News / Science & Technology

NASA Probe Proves Einstein Right

Research leads to groundbreaking technologies

Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time.
Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time.

Multimedia

Audio
Rosanne Skirble

Albert Einstein was right. The U.S. Space Agency (NASA) released data this week from its Gravity Probe B spacecraft, whose primary mission while in Earth's orbit was to test Einstein’s 1916 Theory of Relativity. While the experiment evolved over decades, the results confirm Einstein’s work on the physical laws of the universe.

A Stanford University scientist first proposed an experiment to test Einstein’s theory in 1959 by rotating gyroscopes in space. Beset by launch delays, budget woes, faulty data and several federal investigations, Gravity Probe B was finally approved and was launched in 1984. The onboard experiment tested two of Einstein’s theories.

The first, explains lead investigator and Stanford University professor Francis Everitt, is the "geodetic effect." "In Einstein’s universe, space and time are warped by gravity. And what happens is the earth distorts the space around it very slightly by its gravity. And it’s 1.1 inches in 25,000 miles (2.75 centimeters in 40,000 kilometers). So it’s a rather modest distortion."

Gravity Probe B prior to launch in 2004
Gravity Probe B prior to launch in 2004
The second of Einstein’s theories that was put to the test is "frame dragging," which is the tendency of a spinning object to pull the fabric of space and time with it as it rotates, a phenomenon Everitt likens to the Earth immersed in a sea of honey.

"You can imagine that the honey would be dragged around with it, hence your pointer in the honey would be dragged around and that’s what happens to a gyroscope.So the earth actually drags space and time around with it."

Gravity Probe B housed several state-of-the-art technologies that did not exist when the Stanford group first conceived their gravity experiments. Among them, Everitt says, were four precision gyroscopes one million times more sensitive than any available back in the 1960s.

"Spheres the size of a Ping-Pong balls go in a quartz housing. We electrically suspend it. We spin it up by means of gas. (We) get it spinning to 5,000 rpm (revolutions per minute), pump out the gas to an extremely high vacuum and there we’ve got our gyroscope."

Once in orbit, the gyroscopes - spinning like a child’s top - were designed to keep Gravity Probe B perfectly aligned with a distant reference star. In confirmation of Einstein’s theories they experienced minute but measurable changes in the direction of their spin as they were pulled by earth’s gravity. 

Over the years, insights gained from Gravity Probe B have spawned a wave of new technologies, including the Global Positioning System, or GPS, a network of earth-orbiting satellites that have become essential for precise navigation on land and sea.

Former NASA manager Rex Geveden says despite the odds that the Gravity Probe B mission would fail, its success is a triumph of the human spirit - and intellect. "It’s a reminder of the sort of greatness that humans can get to when they put their hearts and minds on an objective like this."

Albert Einstein, who died in 1955, never dreamed that his Theory of Relativity would or even could be proved. In his book, The Meaning of Relativity, the famed physicist wrote: "...confirmation of them by laboratory experiments is not to be thought of."

Gravity Probe B lead investigator Francis Everitt adds, "Thanks to NASA we’ve done more than think about them. We’ve measured them."

The findings will appear in a forthcoming issue of the journal Physical Review Letters.

You May Like

At Khmer Rouge Court, Long-Awaited Verdict Approaches

First phase of trial, which is coming to an end, has focused on forced exodus of Phnom Penh in 1975 - and now many are hopeful justice will be served More

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities More

Video Information War Rages Alongside Real One in Ukraine

Downing of Malaysian airliner, allegations of cross-border shelling move information war in war-torn country to a new level More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Information War Rages Alongside Real One in Ukrainei
X
Al Pessin
July 31, 2014 8:13 PM
The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video Information War Rages Alongside Real One in Ukraine

The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict in Gaza, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities. Probably the most important destination is the local bakery. VOA’s Scott Bobb reports from Gaza City.
Video

Video US-Funded Program Offers Honduran Children Alternative to Illegal Immigration

President Obama and Central American leaders recently agreed to come up with a plan to address poverty and crime in the region that is fueling the surge of young migrants trying to illegally enter the United States. VOA’s Brian Padden looks at one such program in Honduras - funded in part by the United States - which gives street kids not only food and safety but a chance for a better life without, crossing the border.
Video

Video 'Fab Lab' Igniting Revolution in Kenya

The University of Nairobi’s Science and Technology Park is banking on 3-D prototyping to spark a manufacturing revolution in the country. Lenny Ruvaga has more for from Nairobi's so-called “FabLab” for VOA.
Video

Video Gazans in Shelled School Sought Shelter

Israel's air and ground assault against Hamas-led fighters in Gaza has forced many Palestinians to flee their homes, seeking safety. But safe places are hard to find, as VOA’s Scott Bobb reports from Jabaliya.
Video

Video Rapid Spread of Ebola in West Africa Prompts Global Alert

Across West Africa, health officials are struggling to keep up with what the World Health Organization describes as the worst ebola outbreak on record. The virus has killed hundreds of people this year. U.S. President Barack Obama and other world leaders are watching the developments closely as they weigh what actions, if any, are needed to help contain the disease.
Video

Video Michelle Obama: Young Africans Need to Embrace Women's Rights

U.S. first lady Michelle Obama urged some of Africa's best and brightest to advocate for women's rights in their home countries. As VOA's Pam Dockins explains, Obama spoke to some 500 participants of the Young African Leaders Initiative, a six-week U.S.-based training and development program.
Video

Video Immigrant Influx on Texas Border Heats Up Political Debate

Immigrants from Central America continue to cross the U.S.-Mexico border in south Texas, seeking asylum in the United States, as officials grapple with ways to deal with the problem and provide shelter for thousands of minors among the illegal border crossers. As VOA's Greg Flakus reports from Houston, the issue is complicated by internal U.S. politics and U.S. relations with the troubled nations that immigrants are fleeing.
Video

Video Study: Latino Students Most Segregated in California

Even though legal school segregation ended in the United States 60 years ago, one study finds segregation still occurs in the U.S. based on income and race. The University of California Los Angeles Civil Rights Project finds that students in California are more segregated by race than ever before, especially Latinos. Elizabeth Lee reports for VOA from Los Angeles.

AppleAndroid