Photographing the invisible

What is dark energy? What is a thingamabob? What is the point of Jeremy Kyle? These three questions share one common answer: nobody really knows. In fairness, the second question has a deceptively simple answer. A thingamabob is merely a euphemistic term used to denote a whatchamacallit. The third question, meanwhile, makes about as much sense as asking why wasps exist; because life is cruel.

Now that that’s sorted, I’d like to focus on my first question. What is dark energy? Let me tell you what we do know. The universe is expanding and this has been known for some time. What is more interesting is the fact that the rate at which the universe is expanding is accelerating. This came as such a surprise in fact, that in 2011, Professors Perlmutter, Schmidt and Riess were awarded the Nobel Prize in Physics just for realising that it was the case. ‘But why is this acceleration so surprising?’, I hear you think. Because, my dear thinker, the existence of gravity means that far from getting faster, this rate of expansion should be slowing down.

To put it another way, we all exist inside a giant balloon. Somebody is blowing into our balloon causing it to expand. For the sake of alliteration, let’s call this person Brenda. The fact that breathless Brenda has a finite amount of air in her lungs led us to assume that she would be coming to the end of her inflationary campaign. In actuality, Brenda seems to be blowing into the balloon with more gusto than ever before. Something must be enabling breathless Brenda with finite breath to breathe more briskly…but what? Dark energy, of course.

Dark energy is the name that scientists have bestowed upon that which is causing the universe to expand at an accelerated rate. We know that something must be causing this to happen and whilst we don’t know exactly what it is, we have deemed it deserving of a name.* ‘Dark’ to scientists is like ‘God’ to atheists. It’s a word that is used to represent the gaps in our knowledge.

Another thing that we know about dark energy is that we can’t see it; hence the ‘dark’ bit. Imagine my surprise, therefore, when I happened upon the news that for the past eight years, scientists have been busy constructing something called the Dark Energy Camera, or DECam** for short. With its 570 megapixels, DECam is the world’s most powerful camera and its sole purpose is to search for something that, by definition, cannot be photographed. To my simple brain, this seemed somewhat akin to building the world’s finest colander to trap fog.

Despite my initial reservations, DECam took its first pictures of the Formax cluster of galaxies earlier this month. Over the next five years, scientists participating in the Dark Energy Survey (DES) collaboration intend to produce a detailed, three-dimensional map of one-eighth of the night sky. As the University of Nottingham’s Professor Alfonso Aragón-Salamanca told ScienceOmega.com, the high resolution images captured by this camera will enable scientists – indirectly – to learn more about the mysterious nature of dark energy. If you ask a scientist what dark energy is in 2018, he or she might actually be able to tell you.

Patience may well be a virtue, but as a member of a generation whose collective attention span has been eroded by television and video games, I find myself unwilling to wait half a decade for an answer. Instead, I am going to put forward two possible*** explanations of my own concerning the nature of dark energy. Have I conducted any research to support my hypotheses? No. Did I have any understanding of dark energy as a concept before Monday of last week? No. Will I shamelessly accept a Nobel Prize if one of my theories turns out to be correct? Absolutely.

With this in mind, let me begin by suggesting that the universe is not expanding. Galaxies are not accelerating away from one another. Instead, space-time is simply growing in size. As the fabric of the universe gets bigger, it looks as though matter is hurtling outwards whereas in fact, it is simply doing what it’s always done. Nothing is moving. Space-time is just expanding. You might well ask what is causing space-time to expand. After all, dark energy is a term used to describe that which is causing the rate at which the universe is expanding to accelerate, so it could just as easily be applied to that which is causing space-time to grow at an accelerating rate. Well, I think that time itself might be causing this to happen. It stands to reason that as more time goes by, space-time gets bigger. This is basic science people.

Of course, there exists a minute chance that my space-time theory will be proven wrong and every good theorist should have a backup.**** My second theory, therefore, is that we have already discovered dark energy but we haven’t yet put two and two together. Dark energy is all around us but it is a substance that is completely mundane. Personally, I am punting for apples but it might just as easily be chaffinches. Apples/chaffinches***** are causing the universe to expand at an accelerated rate, and if all of the apples/chaffinches***** were to disappear, our entire cosmos would collapse in on itself. What property of these mundane substances is causing this to happen? That is a question for scientists to answer.

After all, I’m just a humble visionary.


* Like Jeremy Kyle
** This is not shorthand for the Prime Minister of the United Kingdom of Great Britain and Northern Ireland David William Donald Cameron
*** Probably
**** Just ask Einstein to discuss what is special and what is general
***** /paper clips