concerning the structure of the nucleons" and Rudolf Mössbauer "for his researches concerning the resonance absorption of gamma radiation and his discovery in this connection of the effect which bears his name"." [Source] [Source]

Word of the Day: Centripetal Acceleration is an inward acceleration experienced by an object experiencing curved or circular motion. So, consider F = ma, Force is equal to Mass times Acceleration. So, we have examined in two previous words of the day what mass and acceleration are. So if we have an object of constant mass, and it starts to experience curved motion, the velocity is changing all the time, because THE DIRECTION OF THE VECTOR IS CHANGING. In circular motion, the acceleration is always pointed radially inwards towards the center of the circle. The force generated by this acceleration is known as centripetal force. Many people confuse this with centrifugal force. Now, imagine you're driving a race car around a track about to take the first half-circle curve. We know the radius of this circle, and can read from the speedometer the speed. The centripetal force can be calculated as F = m*v^2/r. So the force is dependent on the radius of the curve, because this defines how tight the curve is, how fast you're going, and the mass of your car. Now, a body moving wants to travel in a straight line, so there must be an unbalanced force in order to create the circular motion of your car. What gives this force is the friction between the tires and the track. This friction will only sustain a car going in a circle up to a certain velocity for a given radius of curve. After that, the car will begin to move in a straight line again, and is what causes cars to skid on curves.

Quote of the Day: "The fact that mankind persists shows that the cohesive force is greater than the disruptive force, centripetal force greater than centrifugal." -Ghandi

Keywords: Centrifugal, Force, Acceleration, Curve, Circular, Motion, Centripetal, Friction.

Thursday, February 4, 2016

04 February 2016- Centrifugal Force | PWN Physics 365

On this day in physics: 04 February 1600- Johannes Kepler begins work with Tycho Brahe. Tycho Brahe was one of the most prolific astronomers of all time, and had years and years of astronomical data. Johannes Kepler had the mathematical know how and intrigue to take this wealth of data and transform it into Kepler's Planetary laws of motion, which describe how planets move around the Sun.

Word of the Day: Centrifugal Force- A centrifugal force is what is known as a "fictitious" or "false force" experienced by objects undergoing some sort of curved motion or circular motion. When turning in a circle, the object experiences the sensation of an outward force. Imagine your clothes in the dryer going through the final spin. All of the clothes stick to the outside of the dryer, spinning in a circle. It is possible to experience this sensation on many amusement park rides. The force is so strong that on some rides, while spinning at a certain rate, the floor can be lowered or removed, and riders will be pushed to the outside rim of the ride. Imagine swinging a ball on a string in a circle. In this scenario, the only force truly acting on the ball is the tension of the string pulling inwards. However, the ball is not flying outwards, so there must be a balancing force. This is the centrifugal force at work. This is what allows centrifuges to sort matter by density, or what causes the remnants of an almost empty ketchup jug to move to the nozzle when you swing it in a circle.

Quote of the Day: "The fact that mankind persists shows that the cohesive force is greater than the disruptive force, centripetal force greater than centrifugal." -Ghandi

Keywords: Centrifugal, Force, Acceleration, Curve, Circular, Motion.

Tuesday, February 2, 2016

03 February 2016- Inertial Reference Frame | PWN Physics 365

On this day in physics: 03 February 1966- The Soviet Luna 9 Spacecraft landed on the moon, making it the first "soft landing" on a non-earthen body in human history. A soft landing is a controlled landing (i.e. not a crash) where there is no major damage to the craft. The probe was unmanned, it did contain a camera to take pictures which were sent back to earth until 6 February when the batteries finally died. [Source].

Word of the Day: Inertial Reference Frame- An inertial reference frame is one that is not accelerating. It is a theoretical construct, but very useful in the theory of relativity. Imagine yourself right now, sitting. To you, you're not moving, even if you're driving, or riding, or running, or walking. But, for this argument, let's say that you are sitting, totally still. You're holding a ball (why not) and decide to throw it. Once it's thrown, it is subject to the acceleration of gravity, and so if you're the physics type, you'd be able to do some calculations about its motion, and would be able to say for certain that from your inertial reference frame of not moving, that the ball had a certain velocity, a certain acceleration, etc. And all those calculations are totally valid considering your perspective of being totally motionless, but then remember that you're on a planet, spinning around its axis, which is revolving around the sun, which is in an arm of a spiral galaxy. So you're not really stationary. But, theoretically you're totally still. If you were to be sitting on the couch, and in front of you there was an elevator which was to be rocketed upwards exactly opposing the acceleration of gravity. Once the rocket launched, someone inside the elevator would have a perceived weightlessness, and there is no experiment that could be done from within the elevator to find out if he was truly motionless, or undergoing correspondingly opposing accelerations. If you were to leave earth's atmosphere, and enter a truly weightless environment, far from the shackles of planetary gravity, and the rocket were to continue accelerating at the same rate of gravitational acceleration, 9.81 m/s^2, anyone inside the elevator would feel as though they were standing on Earth, and they would not be able to tell if they were being accelerated by a rocket, or if they were being gravitationally attracted by a mass. This led Einstein to the conclusion that mass warps spacetime. The problem is that there is no truly inertial reference frame from which all measurements can be made, because something is always moving with respect to something else, or so we believe in 2016. Tune in in 100 years to see if this podcast still holds water.

