Q: But isn't everything really connected? Doesn't the quantum world pervade everything that we see around us?
A: Of course it does. So does classical physics. The quantum world does pervade everything around us, but as Richard Feynman liked to say, "Scientific creativity is imagination in a straitjacket." Not everything is possible. That's what makes the world so interesting. It is true that quantum mechanics is extremely strange, and on extremely small scales for short times, all sorts of weird things happen. And in fact we can make weird quantum phenomena happen. But what quantum mechanics doesn't change about the universe is, if you want to change things, you still have to do something. You can't change the world by thinking about it.
We are connected to the world by many things: by light and sound and heat. We do, at subatomic scale, behave quantum mechanically. But we behave like classical objects for a reason: We're big, we have lots of particles, they interact. All the weirdness of quantum mechanics gets washed out on the scale that we can experience. That's why we experience a classical world.
The weirdness of quantum mechanics is reserved for either very specially prepared configurations in the laboratory, or scales that are so small that quantum-mechanical effects are significant.
We're also connected to the universe by gravity, and we're connected to the planets by gravity. But that doesn't mean that astrology is true. With quantum mechanics, there's a notion that observers affect the things that they're observing. That's not always true, but it's often true. That's one of the very strange properties of quantum mechanics. Therefore people get the notion that there's no objective reality, and that you can literally impact on the external world just by doing things internally. That's not the case. If you want to affect something in the external world, you have to do something to it. You can't just hope for the best. You can't bring good things to you by thinking about them.
The quantum mechanical correlations, the spooky action at a distance that quantum mechanics brings up, is true only for very specially prepared systems that are isolated from the rest of the world, completely. And we are certainly not isolated from the rest of the world. We're bombarded by many things every second of the day, and a result, we're not specially prepared quantum mechanical systems, nor can we exert weird quantum powers over other objects.
You'll notice that some of the things that Krauss talks about has a ring of familiarity if you have read my blog entry on why quantum mechanics is so difficult for the general public, and why it is susceptible to being abused.
One would hope that people would read this article and stop being taken in by all of these quackeries. Would Oprah invite Krauss to clarify all the misinformation that she helped spread when she touted "The Secret" on her show? I highly doubt it.
Zz.
1 comment:
I tend to tell people that if QM were literally lawless then you couldn't do repeatable experiments with it, and in general it wouldn't be reliable enough to build things like the innards of cell phones, and so on.
I isn't indeterminate, and it doesn't allow anything & everything. It's just that what it determines and what it allows aren't the same things which are in classical mechanics.
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