5 More Great Discoveries That Haven’t Yet Been Made

A while ago, we wrote about great discoveries that haven’t yet been made.

Since that article was written, we’ve got one baby-step closer to the resolution of the Fermi paradox: a planet has been discovered orbiting the closest star to our sun, Proxima Centauri. The planet has been called Proxima b (inventive) and it seems to have some interesting similarities to Earth. The distance it lies away from its sun means that it’s at a temperature where if there was water on its surface, it might be in liquid form. We’ve found other planets this life-friendly distance away from their sun before, but never one as close to us as Proxima b.
Of course, we’re still a far distance from needing to drastically expand our planetary Christmas-card list; there’s no evidence at all for life on Proxima b. Whether aliens exist remains an unsolved mystery – so no need to update our previous article just yet. In fact, there are even more great discoveries yet to be made than we had room for in that article. Here are some that we found particularly interesting.

1. Why we sleep

It’s pretty clear that humans and most other animals need sleep. Lab rats have died after being kept alive for periods of 11 to 32 days. The world record for staying awake without stimulants is held by Randy Gardner, who stayed awake for 11 days. By the end of that period, he was still in some ways capable – beating a researcher at pinball, and holding a coherent press conference on his final day awake – but was also experienced symptoms such as paranoia, moodiness, hallucinations and some symptoms similar to dementia. However, once Gardner then went to sleep having beaten the world record, he recovered entirely from all of his symptoms.

Another way of looking at this is that for lab rats at least, lack of sleep is fatal much sooner than lack of food – but despite this, recovery from lack of sleep seems to be much quicker and easier than recovery from an equivalent period of starvation. But the evidence is patchy. Fatal familial insomnia is an extremely rare condition that provides some additional insight – patients with it gradually lose the ability to go to sleep fully, and suffer similar symptoms to those experienced by Randy Gardner, including paranoia, hallucinations and dementia. There’s no known cure, and it’s invariably fatal after about 18 months from onset. Thankfully, it’s genetic and only about 40 families worldwide carry the relevant gene.
So it’s evident that sleep is necessary for survival. But we don’t really know why. Sleep seems to enable our bodies to repair themselves, especially the brain. Prof Maiken Nedergaard explained that this process happens primarily while we’re asleep with a delightful analogy: “You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can’t really do both at the same time.”
Still, sleep seems illogical. Other animals sleep much less (African elephants get by on just 3.3 hours) and dolphins never go fully to sleep as they have to be conscious to breathe, so instead one half of their brain sleeps at a time. Humans have evolved to sleep for an average of 7.75 hours, which makes us especially vulnerable to attack for a full third of the day. What is it about the process of sleep that makes that degree of vulnerability worthwhile, and just why do we need it so much? As things stand, we simply don’t know.

2. What causes lots of diseases

If you were startled by how little we know about general anaesthetic from reading the previous article about great discoveries that haven’t yet been made, this will shock you more.

We have made incredible progress in Medicine over the past century. Over the course of the 20th century, smallpox killed an estimated 300-500 million people, but has now been completely eradicated. We’re close to eradicating polio, Guinea worm disease and the tropical disease Yaws. In the 1970s in Britain, a little under 5 in every 10 people with skin cancer survived for more than 10 years. Now, it’s 9 in 10. You could be forgiven for thinking that our understanding of diseases must be near-perfect by now – in fact, as we discussed in the previous article, that belief has launched conspiracy theories that our understanding of Medicine is so advanced that the only reason we don’t have a cure for cancer is that drug companies are keeping it from us.
In fact, there are a host of common diseases whose causes we don’t know. In some cases we can cure a disease without understanding the cause (in the same way that we have used aspirin as a painkiller for centuries despite not knowing how it works until the 1970s) but in other cases our ignorance of the cause prevents us from developing a cure. Such conditions include Bell’s palsy (a type of facial paralysis that affects around 1.5% of people at some point in their lifetime), cluster headaches (excruciatingly painful headaches affecting about 0.2% of the population), fibromyalgia (a chronic pain condition that affects 2-8% of the population, with women much more often affected than men) and irritable bowel syndrome (abdominal pain affecting 10-15% of people in the developed world, and higher percentages in developing countries).
In some cases, the cause of a disease is unknown because there’s no real point in researching it. Pityriasis rosea is a case in point – it’s a skin rash that can be very itchy, but in three-quarters of cases is just a little unsightly, and goes away on its own in eight to twelve weeks. Research into curing it would be a waste of money. But for conditions such as fibromyalgia and IBS, a better understanding of the causes, enabling a cure to be developed, would considerably improve the quality of life of millions of people worldwide.

3. How to predict prime numbers

There would be a Fields Medal (equivalent to a Nobel Prize) for the mathematician who figured out a formula for generating prime numbers. No formula that can be calculated with a feasible level of computing power exists. But at the same time, an awful lot of people are counting on the idea that such a discovery is impossible, and it might prove disastrous for the world economy if the formula ever were discovered.

