Natural History Questions to Which Nobody Knows The Answer


Nov 11, 2014 by British Blog

Believe it or not, in the twenty first century there are still some very fundamental questions to which nobody - not even Stephen Fry or Stephen Hawking - knows the definitive answer.

What is more, not all of these questions are about the 'big topics' of philosophy and religion: some of the most pressing of these questions concern day-to-day events in the natural world.

A few of them follow below  - do you have the answer to any of these great mysteries?


Why, and how, do cats purr?

Ask most people why cats purr and they'll say, ‘because they're happy.’ Yet cats also purr when they are frightened, upset or hurt and what is more - nobody really knows how they do it. There certainly is no distinct 'purring mechanism' in the cat's throat, although some speculate that cats purr by controlling the movement of their larynx.

Not all cats purr, but those that do include cheetahs and ocelots.

Some scientists have suggested that cats purr for attention, in much the same way that babies cry, but the truth is that nobody really knows.


Why do humans experience hypnic jerks?

Often, when just on the edge of sleep, humans feel a sudden jolt, which frequently wakes them up. Around 70% of people are thought to experience this. Although there has been a great deal of speculation, nobody actually has a clue why hypnic jerks happen.


How many species of animal are there?

Even most taxonomists (scientists who identify and catalogue types of animal) will not hazard a guess at the number of creatures living on Earth. Those who have been brave enough have suggested numbers from 5 million to 100 million; currently around 2 million species have been formally identified.

All this vagueness is down to various factors, one of which is that 99% of the Earth's living space is underwater, and so far barely 10% of that space has been explored.


What is the exact length of (any) coastline?

Measuring coastlines accurately is difficult because they meander all over the place - it's not like measuring a straight line. The results of measurement also depend on how detailed the source material is; consider, for example, the number of geological ins and outs to be measured on the actual coastline of an actual place, compared with measuring a vastly less detailed aerial photograph or satellite image.


Do fish feel pain?

A 2010 study from Norway concluded that fish can 'probably' (note 'probably') feel pain. However, another, German, study published in 2013 suggests that fish do not feel pain - at least not in the way that humans do. This is apparently because fish lack physical structures that are comparable to those that humans need to feel pain.

However, saying that fish probably do not feel pain in the same way that humans do is not only delightfully vague, but also fails to assert whether fish do, or do not, feel pain of any kind. Therefore, the jury is still out on that one.