Cosmic Horizons

Everyone loves black holes. Immense gravity, a one-way space-time membrane, the possibility of links to other universes. All lovely stuff. A little trawl of the internets reveals an awful lot of web pages discussing black holes, and discussions about spaghettification, firewalls, lost information, and many other things. Actually, a lot of the stuff out there on the web is nonsense, hand-waving, partly informed guesswork. And one of the questions that gets asked is "What would you see looking out into the universe?" Some (incorrectly) say that you would never cross the event horizon, a significant mis-understanding of the coordinates of relativity. Other (incorrectly) conclude from this that you actually see the entire future history of the universe play out in front of your eyes. What we have to remember, of course, is that relativity is a mathematical theory, and instead of hand waving, we can use mathematics to work out what we will see. And that's what I did. ...

Proton: a life story  by Geraint F. Lewis 10 35 years: I’ve lived a long and eventful life, but I know that death is almost upon me. Around me, my kind are slowly melting into the darkness that is now the universe, and my time will eventually come. I’ve lived a long and eventful life… 10 -43 seconds: A time of unbelievable light, unbelievable heat! I don’t remember the time before I was born, but I was there, disembodied, ethereal, part of the swirling, roaring fires of the universe coming in to being. But the universe cooled. From the featureless inferno, its character crystalized into a seething sea of particles and forces. Electrons and quarks tore about, smashing and crashing into photons and neutrinos. The universe continued to cool. 1 second: The intensity of the heat steadily died away, and I was born. In truth, there was no precise moment of my birth, but as the universe cooled my innards, free quarks, bound together, and I was suddenly there!...

Quick post. I've taken a bit of a hiatus from publishing in The Conversation  for a while, for mildly political reasons that I will talk about some day. But I decided to get back on this horse and have written an article called  Grey is the new black hole: is Stephen Hawking right? I'll let you have a read and I'll be happy to answer questions below. But for now, here's "Colin"

It's the week for submission of Discovery Projects , our main funding route through the Australian Research Council. Our current proposal is almost 150 pages long, and I feel like we've been working on it since the Cosmological Dark Ages . It will be good to submit it, but don't think that means I get a break. No, it's time to catch up on all the stuff that has been on the back-burner when grant writing :) So, a quick post today on an article I wrote for The Conversation called "Cutting through the spin on supermassive black holes" . As the name suggests, I describe how astronomers can not only measure the mass of black holes, but can also calculate their spin. I must admit that the article is a little long compared to others I've written for The Conversation, and what is published is the shortened version. It's a topic that I think is pretty cool and I put in too much detail. I'll let you read the article, and will happily answer any que...

A very quick post tonight. I was interviewed to comment on the discovery of a very massive  black hole , much more massive than we would expect from the galaxy in which it is found. This is a big black hole. Say it slowly... 17 billion times more massive than the Sun. That is a lot of mass in a very small volume. The article is presented in  The Conversation . You can read it  here , and, as ever, I am happy to address any questions in the comments spot below. Black holes. You have to love them!