That’s because a lot of systems are constructed on the assumption that prime numbers cannot be predicted. For instance, many important algorithms in cryptography depend on prime numbers – these are the systems that ensure, for instance, that your credit card details can’t be stolen from an encrypted webpage. RSA is an example of an algorithm that uses prime numbers. It uses two keys – a ‘public key’ that is the result of multiplying two very large prime numbers together, and a ‘secret key’ that is those two prime numbers. It’s very easy to multiply the primes together, but very hard to figure out which two primes the ‘public key’ might be made of. Users with the public key can encrypt their message easily, but it’s effectively impossible to decrypt the message without having the secret key. If a formula existed to figure out quickly and easily what the two primes were, the system breaks down completely.
And this is just one example of how prime numbers are used in the mathematical systems that underpin a lot of computerised processes. Public-key cryptography doesn’t exclusively rely on the difficulty of predicting primes, but also on other mathematical problems that are currently virtually impossible to solve. We would have alternative approaches for encryption if predicting primes became possible, but in the short-term, this remarkable discovery would cause chaos.

2. How many species there are in the rainforest

In the previous article on great discoveries, we discussed the mystery of what lies at the very bottom of the ocean. It’s naturally hard to explore, because of reasons of pressure and light penetration. It makes sense, after a fashion, that we might be ignorant of the depths of the ocean. But we also lack a great deal of knowledge of what exists within the rainforests.
We aren’t even sure about all the people living in the rainforests. There are around 100 uncontacted tribes across the world, who live primarily in densely forested areas in South America and central Africa. Some may still be entirely unaware of the outside world, and live as hunter-gatherers. Contact with the outside world when it occurs can be dangerous, as uncontacted people often lack immunity to common diseases. The size of uncontacted tribes varies, but most number between 100 and 500 individuals – any fewer, and their gene pool becomes unmanageably small; any larger, and remaining uncontacted becomes increasingly improbable.

If in the modern era, 500 people can live in a forest without coming into contact with anyone else, it’s unsurprising that we might be ignorant of a good deal else of what lives in the rainforests. What we do know is that the biodiversity of rainforest regions is incredible: in Europe, north of the Alps, there are 50 species of tree; but even a small portion of rainforest might have in excess of 200. Tropical forests cover only 6% of the surface area of the planet, but contain more than half of all species of plants and animals found on Earth. In Peru’s Tambopata Reserve, 43 different species of ant were found to live on a single tree.
How many different species there are in the rainforests in total is a complete mystery. Estimates range from three to 50 million species. This is one of the challenges that makes conservation of rainforests difficult, because it’s hard to measure how many species we’ve lost through climate change or deforestation when we don’t know how many species were there in the first place. And this matters hugely, because preserving biodiversity helps us in many different ways. A greater range of plants and animals offers possibilities in agriculture, medicine and commerce. Think, for instance, about aspirin (the natural product of willow trees), rubber (from rubber trees) or even maple syrup – the undiscovered world of the rainforest may well hide more plants and other organisms that could be just as useful to us.

3. Whether colours are only in our minds

We know a great deal about colour. We understand that colours appear through varying light frequencies, and we understand how our eyes process those light frequencies and turn them into colours that we can see. We know that there are differences in how different people see colour through the phenomenon of colour blindness, and that some people can detect a greater range of colours than others. The indigenous Himba people of Namibia and Angola categorise colours in an unusual way, focusing on greens and blues as well as the darkness or lightness of colours, and seem to be able to tell the difference between shades of green more effectively than most other people can. We also know that there are animals who can see a greater spectrum of colours than humans can.

Despite these differences, we can also agree on a lot when it comes to colours, such as which colours go together and which ones don’t. Think about the teal and orange phenomenon in Hollywood films: this is where films have been subtly digitally recoloured so that teal and orange shades are brought to the fore relative to other colour tones (it’s particularly obvious when you look at movie posters). Exactly why teal and orange have taken over at the expense of other shades isn’t entirely clear – it’s possibly because it’s a combination that results in bright, contrasting colours without turning actors’ skin to uncomfortably unrealistic colours, as well as giving paler actors a fashionable tan. Either way, we clearly respond in similar enough ways to the shades we perceive as teal and orange for this effect to work.
All the same, there’s no way of knowing whether what you see as orange looks the same as what your friends see as orange – or what people hundreds of years ago saw as orange. Scholars like to discuss the description ‘wine-dark sea’, used several times by Homer in the Iliad and the Odyssey – the question being why he compared the sea to wine when the sea is blue and wine is red. Some have argued that wine in ancient Greece was diluted until it looked blue, or that the Aegean Sea was reddish at the time. Another explanation is that the ancient Greeks simply perceived colour differently to people in modern times, and cared more about the distinction between light and dark than between different colour tones. Exactly what it is that other people see when they see colours continues to remain a mystery.
Image credits: lightbulb; horsehead nebula; sleeping cat; headache; debit card; rainforest;