5. Laughter, why do we do it? Despite the fact that it's something we do every day, scientists aren't entirely sure why humans laugh and there are only a few species on the planet that do it. Despite another fact that many other animals also have complex social structures like our own, they appear to be largely humourless. Don’t kill me laughter isn't necessarily anything to do with humour, anyone who has politely sat through their father-in-law's jokes will attest to that. It is reckoned that only around 20% of laughter is in response to an actual funny joke or a stimulus like tickling, the rest is made up of the polite guffaws and awkward giggles that punctuate conversation without anything really being funny. (don’t lie to me I know I’m in that category) It is also thought that perhaps laughter is used as a way of controlling the behaviour in our social groups. The difference between "laughing with" and "laughing at" , could be the key to this. When you laugh at someone, you are essentially telling them that their behaviour is not acceptable to your group, either pushing them out or forcing them to alter it, whereas "laughing with" is a signal that the behaviour is accepted within the group. The fact that humour plays a role in sexual selection - that women love a sense of humour - could be the reason for its prevalence in humans as it would be a successful trait passed down through generations. Too bad all topics aren’t about that though. And that’s it for laughter I guess, psychologist scientists have better things to do. (more science!!)
4 Why is Ice Slippery Saying that ice is slippery is like saying that water is wet -- it's something we've known for as long as we can be said to have known anything. Presumably, humans as a species knew ice was slippery before we knew fire was hot, or that it existed. But ask anyone why, and they won't be able to give you any better explanation than one of those cave people would have. Our intern Thoog suspects that either evil spirits or flash thawing is the culprit. Although at this point, most of you are probably screaming "It's water, stupid!" -- and that's more or less the answer that scientists have always concluded. Even in some modern textbooks you can still read the popular explanation: Unlike most substances, ice expands when it freezes. So when you walk on it, you're actually compacting it back into slippery old water. Sounds simple, right? Experiments have shown that your puny body doesn't exert nearly enough pressure on ice to squeeze even a tiny bit of it into liquid. Science: "We don't know ... ice fairies, maybe? (hey listen! I have the answer) *Zelda rap* hey listen you annoying- " There are some competing theories, though none of them are better than the others. One popular theory is that ice is not actually slippery at all. Though this sounds like something that science, exasperated, would proclaim while waving a gun in your face to make you stop asking stupid questions, a guy named Dr. Salmeron thinks that the roughness on the surface of ice is actually so high that, ironically, it becomes slippery when you flash-melt it due to the sheer friction you're applying to it. Of course, in the same breath, Dr. Salmeron admits he may be talking out of his ass. (sigh) or it’s so smooth of a surface, that there’s no friction at all. (it’s complicated!!)
3. why does boiling water freeze faster than cold water
