This is a quick post to highlight an excellent new PDF reader on macOS called PDF Guru (iTunes store). It is a recently revamped version of PDF Reader X.
I’ve only used it for a week, but it’s the best PDF reader I’ve experienced for reading academic articles. It’s snappy and reminds me of Chrome when it first came out. Draggable tabs. Split view. Plays well with Zotero. Can easily add native PDF annotation and search through the existing ones. (And it saves annotations fast when you close the file.Competitors either do this slowly or, like Skim, use a non-native annotation format that can’t be read by other PDF readers.a ) The UI for “find” displays a lot of info intuitively.Edit 2018-1-12: And you can search for any unicode character! Really useful for searching a document for math.b Everything is just nicely designed. I haven’t yet run into a limitation on the free version, but it’s worth upgrading to Pro to support the developer (only $20).
Beware that this is the first version following a big re-write of PDF Reader X, and it’s not completely stable. I’ve gotten it to crash a few times, but the developer has been very responsive to feedback and I’d wager on the stability improving soon. (Edit 2018-1-7: After upgrading to the new version, 3.0.20A, a couple weeks ago, I haven’t experienced any crashes. Looks stable.)
I’m advertising Guru because I think the current selection of PDF readers for academic reading is pretty bad.I have no connection to the developer.c I strongly prefer Guru
(instability and all) over these other PDF readers on maxOS that I have tried: FoxIt, Preview, Adobe Acrobat Reader, and Skim.… [continue reading]
The Perimeter Scholars International (PSI) program is now accepting applications for this Master’s program, to start next fall. The due date is Feb 1st. Me previously:
If you’re in your last year as an undergrad, I strongly advise you (seriously) to consider applying. Your choice of grad school is 80% of the selection power determining your thesis topic, and that topic places very strong constraints on your entire academic career. The more your choice is informed by actual physics knowledge (rather than the apparent impressiveness of professors and institutions), the better. An additional year at a new institution taking classes with new teachers can really help.
Here’s the poster and a brand new propaganda video:
… [continue reading]
One of the main sources of hubris among physicists is that we think we can communicate essential ideas faster and more exactly than many others.This isn’t just a choice of compact terminology or ability to recall shared knowledge. It also has to do with a responsive throttling of the level of detail to match the listener’s ability to follow, and quick questions which allow the listener to hone in on things they don’t understand. This leads to a sense of frustration when talking to others who use different methods. Of course this sensation isn’t overwhelming evidence that our methods actually are better and function as described above, just that they are different. But come on.a Robin Hanson‘s Age of Em is an incredible written example of efficient transfer of (admittedly speculative) insights. I highly recommend it.
In places where I am trained to expect writers to insert fluff and repeat themselves — without actually clarifying — Hanson states his case concisely once, then plows through to new topics. There are several times where I think he leaps without sufficient justifications (at least given my level of background knowledge), but there is a stunning lack of fluff. The ideas are jammed in edgewise.
Academic papers usually have two reasons that they must be read slowly: explicit unpacking of complex subjects, and convoluted language. Hanson’s book is a great example of something that must be read slowly because of the former with no hint of the latter. Although he freely calls on economics concepts that non-economists might have to look up, his language is always incredibly direct and clear. Hanson is an academic Hemingway.
Most of what I might have said on the book’s substance was very quickly eclipsed by other reviews, so you should just read Bryan Caplan, Richard Jones, or Scott Alexander, along with some replies by Hanson.… [continue reading]
I thought this criticism by Ars Technica of the woeful state of Wikipedia’s science articles was mostly off the mark. (HN Comments.) The author framed it as a conflict between laymen and specialists, claiming that scientific articles are targeted at specialists at the expense of laymen, with lots of jargon, etc. I eagerly agree with him that there are lots of terrible science articles, and that some technical articles could use better context and introductory bits. But I think this is largely a problem of not having enough skilled science writers rather than a purposeful choice between laymen and specialists. Due to the curse of knowledge the specialists literally do not understand what is and isn’t accessible to laymen; they see through the jargon like the matrix. And the laymen do not get in their gut how many true technical dependencies there really are, that unless you understand topics X and Y, topic Z is pretty much useless. They assume that all this jargon is used by the specialists either because they are too lazy to translate, or are purposefully constructing barriers to entry. I empathize with skilled science writers (which are unfortunately rare), because their best articles often go unnoticed as both laymen and scientists read them and shrug “Yea, that’s pretty clear. Was that really so hard?”.
The examples used in the editorial, like “Rabi oscillation“, are the sort of scientifically deep topics, with many dependencies, that one will never be able to write more than a few layman-accessible sentences about. If you don’t know what a Hilbert space is, there’s just not that much to say about Rabi oscillations.… [continue reading]
[Just shooting from the hip here, for fun.]
