As I said about a week ago, I'm enjoying theoretical physicist Matt Strassler's book, Waves in an Impossible Sea: How Everyday Life Emerges from the Cosmic Ocean.
I've made my way through chapters about Motion, Mass, and Waves. Then I'll get to read about Fields, Quantum, Higgs, and Cosmos. Strassler is an engaging writer. He makes science readable, though it still takes some work to grasp his core points.
One of the things I most enjoy about the book are the facts about the world based on physics that I either never knew, or once knew and needed reminding about. For example...
-- While weight usually is closely associated with mass in everyday life, weight and mass are very different on the moon. There the human body weighs much less than on Earth, but if someone tries to throw a brick on the moon, it would take just as much effort as on Earth, since mass is unchanged by reduced gravity.
-- Rest mass is different from relativistic mass. If an object is stationary, and so is the person measuring the mass of the object, this rest mass will be an objective quality that everyone agrees on. However, if an object is in motion, or an observer is, the theory of relativity shows that the relativistic mass will be larger than the rest mass. A proton accelerated to full speed inside the Large Hadron Collider has a relativistic mass thousands of times greater than its rest mass.
-- If the moon somehow stopped moving, it would fall toward the center of the Earth under the influence of gravity. If the moon was moving more rapidly, it would escape Earth's gravity and soar away from our planet. As it is, in common with all the other planets and moons in our solar system, the moon is delicately balanced at the exact point where it continually falls toward Earth but never moves either toward Earth or away from Earth. Hence, it orbits.
-- Nothing is required to maintain the moon in its orbit around Earth, or Earth in its orbit around the Sun. Since there is no friction in space, and an object in motion maintains that motion unless something interferes with it. the moon and Earth will keep on orbiting forever -- at least, until the Sun expands into a giant fireball that will obliterate our planet many billions of years from now.
-- A pendulum clock (my mother had one, probably from my grandmother) is able to keep accurate time even as the non-electric spring mechanism powering the clock winds down because the frequency of a pendulum, how often it swings, remains the same even as its amplitude, how widely it swings, changes. This is a basic feature of the universe, as waves such as electromagnetism have the same feature: a constant frequency and inconstant amplitude. If this wasn't the case, music would be impossible, since the pitch (if that's the right word; I'm not musical) of a note would change with volume.
Strassler writes about how science provides truths about reality that our senses are clueless about.
Many other scientific instruments, including various kinds of telescopes, not only magnify an object but convert an invisible phenomenon into a visible image. Nor is this limited to sight: an ordinary radio is a device for turning radio waves, a form of invisible light, into sound waves that our ears can hear, while an ultrasound scanner converts unheard sound into a visible-light image.
We use sensory enhancements every day without even thinking about it, making use of features of the world that not long ago lay beyond our grasp.
People who claim to believe only what their senses tell them are missing out on the vast majority of what there is to know in the universe. They are also deceiving themselves. After all, even a cell phone exploits the unseen and unheard and unfelt. The fact that modern gadgets seem like magic, making use of the universe beyond human senses, points out yet again the weakness of common sense in the physical world.
I liked how Strassler makes the same point that other scientists do: that evolution is aimed at enhancing reproductive fitness, not at revealing truth. For that, we need science.
Nevertheless, what we experience as ordinary existence is an illusion created for us by our brains. It is based on the interaction of our senses with the physical world, not on the physical world directly. The illusion has to help us survive in the real world, so it had better have something to do with reality; it needs to inform us when there's a fruit tree or a hungry tiger nearby.
But beyond that, there's no reason that it needs to be scientifically accurate. The reason that many objects in the world seem opaque and impenetrable is this: for most practical purposes in human life, they act as though they are. But while evolution focuses on what is practical, physics is about what is real, and there's no reason they should agree.
...All of our sensory organs take in information only when it reaches our bodies, not before. What they learn is then used by our brains to gain some idea of the objects around us and to create for our consciousness a picture of the outer world.
We experience that picture as though it were reality, unaware or forgetful of the fact that it is a partial reconstruction of the outside world and in no sense a direct image of it. Everything we know of the environment around us is both indirect and incomplete.
That was a great post, loved it!
