News / Science & Technology

Triple-Star System May Answer Questions About Gravity

Millisecond pulsar, left foreground, is orbited by a hot white dwarf star, center, both of which are orbited by another, more-distant and cooler white dwarf, top right. (NRAO/AUI/NSF)
Millisecond pulsar, left foreground, is orbited by a hot white dwarf star, center, both of which are orbited by another, more-distant and cooler white dwarf, top right. (NRAO/AUI/NSF)

Related Articles

World's Newest Island, Niijima, Keeps Growing

New island sits 1,000 kilometers south of Tokyo and 130 kilometers from nearest inhabited island

Study: Warmer World Will Produce Fewer Clouds

If clouds do not form, Earth would absorb more sunlight

Video Stunning Shots Show Saturn's Hexagon Vortex

The vortex measures some 30,000 kilometers across
VOA News
The discovery of a three-star system may yield clues that help scientists define the true nature of gravity.

The system, which consists of two white dwarf stars and a superdense pulsar, all packed within a space smaller than Earth's orbit around the Sun, could help resolve outstanding problems with Einstein’s Theory of General Relativity.

"This triple system gives us a natural cosmic laboratory far better than anything found before for learning exactly how such three-body systems work and potentially for detecting problems with General Relativity that physicists expect to see under extreme conditions," said Scott Ransom of the National Radio Astronomy Observatory (NRAO).

Using the exact timing of the pulsar’s lighthouse-like beams of radio waves, astronomers were able to calculate the geometry of the system and the masses of the stars with unparalleled precision.

The pulsar, which is 4,200 light-years from Earth, spins about 366 times per second. Pulsars are formed when a massive star explodes as a supernova and its remains collapse into a superdense neutron star, some of its mass is converted into gravitational binding energy that holds the dense star together.

Scientists say that the system could offer the best opportunity to discover a violation of a concept called Equivalence Principle.  This principle states that the effect of gravity on a body does not depend on the nature or internal structure of that body.

The most famous experiments illustrating the equivalence principle are Galileo's reputed dropping of two balls of different weights from the Leaning Tower of Pisa and Apollo 15 Commander Dave Scott's dropping of a hammer and a falcon feather while standing on the airless surface of the Moon in 1971.

"While Einstein's Theory of General Relativity has so far been confirmed by every experiment, it is not compatible with quantum theory. Because of that, physicists expect that it will break down under extreme conditions," Ransom explained. "This triple system of compact stars gives us a great opportunity to look for a violation of a specific form of the equivalence principle called the Strong Equivalence Principle," he added.

Under the strong equivalence principle, the gravitational effect of the outer white dwarf would be identical for both the inner white dwarf and the neutron star. If the strong equivalence principle is invalid under the conditions in this system, the outer star's gravitational effect on the inner white dwarf and the neutron star would be slightly different and the high-precision pulsar timing observations could easily show that.

"By doing very high-precision timing of the pulses coming from the pulsar, we can test for such a deviation from the strong equivalence principle at a sensitivity several orders of magnitude greater than ever before available," said Ingrid Stairs of the University of British Columbia. "Finding a deviation from the Strong Equivalence Principle would indicate a breakdown of General Relativity and would point us toward a new, correct theory of gravity," she added.

"This is a fascinating system in many ways, including what must have been a completely crazy formation history, and we have much work to do to fully understand it," Ransom said.

You May Like

Video Claims to Show Shia Forces in Iraq Executing Sunni Boy

While not yet independently confirmed, brutal killing already has gotten attention of Islamic State followers on social media More

After Six Years, Little Change for Niger Delta's Former Militants

Nigerians who laid down arms in exchange for government amnesty subsidies fear program may end with upcoming presidential elections More

Vietnam Pushes for More Educated Drivers to Curb Road Deaths

Transportation officials hope that making a greater effort to get drivers to learn the rules of the road will reduce fatal crashes More

This forum has been closed.
Comment Sorting
Comments
     
by: Ashish from: India
January 18, 2014 2:19 AM

Special Relativity has been far less tested than Quantum Mechanics. Even Einstein's own suggested platform-and-traincar experiment, which can now be done in table-top form, has not been done.

