Here’s Diego Golombek talking about reading and wondering about time travel—an experience that, when he was a child, excited Diego in a way that led to his eventual unusual career. Diego now studies—and experiments with—biology to try to understand some of the seemingly simply, scientifically mystifying things that happen in nature every day.
This is part of a series of sessions we (David Hu and I, and a film crew) recorded at Georgia Tech. We assembled a little group of scientists (including David) who are renowned for looking at questions others might overlook, and doing research in inventive, clever ways.
The question we asked them: “What happened when you were a kid that somehow led—much later—to your doing unusual science?”
posted by Marc Abrahams in Arts and Science, Improbable Investigators | Comments Off on Innovative Scientists Talk About Their Childhood (8): Diego Golombek and Time
On a broad, bright, moonlit* night would you expect outdoor crime rates to be higher or lower than on an overcast night with little or no moonlight?
Numerous investigations have shown that, as a general rule, increasing environmental light levels can lead to a decrease in outdoor crime rates. By extension then, one might think that bright moonlit nights would feature less crime than when it’s overcast. But one might be wrong. A new study by Jacob Kaplan at the University of Pennsylvania – Jerry Lee Center of Criminology, and published via the Social Science Research Network comes to a conclusion that some might find counterintuitive.
“The findings indicate that a small amount of light can increase crime.
“Widely referred to as ‘spacer’ GIFs, these single-pixel, transparent GIFs were used first and foremost as a way of controlling the placement and presentation of content on a website. They were invisible, or rather transparent, i.e. whatever was behind them showed through. However, they still took up space. So a designer could encode into their HTML document any number of spacer GIFs to appear in a row in order to control the placement of any given element on a page. This provided a means of controlling exactly where visual elements would appear on a given web page. As is evident in Fig. 1, they only become visible when broken, when the link to the image file no longer resolves. These tiny files, the presence of which is only conspicuous when they are no longer present, are invaluable aids… enabling scholarly research on the history of the web.”
A Web Site of Its Own, Sort Of
Devotees of the spacer GIF are welcome to visit a web site devoted to the spacer GIF: spacergif.org
“Humans tend to swing their arms when they walk, a curious behaviour since the arms play no obvious role in bipedal gait. It might be costly to use muscles to swing the arms, and it is unclear whether potential benefits elsewhere in the body would justify such costs.”
If you’re a living thing, energy is a very precious resource. Not the sort of thing to be wasted. So it’s easy to jump to the conclusion that actively swinging your arms while walking could be squandering precious energy. But two experimental studies : Umberger, B. R. (2008). Effects of suppressing arm swing on kinematics, kinetics, and energetics of human walkingJ. Biomech. 41, 2575–2580, and Collins, S. H., Adamczyk, P. G. and Kuo, A. D. (2009a). Dynamic arm swinging in human walking.Proc. Biol. Sci. 276, 3679–88. showed that people who walk with their arms purposely held at their sides actually consume more energy rather than less, Nevertheless, excessive arm swinging could well be wasteful – leading to the question ; What is the optimum amount to swing one’s arms?
A new paper in the journal Biology Open addresses such a question – for the first time.
“ […] increasing arm swing amplitude leads to a reduction in vertical angular moment and ground reaction moments, but it does not lead to a reduction in cost of transport for the most excessive arm swing amplitudes. Normal or slightly increased arm swing amplitude appears to be optimal in terms of cost of transport in young and healthy individuals.“
The best energy efficiency was found to be an arm swing amplitude of between 0.3 and 0.6 m. Any swing above or below that (or walking with folded arms, or with arms swinging in-phase with the legs rather than the normal out-of-phase) increased energy consumption above normal levels.
The authors also note that :
“Independent of how arm swing is executed, it appears to play an important part during human locomotion. However, what this role is exactly, is still unknown”
