Defining characteristics of metals
By: D. Vogt
There are two basic definitions of metal, the astronomical one and the chemical one. Astronomically, "metals" can refer to all elements heavier than hydrogen and helium. In chemistry, metal is used much more specifically. Metals are elements which form ionic bonds by releasing electrons and...
By: Wayne Leon Learmond
What would it take to travel to the Planet Mars? What are the dangers that one would face if such a journey where possible? And, also, what would be the psychological effects on the human mind, as well as the supplies one would have to...
By: Alison Bowler
The Swedish chemist Johan Gottlieb Gahn discovered the element manganese (symbol Mn, atomic number 25), a gray-white, hard, brittle metallic element, in 1774. Its relationship with man and most other life on Earth has a long history, as it is an essential element. A deficiency...
Characteristics of a blue moon
By: Tim Harry
Most people will have heard of the phrase “once in a blue moon”, meaning something that occurs infrequently. It is a phrase that comes about directly from the cycle of the lunar moon, and today it relates to the appearance of a second full...
The difference between enthalphy and entropy
By: Alexius Tan
Enthalpy and entropy are terms commonly encountered in the field of thermodynamics. In a very simplified model of explanation, both the terms enthalpy and entropy are measure of energy. Before I continue with explaining each of them, I feel it is necessary for me to...
Contacting aliens
By: Lee Pringle
First Contact: A Short Study When we think of first contact with a non-human civilisation, we imagine them either landing on the White House lawn, appearing over our cities in massive ships or sneaking into our bedrooms at night scaring the willies out of us...
What happens to a spacecraft on a Hohmann transfer orbit
By: D. Vogt
A Hohmann transfer orbit is a special and common type of spacecraft maneuver which is used to move the spacecraft between two orbits. It was also known as a Vetchinkin transfer orbit during the Cold War, after a Soviet mathematician at the time credited by...
An explanation of Newton's three laws of motion
By: Reynold Conger
Sir Isaac Newton was one of those renaissance men who made contributions in a number of fields. What separates him from the rest of the scholars of history is that so much of his teaching has endured with minimum change. Before his time, no one...
What happens at the Vernal Equinox?
By: Bruce Tyson
Vernal Equinox is the term used to describe the moment in time when the middle of the sun is observable directly overhead from a location on the equator. The Vernal Equinox happens once every year on either March 20th or 21st. The exact time of...
Biography: Edwin P. Hubble
By: D. Vogt
Edwin P. Hubble (1889-1953) is one of the most important historical American astronomers. He was responsible for the confirmation that stars and other galaxies existed far beyond our own Milky Way Galaxy, and - using the principle of the red shift, or the effects on...

 

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