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To everyone in this thread bringing up things we don't understand yet: you're right, but probably missing the point he's trying to make. What he means is that

• ktRolster 10y ago
  By analogy, it's like saying we know conceptually what a Turing machine is and how it works, but not everything about computer science and software engineering. That's reverse of what he is saying. As you say, we understand the Turing machine (the most basic elements), but we don't understand everything it implies. Whereas in physics, we don't understand the most basic elements, but we do understand what those elements imply (at least, the article asserts that we do).
  • macspoofing 10y ago
    >Whereas in physics, we don't understand the most basic elements I think he's saying we fully understand 'the most basic elements' in so far how they underpin the 'domain of everyday life'. It's a little like saying that the underlying physics behind the motion of bilard balls are completely understood with just Newtonian mechanics, even though Newtonian mechanics themselves are incomplete if applied to other domains - like explaining the motion of the planet Mercury.
  • Steuard 10y ago
    I think you're both right. Carroll is claiming that in physics, there is one essentially complete layer of description that we fully understand: the layer consisting of the standard model (based on quantum field theory) plus general relativity. We don't understand the smaller, more fundamental layers (string theory is one attempt at that, and there are others), and we don't understand every last detail of how that layer gives rise to the larger, more familiar layers (we've only very recently even been able to deduce the mass difference between protons and neutrons based on standard model computational physics). But the point is that our understanding of this one particular layer is broad and solid enough to essentially guarantee that every other observable feature of real life can be traced back to a set of principles that we understand.
• macspoofing 10y ago
  Sean Carroll is very good speaker and a tremendous communicator of science. He has a bunch of talks on youtube, and they are all very enjoyable to listen to. And if you're into that sort of thing, his debate with William Lane Craig is fun and informative (https://www.youtube.com/watch?v=GKDCZHimElQ https://www.youtube.com/watch?v=GKDCZHimElQ)
• deleted 10y ago
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• sanxiyn 10y ago
  > every physical phenomenon we're capable of observing here on earth with any instruments we've invented to date This is stronger than "everyday life" claim, and likely false. Note that the article carefully excludes "fancy telescopes": there is a reason. For example, we can observe supernovae. We don't have satisfactory model of core-collapse supernovae yet. In other words, if you set initial condition to right before explosion and simulate forward, stars don't explode in simulation. And critically, it is seriously entertained that this may be due to physics beyond the Standard Model, unlike life or superconductivity: e.g. http://arxiv.org/abs/0710.3112 http://arxiv.org/abs/0710.3112
  • visarga 10y ago
    > For example, we can observe supernovae. We don't have satisfactory model of core-collapse supernovae yet. Toddlers. We don't have a model of toddler collapse either. See her now, in 10 seconds - poof! How can we predict that with our current physics knowledge?
    • sanxiyn 10y ago
      No one seriously expects model of toddler collapse to lead to novel physics. Some (admittedly minority) serious physicists expect model of supernova to lead to novel physics.
      • visarga 10y ago
        But we can't predict when a toddler will collapse, or when she will start throwing toys, using the current understanding in physics, even if "The Laws Underlying the Physics of Everyday Life Are Completely Understood". What I am getting at is that we only understand the Low Level laws. We still can't understand, for example, financial markets or the weather. Complex dynamic systems are still beyond our horizon of understanding, even if we know how elementary particles behave. Another example, and this one is very basic: Predict the state of a system of 3+ bodies moving in space. https://en.wikipedia.org/wiki/Three-body_problem https://en.wikipedia.org/wiki/Three-body_problem
• millstone 10y ago
  > mathematically capable of predicting every physical phenomenon we're capable of observing here on earth "Mathematically predict" is too strong. For example, we can observe the mass of the electron here on earth, but our theories do not mathematically predict it. There are many similar parameters whose values must be determined empirically. There's also the converse: properties we can mathematically predict, but for which we do not have a good theory. An example is the mass of the Tau: predicted by the Koide formula, but we don't really know why.
• allenz 10y ago
  Good point, Carroll distinguishes between "manifestations of the underlying laws" and the laws themselves. Still, this is an impossible claim to make, because you can't prove a negative. Given all these everyday phenomena we can't explain, it is entirely conceivable that one of them will require a modification of QFT. Personally, I think that consciousness or memory (which we all experience every day!) could rely on weaker interactions than the ones we know of. I find it unlikely but certainly possible that we aren't yet mathematically capable of predicting conscious behavior.
• andrepd 10y ago
  That's both true and not. Yes, it's true that the point is akin to saying that even though we have the equations to understand fluid dynamics we don't understand the weather more than in a rough general way and aren't able to make predictions ahead of a few measly days. But it's also true that even the theory behind it isn't "true" in the absolute sense. We don't have a renormalizable quantum field theory of gravity. Therefore our current understanding is most certainly incomplete, much in the same way Newtonian physics alone wasn't complete in its description of phenomena.