Grammar for Science, Technology: Prefixes, Measurements
2024-05-31
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1What do news stories about space travel, technology, or energy production have in common?
2Well, one way to answer this question is to look at special prefixes that are often used with measurements in science and industry.
3These prefixes are especially important to people studying in the STEM fields of science, technology, engineering, and math.
4Let's start with some important terms and ideas.
5Prefixes are additions to the beginnings of words.
6When we add a prefix to a word, it changes the meaning of the existing word, and the result is a new word.
7Let's take an example to clarify the point. We have the prefix "un-," meaning not.
8Then we have the full word "happy."
9When we add the prefix "un-" to the beginning of the word "happy," we get the word "unhappy."
10There are many kinds of prefixes.
11For today's lesson, we will pay attention to one kind of prefix: prefixes related to large amounts.
12The National Institute of Standards and Technology (NIST) is a U.S government agency that works on measurement science.
13NIST has a public list of prefixes used for amounts, or quantities, and their meanings.
14The list is long. But there are only a few of these prefixes that are important for everyday uses in the sciences and industry.
15The prefixes that mean one thousand, one million, one billion, and one trillion are useful to know for most kinds of science, energy, and technology stories.
16Here is how NIST defines these prefixes:
17Kilo- means thousand.
18Mega- means million.
19Giga- means billion.
20Tera- means trillion.
21In science and industry, we often use large number prefixes to express measurements of distance, energy, or weight.
22An example of a distance measurement is a meter.
23An example of a power measurement is a watt.
24Let's take an example that everyone knows: one kilometer.
25We have the prefix kilo-, meaning one thousand, and the unit of distance, a meter.
26Let's listen to how Bryan Lynn uses the term "kilometer" in a recent science story on our website:
27NASA estimates the moon sits an average of about 382,500 kilometers from Earth.
28The exact distance changes because of the moon's orbit around Earth.
29The average distance from Earth to Mars is 225 million kilometers.
30Our example shows an important point about agreement.
31Note that in our example, we make the measurement of distance plural.
32We add an -s to the end of kilometer, and so we get the term "kilometers."
33So, we say one kilometer, two kilometers, and 300,000 kilometers.
34The idea is that the prefix changes the meaning of the word, but the word must still agree in terms of being singular or plural.
35So, do not forget about the plural markers we use at the ends of words.
36We can carry this same idea to an energy story.
37A watt is a unit of power.
38When we use prefixes to change the meaning, we arrive at a term such as a megawatt - meaning a million watts - or a gigawatt - meaning a billion watts.
39Let's listen to part of a recent report about wind energy development in 2023.
40The Global Wind Report, published recently by the Global Wind Energy Council (GWEC), a trade group, said the world developed 117 gigawatts of new wind power capacity, a 50 percent increase from 2022.
41Note that in our example, the power capacity measurement is expressed in gigawatts.
42Once again, we add the -s ending to gigawatt because it is plural: 117 gigawatts.
43Let's take some time to work with these ideas.
44Imagine you want to describe the amount of data that a hard drive can hold.
45Use the prefix "tera-" and the unit of computer information, a byte, to describe the storage capacity of the hard drive.
46Pause the audio to consider your answer.
47Here is one possible answer:
48This hard drive has one terabyte of data storage capacity.
49Here is another possible answer:
50This hard drive has two terabytes of data storage capacity.
51We will end this Everyday Grammar with a call to action.
52Write us a short description of something related to science, energy, or technology.
53Be sure to use prefixes such as kilo-, mega-, giga-, or tera-.
54Try to connect your description to something related to your country or your life.
55You can write us your answers in an email to learningenglish@voanews.com
56In a future Everyday Grammar, we will give feedback on some of the messages we receive.
57I'm John Russell.