| Page |
Location |
Original |
Revision |
Date Posted |
| 28 |
par. 3, lines 7–8 |
"...is about one sixth that of the Earth." |
"...is much smaller than Earth's mass. As a result, the moon's gravity is about one sixth that of Earth's." |
07-Mar-2000 |
| 28 |
Fig. 1-22, caption |
"The mass of planet Neptune...
the moon's mass..." |
"The gravity of planet Neptune...the moon's gravity..." |
07-Mar-2000 |
| 49 |
par. 4, lines 3–4 |
"...suddenly became dim and disappeared, only to brighten again." |
"...became dimmer, then brightened again." |
07-Mar-2000 |
| 49 |
Fig. 2-3, caption, line 3 |
"...seems to dim and disappear. When does it reappear?" |
"...becomes dimmer. When does it become bright again?" |
07-Mar-2000 |
| 50 |
par. 1, line 3 |
"...reason for Algol's winking on and off." |
"...reason for Algol's dimming and brightening." |
07-Mar-2000 |
| 50 |
par. 1, lines 11–12 |
"...the smaller star seems to disappear. Can you explain why it reappears again?" |
"...the smaller star becomes dimmer. Can you explain why it becomes bright again?" |
07-Mar-2000 |
| 51 |
par. 5, line 4 |
"Astronomers believe that almost all..." |
"All..." |
07-Mar-2000 |
| 52 |
par. 2, lines 3–4 |
"Globular clusters, which are more common, are..." |
"Globular clusters are..." |
07-Mar-2000 |
| 52 |
par. 4, lines 1–2 |
"Once you have passed what seems like a thousand or more globular clusters,..." |
"Once you have passed what seems like a hundred globular clusters,..." |
07-Mar-2000 |
| 53 |
Fig. 2-7, caption and photos |
"The photographs show the Red Nebula (right) and the Tarantula Nebula (left)." |
"This photograph shows the Tarantula Nebula."
Delete the right photograph. |
07-Mar-2000 |
| 54 |
Fig. 2-8, caption, line 3 |
"...several trillion or more stars." |
"...several billion or more stars." |
07-Mar-2000 |
| 57 |
Section Review #3 |
"3. Many binary stars are called eclipsing binaries." |
"3. Some binary stars are called eclipsing binaries." |
07-Mar-2000 |
| 58 |
Fig. 2-13, caption, lines 10–12 |
"Parts of the constellation Sagittarius are seen in this X-ray photograph." |
"The remains of a supernova are seen in this X-ray image." |
07-Mar-2000 |
| 60 |
par. 2, lines 3–4 |
"In fact, wavelengths from an approaching star often appear..." |
"Because of this, wavelengths from an approaching star appear..." |
07-Mar-2000 |
| 61 |
par. 1, lines 3–6 |
"Galaxies near the edge of the universe are racing away from the center of the universe at tremendous speeds. Galaxies closer to the center are also moving outward, but at slower speeds." |
"Galaxies that are far from our galaxy are racing away from our galaxy at tremendous speeds. Most galaxies that are closer to our galaxy are also moving away from us, but at slower speeds." |
07-Mar-2000 |
| 61 |
par. 2, lines 13–15 |
"The fastest moving...the big bang." |
Delete both sentences. |
07-Mar-2000 |
| 62 |
par. 3, lines 3–8 |
"But even as the galaxies were forming, the matter inside the galaxies continued to race away from the area where the big bang had occurred....All of the galaxies are speeding away from the center of the universe." |
"But even as the galaxies were forming, the clumps of matter that made up the galaxies continued to race away from the other clumps of matter....Almost all of the galaxies are speeding away from each other." |
07-Mar-2000 |
| 62 |
par. 4, lines 9–11 |
"So the future of an open universe is one in which there will be nothing left. An open universe leads to total emptiness." |
"An open universe will eventually become cold and dark." |
07-Mar-2000 |
| 63 |
par. 1, line 2 |
"...galaxies back toward the center of the universe." |
"...galaxies back together." |
07-Mar-2000 |
| 63 |
par. 2, lines 1–3 |
"As the galaxies race back toward the center of the universe, the matter and energy will again come closer and closer to the central area." |
"As the galaxies race back toward each other, the matter and energy will again come closer and closer together." |
07-Mar-2000 |
| 63 |
par. 2, lines 10–12 |
"In a closed...100 billion years." |
Delete sentence. |
07-Mar-2000 |
| 63 |
par. 3, lines 1–5 |
"If the universe...the universe did." |
"A light-year is the distance light travels through space in one year. If an object is 1 billion light-years away from Earth, then it has taken 1 billion years for the light from that object to travel to Earth." |
07-Mar-2000 |
| 63 |
par. 4, lines 2–3 |
"They give off mainly radio waves and X-rays." |
Delete sentence. |
07-Mar-2000 |
| 63 |
par. 5, lines 1–3 |
"If the big...the big bang." |
"If the big-bang theory is correct, quasars were among the first objects formed after the big bang." |
07-Mar-2000 |
| 64 |
par. 1, lines 1–3 |
"So when scientists observe quasars, they are observing the very edge and the very beginning of the universe." |
"So when scientists observe quasars, they are observing the very beginning of the universe." |
07-Mar-2000 |
| 64 |
Section Review #4 |
"Connection--Social Studies..." |
"4. What can astronomers infer from the fact that other galaxies are moving away from ours?" |
07-Mar-2000 |
| 65 |
par. 2, lines 4–5 |
"Medium-sized stars make up the majority of the stars you can see in the sky." |
"Medium-sized stars make up the majority of the stars in the sky." |
07-Mar-2000 |
| 65 |
par. 2, lines 7–8 |
"Many of these stars are very bright." |
Delete sentence. |
07-Mar-2000 |
| 65 |
par. 2, lines 9–10 |
"...of the sun and is the brightest star in the night sky." |
"...of the sun. Sirius is the brightest star in the night sky, mainly because it is close to the Earth." |
07-Mar-2000 |
| 66 |
par. 1, lines 1–3 |
"Supergiants, however, pay a price for their huge size. They die off quickly and are the shortest-lived stars in the universe." |
Delete sentences. |
07-Mar-2000 |
| 66 |
par. 6, line 5 |
"...the flame will burn bright yellow." |
"...the flame will glow bright yellow." |
07-Mar-2000 |
| 67 |
par. 4, lines 9–11 |
"...total little more than 4 percent..." |
"...total less than 4 percent..." |
07-Mar-2000 |
| 68 |
Fig. 2-24, caption, lines 1–4 |
"The brightness of these stars in the Trifid Nebula, as..." |
"The brightness of these stars, as..." |
07-Mar-2000 |
| 69 |
par. 3, lines 7–10 |
"Astronomers call these pulsating stars Cepheid (SEF-ee-id) variables because the first one was discovered in a group of stars called Cepheus." |
"One group of these pulsating stars is called the Cepheid (SEF-ee-id) variables because the first one was discovered in the constellation called Cepheus." |
07-Mar-2000 |
