Australasian Science: Australia's authority on science since 1938

An App Knows You Better than Your Real Life Friends

By Magdeline Lum

Facebook “likes” can profile your personality more accurately than your friends and co-workers.

An app on Facebook has proven to be a better judge of personality than close friends and family. A study led by a team of researchers at the University of Cambridge and Stanford University recruited 86,220 volunteers who provided access to their Facebook “likes”.

As part of this study the volunteers completed a 100-item personality questionnaire using an app called myPersonality, and self-reported personality scores that measured the five major personality traits – conscientiousness, extraversion, agreeableness, openness and neuroticism. More than 17,000 of this group had one family member or friend judge their personality traits from a 10-item personality test, while more than 14,000 were judged by two.

The results of the study showed that myPersonality could predict a user’s personality better than a co-worker based on just 10 Facebook likes. And when myPersonality went head-to-head with friends, the app came out top again – it was better at predicting personality traits than a friend who had been given 70 Facebook likes.

However, the app could not match family, requiring 150 Facebook likes to predict personality traits better than a parent or sibling, and 300 Facebook likes for a spouse.

The average Facebook user in this study liked 227 Facebook pages.

Physics of Beer Bottle Prank Akin to Deadly Eruptions

The physics of a bar prank known as beer tapping could lead to better understanding of lethal eruptions of gases. Beer tapping is where the top of a newly opened bottle of beer is hit, and within seconds foam gushes out along with the beer, creating a mess. What is also required is a victim with a sense of humour.

A group of physicists at Carlos III University of Madrid in Spain studied the formation and behaviour of bubbles during beer tapping. It sounds like a plot from The Big Bang Theory but this research has been published in Physical Review Letters.

The experimental set up involved beers, high-speed cameras, laser pulses and computational modelling. The bottles were tapped while high-speed cameras recorded the events before, during and after the beer tapping. The laser pulses were fired into the beer to provide a point of origin for bubbles to form to make the examination of data easier.

The scientists observed that the tap to the beer bottle creates compression and expansion waves that start from the point of impact and then move back and forth throughout the contents of the beer bottle. These waves cause bubbles to appear and also to collapse.

This was not all that was happening, as larger bubbles named “mother bubbles” would form. The mother bubbles would break up, leading to the creation of “daughter bubbles” that grow at a much faster rate than mother bubbles. Cascades of daughter bubbles form at a rapid pace, creating explosions of upward rising foam in a mushroom cloud shape towards the opening of the bottle. It takes a mere second for the plumes of bubbles to reach the size of the bottle they are in and overflow.

How do the observations of bubbles in a beer bottle relate to eruptions? There is a particular type of eruption known as limnic eruptions. These are rare events when dissolved carbon dioxide suddenly erupts from a deep lake. As carbon dioxide is denser than air, the odourless and colourless gas suffocates wildlife, livestock and people in the area as it dissipates.

A limnic eruption is thought to have released 90 million cubic metres of carbon dioxide, killing 1700 people and 3000 cattle. A better understanding of the physics of a limnic eruption could lead to better predictions of when one could occur and how much carbon dioxide could be released.

Another practical application of this work is the simulation of accidental releases of carbon dioxide from carbon sequestration wells where large amounts of the gas are dissolved in water and diverted to aquifers below the surface.