Physics Archives - Page 6 of 8

01Jul 2015 by Vincent Summers 1 Comment

Edge Effects for the Universe?

Physics

[caption id="attachment_7377" align="alignright" width="480"] Introducing the universe.[/caption] A strange thought crossed my mind. I was in that twilight state between awareness and sleep. What about the edges of the universe? Does the universe experience edge effects? Materials all have their own properties. Metals, for instance, have a melting point. They have conductivity, density, malleability, and ductility. Liquids, gases, and plasmas have properties as well. A material or an object can act differently at its interior, than at its edge. Consider some objects interacting with electromagnetic radiation. Magnets and Capacitors Capacitors exhibit so called Casimir edge effects. The electrical field between capacitor plates behaves differently at the edges, than between the centers. The same is true of the edges of magnets. Frequency Skin Effect Electrical engineers understand the high frequency skin…

17May 2015 by Vincent Summers 1 Comment

Massless Strings and Frictionless Pulleys

Physics

Massless strings and frictionless pulleys? Whoever heard of such things? I attended Drexel University. Well, at first it was the Drexel Institute of Technology. I majored in chemistry. It was strongly suggested I major in chemical engineering. But I refused to change. Why? Because I didn't care what use humans put chemistry to. I loved chemistry and that was all there was to it. Unfortunately (or so it seemed at the time) majoring in chemistry didn't mean all my courses would be chemistry courses. Physics - Massless Strings & Frictionless Pulleys Well—unavoidably—I was required to take a certain amount of physics. And introductory physics requires the use of simple mathematics, including calculus. But physics equations can be difficult to derive. Simplification wherever possible was the mandate. This simplification required us…

03Jan 2015 by Vincent Summers No Comments

Atomic Electron Quantum Numbers Overview

Physics

[caption id="attachment_6527" align="alignright" width="440"] 3d(yz) Orbital[/caption] Physicists and physical chemists speak of the four quantum numbers for each one of an atom's electrons: n, l, m, and s. Each of these variables incorporates specific characteristics of any electron orbital. The four quantum numbers are as follows: n: principal quantum number l: angular quantum number m: magnetic quantum number s: spin quantum number The Quantum Numbers: Here's "n" There is good reason to list the numbers in this order. The principal number n tells us an orbital's size. An increase in n moves an electron farther from the nucleus. This move takes energy, just as it takes energy to lift a person under the influence of gravity. Therefore n can be taken to be the energy quantum number. Here's "l" The…

22Sep 2014 by Vincent Summers 2 Comments

Calculate Radiation Energy By Wavelength

Physics

[caption id="attachment_6281" align="alignright" width="480"] Rainbow Light[/caption] Light exhibits properties that make it seem to have a dual-nature. Sometimes it resembles a particle. Sometimes it resembles a wave. In this article, the energy of a particle will be calculated using a wave property - wavelength. The energy is radiation energy. Radiation from the electromagnetic spectrum in order of decreasing wavelength begins at the low end with radio waves and microwaves. Next is light radiation from the infrared region, the visible and the ultraviolet. Highest in frequency are the x-rays and cosmic radiation. The wavelength range is from approximately 100,000 centimeters to one ten-billionth of a centimeter! The Nature of Light Scientists do not completely understand light. So far it has best been described as possessing two natures. Sometimes it acts as…

20Aug 2014 by Vincent Summers No Comments

What Happens at Absolute Zero?

Physics

[caption id="attachment_7397" align="alignright" width="440"] Bose-Einstein condensate at billionths of a degree. Image by NIST[/caption] Classical physics suggests that at absolute zero, particles cease all motion. But what about quantum mechanics, the science of the very small? Ah, therein lies the rest of the story. From Gas to Frigid Solid It is well established fact that heated gas atoms or molecules move with great vigor. In fact, gas expands as energy increases, due to increased particle momentum. The reverse is also true. Cool a gas and it shrinks. Particle motion decreases. Particle momentum decreases. The atoms or molecules come closer together. At some point a liquid forms. Cool the liquid further and the result is a solid. Keep cooling the solid, and in theory it is possible to reach the coldest…