I think we should send humans to Mars, but I don’t really think it’s possible to justify it as an instrumental means of achieving other more concrete goals. (I just take it as an intrinsic goal.) But here is Robert Zubrin making the best instrumental case I’ve heard.
My biggest criticism is that not finding evidence of life on Mars does not imply life is extraordinarily rare, because there are other options besides easy-starting life (with the great filter somewhere after) and extremely-hard-starting life. If you think it’s possible that there’s a filter strong enough to prevent single-cell life from developing interstellar travelI’m skeptical. When it comes to estimating extremely unlikely events, with multiple independent unlikely steps that all need to happen quickly, the development of the first replicator seems to require vastly more steps than relatively simple things like sexual reproduction. The only thing that makes me uncertain is the possibility that there are extremely simple replicators that resemble nothing like minimal cells, and there is a relatively natural progression to minimal cells that simply isn’t large enough to leave fossils. I would love to update on this if you know something I’m not thinking of.a , then it’s still very possible that single-cell life is hard-enough to start that we wouldn’t expect to find it on Mars, yet is still relatively common in the galaxy. Indeed, it’s easy (assuming a strong late filter) to imagine that life is easy to start with liquid water plus X, where X is a relative common planetary condition that just has never existed on Mars.
That said, Zubrin’s argument is better than I was expecting, and I agree that getting a quasi-definitive answer on whether there was ever life on Mars — even with my strong prior against it — is probably the best new evidence we are likely to collect for a very long time with regard to the prevalence of life in the universe.… [continue reading]
If you’re a fellow nerd, you know that New Horizons is bearing down on Pluto. It had a scary hiccup a few days ago but recovered quickly. Closest approach occurs on Tuesday.
The data connection from Pluto is very slow (~1kbit/s, I believe). Furthermore, the one-way latency is over 4 hours, and the spacecraft can’t transmit to Earth at the same time it is photographing. So to a good approximation, the encounter will take place over just a day or two of near radio silence, followed by several months of images and other data slowly dripped back. (New Horizons can’t see much once it’s gone past Pluto since everything will be dark, other than a few measurement of the atmosphere by looking at sunlight passing through it.) For excellent details and links about what you can expect to see when, look here and here. For a nice Wikipedia-level PDF, see here, and for an infinite rabbit hole of message board links, see here.
Added: New image, still well below the max resolution we will eventually see.
Added: New Horizons survived the encounter.… [continue reading]
I often hear very smart and impressive people say that others (especially Americans) who don’t travel much have too narrow a view of the world. They haven’t been exposed to different perspectives because they haven’t traveled much. They focus on small difference of opinion within their own sphere while remaining ignorant of larger differences abroad.
Now, I think that there is a grain of truth to this, maybe even with the direction of causality pointing in the correct way. And I think it’s plausible that it really does affect Americans more than folks of similar means in Europe.Of course, here I would say the root cause is mostly economic rather than cultural; America’s size gives it a greater degree of self sufficiency in a way that means its citizens have fewer reasons to travel. This is similar to the fact that its much less profitable for the average American to become fluent in a second language than for a typical European (even a British). I think it’s obvious that if you could magically break up the American states into 15 separate nations, each with a different language, you’d get a complete reversal of these effects almost immediately.a But it’s vastly overstated because of the status boost to people saying it.
The same people who claim that foreign travel is very important for intellectual exposure almost never emphasize reading foreign writing. Perhaps in the past one had to travel thousands of miles to really get exposed to the brilliant writers and artists who huddled in Parisian cafes, but this is no longer true in the age of the internet. (And maybe it hasn’t been true since the printing press.)… [continue reading]
It seems to me that I can accurately determine which of two people is smarter by just listening to them talk if at least one person is less smart than I am, but that this is very difficult or impossible if both people are much smarter than me. When both people are smarter than me, I fall back on crude heuristics for inferring intelligence. I look for which person seems more confident, answers more quickly, and corrects the other person more often. This, of course, is a very flawed method because I can be fooled into thinking that people who project unjustified confidence are smarter than timid but brilliant people.
In the intermediate case, when I am only slightly dumber than at least one party, the problem is reduced. I am better able to detect over-confidence, often because I can understand what’s going on when the timid smart person catches the over-confident person making mistakes (even if I couldn’t have caught them myself).
(To an extent, this may all be true when you replace “smarter” with “more skilled in domain X”.)
This suggests that candidate voting systems (whether for governments or otherwise) should have more “levels”. If we all want to elect the best person, where “bestness” is hard to identify by most of us mediocre participants, we would do better by identifying which of our neighbors are smarter than us, and then electing them to make decisions for us (possibly continuing into a hierarchy of committees). This is an argument for having federal senators chosen by state legislatures.
Of course, there are many problems with additional levels, e.g. it is difficult to align incentives across just two levels.… [continue reading]