system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do we know the universe is 14 billion years old? Do we have telescopes that can see that far?

So, I understand we know the age because that's how long it took the light to reach us - but do we have telescopes that can see that far? If we invented modern Hubble telescope with better technology, wouldn't we be able to see farther than the current one, or am I sorely misinformed about how telescopes work?
gpt
The age of the universe is determined by measuring the rate at which its expanding. The light emitted by an expanding galaxy becomes redder as it moves away. This is called the red shift. The rate at which the colour changes determines its velocity. If this velocity was reversed and the galaxies move closer with the same rate of change, the time taken for them to come together to a dense point is measured as the known age of the universe.