AdventWord 2023: Light

Warning – nerdy ramble alert!

Let's talk about light...

Light, scientifically speaking, is both weird and fundamental. Let’s take weird first. From the time of the ancients, light was believed to be composed of particles, and indeed it is. In the modern era these particles are called “photons”, and once it was realised that they travel at a finite speed much effort was expended in ever more precise measurements of that speed.

 During the 19th century, however, as experiments deepened our understanding of the newly discovered radio waves, it was noticed that the speed of light and the speed of radio waves were suspiciously similar – as in exactly the same! At least as far as we could measure. Then came the famous double slit experiment that proved incontrovertibly that light behaved as a wave.

So, the answer to the question “is light a particle or a wave?” is “yes, depending on how you’re measuring it”. Like I said, it’s weird.

On the fundamental part, think of a scientific equation. Got one? I’d wager a small sum that it’s


Mainly because it’s the most famous single equation is history, being part of Einstein’s general theory of relativity. I’d also wager a small sum that you probably don’t know what it means, so permit me a moment to explain it.

The letter E is used to denote energy, m is mass, and C is the speed of light. Expressed in this form it tells us two things, one of which is interesting while the other is mind-blowing.

hand touching light
Photo by Dyu Ha on Unsplash

The interesting & mind-blowing...

The first is that the amount of energy contained in anything is equal to its mass multiplied by the speed of light and multiplied by the speed of light again. For us here on earth, mass can be simplified as weight, so take a small object (a sugar cube is easy to visualize), multiply the weight of that cube by the speed of light (a very big number) and then multiply it by that value again and you end up with a stupendously big number. If you could extract all the energy contained in a sugar cube at the atomic level, it could power an average kettle for nearly 223,000 years.

That’s just the interesting bit!

The mind-blowing bit is that matter and energy are interchangeable. If you can convert matter into energy then you can also convert energy into matter. Me, you, and all matter in the universe are condensed energy. The amount of energy required to make it is beyond human understanding and it happened around 14 billion years ago. If that doesn’t blow your mind then either you’re not paying attention or you’re a mathematician – in which case all this has been very boring and I probably lost you to boredom two paragraphs ago (in which case I apologise and you can go back to your chalkboard now).

This has been a long-winded way of saying that the value of C crops up in scientific equations all over the place and is (as far as we can tell) one of the intrinsic values of the universe, doesn’t change and has been the same since the beginning of time, hence the fundamental claim.


Twinkly lights

Except for a few exotic lifeforms, from a biological perspective light is just as fundamental and to many mammals (yay mammals!) plays a part in many of our processes, mental as well as physical. My personal reaction to winter darkness is that my mood becomes low and my energy levels drop dramatically. I need to replace the lost light with something to see me though to spring. The best answer I have discovered is TWINKLES!


Lots and lots of lights all around the house – my desk, the stairway bannisters, the walls, the bookshelves, just TWINKLES EVERYWHERE!

It has been known when the twinkles are not installed early enough for me to be overcome with a manic need to install them, however haphazardly but TWINKLES NOW! NOW! My poor family, some pity is probably in order here.

So allow me to wish you and yours the light that you need to see you through the dark times until the sun forgives us and blesses us all once again.

Merry Christmas and a happy new year from the rambly nerd contingent.

Picture of Vincent Heywood

Vincent Heywood

MBS Director

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