Re: 51% of Americans don't accept the Big Bang theory
Well this is what NASA says on the age of the universe
Until recently, astronomers estimated that the Big Bang occurred between 12 and 14 billion years ago. To put this in perspective, the Solar System is thought to be 4.5 billion years old and humans have existed as a genus for only a few million years. Astronomers estimate the age of the universe in two ways: 1) by looking for the oldest stars; and 2) by measuring the rate of expansion of the universe and extrapolating back to the Big Bang; just as crime detectives can trace the origin of a bullet from the holes in a wall.
And looking at the wiki article
In physical cosmology, the age of the universe is the time elapsed since the Big Bang. The best measurement of the age of the universe is 13.798±0.037 billion years ((13.798±0.037)×109 years or (4.354±0.012)×1017 seconds) within the Lambda-CDM concordance model
Yes we might not know the exact age of the universe but using the NASA link but everything I've heard or read about the universe said a big bang and I've heard various ages between 12-15bn years. But it's not like i look up that inofrmation every month to see if it's change. So x years ago I might have heard it was 12bn years old, it's not unreasnable to think during the period since I last heard the figure and today that number has been revised. So if the 13.8bn years old is current figure it's not unreasanble for a survey to use that. If the survey was done in a decades time the figure might be 13.6bn years old.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.