Physics in the real world - During my visit to Broomfield Hospital I witnessed two aspects of physics in every day use. These were X-Rays and ultrasound; they both do similar jobs, although they both have limitations.

Physics in the real world

During my visit to Broomfield Hospital I witnessed two aspects of physics in every day use. These were X-Rays and ultrasound; they both do similar jobs, although they both have limitations.

A German physicist named Wilhelm Roentgen first discovered X-Rays in 1895, the discovery of X-Rays revolutionised medical science, and it allowed doctors to see through human tissue, to examine broken bones, swallowed objects, and with a modified version, to examine tissues such as the lungs.

They can be used to study the softer tissue of the body, they do this by introducing “contrast media” into the body, this is often a barium compound. If the doctor wants to examine the blood vessels it will be injected into the blood stream.

X-Rays can also be recorded as a moving image by a process called fluoroscopy, in which the X-Rays pass through the body onto a fluorescent screen, creating a moving X-Ray image, which can then be recorded onto a film.

X-Rays are not only used in the medical world, they are also used in airport security, to scan your bags. They are also used to detect flaws in big castings, to study quantum mechanics, crystallography and cosmology.

The only problem with X-rays Is that they are a form of ionising radiation, which means that when it hits an atom, it can knock an electron off, turning the atom into a ion. Ions can then collide with more atoms to create more ions. This can cause defects in strands of DNA, this can either cause cancerous cells or, it can kill off the DNA making the patient ill. Prolonged exposure to X-Rays causes Radiation sickness. Which is why the operators of X-Ray machines stand behind lead shields.

X-Rays are wavelike forms of electromagnetic radiation, very much like visible light. The difference between the two is the wavelength; X-Rays have a much shorter wavelength. They also have a very high energy level and can pass through most things.

X-Ray machines work by beaming X-Rays through a series of filters, then on to the patient. A camera on the other side of the patient records the pattern of X-Rays that pass all the way through the patient’s body. These are recorded in the same way as an ordinary camera would, except that the X-Rays set off the reaction instead of normal light.

Ultrasound was a major development in modern medicine, allowing doctors to see in to the human body without the use of ionising radiation. Ultrasound originated in the work of physicists exploring energy propagation by sound waves. Fifteen years before Roentgens discovery of the X-Ray, Pierre and Jacques Curie explained piezoelectricity and developed the principle, which led to the development of ultrasound. In the early 1900’s a group led by Paul langevin experimented with ultrasound to detect submarines. It was not until the late 60’s that ultrasound became a recognised medical tool.

Ultrasound is ...