More on this book
Community
Kindle Notes & Highlights
Read between
August 9 - October 13, 2022
Physics is a science and as such has the purpose of describing observations of natural phenomena. Yes, we use mathematics in physics, and plenty of that, as I’m sure you have noticed. But we do this not because we know the world is truly mathematics. It may be mathematics—this possibility is known as Platonism, but Platonism is a philosophical position, not a scientific one. All we can tell from observations is that math is useful to describe the world. That the world is math—rather than just being described by math—is an additional assumption. And because this additional assumption is
...more
Physicists may not consciously subscribe to the idea that math is real and when asked will deny it, but in practice they do not distinguish the two. This conflation has consequences, for they sometimes erroneously come to think their math reveals more about reality than it possibly can.
Postulating that all math is real is such an unscientific, superfluous assumption—it doesn’t help us describe nature any better. But just because there’s a lot of math that we don’t need doesn’t mean it does not exist either. Postulating that it doesn’t exist is also superfluous to describing our observations.
Science is about finding useful descriptions of the world; by useful I mean they allow us to make predictions for new experiments, or they quantitatively explain already existing observations. The simpler an explanation, the more useful it is.
I personally find the second law of thermodynamics highly suspect and don’t think conclusions drawn from it today will remain valid when we understand better how gravity and quantum mechanics work.
imagine your perception of time as a collection of photographs in different stages of fading. The moment you call Now is the photograph that’s least faded. The more faded a photograph is, the more it is in the past. You don’t have photographs of the future. At each moment, the Now is your most vivid, most recent photo, with a long trail of fading snapshots behind it and a blank for the future.
Throughout our lives, we repurpose atoms that previously belonged to other animals, plants, soil, or bacteria, atoms that were created in the Big Bang or by stellar fusion. A carbon-dating study in 2005 found that the average cell in the adult human body is only seven years old. Though some cells stay with us pretty much our whole life, skin cells are on average replaced every two weeks, and others (like red blood cells) are replaced every couple of months.
A good scientific hypothesis is one that is useful for calculating the outcomes of measurements. You can therefore tell whether a hypothesis is any good just by looking at whether scientists actually—and successfully—use it to calculate measurement outcomes.
I realize that physicists have a reputation of being narrow-minded. But the reason we have this reputation is that we tried the crazy stuff long ago, and if we don’t use it today, it’s because we’ve understood that it doesn’t work. Some call it narrow-mindedness; we call it science. We have moved on.
Most hypotheses for the early universe, for example, are just complicated stories that are unnecessary to describe anything we observe. The same goes for attempts to find out why the constants of nature are what they are, or theories that introduce unobservable parallel universes. This isn’t science. It’s religion masquerading as science under the guise of mathematics.
Scientists are often—all too often—required to justify their research by demonstrating practical applications. But we have another reason entirely for our research: the desire to make sense of our own existence.
All currently known evolution laws in the foundations of physics are differential equations.
It wasn’t Lisa Randall.
