Featured Research

from universities, journals, and other organizations

Spacetime: A smoother brew than we knew

Date:
August 23, 2012
Source:
Michigan Technological University
Summary:
Spacetime may be less like beer and more like sipping whiskey. Or so an intergalactic photo finish would suggest. Physicists reached this heady conclusion after studying the tracings of three photons of differing wavelengths that were recorded by NASA's Fermi Gamma-ray Space Telescope in May 2009. Photons from a gamma-ray burst jetted 7 billion light years across the universe and arrived at Earth in a dead heat, calling into question just how foamy the universe may be.

Gamma-ray burst.
Credit: Image courtesy of Michigan Technological University

Spacetime may be less like beer and more like sipping whiskey. Or so an intergalactic photo finish would suggest.

Physicist Robert Nemiroff of Michigan Technological University reached this heady conclusion after studying the tracings of three photons of differing wavelengths that were recorded by NASA's Fermi Gamma-ray Space Telescope in May 2009.

The photons originated about 7 billion light years away from Earth in one of three pulses from a gamma-ray burst. They arrived at the orbiting telescope just one millisecond apart, in a virtual tie.

Gamma-ray bursts are short-lived bursts of gamma-ray photons, the most energetic form of light. They can originate far across the universe, and astronomers believe many are caused by giant stars collapsing, often billions of years before Earth was formed.

"Gamma-ray bursts can tell us some very interesting things about the universe," Nemiroff said. In this case, those three photons recorded by the Fermi telescope suggest that spacetime may not be not as bubbly as some scientists think.

Some theories of quantum gravity say that the universe is not smooth but foamy -- made of fundamental units called Planck lengths that are less than a trillionth of a trillionth the diameter of a hydrogen atom. Planck lengths are so small that there's no way to detect them, except via photons like those that make up gamma-ray bursts.

Here's why. The wavelengths of these photons are some of the shortest distances known to science -- so short they should interact with the even smaller Planck length. And if they interact, the photons should be dispersed -- scattered -- on their trek through Planck length-pixelated spacetime.

In particular, they should disperse in different ways if their wavelengths differ, just as a ping pong ball and a softball might take alternate paths down a gravely hillside.

You wouldn't notice the scattering over short distances, but across billions of light years, the Planck lengths should disperse the light. And three photons from the same gamma-ray burst should not have crashed through the Fermi telescope at the same moment.

But they did, and that calls into question just how foamy spacetime really is. "We have shown that the universe is smooth across the Planck mass," Nemiroff said. "That means that there's no choppiness that's detectable. It's a really cool discovery. We're very excited."


Story Source:

The above story is based on materials provided by Michigan Technological University. The original article was written by Marcia Goodrich. Note: Materials may be edited for content and length.


Journal Reference:

  1. Robert Nemiroff, Ryan Connolly, Justin Holmes, Alexander Kostinski. Bounds on Spectral Dispersion from Fermi-Detected Gamma Ray Bursts. Physical Review Letters, 2012; 108 (23) DOI: 10.1103/PhysRevLett.108.231103

Cite This Page:

Michigan Technological University. "Spacetime: A smoother brew than we knew." ScienceDaily. ScienceDaily, 23 August 2012. <www.sciencedaily.com/releases/2012/08/120823111507.htm>.
Michigan Technological University. (2012, August 23). Spacetime: A smoother brew than we knew. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/08/120823111507.htm
Michigan Technological University. "Spacetime: A smoother brew than we knew." ScienceDaily. www.sciencedaily.com/releases/2012/08/120823111507.htm (accessed October 21, 2014).

Share This



More Space & Time News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins