I’ve started a new project at the University of Sydney. I’m still at the same desk, but I’ll be doing something a bit different. More details soon, but basically I’ll be using cosmological simulations of galaxy formation to try to make precise the connection between the fundamental parameters of cosmology – like the density of matter, the lumpiness of the early universe and the cosmological constant – and the conditions required by stars, and hence anything that requires stars.
For a brief overview of why anyone would do this, here’s a short presentation I gave at the Australian Academy of Science’s “Australian Frontiers of Science – The edges of astronomy” meeting in December 2014. My talk starts at 25:09. I think it’s queued up below. The other talks are also well worth your time:
The edge of the Universe—a fundamental limit how much we can know? – Associate Professor Tamara Davis
The small-scale spatial limits to the Universe – Dr Alessandro Fedrizzi
The edges of knowledge —the ‘physics is done’ syndrome – Associate Professor Michael Murphy
That’s a great talk. Of course I don’t understand the mathematics or half the physics, but the point is clear (I think). I liked your TS Eliot ending!!
Just one question. Is the pictorial simulation you showed part of the simulation software you’ll be using? It seems strange to me that what must be a very complex mathematical simulation would have a pictorial component. (Though it certainly was fun!)
The simulations contain a map of all the gas and stars, so the spatial information is all there to create an image. The mathematics is fairly complicated, but the output isn’t particularly. Part of what I’ve been doing at Sydney is developing a “synthetic pipeline”, which can take simulations like these and produce realistic images, as if we observed the simulated galaxies with a real telescope.
Congratulations! This is so exciting! Great talk btw (I think you’re pretty good at keeping your talks interesting). In a BBC documentary with Martin Rees, he said something to the effect that we can plug in different values for the constants in simulations and see that the Universe evolves dramatically different. But I don’t think he meant literally that this has been done (I’ve not seen any papers about it), but I thought it would be something really cool to try out.
Hence my big excitement over this. Since many of the papers on cosmological fine tuning are order of magnitude estimates, I could imagine that actually experimenting in cosmological simulators would pin down the numbers much more accurately on how sensitive the Universe is to changes in initial conditions and constants. It reminds me a little bit of the contrast in earlier studies of the habitable zone around stars. First they were very rough estimates, and then Michael Hart did a study where he tried to simulate the evolution of Earth’s climate over billions of years (although his model didn’t incorporate important effects that was included later).
So while this project may be a little out of the ordinary compared with typical research (as you and the other panelists discuss), I think work like this would be quite beneficial. Good luck with this project. I’ll be following updates on this for sure. 🙂
Cheers!
Thanks. I know it’s Real Serious Science, but it looks like real FUN as well!