Hi folks,

I am a bit confused about a citation given in this opinion piece and ask for your help. In paragraph 5, the author mentions the effect of manual labor and cites an article published in the International Journal of Surgery Oncology. In this article they state that:

"Adults working in unskilled manual profession are over 4 times more likely to be classified as morbidly obese compared with those in professional employments",

and they show a graph to support this. However, the graph seems to show the opposite. I looks like males who perform manual labor have a lower prevalence of obesity than those of non-manual labor. Am I reading this wrong?

You're not wrong. The graphs (figures 7 and 8) don't match the numbers. I think the graphs are mislabeled.

But even if the graphs are mislabeled, the numbers don't agree with the statement. The 2010 data for prevalence of obese men shows an increase from 27% to 29%... without error bars given. In what world does that translate to "over 4 times more likely to be classified as morbidly obese"?

I would guess it's more like environmental temperature leads to behavioral changes that then affect the average energy expenditure.

In addition to the other comment suggesting yoga for back pain, I might recommend you see a physiotherapist. You want not only stretching but also strengthening and it's difficult to figure this stuff out yourself. In my case, I found out I had no idea how to correctly activate my transversus abdominis, which is a muscle that should be active during all waking hours to support the spine.

For a textbook where the author does a brilliant job of introducing a complex topic:

Spacetime and Geometry an Introduction to General Relativity by Sean Carroll.

Also the textbooks by David Griffiths and Gill Strang mentioned in other comments.

I didn't learn electronics with this book, but I really wish I did. I used it to give tutorials for an undergraduate electronics course for physics students and it was immensely useful and well organized.

The work book that goes along with it is also top notch.

You could also check out Sean Carroll's Spacetime and Geometry. It's my favorite textbook.

Supplement with the second half of Wald's book for exploring some concepts

Sugar is common for curing meats like bacon. I don't know if it plays a role in pulling out the water like salt does, but I know some use it to offset the strong saltiness. I think it also provides for some bacteria which help preserve the meat.

I guess an important point to make is how easy it is to consume a sugary drink. I can very easily sit down and drink a tall glass of orange juice but not so easily could I sit down and eat the six oranges that would be used to make that oj.

I just ate 3 carrots and I definitely don't feel for a 4th.

Meanwhile, I'd have to eat 3 pounds to equal a bottle of coke: http://www.sugarstacks.com/carrots.htm

Pretty crazy. And eye-roll inducing when people bring up sugar in vegetables/fruits. As if it's your apple habit keeping you wide.

I believe he was often very silent about political or ethical matters of the "The Gadget". In contrast to other physicists at the time, like Oppenheimer and Szilard.

Hey great work. Electron beam technology has quite an interesting history and has been used for many applications.

I work at an atomic physics research institute and am currently building an electron beam ion trap. We use a compressed electron beam to ionize atoms into a highly charged state and then use these ions to observe things like electronic structure of the atom and quantum electrodynamic effects. We have an electron gun that can be biased up to 60 kV and we have a 7 Tesla superconducting coil combined with some einzel lenses to guide and compress the electron beam into the trapping area where we ionize the atoms.

I've never thought to bring my work home with me but this would be a really really cool project to undertake. Thanks for sharing.