Skip to main content

Dark Energy & Its Discontents

Dark Energy & Its Discontents
Peter Coles, University of Sussex
BRLSI Friday 24th April 2015
Notes by William Gaskell AMInstP

Parsec is about 3 lightyears
Calcium “doublet” signature on spectrum is marker used to measure Doppler shift with red/blue shifted light from galaxy/star indicaates relative velocity galaxy/star is moving away/towards us.
Hubble’s law is:
 v=H0D
Which describes how Universe is expanding but Hubble never wrote about it and he got his constant wrong by a factor of 10.

Alexander Friedman took Einstein’s Theory of Relativity and developed a more comprehensive model from it “The Freedman Model” – or The Big Bang Model.

Dark Energy is something that creates gravity but is not stuff – it’s like pressure that the vacuum of space exerts on matter.
Dark Energy increases as space expands, as it is a constant like the Hubble constant, but space expands in order to spread out the energy density of matter evenly.
Photosphere is the visible edge of the Sun, where gas density falls past the visible threshold where it is no longer opaque, which is a similar concept to the edge of the cosmos.


Comments

Popular posts from this blog

Notes from Energy & Utility Forum 2017

1. Robert Symons, CEO of Western Power Distribution said: “Energy demand could rise by 100% by 2030. Smart grids will be needed to manage electric vehicle charging so that the usage does not exceed the supply capacity at any time during the day.” 2. Spoke to Harry Vickers, Business Development Manager of Camborne Energy Storage, Camborne Capital at the Energy and Utility Forum in London on October 23rd 2017. He told me his company is working with Elon Musk to bring Tesla battery grid storage solutions to the UK. 3. Spoke to Sally Barrett-Williams, Chairman of Energy and Utility Forum on October 23rd, who said subsidies for solar projects had ended and her company’s focus has shifted to energy storage schemes. 4. Spoke to Simon Dowland, PhD, at 13:00 on Sunday 29th October, Simon is now working up in Cambridge at the Cavendish Physics Laboratory at the University of Cambridge, he is working in industry for the company Eight19 Ltd a spin off from a research project to bring ne...

We are mighty full of ourselves now, aren't we?

Vice-President Communications, Anthony Gaskell OE. Formula 1 needs more money in it to go back to how it was before. They need to get more serious. This is reminiscent of the good old days, the jet-set life and clean country living, where furniture and furnishings were made to the highest possible standard and there was no compromise on quality. Bad eye sight is like bad posture, it can be corrected without drugs or mechanical support. Eye-sight is a skill just as much as it is a transient attribute, many Opticians and others would say that eye-sight degrades with age and I would call them eccentric as typically one can expect that eye-sight would improve with age unless there was a problem. Ageing is a disease. A white British man with a PIO card as a businessman in Dubai , disappointed at a meeting. It is believed that Indians are descended from white-skinned peoples and that the truest Indians still have the whitest...

Thoughts of Grandma and Grandpa

Grandma and Grandpa at home in their 1 acre garden Grandpa was a scientist but no one paid him too much heed. He was a naval officer, Chief science officer, presumably naval lieutenant or, perhaps commander. I have never found out but I presume to have inherited the rank in British society. He had written about a voyage subsequent to WW2 where his ship promoted most ratings to officer rank, a 20 th century voyage of discovery where everyone made progress on their naval rank post war, so that most of the ships complement ended up as officers at the end of the voyage. This was led by a Rear-admiral so it must have all been legitimised by the mandarins at Whitehall. Grandpa never really approved of their pandering to communist sympathies. How many tweets make a twat again David Cameron? I think he was talking about Nick Clegg. #JokeOfTheDay my grandma thought I was an upper-class twit after I went to Eton. She thought it was more important to get a car and go on dates and make ou...