Hello, and welcome to another podcast by practising English. And today we're going to talk about very large numbers, how to use them. And also an interesting article about outer space. Here we go...
Now, when we talk about numbers, I mean, large numbers, hundreds, thousands, millions, [billions] and trillions. Well, we usually use them in the singular. So we say a million, or 1 million, 2 million, two million five hundred thousand, several million. So we don't put the s on the end of these large numbers.
Now, we can use an s, but only when we say millions of something. So for example, we could say the thousands of stars in the night sky, and when we say that, then we do use the s. Millions of, hundreds of, hundreds of planets, thousands of planets.
The other thing about large numbers is that in British English, we put an 'and' before the tens [US English does not do this]. So for example, we say a/one hundred and fifty-six (156); ten thousand, five hundred and twenty-one (10,521); three billion, three hundred million, fifty thousand six hundred and three (3,300,050,603).
Now, in this article, I'm going to be using large numbers because we're talking about space. And when we talk about outer space, then we are talking about vast distances and vast numbers. So in this podcast, listen out for how large numbers are used and the different constructions that are used to talk about huge numbers and vast distances. You can also find an audio script of this recording.
If you were looking up at the night sky last summer, the summer of 2020, you may have seen a small point of light in the dark sky in the Northern Hemisphere, during early July, if you had taken out your binoculars, you would have seen that that point of light, in fact, had a tail in the classic shape of a comet.
But as I say, you could even see it with the naked eye, which means you can see it without any use of binoculars, or telescopes. But then suddenly, it disappeared. And it won't be seen again. Well, it will be but not for a long, long time. In fact, it won't be seen again for another six thousand, eight hundred (6800) years. But during its short visit to our part of the solar system, astronomers gave the comet a name. Rather a boring one really - C forward stroke two 0 0 two F three(C/2002F3). Although it did have a nickname as well, and that nickname was Neowise.
Now it is possible to see quite a few comets which visit our part of the solar system. And as they near the sun, the heat pushes out a long tail of melting ice and pieces of rock.
The orbit of comets is usually in the shape of an ellipse. It isn't like the planets of our solar system, which more or less have orbits which are fairly round. But what was unusual about this comet was that it didn't come from where most comets originate from. Most of the comets that astronomers see, come from just the other side of Neptune, an area of space called the Kuiper belt. But the comet Neowise came from much further away than that. It came from an area of space in the extreme reaches of our solar system, from an area of space called the Oort cloud and that is spelled OORT - Oort.
Now the Oort cloud was first predicted by Jan Oort in 1950. He tried to explain why some comets seem to have a longer orbit than those that came from the Kuiper Belt. Kuiper Belt comets are short period comments, which usually take less than 200 years to orbit the sun. But comets like Neowise took between 200 and 1000 years to complete just one orbit of the sun. Why was this? Jan Oort theorized that there must be a huge sphere of ice which engulfs the solar system, a sphere of ice so far away, that no man-made probe has ever reached it.
The objects which inhabit the Oort cloud are probably just lumps of rock and ice. Some may be very small, whereas others may be the size of dwarf planets. That is a few tens of kilometers across. This sphere or shell of objects, called the Oort cloud is thought to begin somewhere around three hundred and six million (306,000,000) kilometers to seven hundred and fifty-six billion (756,000,000,000) kilometres from the sun. That is a distance which is equivalent to two thousand (2000) to five thousand (5000) times the distance from the Earth to the Sun. In fact, some astronomers estimate the Oort cloud may stretch out further into space perhaps some fifteen trillion (15,000,000,000,000) kilometers to twenty-nine trillion (29,000,000,000,000) kilometers away from the sun.
The Oort cloud, although part of our solar system is so far away, that it probably contains material from other stars - alien material. Astronomers believe this is because it is thought that our sun was born from a cluster of stars which were close together, and which spread out into the deep reaches of space separating from each other. As time went by, it is probably true to say that comets like Neowise, could have originated from alien stars.
Astronomers would love to be able to drill down into the core of a comet and find the material which exists there. If we could understand the nature of the Oort cloud, and the nature and substance of the comets that come from it, astronomers could get some important clues about the origins of our solar system, and how it was formed.
Our most distant spaceprobe, Voyager one, which has recently passed the dwarf planet Pluto, left Earth only forty (40) years ago, and it is only one tenth (1/10) of the distance to the edge of the solar system and the Oort cloud, and will take another three undred (300) years before it arrives there.
Bye for now.
Copyright © 2023 Practising English
All rights reserved