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Science Questions with No Answers!
My students believe that I have all the answers; students everywhere rely on their teachers to respond to their questions with (relatively) straightforward answers. What I try to teach my students, however, is not all questions have answers - there really are things we do not know!
Ignorance is not necessarily a burden, but a strength. Understanding the limits of your knowledge or ability can help you improve. Students asking questions I do not know the answer to is usually a sign of their own improving knowledge. Nothing is more satisfying than having a student ask a question beyond the syllabus, beyond the test, and beyond current scientific understanding. A favourite extension task of mine is to set a student a research task on a question to which we do not know the answer.
This hub examines the lingering questions in science. They are ranked in no particular order and, if I have missed your favourite, please add it in the comments section. It may be that, one day, some of these questions are answered. Others, by their very nature, will remain - like God - unknowable.
1. What Causes the Jerks in our Sleep?
You lay your head down after a long day, you slowly unwind and start to drift off when....JERK! Your whole body violently jolts and you are suddenly wide awake. This involuntary muscle spasm even has it's own name: a myoclonic twitch. This doesn't mean we know what causes it though! Some scientists have suggested it is merely a random muscle twitch; others think that as your body cools and relaxes, your brain believes you are falling and tries to save you!
How may we regrow limbs?
2. Why can't we Regrow Limbs?
Like many animals, we are vulnerable to serious injury. Whilst skin or some bone injuries are not beyond our body's built-in repair mechanisms, injury or assualt of our major organs, or the loss of a limb, is well beyond them. Once you lose a hand it is gone forever.
There are a small number of animals that can regenerate lost limbs and even lost organs. Many species of lizards can consciously detach their tails as a distraction to aid their escape from predators. After a few days or weeks, the tail will regrow. This pales in comparison to the salamander, who can regrow parts of it's liver, kidneys, heart and even it's brain.
Despite huge research efforts, we still do not know what allows some species to regrow limbs whilst others cannot. The body must have had the information to grow a limb in the first place, or they would not have grown in the womb! What is unclear is how or why this ability is irretrievably lost...or even if it IS irretrievable.
This fantastic book is one of my personal favourites. It has a witty, easy-going style and will surprise you with 501 things we don't know on topics from Biology and Cosmology to Literature, History and Music
3. How do General Anaesthetics Work?
General anaesthetics are used before major surgery to send a patient to sleep. They are a cocktail of different drugs that work together to knock you out, keep you under, numb your senses and relax your muscles. But we dont know exactly how they work! We have the general idea that they block molecular messages sent between nerve cells, but as to exactly which cells, which neurotransmitters, and the precise biochemistry we remain, to a greater or lesser extent, in the dark. One way we could find out is to deliberately interfere with the anaesthesia process...but this has serious ethical implications.
4. Are We Living in the Matrix?
This may seem like a daft question, but it is one we simply cannot answer. We are dependent on the information we receive from our senses, but as any optical illusion will prove, we cannot externally verify whether what our senses are telling us is true. Perhaps it is merely the act of experiencing something that makes it real - but then you must ask, are hallucinations 'real?' For this reason, we can never know if we are merely algorithms in a computer simulation, just as we can never know what is real, or if reality even exists.
Which mystery would you most want solved:
How to Reverse Aging?
5. What Causes Aging?
Since the dawn of Mankind, philosophers, alchemists, priests and scientists have searched for the secret to eternal life. We have seen the search for the Philosopher's Stone and the Fountain of Youth; these quests are futile, but perhaps by understanding aging, we could delay or even halt it's advance.
Unfortunately we are at a loss to explain why aging occurs. There are several hypotheses, including one about the shortening of sections at the end of each of our chromosomes called 'Telomeres.' Whilst it has been proven that older individuals have shorter telomeres, why this happens, and even how to reverse it we still don't know how telomeres are linked to the physical symptoms of growing older.
The 2009 Nobel Prize in Physiology or Medicine was awarded to scientists working on Telomeres. Even these academics admit that telomeres are just one small piece of the aging puzzle.
6. What is Dark Matter?
Various physicists have calculated the amount of matter there should be in the universe, based on it's rate of expansion and estimated age. Strangely when we add up all the matter we can find in the universe, we come up significantly short! There isn't enough matter in the universe to explain why galaxies are behaving as they do. So Scientists 'invented' dark matter:
Dark matter is matter that we cannot see or detect with current methods, but must still be out there. It is estimated that more than 80% of the matter in the universe must be 'dark matter'. It describes how galaxies spin, why the universe is expanding at it's current rate and how galaxies form. Without dark matter, our universe could not have held together after the big bang.
As to what dark matter is...that is still a mystery!
The Death of the Universe?
7. Will the Universe Last Forever?
Throughout the history of Mankind, our greatest minds have tried to say how our universe came to be, and how it will end. Every religion has it's own Creation story and it's own ideas of how life will come to an end*.
Ever since the idea that the Universe had not always existed became mainstream among scientists, those same scientists have tried to predict how, if and when the universe will end. There are many grizzly scenarios on the table:
- Heat Death - a natural consequence of the laws of thermodynamics where the energy of the universe has become equally spread out and no further reactions can take place.
- The Big Crunch - the opposite of the Big Bang: after the momentum from the universe-starting explosion dissipates, the gravity of the universe starts pulling everything back from whence it came.
- The Big Rip - this occurs if gravity is not sufficient to overcome the inertia of the expanding universe: everything just keeps on going until all particles are infinitely far apart from each other.
Which of these occurs, if any, is up for debate and, ultimately, unknowable. None of these scenarios are set to take place for tens of billions of years.
8. What Causes the Magnetic Poles to swap?
Our Earth is protected by a giant magnetic field originating from the core of the planet* Without it, energetic particles from the Sun would destroy our atmosphere and kill all life on Earth.
By looking at certain types of rock, we can see that the magnetic field has existed for as long as the oldest rocks on Earth. But when scientists looked more closesly, they found that the magnetic poles swap places every million years or so. More worryingly, we are well overdue for a swap! This raises interesting questions:
- Why do the poles swap?
- How long do they take to swap?
- What effect will it have on life?
- What effect will it have on our electronic life?
We believe that a swap may take around 5000 years to occur, but what might happen to the level of protection during that time, we do not know.
* Interestingly, we still don't know exactly what causes the magnetic field!