Ordinary Things Scientists Don't Actually Understand



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Vote up the everyday mysteries you thought were scientific slam dunks.

Science has done a great deal to demystify the world. Things that would once have been ascribed to the supernatural or to gods have, thanks to the scientific method, been explained rationally (even if, all too often, some scientific concepts remain poorly understood).

Numerous ancient mysteries of the world have been solved through experimentation - and there have been many strange and unusual examples of these. However, while science has managed to discover some fascinating things about both earth and space, there are a number of surprisingly common things it has yet to fully understand. 

These aren't the “big think” mysteries like reconciling quantum physics and relativity, or understanding the fundamental nature of time itself. These are things you'd expect scientists to have a handle on - like how bicycles work, or why sand is soft. Vote up the concepts you were sure humans had figured out by now.


  • Why We Can Ice Skate
    Photo: Sair000 / Wikimedia Commons / CC-BY-SA 4.0
    223 VOTES

    Why We Can Ice Skate

    For many people, going ice-skating is a key part of winter life. It is another of those everyday phenomena, however, that many people take for granted and which lacks a concrete explanation from science. Previously, it was believed the pressure of the skate lowered the temperature of the ice enough so it would start to melt, and the resultant skin of water enabled the skater to glide across the ice. Unfortunately, this hypothesis doesn’t hold up. 

    In fact, it would take a significantly larger amount of pressure in order to lower the melting temperature of ice, far more than any skater is likely to bring to bear. 

    While it’s still unclear about the mechanism that allows ice skating to take place, there are some working theories. One proposes the water molecules at the surface may not be bound as tightly, while others propose there are flaws in the structure of ice that allows for it to enter the liquid state.

    223 votes
  • 2
    147 VOTES

    What Makes Sand Soft

    There are few things more pleasurable than dipping one’s bare feet into the sand at the beach. The soft texture of it seems to be innately calming. However, for scientists, the softness of sand is also perplexing, precisely because there is so much about this particular tactile quality that eludes understanding.

    For example, most people notice how sand on the surface of the beach feels softer than the layers underneath, because the latter have been compacted. Nevertheless, scientists have spent a great deal of time studying this very common material, and some rules do seem to apply. For example, the smaller the grain, the more likely it is the sand will feel soft, because they are able to move more easily. On the other hand, if they are too small, moisture will often make them stick, negating the soft feeling and replacing it with a clumpiness.

    147 votes
  • 3
    117 VOTES

    Why We Yawn, And Why It's Contagious

    Yawning is one of those physical actions it seems impossible to escape. In addition, anyone who has been in the presence of someone else who is yawning can attest to a simple fact: it’s contagious. Given how common yawning is and how quickly it seems to spread, it is all the more remarkable to discover how little science actually knows about it. 

    Prevailing wisdom suggests the process is the body’s way of getting more oxygen-rich blood to the brain, since it seems possible humans take fewer deep breaths when they are tired. However, the actual neurology behind the need for this particular process is still somewhat lacking. Many other animals yawn as well, however. The contagiousness of yawning may stem from social mirroring, which is the process by which animals mimic the behavior of others, particularly those actions that might seem to be beneficial.

    117 votes
  • 4
    196 VOTES

    Why We Cry

    Crying is, of course, one of the experiences almost all people have had at one time or another. On the one hand, the process has a physiological benefit, as it helps to wash away debris from the eyes. However, its linkage to emotion seems to be unique to humans, and there isn’t yet a consensus on why humans have developed this particular behavior, as emotional crying has no specific linkage to a physical benefit. 

    Though there seem to be some chemical differences in emotional tears (as opposed to, say, those shed while peeling an onion), there isn’t yet a consensus as to what physical good crying does. 

    As with many other physical processes, however, it seems this one developed as a social mechanism. For example, it could have developed as a means of encouraging others to develop empathy, or to demonstrate submissiveness (thus averting more violence). And, because tears are so evident on the face, they remain a key way for humans to communicate their feelings to others.

    196 votes
  • 5
    86 VOTES

    How Tylenol Works

    Tylenol is one of those over-the-counter drugs that has become nearly ubiquitous. After all, one can walk into almost any drugstore or gas station and find it for sale. It’s easy to see why this would be the case, as it is often effective at dulling various sorts of ordinary pain. However, what is surprising is how little scientists know for sure about how it (and its generic form, acetaminophen) functions and why it is so effective at mitigating pain.

    In fact, the physician' note that accompanies the bottle is clear about the fact: It’s simply not known either where the medicine works or the process it uses to do so. Research suggests its efficacy may stem from any of a variety of sources: Because it blocks an enzyme involved with the sensation of pain; because it engages with the endocannabinoid system (which is also involved in feeling pain); or by adjusting the signals sent by serotonin. It is also possible, and even likely, it is a combination of all three.

    86 votes
  • 6
    95 VOTES

    Why Cats Purr

    Cats are known for many things, but one of their most well-known characteristics is the purr. If one has ever had a cat - or even just encountered one that belonged to someone else - then one is likely to have heard this sound, the cute rumble which seems, according to the prevailing wisdom, to signify the little ball of fur’s contentment. However, cats are also known to purr for a number of other reasons, and some even do it when they are frightened. What’s more, not all felines can do it, with some of the big cats such as lions and tigers unable to do so.

    Though their motivations remain fuzzy, most scientists have come to believe cats engage in this behavior as a soothing mechanism. What’s more, there is also evidence they may do it in order to encourage bone growth, since the frequency at which they purr encourages the regrowth of tissue.

    95 votes