Science This Week | New way to settle the universe expansion dispute, risk of dengue on the rise as the planet warms and more Premium

Check out The Hindu’s science wrap featuring top 7 stories on new discoveries, findings, and studies in the scientific world from this week.

From finding out a way to solve the Hubble constant to figuring out the complex food web that existed during the Mesozoic era, here are the top findings and discoveries from the field of science.

A group of scientists may have found a way to determine the rate of expansion of the universe also known as the Hubble constant. While the study’s predictions may only be tested in the 2040s, their method “will provide an independent measurement of cosmological parameters,” one of the scientists involved in the study said. Two details are required to calculate the value of the Hubble constant: the distance between the observer and astronomical objects, and the velocity at which these objects are moving away from the observer as a result of the expansion of the universe. So far, scientists have used three methods to get these details

Anatomist Thomas Henry Huxley suggested that the birds of today could be the descendants of the extinct dinosaurs in 1869. The proof of Huxley’s idea came a century later, yet some mysteries persisted as well. One was that both birds and dinosaurs have and had brains of a similar size – even as other parts of dinosaurs evolved to become smaller. The brain generates heat that needs to be moved away, so how did the smaller bird cranium manage this? A study suggests the nasal cavity might have the answer.

A dramatic fossil unearthed in northeastern China shows a pugnacious badger-like mammal in the act of attacking a plant-eating dinosaur, mounting its prey and sinking its teeth into its victim’s ribs about 125 million years ago, a new study has found. Dating to the Cretaceous Period, it shows the four-legged mammal Repenomamus robustus - the size of a domestic cat - ferociously entangled with the beaked two-legged dinosaur Psittacosaurus lujiatunensis - as big as a medium-sized dog. The scientists suspect they were suddenly engulfed in a volcanic mudflow and buried alive during mortal combat.

Stunning drone footage has revealed details of the Batagaika crater, a one-kilometre-long gash in Russia's Far East that forms the world's biggest permafrost crater. In the video two explorers clamber across uneven terrain at the base of the depression, marked by irregular surfaces and small hummocks, which began to form after the surrounding forest was cleared in the 1960s and the permafrost underground began to melt, causing the land to sink. Scientists say Russia is warming at least 2.5 times faster than the rest of the world, melting the long-frozen tundra that covers about 65% of the country's landmass and releasing greenhouse gases stored in the thawed soil.

The World Health Organization warned that cases of dengue fever could reach close to record highs this year, partly due to global warming benefiting mosquitoes that spread it. Dengue rates are rising globally, with reported cases since 2000 up eight-fold to 4.2 million in 2022. In Januray, WHO warned that dengue is the world's fastest-spreading tropical disease and represents a "pandemic threat". A warmer climate is thought to help the mosquitoes multiply faster and enable the virus to multiply within their bodies. Increased movement of goods and people and urbanisation and associated problems with sanitation as other factors behind the increase.

The World Health Organisation (WHO) recently reported that around one in six couples globally are affected by infertility. For many years people tended to blame women for a couple’s infertility. But it’s now known that male factor infertility contributes about 50% of total cases. And men worldwide are experiencing a worrying trend of decreased sperm count and quality. A new study suggests that these “contaminants of emerging concern” might be contributing to the male infertility crisis in surprising ways. It describes the effects of contaminants such as pharmaceuticals and pesticides on male reproduction. These contaminants can affect men’s reproductive fitness either by interacting with their brain, or by targeting the reproductive organs such as the testes directly.