Not because any of that was new per se, but I loved the sheer sense of the wonder that is the world, and the wonder that is the human endeavor to understand it all generally, and science particularly, that your quotes so well express and celebrate, and you as well in your commentary, Brian.
And it was fascinating properly going through out those specifics as well. While none of them was new per se, but it was still fun to properly think through each of those specifics.
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And one of those specifics required me to brush up a bit, stuff learned a long time ago, back when the world was young. The part about mass increasing when your velocity increases. Does mass increase, or does it decrease? And why does it do that, exactly, per relativity principles? Afraid I couldn’t clearly think that through on my own steam, not to my satisfaction. And I had to look it up.
Here’s why, the basics of it (for the benefit of those whose basic grasp of relativity might have gotten rusty, as mine has):
Link: https://bigthink.com/hard-science/speed-of-light/
And here’s another brief article that discusses this with a bit more nuance, and with just a wee bit of math thrown in. (Only very basic math, nothing to get scared about, not even if your grasp of all this has gone all rusty, like mine has.)
(It’s a simple enough article, and short enough, but ideally read the one above first, and then this. Assuming your de facto starting point is as basic on this specific as mine was.)
Link: https://www.wtamu.edu/~cbaird/sq/mobile/2013/06/18/can-you-go-fast-enough-to-get-enough-mass-to-become-a-black-hole/
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And that bit, about how a pendulum’s frequency does not change as its amplitude does? That’s straightforward enough, but I completely loved the specific everyday example there that illustrates and explains that principle. I mean how the pitch of a (musical) note is not affected by volume.
(That’s an example I’ve not heard before, and yet it’s so very apposite. Or maybe I *have* heard it discussed, back when, and have ended up completely forgetting it. Either way, loved it.)
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Science is a truly wonderful thing. It’s a pity most students are not fired with the beauty of it when they’re actually being taught it. I know I wasn’t, back when. I mostly studied it back then as something not particularly unpleasant, and certainly looked to it as knowledge whose utility and necessity there was no doubt about; but not as something remotely inspiring. It was philosophy that fired me up then, including religious philosophy and theology as well. Which is good, which is great; but my point is, the fact that science speaks to exactly those very same questions, except it speaks to them so much more reliably and sensibly and coherently, is a fact that most students do not end up grokking, as I had not, back then. The true wonder that is science is something I had to rediscover all over again, much later. …In my/our defense, rarely is science actually taught in those terms, nor really appreciated in those terms by most workaday teachers and professors, so no surprise really.
Posted by: Appreciative Reader | October 12, 2024 at 09:15 AM
I just now revisited my comment, in order to check out those two articles one more time. (I'd only speed-read through them, given time constraints, and while that was adequate enough for my purpose, but I wanted to make sure now, over a more careful read, that I wasn't going away misreading anything.)
Haha, how right you are, Brian, to title your post as you do. Absolutely, common sense is indeed a poor guide to objective reality, particularly such of it as lies well beyond the scope of experiences us homo sapiens evolved to deal with.
Just to point out one very obvious fallacy that, despite how obvious it is, I've personally seen asked, and in fact been asked myself, many times, both IRL as well as in comment conversations right here. That fallacy goes something like this: Your big bang is completely weird, your quantum whatsis is completely crazy, so why reject my particular beliefs --- about the Trinity, about God generally, about sonny boy getting skewered on the cross to save us, about Advaitic Brahma/Oneness, about yogic superpowers, and so forth --- even though my pet beliefs are no more crazy than yours, and in some cases less crazy and offers a more complete explanation all things considered?
Yes, I know. Completely utterly obvious. And yet, so many do, in all seriousness, think this and voice this.
The answer to that simple puzzle is straightforward, and twofold:
1. First, how crazy a proposition sounds is irrelevant. More crazy or less crazy doesn't matter. Because, and as you point out, intuition is a poor guide to objective reality.
2. And two, because evidence!
Heh, this is so elementary that it may appear like strawmanning to even mention this. And yet many's the time I've personally been asked this, both IRL as well as right here; and even more times seen this asked in serious discussions.
No, the fact that QM is weird, or the fact that the BB leaves many questions unanswered, does NOT mean that that lets open an opening for either random speculations or for detailed structured but completely unsupported theology.
Posted by: Appreciative Reader | October 12, 2024 at 09:59 PM