The universe is 13.7 billion years old (accurate to 1 percent),
Are they real? Are they absolute? Or merely the accuracy of this particular observation not including the errors in all the other observations on which they are built.expanding at the rate of 71 km/sec/Mpc (accurate to 5 percent),
It seems utterly mind boggling. Quite the most amazing thing I have seen on APOD, which is quite the best source of amazing things on the 'net.
For example, if the expansion rate is uncertain to 5%, how can the age be certain to 1%?
And the composition figures? Any accuracy estimates on them?
I'm only qualified enough to look upon those accuracy figures with awe and amazement, but not enough to judge them right or wrong.