A Catalyst article about ants. A colony consists of hundreds, even thousands, of ants working diligently and cooperatively, perhaps to kill and carry a large prey item, build a large nest structure or develop and use road-like networks for foraging. Collectively, colonies of social insects can do amazing things and...

The animal kingdom contains an abundance of exquisite natural patterns from the stripes of an angelfish to the spots of a leopard. But how do these arise during early development? This Catalyst article looks at Turing mechanisms as a way of explaining how patterns develop as an animal grows.

In 1952, Alan...

A Catalyst article about the Hubble telescope exploring a barred spiral galaxy, known as NGC1672 in the astronomers’ New General Catalogue. The image was made by the Hubble Space Telescope (HST), and was released in April 2007. NGC 1672 is situated 60 million light years away, in the constellation of Dorado. The...

A Catalyst article about Hurricane Katrina which caused many deaths in August 2005, and vast damage along the coastline of the Gulf of Mexico in the USA. Hurricanes are an unfamiliar phenomenon here in the UK. Why is this? And can people expect to see more hurricanes in future as a result of climate change? The...

A Catalyst article about hydrogels. Soft contact lenses, disposable nappies, hair gel and plant water crystals all make use of substances called hydrogels. These are polymers which have the unusual property of being able to absorb huge quantities of water. The article looks at the structure of hydrogels and their...

As the need to find alternative cleaner forms of energy increases, scientists are looking to technologies, such as Hydrogen Fuel Cells (HFCs), as a power source for transportation.

This Catalyst article explains how hydrogen and oxygen gas can be used in a redox reaction to produce electricity, and the...

This edition of iSquared magazine features:

The soliton: A w...

This Catalyst article describes an experiment in which, using a microwave oven, water can be boiled in a cup made of ice, allowing all three states of water to be seen at once. The article explains what equipment needed to carry out the experiment, instructions, and a detailed explanation of why it works.

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A Catalyst article about the discovery of puerperal fever by Ignaz Semmelweis a doctor in a maternity ward in Vienna general hospital. The article looks at his observations into death rates and shows how scientists use observations and theories to make practical changes that can improve life. In the case of...

A Catalyst article about giant asteroids. Astronomers say that, one day, a giant rock from space will collide with the Earth and cause mass devastation. This could lead to the extinction of many species, including humans. The article looks at what can be done to prepare for such an impact and what happened when a...

A Catalyst article about in vitro fertilisation. About one in six couples gets help from specialists because they cannot conceive. One possibility is to use in vitro fertilisation (IVF). ‘In vitro’ means ‘in glass’ and refers to the fact that fertilisation takes place in a laboratory dish or test tube, hence the...

This Catalyst article describes how the human body is affected by low atmospheric pressure at high altitudes. The article looks at the dangers that await the unwary traveller and explains how, if people understand their bodies, they can avoid the worst problems of life at high altitudes.

This article is from...

This Catalyst article explains how in nature, bioamplification causes substances to become more concentrated as they move from eater to eaten along a food chain. This sequence occurs in relation to the concentration of pesticides like DDT along a food chain, and causes problems for those animals, like birds of prey...

A Catalyst article describing how the VISTA telescope, which is located in Chile, works. It detects infrared radiation - electromagnetic radiation beyond the red end of the spectrum. This has two great benefits:

*The telescope can detect radiation from distant stars which are otherwise hidden behind clouds...