What are stalagmites and stalactites? They are deposits of minerals that form in caves. Stalactites hang down from the top of the cave and stalagmites rise up from the ground. To help you remember, stalactites have a “c” for ceiling and stalagmites have a “g” for ground. If you want another way to remember which […]
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What is CRISPR? It is a way of editing genes and it stands for Clustered Regularly Interspaced Short Palindromic Repeats. It works by separating the genes inside the DNA and inserting a mutation. To begin with, let’s look at what DNA and genes are. DNA is inside all of our cells and it holds the
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Why does time go forward not backward? Because of entropy. Entropy is the measure of how random and dispersed the energy and mass in a system are distributed. It is described by the Second Law of Thermodynamics, which says that the entropy of a closed system increases over time. The system has to be closed
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Is a force field possible? In theory, there are several possibilities, such as warping space time, electric fields, directional lasers, a controllable plasma, a magnetic field, and others. We have all seen science fiction movies where a spaceship is protected by a forcefield that destroys enemy fire when it comes into contact. The recent movie
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What is the pH scale? It probably stands for potential of hydrogen and it shows how much hydrogen is in a substance. The pH scale is written with a capital H because the symbols for the elements are always written with a capital. However, when the scale was invented by a Danish chemist called Soren
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Why do we sneeze? We usually sneeze in order to remove an irritant from the nose. There are many different things that make people sneeze, but the most common cause is when there is an irritant in the nose. This could be smoke particles, it could be dust, it could be anything. The nose is
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Why does iron rust? The iron atoms react with oxygen molecules to produce iron oxide, which is rust. Other metals don’t rust because only iron, or metals with an iron alloy can rust. This is because rust is iron oxide. Other metals can react with oxygen in different ways or corrode, but only iron can
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Why is mercury poisonous? It can damage the nervous system, kidneys, liver, and immune systems of people and animals. Mercury is a heavy metal. Heavy metals are metals that are very dense and have a high atomic number. Mercury has an atomic number of 80. It melts at -38.83℃, which means it is liquid at
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Do all liquids expand when they freeze? No. Water is the only liquid that expands when it freezes. There are four states of matter: solid, liquid, gas, and plasma. As almost all substances go from the solid phase to the liquid phase and then to the gas phase, they become less dense. This is all
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Why does a boomerang come back? One wing travels faster than the other which causes it to fly in a circular path. However, not all boomerangs are designed to come back and the one most people are probably thinking of is the modern version of the boomerang. The boomerang was a weapon used by the
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