An article in the Wall Street Journal this week got me thinking about the old question “If a tree falls in a forest and there’s no one there to hear it, does it make a sound?” I always used to wonder why anyone would ask such a silly question, since it seemed obvious to me that the answer was yes.
It depends on how you define “sound,” though. The falling tree creates the vibrations we call sound waves, but strictly speaking, those don’t become “sound” until they enter someone’s ear, then are translated to “sound” by the sense of hearing. Of course, I don’t think it has to be a person who hears the sound. Most forests are full of animals that have at least as good a sense of hearing as we do.
I discovered, however, that the point of the question as originally asked was something different. Does something exist if there is no one to perceive it? My answer would be “Of course” – but it is also clear that the thing’s existence cannot be proven if no one observes it in any way. Is there any meaning to speaking of the existence of something totally outside our knowledge?
(As an aside, here is a humorous look at the question, from the point of view of science fiction. It has nothing to do with the rest of this post, but it’s amusing, and it also raises some interesting questions.)
Even when we do perceive something, can we prove that external reality corresponds to our perception? Is it possible that we are, like people in The Matrix, experiencing a simulated reality that exists only in our minds? Since all our sense perceptions take place in the brain, it is impossible to prove that they do correspond to the real world. Not that I seriously doubt that the real world exists – but it’s good to keep in mind that it is possible for the brain to “perceive” something that does not correspond to external reality.
And that’s where this article from the Wall Street Journal comes in. Scientists are developing new ways to ease suffering for people in chronic pain. Traditionally, the way to fight pain has been to eliminate the cause of pain. When possible, that is certainly the best path. After all, pain’s purpose is to alert you that something is wrong in your body so that you can fix it. Left untreated, the conditions that cause pain will usually cause long-term damage to the body.
Sometimes the condition can’t be treated, however, and narcotic painkillers have their own drawbacks. New therapies are based on the fact that pain, as a sensation, exists not at the source of the pain but in the brain. I remember, back in elementary school, watching the Bell Labs movie Gateways to the Mind. It was fascinating to learn that everything that we sense is a result of communications running from nerves in our sense organs to the brain.
What if you stop the message from going to the brain? Or at least interfere enough with the signal that what gets to the brain is far different? In most cases, such stopped or distorted signals are a problem, either annoying or serious depending on the situation. But if the messages that are tampered with are pain messages, interfering with the messages means that the brain no longer sense terrible pain.
You wouldn’t want to do this if there were a better therapy, of course. Pain has its purpose (the lack of pain is what makes leprosy so serious). I remember when I got my finger anesthetized (after having a sewing machine needle go through it, back when I was a teenager), and I kept whacking my finger on objects trying to feel something. I knew I might cause further damage to my finger by doing so, but I couldn’t stand not feeling it.
If the pain comes from an untreatable chronic condition, however, the pain is serving no purpose since the person is well aware of the condition. I don’t know what unforeseen side effects this treatment may have, but since it is narrowly targeted at a particular nerve, its side effects are probably less harmful than those of traditional painkillers.
Of course, I hope never to need such therapy.