One aspect of experimental physics that I've always found interesting is the funny, specialized expertise that can be very hard to transcribe into a "Methods" section of a paper - the weird little tricks or detailed ways of doing things that can make some processes work readily in one lab that are difficult to translate to others. This can make some aspects of experimental work more like a craft or an art, and can lead to reputations for "magic hands", or the idea that a group has some "secret sauce".
An innocuous, low-level example: My postdoctoral boss had basically a recipe and routine for doing e-beam lithography on an old (twenty+ years), converted scanning electron microscope, plus thermal evaporation of aluminum, that could produce incredibly fine, interdigitated transducers for surface acoustic waves. He just had it down cold, and others using the same kind of equipment would have had a very tough time doing this at that resolution and with that reliability, even with all the steps written down, because it really was a skill.
Another possible example: I was talking today with an atomic physics colleague, and he mentioned that there is a particular isotope that only one or two AMO groups in the world have really been able to use successfully in their ultracold atom setups. The question was, how were they able to get it to work, and work well, when clearly other groups had tried and decided that it was too difficult?
Any favorite examples out there from readers?
10 comments:
Stm tips: etching and imaging. success rates are all over the place even for different folks in the same group using the same equipment.
I had a colleague working fruitlessly for a year to reproduce a pulsed laser deposition recipe reported in the literature. Then, at a conference, she asked the original author for any tricks. He mentioned that they used a very non-standard distance, which wasn't reported in the paper. When my colleague copied this, she was able to reproduce their results. So much wasted effort! All to save a paragraph or two of details in an online medium where space is effectively infinite. I don't want to be one of those people says scientific publishing is broken, but had this been a blog post with a comment section, it could have been resolved much faster, potentially.
I think it comes down to the fact that people don't really respect experimental physics enough to treat these things as something that should be published thoroughly.
Think about it, in principle one could write a publish a long document, with videos, photos, etc. to teach others how to do these processes. The reason we don't is that there simply isn't a motivation for doing it. It's a public good that everyone could use, but no one is willing to fund.
In my own group we take rigorous notes and videos of complex procedures to teach new students and postdocs. Although we are open to each other internally, I don't see any practical motivation for publishing these methods publically, nor even a proper venue to do so.
I think it's difficult to teach skills, whether that be cooking, flying aircrafts, etc. But as experimental scientists, we should be the best at figuring out how to teach experimental skills.
> but had this been a blog post with a comment section, it could have been resolved much faster, potentially.
https://scipost.org/SciPostPhys
Anon@2:08, that’s the idea behind the Journal of Visualized Experiments (https://www.jove.com/), but as you say, it’s very tough to capture skills rather than procedures.
@Douglas Natelson
I wouldn't say it's tough, I think it's more that the teaching it is tedious, with little payout at the end. Really it comes down to the fact that you really get nothing at the end except more skilled competitors (and have done some good for humanity...).
I've experienced this over and over. I and my current Department head have magic fingers. The post doc I worked with in grad school (Y. T. Lee) does ... but none of the other grad students in our group did. My own grad students, and the ones I had as my T.A.s had various degrees of them.
I've actually been able to analyze to some degree what enables magic fingers. First, one needs to have a feel for the various parameters, such as that "unusual distance", that matter. This comes from a wide knowledge of such things as ordinary mechanics, the laws of quantum mechanics, and a practical knowledge of electronics (such as I personally got from TV repair, Ham radio, and two years (at Rice) working as a technician on two mass specs using all vacuum tubes).
Second, one has to have the ability to tie these to the "clues" one sees when tweeking knobs on an apparatus. One needs to see correlations between the knobs and the signals, in multiple dimensions, and tie them to the physics. One's brain has to be "attuned" to these things. This is in some ways equivalent to seeing new and different ways of doing math proofs.
A good example is our own undergrad P. Chem lab in which we have a homemade ICR mass spec and a very old standard LEED/Auger apparatus. These have lots of knobs. The students eventually get the hang of the LEED, all of them. The T.A.s easily learn it. But the Auger is different. I've tried to explain to numerous T.A.s over the years how to set it up from scratch, explaining how everything ties together, and illustrating them. But the analog lock-in we use is just too complicated! They understand the principle, but how to set it up so that the (very weak!) signal makes it through the whole thing without clipping in the intermediate stages seems to elude them. It's just too much to expect them to learn how to understand practical electronics! I suspect that digitizing the signal and references with a really good pro-grade 24 bit audio system and computer processing would fix this, but somebody who understands would have to write the computer program.
The home-made ICR is complicated, but eventually we generated a cook-book procedure that works, though it took lots of feedback from students. They have to be able to recognize the non-linear effects of space charge and how to get use it to get big signals.
Example: all nanoparticle synthesis.
There are people with natural talent for working with their hands, and others without. For those that can't naturally, they just need to a good coach and a lot of practice, just like any trade out there. Let's not be lazy and give up on good coaching and lots of practice.
I think it is a non scientific topic. It actually demonstrates that the "magician" does not understand the trick (if it can not be explained and thought to others). I remember Batlogg from the Schon case, saying how magical is their deposition machine...
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