【推荐1】Water flying through the air, loud music, and an excess of brightly-coloured shirts can only mean one thing – it’s Songkran, the traditional Thai New Year.

Though several countries throughout Southeast Asia observe this Lunar New Year celebration, Thailand’s wet and wild festivities have gained global attention with international travellers flocking to the kingdom to experience city-wide water fights.

The dates for Songkran are 13–15 April each year, though sometimes the national holiday is extended if it falls on a weekend. Traditionally, each day was coupled with different customs, such as cleaning the house or preparing food for local monks. Many people still follow these practices, but not necessarily on specific days.

In its simplest form, Songkran is a time where families come together. Those living and working away from their family home will travel to spend a few days with their relatives. Younger generations will pour silver cups of jasmine-scented water over the hands of older family members, and everyone will show their respect to Buddha statues by doing the same.

Thais are typically calm, modest people, but they also place great importance on fun and Songkran is seen as a time to let loose. April is typically the hottest time of the year and everyone can use a break from the heat as well as the usual social conventions.

The custom of water splashing seems to have evolved from the tradition of people dipping their fingers into the bowls of fragrant water and sprinkling them on others as a show of respect. Over time, the gentle water blessings gradually became mass water fights where everyone grabs a water gun or bucket to spray and splash all around, filled with a sense of fun and playfulness.

【推荐3】During the pandemic, masks and other forms of personal protective equipment (PPE) have become familiar fixtures of our daily lives. They have helped ensure the safety of ourselves and our loved ones. Yet, the improper disposal of PPE has contributed to a hazardous trend — the accumulation of medical waste and the littering of our planet.

Every month, we use nearly 129 billion masks. In a recent report, the United Nations found that from March 2020 to November 2021, around 87,000 tons of used masks and gloves have become non-disposable waste.

This is very worrying, as the waste traps animals and affects the health of our communities. When not properly discarded (丢弃), PPE waste may be blown into local rivers and streams or mistaken by birds as materials for building nests. It is harmful to the environment because most PPE is made from plastic fibers. These fibers can never fully degrade, and instead, break down into microplastics and nanoplastics that linger in our oceans.

At present, many healthcare facilities do not have systems that can deal with the increasing amount of medical waste. As a result, facilities have resorted to burning medical waste. This can put healthcare workers at a higher risk of catching the disease, and communities near landfills (废弃物品填埋场) can be influenced by the poisonous air from the burn pits.

Instead of traditional masks, the United Nations recommends using safe, biodegradable masks or washable cloth masks as an alternative. Sealing used masks and gloves in a separate bag and cutting mask straps before throwing them away can also prevent PPE from ending up in unintended locations, such as sewage systems on streets.

However, it is important to note that masks should not be placed in household recycling bins because most garbage collection systems in cities are unable to dispose of the materials. Ultimately, knowing how to responsibly discard our PPE can help us not only protect the environment but also ourselves and other individuals in our community.

【推荐1】A 2020 study in the journal Science concluded that marine heat waves have increased more than 20-fold as a result of climate warming. The authors found that in the first decade after satellites began recording ocean temperatures (i.e., after 1981), there were 27 large marine heat waves, with an average duration of 32 days and an average peak temperature anomaly of 8.5°F; in the 2010s, there were 172, which lasted 48 days on average with an average peak temperature almost 10°F above normal.

Much remains unclear about marine heat waves. For example, explains Nicholas Bond, research scientist at the University of Washington and Washington’s state climatologist, there is the question of why so many persist for weeks or months. “There must be something else going on that helps maintain them,” he says. He notes that one explanation is that as the ocean surface warms, it radiates heat into the atmosphere that prevents cloud cover from forming, exposing the seawater to increased sunlight and further warming.

However, enough is known about marine heat waves for scientists to be gravely concerned about their potential impacts. Of special note is the fact that those impacts can last long after the heat waves have disappeared. After three years of the Blob, the waters of the northeastern Pacific began to cool in 2016; but years later, scientists are still determining the extent to which the region’s ecosystem is likely to return fully to its pre-Blob status. Similarly, notes Scannell, who is a data scientist with Jupiter Intelligence, Inc., following the 2010-11 Western Australia event, “lots of kelp(巨藻) forests died, and it takes literally decades for those ecosystems to bounce back”.

Eric Oliver, a scientist from Dalhousie University in Nova Scotia, Canada, expressed his own opinion about the potential impact of the heat waves in tropical waters. “I think that’s really a tough issue,” he says. Life in the tropics, he notes, is adapted to “quite a narrow range of temperatures. So that’s where things can get really messy. We can have complete shifts in tropical systems.”

【推荐3】The sounds of the Northern Lights have been a mystery to scientists for over a century. But now it seems that a researcher has figured out how auroras (极光) really make sounds.

“It has pretty much been confirmed all over the world,” historian Fiona Amery said. “ In Canada, Norway and Russia, they are all hearing very much the same sounds.”

“The auroras can occur hundreds of kilometers above the ground,which strengthens opinions that their sounds are just a false impression,” said Fiona. Many scientists argued that auroras were too far away to hear and that any sound would take several minutes to reach the ground, so it was impossible for them to change in time with the auroras.

However, other scientists were convinced that the Northern Lights really made noises. In the 1920s, Canadian astronomer Clarence Chant first suggested a mechanism by which they could occur: The motion of the aurora caused changes in the electrification of the atmosphere that created crackling sounds close to the ground. Almost 100 years later, Clarence’s suggestion seems close to what could be the true reason for the sounds.

In 2012, an expert named Unto Laine showed a recording of auroral sounds after years of monitoring auroras. In 2016, he announced the mechanism that makes the sounds: an inversion layer (逆温层) of cold air in the atmosphere that can form below an aurora and a short distance above the ground in calm weather.

Unto argues that visible changes in the aurora cause changes in the inversion layer, causing accumulated electricity to discharge as sparks (火花) that create sounds that can be heard. That explains how the sounds correspond with the aurora’s visible movements — they begin to happen in the inversion layer only about 75 meters above the observer.