The Universe May Be Defective
In a little over a year, on July 31st, 2008, the European Space Agency will launch Planck, a mission “designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution.”
This mission will improve upon the WMAP (Wilkinson Microwave Anisotropy Probe) data set, which mapped the cosmic microwave background at a resolution of 13 arcminutes. Planck will have an angular resolution down to 5 arcminutes.
The WMAP data really advanced our understanding of the conditions in the early universe and helped to support the idea the universe underwent a period known as ‘inflation’. This was a time when many cosmologists believe the universe underwent a very rapid expansion after which it cooled and began to clump into galaxies and clusters of galaxies.
If this idea was true, then clumps of energy should be seen in the CMB, and the WMAP team found exactly that:
Image Credit: NASA/WMAP
This clumpiness was a huge discovery and helped support cosmological models that included the inflationary period and made the models that did not less attractive.
This is a perfect example of the need to take actual measurements so that we can whittle away at the voluminous number of models cluttering cosmologist’s desks. We don’t need more models, we need more data. Planck is one mission designed to get rid of more models.
Planck will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure.
One of the models that got, not discredited exactly, but became much less attractive after the WMAP data was taken was a competing idea that instead of undergoing an inflationary period, the fabric of space contained ‘topological defects’:
such esoteric entities were first proposed in the 1970s, when physicists realised that the processes that gave rise to particles and forces in the early universe could also fracture space, creating twists and knots, dubbed textures, or “cosmic strings” that stretch across the universe.
These defects could also explain how galaxies and clusters of galaxies could form in the early universe.
It didn’t help that the topological defects idea was supported and predicted by string theory, something that is notoriously hard to understand and even harder to support with actual data. String theory is really irritating to many people, myself included.
But now, some cosmologists have found a ‘knot’ in the CMB that signals ‘not-so-fast-wait-a-goddam-minute’ to the defective universe idea.
But now it seems that cosmologists may have turned their back on defects prematurely. String theorists have recently discovered a small selection of models predicting that topological defects exist and could leave imprints on the CMB. “Finding evidence of defects will really help us rule out a vast number of our models,” says string theorist Renata Kallosh of Stanford University in California.
Here’s my favorite part: “help us rule out a vast number of our models”. Yeah, baby.
That’s the great thing about science, you can speculate and model till you’re blue in the face, but when the data come out, your precious model better match up.
IF these knots are real, and IF they are of the nature predicted by (gag) string theory, then they’ll show up in more accurate measurements of the CMB, exactly the kind of measurements instruments on board Planck will make.
Finally, a way to actually measure whether string theory is nothing but smoke and mirrors or not.
I’m looking forward to this mission more than any other on the drawing board. High resolution CMB maps, now THAT’s good astronomy porn.
All that and one less model…
Technorati Tags: cosmic microwave background, cosmology, esa, planck, planck mission
Related Stories
POSTED IN: cosmology
0 opinions for The Universe May Be Defective
No one has left a comment yet. You know what this means, right? You could be first!
Have an opinion? Leave a comment: