Science with Dr Karl: Extraordinary X-rays
X-rays are under the microscope with Dr Karl…
On 22 December, 1895 the German physicist Wilhelm Röntgen took the first ever medical X-ray. It was of his wife’s hand! X-rays are a form of electromagnetic radiation. When this light passes through the body and onto a photographic plate, pictures of bones and some organs are produced, and can show signs of damage or injury that we wouldn’t be able to see otherwise!
After Röntgen’s discovery, medical doctors started using X-rays. On 11 January, 1896 in the UK, John Hall-Edwards carried out the first medical use of X-rays when he photographed a metal needle stuck inside
a workmate’s hand.
But within a month, doctors reported the first side effect of this radiation – hair loss! In February 1896, William Lofland Dudley of Vanderbilt University in the USA spent an hour X-raying the head of a child (that is much longer than an X-ray takes today!) with his own head very close to the X-ray tube. Three weeks later, he had a bald spot on his head! Soon there were other reports of the harm caused by too much radiation.
UPSIDES AND DOWNSIDES
So they have upsides and downsides. The upside is they can show hidden damage inside the body, helping doctors to diagnose patients more efficiently. The downside is the side-effects radiation has on the body. But in the right amounts, the radiation can be used for good! Doctors can carefully aim skinny, powerful beams of X-rays at bad cells – such as cancer cells – and kill them. So X-rays can be used for both diagnosis and treatment. Wow!
BEYOND THE BODY
X-rays also have non-medical uses. In the 1950s,they revealed the spiral staircase shape of our DNA, thanks to X-ray crystallography by Rosalind Franklin.
Inside a jet engine, a single turbine blade the size of the palm of your hand can generate 500kW. If these blades fail, they can destroy an entire jet plane. So they are scanned for cracks using X-rays!
And of course, at airports, your luggage is scanned with X-rays to look for dangerous and illegal items – much faster than unpacking everything to show the security guards!
Microscopic and precise beams of X-rays draw tiny patterns to help make the powerful silicon chips inside your smartphone and computer!
So, X-rays make our lives better in many ways. What an amazing invention!
DID YOU KNOW? Under very special (and very dangerous!) conditions you can actually see X-rays! Röntgen himself noted that if he was in the dark and fired very powerful ones at his head, he could just see a pale blue glow. (WARNING! Don’t try this at home!) We still don’t know how they produce this blue glow.
DID YOU KNOW? They are just super-powerful light waves. The difference is that they carry hundreds of thousands times more energy than regular light.
DID YOU KNOW? The ‘X’ stands for ‘unknown’. Röntgen gave it that name because it was an unknown form of radiation.
Cool! so many cool facts!