18Aug 2014 by Vincent Summers 3 Comments

The Ammonia Flip, Quantum Tunneling and Oscillations

Physics

[caption id="attachment_25040" align="alignleft" width="400"] Image U..C. Davis[/caption]Unexplained by classical mechanics, the ammonia flip occurs when an ammonia molecule flips like an umbrella... Quantum mechanics explains how some phenomena occur which are not part of everyday experience. The ammonia molecule can flip when ordinary logic suggests it should not be able to do so. When most people think of ammonia, they think of a household cleaner. Actually, ammonia is a gas. The household cleaner is a dilute solution of that gas in water. Chemists would call that ammonium hydroxide. Ammonia has the very simple chemical formula, NH3. That's the formula; but what's its structure? How would you draw it? Would you draw it like an airplane propeller with the nitrogen being the hub and the tips of the three blades the…

18Aug 2014 by Vincent Summers No Comments

Factors that Complicate Atomic Mass Determination

Physics

[caption id="attachment_8319" align="alignright" width="440"] Nucleus - CC-SA-3.0 by Marekich[/caption] Modern chemistry depends a good deal upon accurately knowing the atomic mass of each of the elements. What factors complicate determining those values? Each of the approximately 90 different natural-occurring elements possesses a nucleus or central core of protons and neutrons, in addition to electrons that orbit around the nucleus. It is important to the chemist or physicist to know the total mass of each element. Can correct values be obtained simply by summing the weight of individual particles in an atom? After all, each of these particles has a precisely known mass. The answer is, No! Such calculations disagree with experimental measurement. An example illustrates the point. Consider Helium-3 An atom of helium-3 has two protons, one neutron, and two…

20Mar 2014 by Vincent Summers No Comments

Temperature Different from Heat?

Physics

[caption id="attachment_5975" align="alignright" width="440"] Thermometer - Image: CDC[/caption] Is temperature different from heat? Yes, even though the two are related. Atoms or molecules, whether of a solid, a liquid, or a gas, vibrate. They may also rotate. They may even move through space. This latter form of motion is called translation. Atoms consist of protons and neutrons in a central core called a nucleus. The nucleus is orbited by one or more electrons. These electrons are called bound electrons, to distinguish them from free moving, unassociated, non-orbiting, electrons. Atoms + Energy Energize atoms and their vibrations, rotations, and translations are almost certain to alter. Exactly what happens depends on the way in which the energy is supplied and the way in which it is absorbed. The greater the atomic or…

19Mar 2014 by Vincent Summers No Comments

Why Metals Conduct Electricity

Electrical, Physics

[caption id="attachment_19272" align="alignright" width="480"] High Voltage Lines.[/caption] Elements are divided into metals, metalloids, and non-metals. Copper is a metal. Sulfur is a non-metal. Antimony is a metalloid. Why do metals conduct electricity? What makes them special? It involves electron mobility—their ability to move about. Individual Atoms and Diatomic Molecules Atoms have a positive nucleus encased by negative orbiting electrons. Atoms of a single substance either stand alone or bind together in small groups only. Helium (He) is monatomic. Hydrogen (H₂) is diatomic. Ionic and Covalent Crystalline Solids Some solids may form crystals. The atoms are packed close together. There are three crystal types. Ionic, covalent, metallic. Ionic crystals conduct some electricity. They are not as conductive as metals because their bonds are local. Their crystals are rigid. They fracture. They…

19Mar 2014 by Vincent Summers 1 Comment

Does Iron Float in Mercury?

Physics

[caption id="attachment_5886" align="alignright" width="440"] Weather Float[/caption] Both substances are heavy and mercury is a liquid, so what do you say? Does iron float in mercury? Mercury is a liquid; some objects should float in it. There are two factors that must be taken into consideration in order to answer the question, Does Iron Float in Mercury? Those two factors are the density of the material under consideration and its geometry. Our focus for this discussion will center on a block of solid iron, 4 cm x 4 cm x 4 cm. Density – the Numbers A material floats if it possesses a lower density. Iron’s density is 7.9 g/cm³ (grams per cubic centimeter). Mercury’s density is 13.5 g/cm³. The iron presses on the mercury, but because it is lighter, it…