1. Unit 4: The Universe Essential Questions 5: Changes in the Universe

2. Essential Question 5: Is the Universe Changing?

3. YES!!! There is overwhelming physical evidence that the universe is changing.

5. The universe is changing every second of every day!!! The universe is filled with more galaxies than we can count, and each galaxy is filled with billions of stars. Therefore, Every second, somewhere in the universe – Old stars are dying Old stars are dying New stars are being formed from clouds of dust and gases. New stars are being formed from clouds of dust and gases. Asteroids fly through space, occasionally crashing into planets and leaving craters, exactly like those we can easily see on our Moon. Asteroids fly through space, occasionally crashing into planets and leaving craters, exactly like those we can easily see on our Moon. The processes by which these developments occur take billions of years, but they are occurring.

6. Kepler Space Probe How do we know this? The Hubble Space Telescope The Hubble Space Telescope Various space probes Various space probes The dedicated work of thousands of astronomers and mathematicians stars The dedicated work of thousands of astronomers and mathematicians stars

7. Universal Expansion That the universe is changing is beyond doubt. Whether it is expanding outward, however, is the subject of debate among some astronomers. That the universe is changing is beyond doubt. Whether it is expanding outward, however, is the subject of debate among some astronomers. Through the use of mathematical calculations and the use of other sophisticated instruments, distances between objects in space can be determined with great accuracy. Through the use of mathematical calculations and the use of other sophisticated instruments, distances between objects in space can be determined with great accuracy. By measuring distances between objects repeatedly over the span of years, movement of those items either towards each other or in opposite directions is determined. By measuring distances between objects repeatedly over the span of years, movement of those items either towards each other or in opposite directions is determined. Because those distances have been found to grow in many instances, scientists concluded that the universe is expanding outward. Because those distances have been found to grow in many instances, scientists concluded that the universe is expanding outward. – But not everyone agrees with this conclusion.

8. Universal Expansion According to measurements, the Universe's expansion rate was slowing down until about 5 billion years ago due to the influence of gravitational attraction of the matter content of the Universe. According to measurements, the Universe's expansion rate was slowing down until about 5 billion years ago due to the influence of gravitational attraction of the matter content of the Universe. Then, the rate of expansion began speeding up. Then, the rate of expansion began speeding up. – Exactly why is unknown, but one theory is the existance of Dark Energy.

9. Universal Expansion- Earth’s Moon At the time it formed, the Moon sat much closer to the Earth. At the time it formed, the Moon sat much closer to the Earth. – It was a mere 22,500km (14,000 miles) away The Moon continues to spin away from the Earth, at the rate of 3.78cm (1.48in) per year. The Moon continues to spin away from the Earth, at the rate of 3.78cm (1.48in) per year. – That’s about the same speed that our fingernails grow. – Today, it is a 250,000 miles (402,336 km) away.

10. Universal Expansion- Earth’s Moon The Moon is moving away from the Earth mainly due to the Earth's tides. The Moon is moving away from the Earth mainly due to the Earth's tides. The Moon is kept in orbit by the gravitational force that the Earth exerts on it, but the Moon also exerts a gravitational force on our planet. The Moon is kept in orbit by the gravitational force that the Earth exerts on it, but the Moon also exerts a gravitational force on our planet. – This causes the movement of the Earth's oceans to form a tidal bulge. Due to the rotation of the Earth, this tidal bulge actually sits slightly ahead of the Moon. Due to the rotation of the Earth, this tidal bulge actually sits slightly ahead of the Moon. Some of the energy of the spinning Earth gets transferred to the tidal bulge via friction. Some of the energy of the spinning Earth gets transferred to the tidal bulge via friction. This energy pushes the Moon into a higher orbit like the faster, outside lanes of a race track. This energy pushes the Moon into a higher orbit like the faster, outside lanes of a race track.

11. Why do we care? 1.In your comp books, write a brief paragraph explaining how you think the Moon moving away has affected the Earth in the past. 2.Then write another brief paragraph predicting the affects the Moon moving further away from the Earth will have in the future. Your Paragraphs It must be 4- 5 complete sentences. Your Paragraphs It must be 4- 5 complete sentences. Explain WHY you believe this way. Explain WHY you believe this way. You have 10 minutes. You have 10 minutes. *If you would like to share your belief, we will discuss them once time is up.