Featured Research

from universities, journals, and other organizations

Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant

Date:
November 28, 2007
Source:
Texas A&M University
Summary:
Einstein's self-proclaimed "biggest blunder" -- his postulation of a cosmological constant (a force that opposes gravity and keeps the universe from collapsing) -- may not be such a blunder after all, according to the research of an international team of scientists.

Kepler's Supernova Remnant, SN1604
Credit: NASA, ESA, R. Sankrit and W. Blair of John's Hopkins University

Einstein's self-proclaimed "biggest blunder" -- his postulation of a cosmological constant (a force that opposes gravity and keeps the universe from collapsing) -- may not be such a blunder after all, according to the research of an international team of scientists that includes two Texas A&M University researchers.

The team is working on a project called ESSENCE that studies supernovae (exploding stars) to figure out if dark energy -- the accelerating force of the universe -- is consistent with Einstein's cosmological constant.

Texas A&M researchers Nicholas Suntzeff and Kevin Krisciunas are part of the project, which began in October of 2002 and is scheduled to end next month after achieving its goal of discovering and studying 200 supernovae. The team uses a 4-meter diameter telescope in Chile during the observing season of October to December to find the supernovae.

In 1917, Einstein was working on his Theory of General Relativity and was trying to come up with an equation that describes a static universe -- one that stands still and does not collapse under the force of gravity in a big crunch. In order to keep the universe static in his theory, Einstein introduced a cosmological constant -- a force that opposes the force of gravity.

Then, 12 years later, Edwin Hubble discovered that the universe is not static -- it is actually expanding. So Einstein scrapped his idea of a cosmological constant and dismissed it as his biggest blunder.

In 1998, however, two teams of scientists, one of which Texas A&M researcher Suntzeff co-founded, discovered that the universe is not only expanding, but its expansion is actually accelerating -- going faster and faster.

"So there had to be some other force that had overcome the force of gravity and is driving the universe into an exponential acceleration," Suntzeff said. This opposing force is what scientists now call dark energy, and it is believed to constitute roughly 74 percent of the universe. The other constituents of the universe are dark matter, which composes about 22 percent of the universe, and ordinary matter, which is about 4 percent.

"Eighty years later, it turns out that Einstein may have been right [about a cosmological constant]," Krisciunas said. "So he was smarter than he gave himself credit for."

The type of supernovae that the ESSENCE team studies all give off the same amount of energy and have essentially the same peak brightness. Researchers can compare the observed brightness of a supernova that they see in the sky to its known actual brightness to figure out how far away the supernova is.

Researchers also look at what is called the redshift of the supernova, which tells them how fast the universe is expanding. When scientists compare the distance of the supernova to its redshift, they can measure the acceleration of the expansion of the universe. This acceleration is caused by the force scientists call dark energy.

The ESSENCE team can then use the value of the acceleration to figure out the density of dark energy, which they then use to calculate what is called the w-parameter. For Einstein's cosmological constant to be correct, the w-parameter must equal -1, and so far, the results of the ESSENCE project seem to confirm that it is indeed very close to -1.

"The magic value is -1 exactly," Krisciunas said. "If the number turns out to be precisely -1, then this dark energy is a relatively simple thing -- it is Einstein's cosmological constant." The team won't have the final results until later next year, but right now, the measurement is coming in at -1 plus or minus 10 percent error, Suntzeff said, so the initial data seems to point to Einstein being correct.

"We can never test [dark energy] in the laboratory, so astronomers have to measure it [through observational data], and one of the ways we're measuring it is with supernovae in the ESSENCE project," Suntzeff said. "Dark energy is completely unexplained by conventional physics. Perhaps this is a manifestation of the 5th dimension from string theory. Or maybe it is a new vacuum energy density that is changing slowly in time. We have no idea, and that is what excites both physicists and astronomers."


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Cite This Page:

Texas A&M University. "Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant." ScienceDaily. ScienceDaily, 28 November 2007. <www.sciencedaily.com/releases/2007/11/071127142128.htm>.
Texas A&M University. (2007, November 28). Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2007/11/071127142128.htm
Texas A&M University. "Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant." ScienceDaily. www.sciencedaily.com/releases/2007/11/071127142128.htm (accessed April 20, 2014).

Share This



More Matter & Energy News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Newsy (Apr. 19, 2014) Nike fired most of its Digital Sport hardware team, the group behind Nike's FuelBand device. Could Apple or an overcrowded market be behind layoffs? Video provided by Newsy
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
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:
from the past week

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