Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Satellite Could See Shadow Of Extra Dimensions
02-13-2007, 09:39 PM,
#1
Satellite Could See Shadow Of Extra Dimensions
From NewScientist:


Quote:* 22:05 12 February 2007
* NewScientist.com news service
* David Shiga


A satellite to be launched next year could see signs of extra dimensions in the afterglow of the big bang, a new study says.

Some theories – such as string theory – that attempt to unify all known forces into a single "theory of everything" posit the existence of extra spatial dimensions beyond the three familiar ones.

But string theory has proven stubbornly resistant to experimental tests (although some physicists say it could be tested in the Large Hadron Collider scheduled to open by the end of 2007).

Now, Gary Shiu and Bret Underwood, both physicists at the University of Wisconsin in Madison, US, say the shape of the extra dimensions could leave an imprint in the afterglow of the big bang. This glow, called the cosmic microwave background, reveals the structure of the universe about 370,000 years after the big bang.

They use a popular model of the universe's early growth called Dirac-Born-Infeld (DBI) inflation, which is inspired by string theory. It is one of a class of ideas called braneworld models, which state that our universe is like a sheet of paper floating in a higher dimensional space.
Subtle effects

Because we are confined to our 3D universe, we ordinarily have no way of seeing the extra dimensions. But Shiu and Underwood show that in this scenario, the big bang's afterglow is affected by the precise shape that the extra dimensions take.

The effects are subtle, however, and Underwood points out that other inflation theories that do not require extra dimensions could probably produce similar signals. So the effects could not be used on their own as proof that extra dimensions are present.

But if some other evidence is found that the DBI inflation scenario is correct, the new study shows that the detailed shape of those extra dimensions could be distinguished by Europe's Planck satellite, which is set to be launched in July 2008 (see the blog Precision cosmology with Planck).

Previous work by Shiu and others has indeed shown that DBI inflation could be distinguished from other scenarios through another effect on the cosmic microwave background – by causing the measured clumpiness of matter in the early universe to deviate in a characteristic way from a random distribution.
Single out

"The really exciting thing is that it's possible in principle – extra dimensions can actually show up in observations," Underwood told New Scientist. "If you know that you're in this particular model, then these details of the geometry can actually be seen."

Licia Verde, a cosmic microwave background researcher at the University of Pennsylvania in Philadelphia, US, says the predicted effects are big enough to be noticeable by Planck. "The prospects are exciting," she told New Scientist.

String theorist Robert Myers of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, cautions, however, that DBI inflation is just one of many scenarios proposed to explain the early universe, each of which could produce subtle effects in the microwave background.

"DBI is one variant which seems to be consistent with what we know," he told New Scientist. "But it will be very difficult to use CMB observations alone to single out the correct story."


http://space.newscientist.com/article/dn11...dimensions.html
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Huge circles on satellite weather pictures Australia and now Germany Hans Olo 23 6,887 02-06-2013, 09:25 PM
Last Post: CharliePrime
  What is happening to the SOHO satellite? yeti 7 2,352 03-10-2012, 07:45 PM
Last Post: CharliePrime
  NASA Satellite Crashes Before Reaching Orbit B4Time 18 2,700 04-09-2009, 09:49 PM
Last Post: rsol
  The Full Potential of Satellite TV NickHedge 2 760 11-16-2008, 09:50 PM
Last Post: NickHedge
  British Skynet Satellite Launched TriWooOx 3 714 03-20-2007, 01:51 PM
Last Post: slothy
  Strange 'shadow' From Chemtrail slothy 25 2,184 02-24-2007, 08:47 AM
Last Post: devkoo
  Scientists Boast Of Creating Extra-dense Memory Circuit subgenius 0 451 01-28-2007, 09:45 PM
Last Post: subgenius
  China Launches Its 'seed Satellite' pizzaman777 1 615 09-13-2006, 05:30 AM
Last Post: JohnDoe1984

Forum Jump:


Users browsing this thread: 1 Guest(s)