As well as floating balloons and making your voice sound funny, helium plays a crucial role in science and medicine – thanks to its cryogenic properties. Although the second most abundant element in the universe, helium is rare on Earth because it is much lighter than air. Helium is produced deep underground by the radioactive decay of uranium and thorium. As it rises to the surface it can become trapped in the same geological features that contain natural gas – from which helium is extracted. For various reasons, the helium industry is currently in a state of flux and medical and scientific users of the gas are concerned about future supply problems – which some worry could be exacerbated by “frivolous” uses of helium such as in balloons. As a result, some in the helium user community are celebrating today as “Helium Conservation Day”. Introduced last year by the company Quantum Design, it falls on the anniversary of the first liquefaction of liquid helium, which was done in 1908 by the Dutch physicist Heike Kamerlingh-Onnes. The above video from Quantum Design explains the importance of helium conservation.
You’ll be delighted to know that researchers have revisited a classic problem in the animal kingdom: why can penguins poo such large distances? The discovery was made in 2003, when researchers from Germany, Finland and Hungary – who bagged an IgNobel prize in 2005 for their efforts – found that some penguins can fire their excreta as far as 40 cm, allowing these aquatic birds to continue to nurture their eggs without sitting in a sea of faeces. Now researchers in Japan have modified this pooping model to calculate the maximum distance that a penguin could manage to fling their dung when at a certain height. Thanks to the penguins’ “strong rectal pressure”, which they calculate to be higher than previous work, the team finds that the maximum distance is 1.34 m, beyond which lies the “safety zone”. The team says this information could be “useful” for zookeepers, who want to avoid getting hit by the firing faeces. So next time you visit the penguin enclosure – do remember to keep your faecal distancing. Spaghetti has long fascinated physicists. In 2005 French physicists used computer modelling and high-speed photography to explain why dried spaghetti usually breaks in two places when bent. The next big pasta breakthrough came in 2018, when researchers in the US came up with a way of ensuring that a bent piece of dried spaghetti only broke in one place – by twisting it.
Now, Fathan Akbar and Mikrajuddin Abdullah of the Bandung Institute of Technology in Indonesia have shown that bending dried spaghetti in the presence of steam reveals a smorgasbord of information about the pasta’s material properties. The duo cantilevered horizontal spaghetti strands over a pot of boiling water and observed their sagging using a video camera. They also did a similar experiment using vertical columns of the pasta. They found that the Young’s modulus (a measure of stiffness) of the spaghetti decreased exponentially in time with steam exposure. This was linked to the rate at which water diffused into the spaghetti and the duo suggest that their technique could be used as a general way of measuring the rate of diffusion of vapour molecules into materials.