Waves                01/25/16

 

Waves are a most peculiar phenomena in the physical universe. To put it concisely, waves are a transfer of energy through oscillations and vibrations from one point to another. Waves are one of the most commonly occurring facets of natural natural world, being present in everything from water perturbations to earthquakes.

 

Waves a multitude of intriguing properties. Unlike particles, when two waves come into contact, instead of colliding, they combine to form an temporary superposition,  and then proceed on the path they were on. This phenomena is known as interference.  During this ephemeral interference state, their directions of oscillations are combined, so if two (or more) were oscillating in the same direction he combined amplitude would be greater and vice versa if tf there directions were incongruous. Waves can also be reflected of reflective media, such as glass. Since waves are commonly are thought of of disturbances through media, their phase velocity is contingent upon such, and if their surrounding media change, then so do their phase velocity. Think of it like a falling ball being dropped into a pool of water, at first the ball only has to face the fluid resistance of the surrounding velocity of the atmosphere, but after coming into contact with the water it will slow down due to the denser material makeup of water. In fact, this is the reason why light changes angles when it strike water!

 

Wave motion comes in two forms, transversal and longitudinal. Transversal waves consist of energy oscillating perpendicular to the direction of movement, while longitudinal waves is the inverse (oscillations occur in the direction of displacement). Since transversal waves can oscillate in any direction perpendicular to the phase velocity, such waves can have multiple directions of oscillation.  Consequently, there is an effect known as polarization, in which the waves have all but a select set of directions filtered out. In addition, there are two (known) types of wave in the universe, mechanical and electromagnetic. Mechanical waves consist of oscillations of material matter, so their entire  exantness is contingent upon the medium that they are suffused in. The latter phenomena is the paramount divergence between mechanical and Electromagnetic waves, as the latter can transfer energy even in complete vacuity. Consequently, since light is an electromagnetic wave, light can move through the vacuum of space unimpinged.

      Sound                    01/24/16

 

“What is sound?”

 

It might come as a surprise to many that all of the opulent varieties of sounds that we listen to are nothing more than simple vibrations of air! Everytime we move our vocal cords, the surrounding medium is perturbed. Consequently, this perturbation stimulates a mechanical wave that propagates throughout the enveloping space. Since waves are contingent on the medium that they travel through, sounds greatly affected by the density, pressure, motion, and viscosity of the aforementioned medium, with the speed of sound being dependent on the density. (Furthermore, if no medium is present, then sound can not exist! The reasoning is simple, if sound is nothing more than a disturbance in a medium and no medium is present, then no sound can be created. It’s like trying to send send an electrical signal with no wiring! So that’s why in space, no one can hear you scream).

 

When such medium disturbances reach the human ear,sound waves collected by the ear lobe are passed through the ear canal which stimulates a vibration in the ear drum. The vibrations in turn are amplified by small bones in the inner ear, and the cochlea (inner ear) turns these mechanical vibrations into electrical signals which are guided by the auditory lobe in to be processed by the ever so scrupulous brain. Furthermore, the brain is able to synthesize information about the sound by determining it’s pitch (frequency), time duration, loudness (amplitude), Timbre (quality), sonic texture, and spatial location.

Isn’t it flummoxing how over the years curious Scientists have corroborated the seemingly insoluble problem of sound? To think that all of our auditory sensations are nothing more than mechanical disturbances in the surrounding medium is absolutely bewildering. And most dazzling is when one considers the fact that all of these sensations are just electrical signals in the brain.

Superconductivity         01/22/16

 

When electrical currents move through material, they encounter something known as electrical resistance which can be described as symmetric in nature to friction in mechanical systems. This resistance causes the current depresses the movement of electrons by converting some of their kinetic energy to heat. However, an interesting property emerges at certain conditions in certain materials known as superconductivity. A material that is superconductive exhibits no electrical resistance, so their electrical efficiency is at a maximum. An electrical current can propagate inexorably even with no power source, which could imply high efficiency systems a consequence. Concurrently, Superconductive materials have an interesting facet to them known as the Meissner effect, in which all magnetic fields are actively expelled from the superconductor. This can be applied to transit systems, which can greatly accelerate long distance travel. However, there is one issue to this effect that impinges on much of it’s pragmatism. The Despondent fact is that these materials only exhibit superconductivity at very low temperatures (near absolute zero), since resistance is proportional to temperature for a collection of materials, so due to the vast energy needed to bring an object to a superconductive state the time elapses is often ephemeral at best. Causally, the development of high temperature superconductivity is seen as a high priority, as then then mass production of superconductive systems can be spurred.

Negative thermal expansion 01/21/15
Some materials in this universe exhibit a very peculiar property known as Negative Thermal Expansion. Under ordinary circumstances, when heat is added to an object, volumetric expansion occurs causally. This phenomenon transpires due to the fact that temperature is simply the average measurement of the vibration of atoms, and when temperature is increased, the range of the vibrations increase proportionally due to the added energy. However, materials that exhibit Negative thermal expansion have the counterintuitive result of contracting. Materials with this property have a large domain of applications, ranging from engineering to dentistry.