And other excellent questions (How do we fall in love?), answered by great minds …
Neuroscientist David Eagleman explains why we can’t tickle ourselves:
[…] Because your brain is always predicting your own actions, and how your body will feel as a result, you cannot tickle yourself. Other people can tickle you because they can surprise you. You can’t predict what their tickling actions will be.
Evolutionary biologist Richard Dawkins breaks down the math of evolution and cousin marriages to demonstrate that we are all related:
[…] Everybody has two parents. That means, since each parent had two parents of their own, that we all have four grandparents. Then, since each grandparent had to have two parents, everyone has eight great-grandparents, and sixteen great- great-grandparents and thirty-two great-great-great-grandparents and so on.
You can go back any number of generations and work out the number of ancestors you must have had that same number of generations ago. All you have to do is multiply two by itself that number of times.
[…] The real population of the world at the time of Julius Caesar was only a few million, and all of us, all seven billion of us, are descended from them. We are indeed all related. Every marriage is between more or less distant cousins, who already share lots and lots of ancestors before they have children of their own.
Alain de Botton explores why we have dreams:
In the olden days, people believed that our dreams were full of clues about the future. Nowadays, we tend to think that dreams are a way for the mind to rearrange and tidy itself up after the activities of the day.
Particle physicist and cosmologist Lawrence Krauss explains why we’re all made of stardust:
Everything in your body, and everything you can see around you, is made up of tiny objects called atoms. Atoms come in different types called elements. Hydrogen, oxygen and carbon are three of the most important elements in your body.
[…]
How did those elements get into our bodies? The only way they could have got there, to make up all the material on our Earth, is if some of those stars exploded a long time ago, spewing all the elements from their cores into space.
How do we fall in love? Author Jeanette Winterson offers this breathlessly poetic response:
You don’t fall in love like you fall in a hole. You fall like falling through space. It’s like you jump off your own private planet to visit someone else’s planet. And when you get there it all looks different: the flowers, the animals, the colours people wear. It is a big surprise falling in love because you thought you had everything just right on your own planet, and that was true, in a way, but then somebody signalled to you across space and the only way you could visit was to take a giant jump. Away you go, falling into someone else’s orbit and after a while you might decide to pull your two planets together and call it home.
Evolutionary psychologist and sociologist Robin Dunbar balances out the poetics with a scientific look at what goes on inside the brain when we love:
[S]cience does allow us to say a little bit about what happens when we fall in love. First of all, we know that love sets off really big changes in how we feel. We feel all light-headed and emotional. We can be happy and cry with happiness at the same time. Suddenly, some things don’t matter any more and the only thing we are interested in is being close to the person we have fallen in love with.
[…] [T]he bits that normally say ‘Don’t do that because it would be crazy!’ are switched off, and the bits that say ‘Oh, that would be lovely!’ are switched on.
Why does this happen? One reason is that love releases certain chemicals in our brains. One is called dopamine, and this gives us a feeling of excitement. Another is called oxytocin and seems to be responsible for the light-headedness and cosiness we feel when we are with the person we love. When these are released in large quantities, they go to parts of the brain that are especially responsive to them.
But all this doesn’t explain why you fall in love with a particular person. And that is a bit of a mystery, since there seems to be no good reason for our choices. […] And here’s another odd thing. When we are in love, we can trick ourselves into thinking the other person is perfect. Of course, no one is really perfect. But the more perfect we find each other, the longer our love will last.