如果在宇宙中已知的物质与能量总量上加上让宇宙膨胀速度加快所需的能量，其结果差不多正好是平坦宇宙所需的物质能量密度。
Add the amount of energy needed to keep cosmic acceleration going to the amount of matter and energy in the universe already accounted for and you have more or less exactly the density of matter and energy needed to make the universe flat .
平坦宇宙