I love this phrase, standard candles, it’s a way of looking at the universe to work out distances in light years.

But I keep getting conspiracy theories about the universe from people on the Internet. I decided to try and explain my point of view.

I explained I’m not a physicist or optical expert. But I’ve read a lot over the years so this is my take on measuring the universe’s size.

This is what I wrote. Please accept my apologies if this is totally wrong. I only have a scant understanding.

I’m no

t an expert in optics but I think they have found the universe is over 13 billion years old based on the time light takes to arrive at earth. The science uses standard candles (globular clusters of stars that have the same light production so they can be used to judge distance because of light intensity). John Gribben explains this well in his popular science books.
Parallax can also be used to measure distance. If you look out of one eye at your thumb at arms length, then at it from your other eye you will see it apparently move. The same can be done from earth observatories. Look at a star at one end of Earth’s orbit around the sun then 6 months later at the other end… Effectively creating a very long thin triangle. The star will move a tiny fraction against the background of other stars. Using simple geometry you can measure the distance. These methods helped to work out how far other galaxies are outside the milky way. I read all of this from books by authors like Issac Asimov, Sir Patrick Moore, Carl Sagan, Brian Cox, and John Gribben among others. Not by watching Fox news.

(the last bit because I was accused of believing things that are on TV)