Physics Archives - Page 4 of 8

08Feb 2017 by Vincent Summers 2 Comments

Differences between Fluorescence, Phosphorescence, Incandescence

[caption id="attachment_16099" align="alignright" width="440"] Iridescence[/caption] Fluorescence, phosphorescence, incandescence. Though they sound similar, yet they are different. The differences need not be intimidating. First we’ll provide a brief definition of each; afterward, an explanation. We’ll add a few other similar sounding terms as well. These include iridescence, chemiluminescence, and radioluminescence. Fluorescence First, let us note that every one of these terms possesses some connection to light. Fluorescence is the rapid, even immediate emission of radiation, visible or invisible, proceeding the absorption of higher frequency (higher energy, shorter wavelength) radiation such as ultraviolet light. Certain rocks and minerals as well as marine biological specimens are fluorescent emitters. Phosphorescence [caption id="attachment_16101" align="alignright" width="360"] Phosphorescence[/caption] Similar to fluorescence, except the radiation takes place slowly over an extended time period. Heat and combustion are not…

21Dec 2016 by Vincent Summers 1 Comment

Energy from Matter – Chemical Energy, Atomic Energy, and Annihilation

Physics, Technology

[caption id="attachment_15861" align="alignright" width="440"] An example of fission: a neutron plus U235 produces U236 which breaks down into Kr92, Ba141, and 3 neutrons.[/caption] Energy (E) is crucial for life; there is no life apart from energy. Fortunately energy derived from matter exists abundantly. It is readily obtainable. Chemical E Our bodies require small installments of energy. This leads us to the dinner table. Our body breaks down the food we eat, liberating chemical energy that keeps us functioning and warm. For instance, there is the digestion of starch into sugar and energy. Sugar is further broken down into carbon dioxide, water, and still more energy. This form of energy can also be called molecular energy, since it comes from the breaking down of molecules. This involves the breaking of chemical…

09Nov 2016 by Vincent Summers 3 Comments

How Can a Rocket Fly in the Vacuum of Space?

Physics, Technology

Recently a friend told me he met a man who doesn’t believe in rockets flying in space. Why not? Because (he said) there’s nothing in space for a rocket to push against. There’s only vacuum—no air. A rocket fly in space? Nah. Rockets in space are products of film studios. A Stupid Thing to Say? That’s not really an entirely stupid statement. Imagine you’re on a chair with wheels. How can you move if you don’t push on something? But the man didn’t fully appreciate the rocket does push on something—or, rather, something pushes on the rocket—its fuel. To Illustrate Imagine one of those kids’ cherry bombs, a quarter-sized explosive kids set off on various occasions. Imagine a cherry bomb tied with a very sewing thread, suspended from a tree…

19Sep 2016 by Vincent Summers 3 Comments

What Is the Difference Between an Orbit and an Orbital?

Astronomy, Physics

[caption id="attachment_15523" align="alignright" width="440"] A 5-D atomic orbital, m=5[/caption] Although words can have multiple meanings, we will consider only the difference between an orbit and an orbital, the path of planets and that of electrons in atoms. Planets (and other astronomy objects) travel in orbits. Jupiter and Haley’s Comet orbit the Sun. Electrostatic forces and selection rules hold electrons in specific atomic orbitals. What is an Orbit? Orbits are generally elliptical in shape. Ellipses are circles that are stretched out along one axis. The degree of stretching is termed eccentricity. The greater the stretch, the greater the eccentricity. Consider the figure below for comparison. The object doing the orbiting travels strictly in the path of the orbit. It does not deviate. In this respect, orbits of astronomical objects are different…

30Aug 2016 by Vincent Summers 2 Comments

Tongue Stuck to a Silver Spoon Eating Ice Cream?

Food, Physics

Ice cream consists of several ingredients. The best ice cream contains cream, milk, flavorings, and sweetener. Most of these ingredients contain water. Water provides fluidity unless the ice cream is frozen solid. Do you enjoy ice cream? You can eat ice cream with a plastic spoon, a stainless spoon, a silver plate spoon, or a sterling spoon. Sterling is solid silver, not a thin layer of plate. If the ice cream is very cold and you eat it with a sterling silver spoon, you may experience a tongue stuck to a silver spoon. With A Plastic Spoon Eat ice cream with a plastic spoon and you will never experience your tongue stuck to it. Most plastics are not only good electrical insulators—they are good thermal insulators as well. Heat is…

16Jul 2016 by Vincent Summers 3 Comments

The Bent Water Molecule – Why Is It Bent?