Time dilation and length contraction are the two central consequences Special Relativity. Forget testing the accuracy of the Length Contraction equation, it has not even been tested that length contraction happens. To put it another way, length contraction has never been observed, and over a hundred years have passed since it was theorized.

General Relativity's failure to explain the observed universe is well known. The evidence against General Relativity is not just in the behavior of galaxies but Earth-side too in the behavior of various launched space-crafts. Dark matter was created to explain failures of General Relativity .

Billions of dollars are being allocated and are being spent to search for Dark Matter. If Special Relativity fails an experiment then no Dark Matter or other such creation can save it. And General Relativity is built on the assumption that Special Relativity is true. It might be wise to spend a tiny amount to at least confirm Special Relativity.

It is good to see that individuals are now committing personal money to help bring about experimental testing of Special Relativity. The owner of below site has committed $7 million.

Ashish Sirohi
Physicsnext.org

by: Cranksy from: USA
January 09, 2014 1:00 AM
A naive but I hope at least a minimally respectable question: If the Theory of General Relativity has always been confirmed when tested, why must it be compatible with quantum theory? What gives quantum theory more "proofiness"?

by: Markt from: Virginia
January 08, 2014 11:50 AM
its all still Greek to me, but I do find space stuff interesting, all the talk of planets, stars and such....one question, though....

While all of this is fascinating, would it not be a better use of a scientists' time to figure out how to grow food to feed thousands where a few were fed before (and thus start putting and end to hunger around the world), or better fuels for vehicles so we no longer have to depend so heavily on oil (which is slowly running out worldwide)?
Its fine that we are learning so much about the solar system and worlds distant from ours, but how about working to find a cure for all the ills suffered by all on this world?
BTW, I really do like astronomy, I just think scientists have their priorities a little bit goofed up sometimes....how many millions of dollars were spent sending rovers to Mars? Could that money have better served people who are homeless and right now freezing on the streets of our own Nation's capital?
In Response

by: Cranksy from: USA
January 10, 2014 1:45 AM
You are saying that two resources, intellectual ability and money, could be better used. My hunch is it wouldn't take as much intelligence as physicists have to solve some of those problems and it needs is more motivation (persons and organizations including countries with your moral sense) to work and spend money that could come from more "frivolous" endeavors than this research .

by: Tom from: space
January 06, 2014 9:27 PM
I truly believe Nikola Tesla had figured out the secrets of gravity over one hundred years ago in his "Dynamic Theory of Gravity".
Unfortunately the government will never give out this information.

by: Reid Barnes from: Birmingham
January 06, 2014 4:21 PM
According to this article: "'While Einstein's Theory of General Relativity has so far been confirmed by every experiment, it is not compatible with quantum theory. Because of that, physicists expect that it will break down under extreme conditions,' Ransom explained." But how can a theory based on non-Euclidean geometry have been confirmed if non-Euclidean geometry with coordinates is self-contradicting? See the Facebook Note, the Rule of Threes (https://www.facebook.com/notes/reid-barnes/the-rule-of-threes/646220272097217).

by: Hank from: 65084
January 06, 2014 4:10 PM
It appears that Einstein's theory of relativity / gravity has spurred so much effort to prove him wrong that "perhaps" a new theory may take over. His theory has done a tremendous amount of good for science even if a small variance is found on his theories.
Breaking the code of gravity will be the true beginning of space travel and new worlds to explore. Great work. Hope you succeed in short order.

by: David Maiolo from: Webster, NY
January 06, 2014 3:40 PM
Thank you - a well written article that did a decent job expanding on an idea that many would have understanding in order to grasp the importance of the star system upon physics. The gravity test being proposed here should help us one day to find a unified theory that allows quantum and classical physics to talk with each other a little more openly.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
NASA Spacecraft Approaches a Dwarf Planeti
X
George Putic
March 04, 2015 8:51 PM
NASA’s Dawn spacecraft will make history on Friday, March 6, when it becomes the first man-made object to orbit a dwarf planet named Ceres. It is located in the asteroid belt between Mars and Jupiter, almost 500 million kilometers from Earth. Among other objectives, Dawn will try to examine two mysterious bright white spots detected on the planet’s surface. VOA’s George Putic has more.
Video

