John Waterhouse - Can We Really Understand Our Universe?

John started his talk by saying if it exists it's in the Universe.

Light travels as wavelengths and photons and it travels at 669,600,000 miles per hour. The next galaxy Andromida is over 2.5 million light years away. So the galaxy we're seeing is how it was 2.5 million years ago . The further we can look further back in time we look deeper into history.

Our sun is hydrogen and helium which creates lines in the spectrum created by these elements so we know how a galaxy works through these key spectral lights.

The next after Andromida is 70 million Light years away. The further in the distance we look the further the spectral lines move to the red. The red shift allows us to measure the distance the Light has travelled. This is like the dopler shift for sound on ambulances. Hubble worked out that all galaxies are moving away from us. But if this is caused by the Big Bang the galaxies should be slowing down but they're actually speeding up.
An explanation cannot tie in to where the sun is we're just a bog standard solar system in a bog standard galaxy.

According to Einstein the Universe consists of space time and it interacts with massive objects. He came up with equation which was solved by the Catholic Priest George Lemaître. He said the Universe is either expanding or contracting. But Einstein no they are being carried away because space time is expanding. He thought he'd got it wrong and put a fiddle factor in. He went to see Hubble and realised he was right originally  without the fiddle factor.

The James Webb telescope launched 18 months ago and we are now looking further back in time. The work done impliesthat the Universe was formed 13.8 billion years ago. The latest Galaxy found is 13.4 billion years old.

As Universe expands it is cooling. So the thought is that helium and hydrogen were formed 3 or 4 hundred thousand years after big bang. Before that it was too hot for atoms to form so from then the first light was created but not at the start as the temperature was around 10 to the power 32 Kelvin. The only particles thought to exist then were protons and neutrons. It was not until about 380,000 years after the Big Bang that elements like Hydrogen and Helium were able to form as the temperature cooled to about 3,000 Kelvin.