Chemistry, Physics

[caption id="attachment_14934" align="alignright" width="480"] Liquid Water (Left) - Ice (Right)[/caption] The water molecule, H₂O, consists of two hydrogen atoms and one oxygen atom. A naïve attempt at writing its structure out in full is H‒O‒H. What’s naïve about this? This drawing is linear—a straight line. It is naïve because the water molecule is a bent water molecule... bent at about 104.5°. It is a good thing for us that this is so, since this imparts a degree of polarity to the water molecule. Polarity, in turn, gives rise to hydrogen bonding. The hydrogen bonding of molecules assures water’s liquidity. In addition hydrogen bonding influences water’s crystallization, so that ice is lighter than very cold water. Ice thus floats, forming an insulating blanket atop lakes and other bodies of water. This…

06Jul 2016 by Vincent Summers 2 Comments

The Molecular Structure of Hydronium Ion Hydrate

Chemistry, Physics

[caption id="attachment_16126" align="alignright" width="440"] Simple hydronium ion, unhydrated.[/caption] Abstract: The water molecule, H2O, can attach a hydrogen ion (H+) perhaps from a dissolved acid, to become a hydronium ion, H3O+, sometimes called a hydroxonium ion. This ion, if surrounded by water molecules, can form additional hydrogen bonds with them as well. The question is what is the molecular structure of the resulting hydronium ion hydrate? The mind conceives two serious possibilities. But what do studies reveal? Background It is a general principle of nature that a system is more stable if charges are spread out as much as possible. In the field of chemistry, the best known example of this involves water. Although the sum total of the electric charge of a neutral water molecule is zero, as the image…

04Jul 2016 by Vincent Summers 2 Comments

Heavy Water –vs.– Regular Water

Chemistry, Physics

[caption id="attachment_14687" align="alignright" width="440"] Heavy Water & Water - Image by Author.[/caption] Hydrogen exists as three varieties or isotopes: protium, deuterium, and tritium. Heavy water, or deuterium oxide (D₂O) is the same compound as ordinary or tap water (H₂O) with one structure difference. Most of the hydrogen atoms in tap water have zero neutrons in their centers, or nuclei. On the other hand, every atom of deuterium contains precisely one neutron. We will not discuss tritium, with its one proton and two neutrons. [caption id="attachment_14693" align="alignright" width="400"] Protium & Deuterium Hydrogen - NASA[/caption] A Closer Inspection of Hydrogen Isotopes The mass of an atom is determined by the nucleus. Since the weight of a proton and that of a neutron are nearly identical, deuterium atoms have a mass essentially double…

02Jul 2016 by Vincent Summers 3 Comments

Why All Helium Has Not Escaped Earth’s Atmosphere

Geology, Physics

[caption id="attachment_14665" align="alignright" width="440"] Hydrogen or Helium?[/caption] Ninety of the elements occur in nature. The smallest and lightest of the elements is hydrogen. Yet, it is abundant in Earth. Almost no hydrogen gas escapes Earth’s atmosphere. This is partly because hydrogen is reactive and exists almost exclusively in combination with other, heavier elements. Helium, too, is a gas. It is the second lightest element. However, it is neither reactive nor abundant. It does not occur in nature in compound form. Why doesn’t it all escape Earth’s atmosphere? Comparing Hydrogen and Helium Although hydrogen is the lightest element and atom, it almost never exists, even as a gas, in atomic form. It assumes, not monatomic form, H, but diatomic form, H₂. The weight of that is twice the weight of an…

18May 2016 by Vincent Summers 6 Comments

Total Energy in One Hydrogen Atom

Chemistry, Physics

[caption id="attachment_14456" align="alignright" width="440"] Hydrogen Bomb[/caption] Hydrogen is the lightest of the elements. However, there are three isotopes of hydrogen. The lightest of these is protium. It contains just one proton and one electron. Let’s determine the total energy of one protium atom. Its mass is 1.007822 atomic mass units. So what is the total energy one hydrogen atom produces if obliterated? By obliterated, we mean 100% conversion from matter to energy, not the mere energy of separation of particles, as in fission. Einstein’s Mass-to-Energy Equation In our calculating, it is important we stick to proper units. If we were cooking and the recipe called for a cup of flour, would we substitute a tablespoon? Our equation is Einstein’s mass to energy expression, E = mc² If the mass is…