This is an extract from the OPIP book. Previously, B(obby) argued to A(lice) that the new discoveries in fundamental physics will be massively surprising. To generate ideas for these discoveries, we should identify the “blind spots” in our thinking (also see “What’s the Problem?”).
A: I have another idea about how we could avoid blind spots: we just conduct more experiments. Blind spots happen mainly in the mind, so if we ask nature directly, it will point us to what we missed.
B: This raises the question of whether progress in physics is more likely to come from the theoretical or experimental side.
A: Which one do you lean toward?
B: I’m also defining the titles of the chapters, so you can easily see wes Geistes Kind[1] I am.[2]
A: I’m not a child of that spirit.[3] A theory holds no value until confirmed in practice. You could also replace “practice” with “reality.” What’s the goal of physics other than achieving confirmed explanations of our reality?
B: You’re right, experiments play a crucial role. I am now thinking more about the initial spark that leads to new discoveries.
A: There are plenty of those from experimental physics too. In 1897, while working on cathode ray tubes, J.J. Thomson discovered that these rays were composed of previously unknown negatively charged particles. These were later named electrons. In 1911, Rutherford directed alpha particles at thin gold foils. He expected them to pass through with only slight deflections. However, some bounced back, refuting the “plum pudding model” prevalent at the time, leading to a new model for the atom: a tiny, positively charged nucleus containing most of the atom’s mass, with electrons orbiting it. Additionally, the discoveries of X-rays in 1895, superconductivity in 1911, and the cosmic microwave background radiation in 1965 are only a few of the many other examples.
B: That’s true, but such discoveries are becoming rarer. We’ve already discovered quite a lot, so the chances that shooting into the dark will reveal new insights are decreasing.
A: Maybe, but again it feels like you’re not giving experimental physics enough credit. Let’s take another example. Before Galileo, the prevailing belief was that heavier objects fall faster than lighter ones. That’s also what Aristotle said, and who are you to question Aristotle? It’s also in line with our intuition. Galileo challenged this, asserting that the mass of objects doesn’t affect their rate of descent. What other way to prove it than climbing the Tower of Pisa and letting objects fall?[4]
B: What a coincidence that you mention this case. It’s a beautiful example of how thinking alone can get you all the way.
A: How?
B: Let’s assume for a moment that heavier objects do fall faster. What if the object cracks up during the fall, so it’s now two pieces that are falling. As each of them has half the weight, they should fall slower according to that theory, right?
A: I guess so.
B: And that cracks me up too. But it gets even more ridiculous. Assume the objects rejoin. That should speed up their fall again, right? If so, how exactly do we define them being “one piece” again? Is tying them together sufficient? What about a string between them? Would glue do it? If so, would regular glue work or does it have to be super glue?
A: I get your point. Right, it doesn’t make sense.
B: No experiments are needed in this case. One can conclude that mass cannot influence the falling speed just through logical reasoning. The final experiment is only for those who believe it has to be super glue.
A: This may be so in this case, but it’s not always so, right?
B: Saying “always” is almost (!) always risky. All I can say is that it’s more often than we think. There is a level of “making sense” that doesn’t leave much doubt about whether it’s true.
A: Until an experiment refutes it.
B: Yes, provided the experiment is correct. Not only thinking can be wrong, but experiments too. In his TED talk from 2007[5], Murray Gell-Mann recounts how he and his colleagues put forward a theory (of the weak force) that was in disagreement with 7 (seven) experiments. They still pursued the theory as it was so beautiful. They were vindicated, and all experiments turned out to be wrong.
A: What are the practical implications of this?
B: If it’s true that sound theories don’t leave much doubt that they are right, then there isn’t a need to spend too much time and money on testing highly speculative theories. The final experiment should feel like just a formality. If it doesn’t, it has too much “hope” mixed into it. That almost always spells trouble, be it in physics, the stock market, chess or anywhere else. I wouldn’t go as far as Nietzsche, who said, “Hope in reality is the worst of all evils because it prolongs the torments of man,” but the more we rely on hope, the fewer rational arguments may be on our side.
A: So let’s keep thinking until it really makes sense.
B: Right. Pen and paper can go a very long way.
Read the entire book by getting your own, personal copy.
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[1] There doesn’t seem to be an English equivalent for the German phrase “wes Geistes Kind” someone is. It symbolizes a person’s mindset, character or beliefs (Geist = spirit, Kind = child) which are expressed indirectly through their words and actions. While the typical author’s reaction might be to find a close English equivalent, this book is all about leading and innovating, so here’s the attempt to introduce another German word into the English language (joining Gesundheit, Schadenfreude and others; we failed by force (Blitz), so let’s conquer English territory like this, hehe.) This reminds me of the story of the two shoe salesmen sent to Africa in the late 19th century to assess the market for shoes. One telegraphed back, “No market here—nobody wears shoes,” while the other excitedly reported, “Glorious opportunities—they don’t have any shoes yet!” It’s always a matter of perspective.
[2] With respect to titles giving away a story without the reader immediately realizing, a good example in literature is Ambrose Bierce’s short story “An Occurrence at Owl Creek Bridge”.
[3] If you don’t understand what this means, you should start reading footnotes. Although, I’m not sure how much sense there is in this footnote addressed to non-footnote-readers.
[4] The story of Galileo dropping objects from the Leaning Tower of Pisa is widely regarded as apocryphal or at least unverified. But it’s a nice picture.
[5] Murray Gell-Mann: Beauty and truth in physics.
