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Hawking mentions values of physical constants that support life as being often given as an evidence that the Universe was designed. I was wondering once if the
by mixedbit 14y ago
Hawking mentions values of physical constants that support life as being often given as an evidence that the Universe was designed. I was wondering once if the values of constants are not enforced by the structure of the Universe, and are not magic numbers that could theoretically be changed. Maybe we don't really understand the underlying mechanism that gives a physical constant a given value, and if we did, it could turn out, that the constant can not possibly have any other value.
Take PI as an example. People very well understand what a PI is and how it can be delivered. Because of this, we do not argue what would happen if PI had a value of 3.15... not 3.14... In a Universe with different PI circles wouldn't be circles, atoms or planets would maybe collapse, but such deliberations do not make any sense because what PI represents enforces the only value that it can have. Maybe the same is true for the electric charge and other constants Hawking mentions?
- cristianpascu 14y agoMath and Physics are two very different realms. There's no a apriori reason for anything in the real world to obey a law or regularity. The fact that it does is amazing. The fact that we are able to think it's amazing is mind blowing. :)
- mixedbit 14y agoBut maybe as we acquire knowledge we will be able to explain why constant have given values. For example: the distance from Earth to the Sun during a given day of a year could in the past be considered a magic number. But today, thanks to Kepler, we understand why this distance has a given value and we know that it could not be different without changing the mass or velocities of bodies.
- kamaal 14y agoWe use mathematical language to explain things around us. Many of the mathematical 'truths' are based around this. If we saw different things mathematical truths would be totally different. You can assume anything to be true in Math and build a universe from that truth. A good book to read around this subject is Godel, Escher, Bach by Douglas Hofstadter
- ithkuil 14y agoPI has this particular value only in a particular geometry. http://www.learner.org/courses/mathilluminated/units/8/textbook/06.php#pi http://www.learner.org/courses/mathilluminated/units/8/textb... This is not just academic, the geometry of the space we are living into is not flat, and thus the PI we measure is not the one you'd expect. The effect of this space time distortion is what keeps you from floating around, and keeps the air you breath stick to the sphere you call home, which btw has that shape for the same reason. So, even though the PI value discrepancy caused by earth gravitational field is very small, it shapes our lives and our origins in a dramatic way.
- duaneb 14y agoWell, you are measuring two different things. Pi is not changing at all.
- ithkuil 14y agoexactly, same thing for α: if it were different (numerically) that would mean that we are talking about a different universe, i.e. we would measuring a different fine structure constant. People in that universe would still call it "α", because we define "α" to be the fine structure constant. That wouldn't change the (numerical) value of α in this universe. In the same way, we define PI to be "the ratio of a circle's circumference to its diameter", and that depends on the kind of geometry where you lay that circle on.
- hnriot 14y agoPI is not something that can be delivered? If you're trying to understand why constants have the value they do then you'd need to know more about physics and not mix up math and physics. Math is used to help understand the physical world, but math transcends physics. The universe need not even exist for math to still be whole and complete. Admittedly we probably wouldn't be in much of a position to appreciate it without a universe around to show how clever it all is. What you're alluding to is the anthropic principal.
- mixedbit 14y agoYou misunderstood me a bit. I gave PI as an example of constant that _can be_ delivered and it is well-understood why it has a certain value. I agree this wasn't a good example, PI is indeed mathematical constant, although it appears in physical equations.
- duaneb 14y agoPi is not a physical constant but a mathematical one; I.e. it can be derived a priori, without a physical universe. A physical constant would be Planck's, or the gravitational constant, or c. Those may well be "arbitrary" for all I know.
- vorg 14y agoc, G, and h need predefined measures of meter, second, and kg to be defined, whether or not they're "arbitrary". There true measure is 1, 1, and 1.
- eru 14y agoDepends. You can choose your measuring system to make some physical constants 1, but not all. And the choice is not obvious for all constants.
- mratzloff 14y agoWell, some multiverse hypotheses say that there are, in fact, other universes beyond our own that have different values, and that these values are random. Some of these may implode on themselves or expand too quickly for life, but we exist because the numbers for this universe were appropriate for creating life.