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What was going on with our brain organoids? As neuroscientists , we use these three-dimensional clusters of cells grown in petri dishes to learn more about how the human brain works. Researchers culture various kinds of organoids from stem cells – cells that have the potential to become one of many different cell types found throughout the body. We use chemical signals to direct stem cells to produce brain-like cells that together resemble certain structural aspects of a real brain . While they are not “brains in a dish” – organoids cannot function or think independently – the idea is that organoid models let scientists see developmental processes that may yield insights into how the human brain works. If researchers better understand normal development, we may be able to understand when and how things go wrong in diseases. When we recently compared our lab’s organoid cells to normal brain cells, we were surprised to find that they didn’t look as similar as we’d expected. Our bra...

Fear of missing out, or FoMO , is commonly described as that anxious feeling you get when you think other people might be having a good time without you. Excessive FoMO is closely related to symptoms of behavioural addiction . It often leads to undesirable behaviour such as the constant checking of social media, even in an inappropriate context, like while driving, and becoming overly preoccupied with reactions to online posts and messages. Our new research has identified the main triggers of this psychological phenomenon, the contexts in which it happens and the types of fears involved in it. We have also suggested new design features which social media platforms could introduce to minimise this most modern form of social anxiety. Humans are fundamentally social creatures. Our identity, beliefs and behaviours come from and are shaped by our interactions with others. From those we know well, to fleeting moments of eye contact with the strangers we walk past on the street. Previous...

DNA evidence often isn’t as watertight as many people think. Sensitive techniques developed over the past 20 years mean that police can now detect minute traces of DNA at a crime scene or on a piece of evidence. But traces from a perpetrator are often mixed with those from many other people that have been transferred to the sample site, for example via a handshake. And this problem has led to people being wrongly convicted . Scientists have developed algorithms to separate this DNA soup and to measure the relative amounts of each person’s DNA in a sample. These “ probabilsitic genotyping ” methods have enabled forensic investigators to indicate how likely it is that an individual’s DNA was included in a mixed sample found at the crime scene. And now, more sophisticated artificial intelligence (AI) techniques are being developed in an attempt to extract DNA profiles and try to work out whether a DNA sample came directly from someone who was at the crime scene, or whether it had just ...

Rats have up to 70 whiskers on their faces, varying hugely in size and shape. Almost every mammal possesses whiskers, but these rodents are what we call “whisker specialists”, meaning they have super-sensitive, moveable hairs that they use to explore and sense their surroundings. Rat whiskers can vary hugely. In our recent research, my colleagues and I analysed 523 whiskers from 15 rats and found that each whisker had a different length and shape. We wanted to investigate more about the shape of these hairs as a first step in understanding what rats feel through their whiskers. [embedded content] Rat whisker movements. We found that rat whiskers can be accurately described by a simple mathematical equation known as the Euler spiral. It’s an example of how special spiral patterns are found throughout the natural world. And spotting them can help us not only understand nature better, but also improve our own engineering. The Euler spiral – also called the Cornu spiral, Spiros or C...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com . What is white-nose syndrome in bats? – Minti F., age 13, Boston, Massachusetts Scientists count bats in the winter to make sure their populations are doing okay. They look in caves and abandoned mines where bats hibernate when it is too cold to hunt for insects to eat. About 10 years ago, during their annual winter bat counts, scientists noticed that bats in caves in New York state were dying. The bats that were still alive had a white fuzzy growth on their muzzles and wings. Scientists didn’t know what it was and named it white-nose syndrome . Little brown bats with white-nose syndrome. Alan Hicks , CC BY-ND Now we know a lot more about white-nose syndrome, a disease that kills bats when they hibernate. I am a scientist who studies bats to learn more about how to protect them. A fungus that infects hibernating bats The ...

The world around us is populated by a vast variety of things – ranging from genes and animals to atoms, particles and fields. While these can all be described by the natural sciences, it seems some can only be understood in terms of biology while others can only be explored using chemistry or physics. And when it comes to human behaviour, disciplines like sociology or psychology are the most useful. This richness has intrigued philosophers, leading them to think about how the sciences are connected (or disconnected), but also about how things in the world relate to one another. Our new project, called the Metaphysical Unity of Science and funded by the European Research Council, is trying to answer these questions. In general, philosophy distinguishes between two main questions in this area. First, there is the epistemological question of how specific sciences or theories are connected to one another. For example, how is biology related to physics or psychology to biology? This foc...

As temperatures were dipping this week, the National Weather Service issued freeze warnings for much of Florida and Georgia, adding a warning in South Florida for “falling iguanas.” University of Florida wildlife ecologist Frank Mazzotti explains the physiology of cold iguanas and why many people in Florida aren’t shedding tears for the iguana-cicles lying around the region. What happens to iguanas when temps drop? When temperatures fall into the 40s and 30s, green iguanas become cold-stunned. They enter what’s called a state of torpor . Their breathing slows down and so does their metabolism. Used to more balmy conditions, this is how tropical reptiles protect themselves from cold temperatures. Torpor is an involuntary response, and the animals trade torpor’s benefit of conserving heat in cold conditions for an increased risk of being snagged by a predator. Torpor causes green iguanas to lose muscle control, and since they live in trees, they fall out of trees. A several pound...

