Chapter,  Paragraph

 1 8 |     compresses 564 million tons of hydrogen into 560 million tons of
 2 8 |         has only used up 2% of the hydrogen it had the day it came into
 3 8 | quintillion stars, each converting hydrogen into helium, thereby reducing
 4 8 |       reducing the total amount of hydrogen in the cosmos. Just think
 5 8 |           everywhere in the cosmos hydrogen is being consumed and if
 6 8 |         going on forever, how much hydrogen should be left?~Suppose
 7 8 |           we would have run out of hydrogen long ago! The fact is, however,
 8 8 |            has 98% of its original hydrogen. The fact is that hydrogen
 9 8 |         hydrogen. The fact is that hydrogen is the most abundant material
10 8 |            in space we can see the hydrogen 21 cm line in the spectrum —
11 8 |            light only given off by hydrogen. This could not be unless