Should A Chair Fear Your Bottom? Well Actually, Science Says No.
Whilst sitting across from an empty seat, you can quickly begin to wonder who may sit opposite you. With a global population of around 7.6 billion people, it could be just anyone. The chances are that you may not know them or the story of their lives. But more than likely, they have a bum. And for a chair, their entire life is about waiting for the next one. But should a chair worry about being sat on? Physics tell us no.
Half And Half Again
You may be familiar with the old conundrum of infinite reduction. It goes something like this;
If you were to drop an object to the floor, it would cover half the total distance of the fall. Then half again, and again. If this continues, it will never reach the ground. So how is it that it can?
On paper, this makes total sense. But drop that paper, and it quickly becomes nonsense. Mathematics has a term for these rules that logically sound, but cannot be tested properly in our Universe, or don’t play out like they should in our day to day lives. These are called Axioms, and are designed to help us develop new tools to understand and change our world.
So for the chair, the foreign bum should never land, but it does. So perhaps the chair cannot find solace in Axioms. But actually, the bum will never truly touch it at all. That’s where physics comes in.
Bums and Bonds
Our universe is held together by four cardinal forces. There is gravity, the weak and strong nuclear forces and electromagnetism. Combined, they can be used to explain (to a high level of accuracy,) most of what we observe in our day to day lives, as well as in the distant past and far future. Their limits are found at the quantum level, but even now theoretical physicists are breaking those boundaries.
So what does this have to do with a Bum? Well a bum, mine, yours and Kim Kardashian’s, is made up of skin, fat, muscle and beneath that bone. These tissues are made of molecules, and those molecules, atoms. Those atoms are made of subatomic particles, such as quarks. No matter what, matter is what you are made of. And this matter must play by the rules.
At the atomic level, the strong nuclear force binds atoms together, gluing protons (which will repel each other,) together using substantial energy, (it is the breaking of these bonds that gives us nuclear fission, as opposed to their formation also utilising the weak force that fuels the stars.) The protons opposite number, the electron, also fiercely repels others. And its at this level that your bum atoms interact with those of the chair.
Very Small Distances
At this tiny level, the interactions between electrons are rather predictable. An electron is a curious thing, showing both the behaviour of a particle (like sand,) and a wave (like sound.) This is called wave/particle duality and plays a large role in how things interact. Even photons, the irreducible energy packets of light, share in these rules.
From a particle perspective, the electrons of two opposing atoms (and thus their larger molecules) cannot touch. They can get close, half by half, but never quite meet up. From a wave perspective, their ‘wave packets’ (i.e, the amplitudes of the signal in space-time) can overlap, but never fall in sequence. This means that the elections, and with them your bottom and a chair, can never quite touch.
So actually the old mathematical axiom runs true, but the explanation can be found in our universe as well as in the equation.
So Should Chairs Fear Bums?
From a perspective of touch, not really. But when it comes to smells, regardless of the physics, we still smell them. The interaction of a particle (of lets say, perfume,) and the cells in your nose still interact. You need a particle of something in your nose to smell it (and even then, it is your brain that creates the smell!) So although physics means that the chair can never truly feel the bum rushing down upon it, it can smell it.
As can you.
- Follow Ben on Twitter so you never miss an article
- Donate. These articles take time, so a few bob for a coffee would be appreciated.
- Learn more about physics at physics.org
- Let me know what you want to learn about.
The opinions expressed in this article are those of Dr Janaway alone and may not represent those of his affiliates. Remember, fear is natural, but how you choose to deal with it is a choice. Image courtesy of Jes