Author Question: In order to tell time at night, the ancient Egyptians of 3000 B.C. used A) sundials, with light ... (Read 100 times)

shofmannx20 · **on:** Jul 27, 2018

In order to tell time at night, the ancient Egyptians of 3000 B.C. used

A) sundials, with light provided by the Moon.
B) water clocks, measuring the flow of water through an opening.
C) hourglasses, measuring the flow of sand through an opening.
D) Moon clocks, which measured time based on the Moon's position relative to the stars.
E) star clocks, which measured time based on the positions of stars at particular times of night and particular times of year.

Question 2

Why does the value of Hubble's constant alone not tell us the fate of the universe?

What will be an ideal response?

lindahyatt42 · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

E

Answer to Question 2

Hubble's constant tells us how fast the universe is expanding today but the fate of the universe (whether it will expand forever or whether the expansion will eventually reverse) depends also on the gravitational pull of all the matter in the universe. Thus to learn about the fate of the universe we must measure not only how fast it is expanding but also how much matter it contains. Hubble's constant changes over time.