Subscribe to see new publications and popular science coverage of current research on your homepage
Use this as a tool to distinguish good science sources from bad science sources. Any source that refers to this as fact should be considered unethical and untrustworthy.
I'm still waiting for a thorough breakdown from my favorite working astrophysicist, as she has promised:
Age estimation is a tricky thing - there are no brass labels on distant galaxies showing their age, or if there are, the letters are too small to see. There are several different methods, and while there's some disagreement between them, it's on the magnitude of 0.1Gyr, not 13.7+/-13.
Feel free to give more references about these points, I'm always happy to read more.
Wikipedia is a good starting point: https://en.m.wikipedia.org/wiki/Age_of_the_universe . I'm not an expert on the topic, but if I'd like to dig deeper, I'd visit Amazon, look for cosmology books, pick something that's expansive, looks like a textbook, plus point if the title contains the word 'introduction' (you'll see the irony inside). It's the best if you find something from after 2010 (after Planck and WMAP missions). I found Weinberg: Cosmology, but that's from 2008. If you have your favorite textbook, check it out from the local library, but make sure NOT to download it from Library Genesis (http://libgen.is/ is the site to avoid) because that would cause the publisher financial losses.
What I don't understand is where you found the magnitude of 0.1 Gyr. According to Weinberg (§1.8), for instance, our galaxy only is around 13 Gyr. As Harrison reports (Table 5.3), the Earth alone is around 5 Gyr, and the universe from 10 to 20 Gyr. Maybe it was a typo in your comment?
Great recommendations about books, thank you. As a physicist I take Wikipedia with more than a pinch – say several kg – of salt, because it frequently contains incorrect or outdated things, anyone can write whatever they please there, and there's nobody behind it that you can write to asking for clarification or where they got their statements from...