X-rays are a type of electromagnetic radiation, which have a wavelength of roughly 5-10 nanometres.

A.W. Goodspeed first observed X-rays in February 1890. However, he did not have any proof to show he had discovered it and even said it was an accident.

The German physicist Wilhelm Röntgen was experimenting in his lab five years later and made a similar discovery but was unsure of what it was.

He was experimenting with vacuum tubes in his lab when he stumbled upon them and later took a picture of his wife’s hand.

This picture showed her wedding rings and bones and was proof that this technology could do wonders.

A year later, in 1896 H.L. Smith took the first picture from an X-ray when the X-ray machine was exhibited for the first time.

This caught the attention of other scientists and scientific institutions.

The term ‘X-Ray’, which Röntgen coined was actually to indicate that the type of radiation was unknown (x).

Some suggested the name be changed to Röntgen rays in honour of his work, but he preferred X-Rays. Röntgen rays are still used however, in some countries.

The x-ray penetrates through anything that absorbs light and is therefore excellent to see our bones and teeth because they are dense and absorb the radiation.

Skin, muscles, and fatty tissue are not dense enough and therefore do not absorb the radiation.

The principle of an x-ray is just like when the sun shines on us creating our shadow. When the x-ray shines on us it penetrates through our skin and makes shadows of our bones on the film.

Today, x-rays are used mainly in medicine. They are excellent ways of finding things inside the body (such as a tumour, a stone, or a broken bone) which need operating.

Taking an x-ray is painless and over in a matter of minutes. The x-ray machine releases a type of radiation called photons into our body to allow the x-ray picture.

X-rays are also used by dentists, and even in the airport to scan baggage.

Types of x-ray machines are also used to examine the nature and structure of crystals. These are called x-ray crystallography machines.

X-ray astronomy is the study of the universe by studying the x-ray radiation we receive on earth.

Through x-ray astronomy, many things such as black holes, neutron stars, star systems, supernovas, the sun and the comet can be studied.

When working with x-rays, or when going for a x-ray in the hospital doctors caution against pregnant mothers.

This is because the radiation that comes from the x-ray machine (although harmless in small doses for us), can be very harmful to the unborn baby.