Quote of the Day: "Nothing happens until something moves."- Albert Einstein [Source]

Keywords: Inertial, Reference, Frame, Space, Time, Acceleration, Gravity.

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Monday, February 1, 2016

02 February 2016- Higgs Boson | PWN Physics 365

On this day in physics: 02 February 1937- Happy Birthday to C.R. Hagen, a theoretical physicist, who is still currently a professor of theoretical physicist at the University of Rochester. He published one of the first papers to describe the "Higgs Mechanism" and be theory on the Higgs Boson, with five other physicists, one of course being the particle's namesake, Peter Higgs. [Source].

Word of the Day: Higgs Boson- The elusive Higgs Boson is a particle in the standard model of physics which was theorized to exist since the 1960s, but was only officially discovered to exist this decade at the Large Hadron Collider (LHC). So what is it. It's a boson, it has no spin, no electrical charge, or "color charge". It lives for about 10^-22 seconds. So why the heck is it important? It is something that is necessary for the standard model in physics to be correct. The Standard Model is what classifies all of matter, like electrons, photons, quarks, bosons, etc. In order for everything to work, there needs to be what is known as a Higgs Field, and a particle known as the Higgs Boson. The Higgs Boson is what allegedly gives matter its mass.

Let's try and understand how it works Imagine putting together a 250 piece puzzle. It's hard, because you don't have the box to see the full picture, but no matter, we're smart people. We get the frame of it together, and start working on the inside. Great, great. But now, we've finished about a quarter of the inside, and we see that two pieces are missing. They are totally framed out by the other pieces that we have, so we know that they need to be there to make the puzzle, but they are gone. So you start to look for them, and 50 years later, you find them. Can you imagine your excitement?

So now that it has been verified to exist, it gives physicists a great confidence that the Standard Model of Physics is correct. In science if you make a theory, and can't back it up with evidence, out it goes. So, physicists for the last 50 years had been tenuously supporting the theory, while trying to make modifications in the event that the Higgs Boson was never found. Now those modifications are unnecessary. It also gives great credence to the Standard Model because the model is able to predict particles that we can then look for and observe, and find to be real.

Quote of the Day: "I never expected this to happen in my lifetime and shall be asking my family to put some champagne in the fridge."- Peter Higgs (on the discovery of the Higgs Boson) [Source]

Keywords: Higgs, Boson, Fisld, Standard, Model, Physics

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01 February 2016- Spacetime | PWN Physics 365

On this day in physics: 01 February 2003- The Space Shuttle Columbia disintegrated in the atmosphere over Texas. Foam on the wing was damaged and allowed hot air inside one of the wings causing it to break apart in the atmosphere. I actually remember when this incident happened, because it was one of only a few tragedies to occur in the space program. It is a painful reminder of how easily things can go wrong during space exploration, but also a vast credit to the amount of engineering that has gone correctly over the past 50+ years of the space program. Anyhow, Physics 365 salutes everyone aboard the Columbia.

Word of the Day: Spacetime- Spacetime is a concept which was first introduced by Albert Einstein which contains 3 spacial dimensions and 1 time direction. It is referred to as the fabric of the cosmos. One very important facet of the notion of spacetime is that it binds time as a dimension, and insinuates that it is subject to the same manipulation as space, meaning that both space and time can be warped by gravity (or mass) and velocity. The faster you move through space, the slower time will elapse for you relative to slower travelling objects. Also, the faster you travel, the shorter space will become for you. Massive objects also warp space time. It's an amazing construct with which we are able to navigate this universe. The most classic example of visualizing mass warping space time is the taught bedsheet and the bowling ball. I think everyone has seen this before. The only thing to realize about this example is that the sheet is only 2 dimensions, and the way that spacetime is warped in our universe is in 3 dimensions (plus time!)

Quote of the Day: "Spacetime tells matter how to move, matter tells spacetime how to curve." -John Archibald Wheeler [Source].

Keywords: Einstein, Fabric, Space, Time, Spacetime, Curve, Matter, Warp, Space, Shuttle, Columbia.

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