What colour are electrons?

For Science!

This isn’t the flippant question it may look like.

“Colour” is a property of subatomic particles, a lot like electrical charge. It has absolutely nothing to do with colour in the normal sense. Just as charge leads to interactions via electromagnetic forces, so colour leads to interactions via so-called strong forces.

Taking that back another step: there are four fundamental forces of nature. The two of them that you are extremely familiar with are the electromagnetic and gravitational forces. These are long-range forces; they act over large distances. The other two, the weak and strong forces, act on the atomic and subatomic scale, so you only encounter their effects in a very indirect way. The strong force is particularly important as it’s the force that sticks the protons and neutrons in the nuclei of atoms together. (You wouldn’t otherwise expect nuclei to stick together; the electromagnetic interactions are between positively…

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States of Matter: Plasma

A great explanation of what plasma is in Physics …

For Science!

At some point during your science studies, you would have been introduced to the idea of The Three States of Matter: solid, liquid, and gas. As you may have realised when thinking about, for example, the melting of glass, or contemplating the nature of a flame, this three state model doesn’t tell the whole story. Solid, liquid, and gas are more like three categories into which more specific states of matter fit. This series explores some of these states which perhaps don’t seem to fit neatly into the three states model as you may have learned it.

Plasma. No, we’re not talking about the watery part of blood. Plasma is often called “the fourth state of matter” because it’s what you get when you keep putting energy into a gas. (Recall: in the three states description of matter, solid + enough energy = liquid, liquid + enough…

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States of Matter: Amorphous Solids

Wonderful post (again) 🙂

For Science!

At some point during your science studies, you would have been introduced to the idea of The Three States of Matter: solid, liquid, and gas. As you may have realised when thinking about, for example, the melting of glass, or contemplating the nature of a flame, this three state model doesn’t tell the whole story. Solid, liquid, and gas are more like three categories into which more specific states of matter fit. This series explores some of these states which perhaps don’t seem to fit neatly into the three states model as you may have learned it.

There is a pervasive, persistent, and entirely incorrect idea that glass is an extremely high viscosity liquid. The reason this comes about makes a certain amount of sense: glass has the same chemical composition as crystalline quartz, but has a liquid-like lack of long-range order.

The associated claim that glass does flow over…

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Brief (and incomplete) History of Nuclear Energy

Exploring the nature of the atom

• Uranium was discovered in 1789 by Martin Klaproth, a German chemist, and named after the planet Uranus.

• Ionising radiation was discovered by Wilhelm Rontgen in 1895, by passing an electric current through an evacuated glass tube and producing continuous X-rays.

• In 1896 Henri Becquerel found that pitchblende (an ore containing radium and uranium) caused a photographic plate to darken. He went on to demonstrate that this was due to beta radiation (electrons) and alpha particles (helium nuclei) being emitted.

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RADIOACTIVITY: The Origins of The Hulk

Comic books offer us an insight into the attitudes and beliefs of society at the time. In essence they are a historical document that we can use to determine how people viewed social issues.

The origins of the Hulk (1962) are no different. Below are a few observations of the Hulk origins story that I have made, but have a look at the comic strip first to see if you can pick out the some attitudes reflected in the comic strip. If I’ve missed any, please post them in the comments.

Hulk3pgOrigin

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AS IF STILL BURNING

Pandaemonium

hiroshima before    hiroshima after

This week marked the 100th anniversary of the start of the First World War. Today marks  the anniversary of an even more grotesque event – the dropping of the atom bomb on Hiroshima on 6 August 1945. Three days later the second bomb was dropped on Nagasaki. These remain the only use of nuclear weapons in warfare.

Some 12 km² of Hiroshima were destroyed, as were around 69% of the city’s buildings. The images above, which were taken by the US military on the day, show Hiroshima before and after the bombing. Some 66,000 people are thought to have died in Hiroshima on the day; probably a similar number again died over the next four months as a result of their injuries or from radiation sickness. So fierce was the heat that people were vaporised but their shadows left upon the walls.

In the years since the…

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Archimedes Death Ray

300px-Archimedes_Heat_Ray_conceptual_diagram.svg“The 2nd century AD author Lucian wrote that during the Siege of Syracuse (c.214–212 BC), Archimedes destroyed enemy ships with fire. Centuries later,Anthemius of Tralles mentions burning-glasses as Archimedes’ weapon.[30] The device, sometimes called the “Archimedes heat ray”, was used to focus sunlight onto approaching ships, causing them to catch fire.” From Wikipedia

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