The UK government recently announced it was planning to increase the use of polygraphs to monitor offenders on probation, specifically those convicted of terrorist offences. This is one of several new measures to prevent a repeat of the recent London Bridge attack , which was committed by an offender out in the community on license. One difficulty with deciding which offenders can be released this way is that offenders can lie about their actions, thoughts and intentions to convince probation officers that they pose a low risk. The government hopes that an increased use of polygraphs will help identify terrorists planning to reoffend. But are polygraphs actually able to do this? Polygraphs are already in use in the UK for probation purposes. Since 2014, high-risk sex offenders have had to undergo polygraphs testing as part of their license conditions. Sex offenders are also routinely asked to undergo polygraphs in the US , but the practice is not common in other countries. Altho...

I was born a Capricorn (please don’t judge me), but the Sun was in the middle of Sagittarius when I was born. As a professor emeritus of astronomy , I am often asked about the difference between astrology and astronomy. The practice of astrology, which predicts one’s fate and fortune based on the positions of the Sun, Moon, stars and planets, dates back to ancient times. It was intermingled with the science of astronomy back then – in fact, many astronomers of old made scientific observations that are valuable even today. But once Copernicus, Kepler and Galileo realized the planets orbit the Sun, rather than the Earth, and Newton discovered the physical laws behind their behavior, astrology and astronomy split, never to be reunited. The science of astronomy is now at odds with one of the basic organizing principles in astrology – the dates of the zodiac. The constellations of the zodiac Over the course of a year, the Sun appears to pass through a belt of sky containing 12 ancient c...

The past decade (2010-2019) was the hottest on record and five of the top 10 warmest single years have all occurred since 2015, according to reports released by the UK Met Office and the World Meteorological Organisation . The current Australian bushfire crisis is also the worst on record , having emerged due to a combination of increased average temperature (roughly 1.5°C above the long term average) and a reduction in rainfall. But can we attribute this to anything more natural than anthropogenic effects? Solar activity, for example, has previously been linked to temperature and is sometimes blamed for climate change. But our new analysis provides evidence for why this isn’t the case. The sun is the dominant source of energy for the Earth’s climate, so quantifying what influence it has had on global temperatures since industrialisation is very important. Like all stars, the sun undergoes variations in solar activity, meaning its energy output varies with time. The visible sur...

The UK government’s chief scientific adviser, Sir Patrick Vallance, recently said he was mounting a drive to recruit more scientists and engineers into the civil service. His comments echo the much-discussed call by the prime minister’s chief special adviser, Dominic Cummings, for more data scientists and other “ assorted weirdos ” to become civil servants. From our experience working with and in government departments, we know that there are many problems in how the civil service uses evidence to support decision-making. And scientists (and other specialists from the social sciences and humanities ), who value sound methodologies and are trained to search for robust evidence, well-designed studies and research questions, could indeed help with that. But more scientists working within current systems won’t be enough. We need a transformation in thinking that goes far beyond what degree civil service recruits studied. Some of this can be achieved by building on some excellent pract...

On January 23 1960, Jacques Piccard and Don Walsh climbed into an undersea craft called Trieste and dived nearly 11 kilometres to the deepest point in the ocean – the Challenger Deep of the Mariana Trench in the Pacific Ocean. Before the 20th-century’s space race even began, explorers were vying to be the first to reach the bottom of the ocean. Jon Copley , Author provided Down there, no sunlight can reach and the water is only ever a few degrees above freezing. The water pressure outside the walls of their vessel was 1,000 times greater than at the surface, but Piccard and Walsh overcame these conditions to enter history as the first Challenger Deep voyagers. The first men to traverse these alien reaches of our world are much less well known than the first astronauts to walk on the Moon. Still, the race they led to the deepest point on Earth’s surface has profound implications for the modern world. The story of the earlier deep-sea pioneers whose achievements led to their dive ...

In 1890, a New York bird enthusiast released several dozen starlings in Central Park. No one knows for sure why Eugene Schieffelin set the birds aloft, but he may have been motivated by a sentimental desire to make the American Northeast more like the English countryside. The consequences of his action were unintentionally massive. Today, there are nearly 200 million starlings in North America. Schieffelin was a member of the American Acclimatization Society , a worldwide effort to diversify local fauna and flora. Similar organizations existed in Europe, Australia and New Zealand. As the British acclimatization society put it, these organizations aspired to introduce “all innocuous animals, birds, fishes, insects, and vegetables, whether useful or ornamental.” Schieffelin’s was not the first attempt to remedy perceived deficiencies in North American bird populations. Some members of these societies, often people with wealth, simply wanted to beautify their surroundings. Other acclim...