Scientists have long tried to explain the origin of a mysterious, large and anomalously cold region of the sky. In 2015, they came close to figuring it out as a study showed it to be a “supervoid” in which the density of galaxies is much lower than it is in the rest of the universe. However, other studies haven’t managed to replicate the result.
Low energy efficiency is already a major problem for petrol and diesel vehicles. Typically, only 20% of the overall well-to-wheel energy is actually used to power these vehicles. The other 80% is lost through oil extraction, refinement, transport, evaporation, and engine heat. This low energy efficiency is the primary reason why fossil fuel vehicles are emissions-intensive, and relatively expensive to run.
We all know eating vegetables is a good way to improve health. And for many years the focus has been on just eating more vegetables, be it fresh, frozen or tinned.
But what if there was a quicker and easier way to get more benefit from our vegetables? Can the way we prepare vegetables boost their nutrition? Does tearing or chopping your lettuce makes any difference? And if we chop, does it matter what type of knife we use?
When the Golden Gate Bridge went up, it was the longest suspended bridge span in the world – cables hold up the roadway between two towers, with no intermediate supports. And the setting had a number of inherent challenges. It cost about US$37 million at the time; building the same structure today would cost about a billion dollars. So how has the design held up over the past 80 years – and would we do things differently if we were starting from scratch today?
The asteroid that struck Earth about 66 million years ago and led to the mass extinction of dinosaurs may have hit one of the worst places possible as far as life on Earth was concerned. When it struck, the resulting cataclysm choked the atmosphere with sulphur, which blocked out the Sun. Without the Sun, the food chain collapsed, and it was bye-bye dinosaurs, and bye-bye most of the other life on Earth, too.
For example, in the summer of 2015, a team of astronomers announced that they found what might be an indication of an alien megastructure around Tabby’s Star (KIC 8462852). However, they were quick to point out that any number of possibilities could explain the strange dimming pattern coming from the star, and subsequent studies offered even more plausible explanations – such as the star having consumed a planet at some point in its past.
Conventional wisdom has it that humans have a poorer sense of smell than most other animals. Sure, we can smell – most of us appreciate the aroma of our morning coffee or a delightful fragrance, and we’re able to detect burning toast or a gas leak. But we have nonetheless long been thought to be relative weaklings in the animal kingdom’s league of olfactory excellence, which puts dogs and rodents near the top.
The gas giants have always been a mystery to us. Due their dense and swirling clouds, it is impossible to get a good look inside them and determine their true structure. Given their distance from Earth, it is time-consuming and expensive to send spacecraft to them, making survey missions few and far between. And due to their intense radiation and strong gravity, any mission that attempts to study them has to be do so carefully.
Once the province of prophets, “hearing voices” is still shorthand for madness. And yet in the past 30 years, a new understanding has been created by voice-hearers themselves, as part of the Hearing Voices Movement. This suggests that uncovering the roots of the voice can potentially help the hearer.
The first Thursday in May is World Password Day, but don’t buy a cake or send cards. Computer chip maker Intel created the event as an annual reminder that, for most of us, our password habits are nothing to celebrate. Instead, they – and computer professionals like me – hope we will use this day to say our final goodbyes to “qwerty” and “123456,” which are still the most popular passwords.
As well as our physical health, the quality of our diet matters for our mental and brain health. Observational studies across countries, cultures and age groups show that better-quality diets – those high in vegetables, fruits, other plant foods (such as nuts and legumes), as well as good-quality proteins (such as fish and lean meat) – are consistently associated with reduced depression.
For decades, some people have embraced the idea that there might be major health benefits from taking vitamins in quantities well beyond the recommended daily requirement. The concept was very popular for a while in the media, but research findings to the contrary gradually made it virtually untouchable for scientists.
The search for life in the Universe takes many paths. There’s SETI, or the Search for Extraterrestrial Intelligence, which is searching for signals from a distant ancient civilization. There’s the exploration of our own Solar System, on Mars, or underneath the subsurface oceans of Europa and Enceladus, to see if life can be anywhere there’s liquid water and a source of energy. And upcoming space telescopes like James Webb will attempt to directly image the atmospheres of distant extrasolar planets, to see if they contain the distinct chemical signatures of life.
When you hear someone laugh behind you, you probably picture them on the phone or with a friend – smiling and experiencing a warm, fuzzy feeling inside. Chances are just the sound of the laughter could make you smile or even laugh along. But imagine that the person laughing is just walking around alone in the street, or sitting behind you at a funeral. Suddenly, it doesn’t seem so inviting.
Since the 1960s, astronomers have been aware of the electromagnetic background radiation that pervades the Universe. Known as the Cosmic Microwave Background, this radiation is the oldest light in the Universe and what is left over from the Big Bang. By 2004, astronomers also became aware that a large region within the CMB appeared to be colder than its surroundings.
Of all the planets in the Solar System, Mercury is the closest to our Sun. As such, you would think it is the hottest of all the Solar planets. But strangely enough, it is not. That honor goes to Venus, which experiences an average surface temperature of 750 K (477 °C; 890 °F). Not only that, but Mercury is also cold enough in some regions to maintain water in ice form
Insects navigate in much the same way that ancient humans did: using the sky. Their primary cue is the position of the sun, but insects can also detect properties of skylight (the blue light scattered by the upper atmosphere) that give them indirect information about the sun’s position. Skylight cues include gradients in brightness and colour across the sky and the way light is polarised by the atmosphere. Together, these sky “compass cues” allow many insect species to hold a stable course.
