VOA慢速英语2021--2020年新的科学发现

New Scientific Discoveries Made in 2020

In 2020, many of the world's top scientists centered their attention on the new coronavirus. Their efforts provided valuable information about the virus and led to new vaccines¹ to fight it.

But there were other big scientific developments in 2020, as well. Here is a look back at some of the notable science stories we covered during the past year.

Plastic-eating bacteria

European researchers identified a new bacterium² that feeds on polyurethane, a kind of plastic that is difficult to recycle or destroy.

The team, from Germany's Helmholtz Center for Environmental Research, said the discovery could help reduce a flood of hard-to-recycle plastics filling up the world's landfills and polluting oceans.

Many polyurethane-based products can release dangerous chemicals into the environment. But the researchers found that the bacterium can produce enzymes⁴ to break down the material.

‘Unlivable' heat by 2070

Researchers from the United States, China and Europe warned that in just 50 years, as many as 3.5 billion people could be facing "near-unlivable" heat.

A study suggests the extreme heat would result from rising world temperatures linked to human-caused climate change. The exact number of people at risk will depend on whether pollutant⁵ levels can be reduced and how quickly the world population will grow.

Under the worst-case predictions for population growth and carbon pollution, the study estimates about 3.5 billion people could be living in extremely hot areas by 2070. That would be one-third of the world's projected population.

Cloud seeding to produce snow

Scientists said they used new measuring methods to confirm that cloud seeding can produce snowfall under the right conditions. Cloud seeding involves injecting various substances into clouds to produce rain, snow or ice that falls to the ground.

American researchers announced they had used radar⁶ and other instruments to measure snowfall levels during experiments carried out in the state of Idaho.

The researchers said that, in several cases, cloud seeding operations measurably increased snowfall across targeted areas.

In some cases, the seeding created new snowfall where no natural snow existed. One cloud seeding operation resulted in precipitation that produced snowfall for about 67 minutes.

Neowise comet

A comet called Neowise provided excellent light shows for people across the world.

Comets are solar system objects made up of ice, rock and dust. Scientists estimated Neowise was about 5 kilometers across. It was the brightest comet to appear above the Northern Hemisphere in 25 years.

Social media users in many countries posted images they captured of the comet as it lit up the sky over their heads.

3D map of universe

Scientists released the largest three-dimensional, or 3D map of the universe ever created.

The 20-year project aims to map the universe using data collected from a telescope in the American state of New Mexico. Researchers said the 3D map produced measurements of more than two million galaxies⁷ and quasars. Quasars are defined as "bright galaxies lit up by material falling onto a central supermassive black hole."

World's oldest known animal

Scientists said in May they had discovered what is believed to be the oldest-known land animal. Remains⁸ of the millipede-like creature were found in Scotland.

Researchers said the small, fossilized creature is estimated to be about 425 million years old. It may have helped lead the way for the many animals that would later live on land.

While the creature is the earliest land animal known from a fossil, soil worms are believed to have lived before them – possibly 450 million years ago.

‘Zeptosecond' measured for first time

German scientists announced they had measured the smallest unit of time ever recorded - a zeptosecond. A zeptosecond is one trillionth of a billionth of a second.

Researchers made the discovery while studying how long it took a photon – a particle of light – to cross a hydrogen molecule⁹. They said the photon crossed the molecule in about 247 zeptoseconds. "This is the shortest timespan that has been successfully measured to date," the team said in a statement.

Words in This Story

recycle – v. to reuse something that has been used before often in another way

enzyme³ – n. a chemical substance produced by living cells that makes particular chemical reactions happen in animals and plants

precipitation – n. rain or snow falling to the ground

three-dimensional – adj. appearing to have length, depth and width

galaxy¹⁰ – n. a large group of stars from the same universe

millipede – n. a small creature that is like an insect and that has a long, thin body with many legs

fossilized – adj. having been changed into a fossil. A fossil is something (such as a leaf, skeleton, or footprint) that is from a plant or animal that lived in ancient times

unit – n. a single thing or a separate part of something larger

timespan – n. a period of time within which something happens, or a period between two events

1 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

2 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

3 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

4 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

5 pollutant   

n.污染物质，散布污染物质者

参考例句：

• Coal itself is a heavy pollutant.煤本身就是一种严重的污染物。
• Carbon dioxide may not be a typical air pollutant.二氧化碳可能不是一种典型的污染物。

6 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

7 galaxies   

星系( galaxy的名词复数 )； 银河系； 一群（杰出或著名的人物）

参考例句：

• Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
• We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。

8 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

9 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

10 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。