Tweet

This Thread may be Removed Anytime!

Twitter may remove this content at anytime! Save it as PDF for later use!

More from @seanmcarroll

Sean Carroll

@seanmcarroll

29 Sep

It is not a remarkable use of rationality to find justifications for opinions we already have or which reassure us. More impressive would be to use rationality to reach conclusions that discomfit ourselves.
nytimes.com/2021/09/29/boo…

Some folks like to celebrate the use of rationality to reach uncomfortable conclusions, but the discomfort usually seems to be for other people.

Of course others might want to find racism even where it isn't. That's why rationality is hard. The test of whether a conclusion makes us feel good or bad about ourselves is far from conclusive, but it's a reasonable first thing to check.

Read 5 tweets

Sean Carroll

@seanmcarroll

14 Mar

Dark matter exists -- an occasional reminder.

The first evidence for dark matter came from the dynamics of galaxies and clusters of galaxies. But these days that is not our *best* evidence. 1/n

For galaxies and clusters, you can imagine modifying gravity instead of positing dark matter. Every physicist and astronomer knows this. It is not a radical new idea. A number of people have built explicit models, and hundreds of people have thought about the possibility.

And it could potentially work, because in both cases you need only change the strength of gravity as a function of distance, not the direction of the gravitational force. Not natural from a field-theory point of view, but worth contemplating.

Read 17 tweets

Sean Carroll

@seanmcarroll

6 Jan

Personal news: I'll be leaving Caltech at the end of the next academic year. Caltech is great, and I've known wonderful people there. They would be happy for me to stay (as far as I know!), but this specific position is no longer a good fit for me, so I've decided to move on.

I honestly don't know where I will be next - there are possibilities, but various wave functions have not yet collapsed. But I'll still be writing physics papers and philosophy papers, hopefully doing real research in more interdisciplinary areas as well, from whatever perch.

And writing, talking, podcasting, etc. And still an external professor at Santa Fe. Things will be pretty much unchanged from an outside-world perspective. But it does mean I'm not taking on students or postdocs at the moment, sorry about that.

Read 6 tweets

Sean Carroll

@seanmcarroll

4 Jan

Idea: space-opera show where the crew is constantly forced to choose between saving people they love and serving the greater good. They choose loved ones every time, like existing shows. Twist is that every time, disaster follows and thousands die.

I mean, if the needs of the many outweigh the needs of the few, the few are going to get the short end of the stick from time to time, right? Let’s give that trolley problem some bite.

(Yes I know some shows do this.)

Read 4 tweets

Sean Carroll

@seanmcarroll

22 Nov 20

It just seems so *reasonable* to say "there might be some evidence, just let the process play out," whether the claim is "there was massive voter fraud" or "UFOs are alien visitors." But in many cases (like these) it's not reasonable at all.

Background knowledge matters. Truth claims don't float out in a vacuum, each to be judged independently. We know something about elections and the strategies of certain actors; we know about technology, perception, and motivated reasoning. That knowledge should inform our priors.

People valorize a certain puzzle-solving kind of intelligence. And solving puzzles is important. But the ultimate goal isn't to be clever, it's to be correct. For that, knowing what information to pay attention to and what ideas to take seriously is more relevant.

Read 7 tweets

Sean Carroll

@seanmcarroll

11 Nov 20

https://twitter.com/mcnees/status/1326542986184847361

Hugh Everett's birthday! Pioneer of the Many-Worlds Interpretation of quantum mechanics. Let us celebrate by thinking about ontological extravagance. I will do so by way of analogy, because I have found that everyone loves analogies and nobody ever willfully misconstrues them.

https://twitter.com/mcnees/status/1326542986184847361

We look at the night sky and see photons arriving to us, emitted by distant stars. Let's contrast two different theories about how stars emit photons.

One theory says, we know how stars shine, and our equations predict that they emit photons roughly uniformly in all directions. Call this the "Many-Photons Interpretation" (MPI).

Read 10 tweets

Share this page!

Sean Carroll

Try unrolling a thread yourself!

More from @seanmcarroll

Sean Carroll

Sean Carroll

Sean Carroll

Sean Carroll

Sean Carroll

Sean Carroll

Did Thread Reader help you today?

Like this author's thread?