Video NASA Spacecraft Approaches a Dwarf Planet

NASA’s Dawn spacecraft will make history on Friday, March 6, when it becomes the first man-made object to orbit a dwarf planet named Ceres. It is located in the asteroid belt between Mars and Jupiter, almost 500 million kilometers from Earth. Among other objectives, Dawn will try to examine two mysterious bright white spots detected on the planet’s surface. VOA’s George Putic has more.
Video

Video Young Muslims Radicalized Online

Young Muslims are being radicalized ‘in their bedrooms’ through direct contact with Islamic State or ISIL fighters via the Internet, according to terror experts. There are growing concerns that authorities and Internet providers are not doing enough to counter online extremism - which analysts say is spread by a prolific network of online supporters around the world. Henry Ridgwell reports from London.
Video

Video African Americans Recall 1960's Fight For Voting Rights

U.S. President Barack Obama and thousands of people will gather in the small southern U.S. city of Selma, Alabama, Saturday, March 7th to commemorate the 50th anniversary of a historic voting rights march that became known as “Bloody Sunday." VOA’s Chris Simkins traveled to Alabama and introduces us to some of the foot soldiers of the voting rights struggles of the 1960’s.
Video

Video Positive Messaging Transforms Ethiopia's Image

Ethiopia was once known for famine and droughts. Now, headlines more often point to its fast-growing economy and its emergence as a regional peacemaker. How has Addis Ababa changed the narrative? VOA's Marthe van der Wolf reports.
Video

Video Cyber War Rages Between Iran, US

A newly published report indicates Iran and the United States have increased their cyber attacks on each other, even as their top diplomats are working toward an agreement to guarantee Iran does not develop a nuclear weapon and to free Iran from international sanctions. The development is part of a growing global trend. VOA’s Al Pessin reports from London.
Video

Video Answers Elude Families of MH370 Passengers

For the families on board Malaysia Airlines flight MH370, an airline official’s statement nearly one year ago that the plane had lost contact with air traffic control at 2:40 AM is the only thing that remains confirmed. William Ide reports.
Video

Video Land Disputes Arise Amid Uganda Oil Boom

Ugandan police say there has been a sharp increase in land disputes, with 10 new cases being reported each day. The claims come amid an oil boom as investors appear to be cashing in by selling parcels of land to multiple buyers. Meanwhile, the people who have been living on the land for decades are chased away, sometimes with a heavy hand. VOA's Serginho Roosblad reports.
Video

Video In Russia, Many Doubt Opposition Leader's Killer Will Be Found

The funeral has been held in Moscow for Boris Nemtsov, the opposition leader who was assassinated late Friday just meters from the Kremlin. Nemtsov joins a growing list of outspoken critics of Russia under the leadership of President Vladimir Putin who are believed to have been murdered for their work. VOA’s Daniel Schearf reports from Moscow.
Video

Video Simulated Astronauts Get Taste of Mars, in Hawaii

For generations, people have dreamed of traveling to Mars to explore Earth's closest planetary neighbor. VOA's Mike O'Sullivan reports that while space agencies like NASA are planning manned missions to the planet, some volunteers in Hawaii are learning how humans will cope with months in isolation on a Mars base.
Video

Video Destruction of Iraq Artifacts Shocks Archaeologists

The city of Mosul was once one of the most culturally rich and religiously diverse cities in Iraq. That tradition is under attack by members of the Islamic State who have made Mosul their capital city. The Mosul Museum is the latest target of the group’s campaign of terror and destruction, and is of grave concern to archaeologists around the world. VOA’s Kane Farabaugh reports.
Video

Video Smartphones May Help in Diagnosing HIV

Diagnosing infections such as HIV requires expensive clinical tests, making the procedure too costly for many poor patients or those living in remote areas. But a new technology called lab-on-a-chip may make the tests more accessible to many. VOA’s George Putic reports.
Video

Video Afghan Refugees Complain of Harassment in Pakistan

Afghan officials have expressed concern over reports of a crackdown on Afghan refugees in Pakistan following the Peshawar school attack in December. Reports of mass arrests and police harassment coupled with fear of an uncertain future are making life difficult for a population that fled its homeland to escape war. VOA’s Ayesha Tanzeem reports from Islamabad.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More