Reply Mon 6 Jan, 2014 07:43 pm
http://news.ubc.ca/2014/01/05/newly-discovered-three-star-system-could-debunk-einsteins-theory-of-general-relativity/

A newly discovered system of two white dwarf stars and a superdense pulsar–all packed within a space smaller than the Earth’s orbit around the sun–is enabling astronomers to probe a range of cosmic mysteries, including the very nature of gravity itself.

The international team, which includes UBC astronomer Ingrid Stairs, reports their findings in the journal Nature on January 5.

Originally uncovered by an American graduate student using the National Science Foundation’s Green Bank Telescope, the pulsar – 4,200 light-years from Earth, spinning nearly 366 times per second – was found to be in close orbit with a white dwarf star and the pair is in orbit with another, more distant white dwarf.

The three-body system is scientists’ best opportunity yet to discover a violation of a key concept in Albert Einstein’s theory of General Relativity: the strong equivalence principle, which states that the effect of gravity on a body does not depend on the nature or internal structure of that body.

“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,” says Stairs, with UBC’s Department of Physics and Astronomy. “Finding a deviation from the strong equivalence principle would indicate a breakdown of General Relativity and would point us toward a new, revised theory of gravity.”

“This is the first millisecond pulsar found in such a system, and we immediately recognized that it provides us a tremendous opportunity to study the effects and nature of gravity,” says Scott Ransom of the National Radio Astronomy Observatory (NRAO), who led the study. “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.”

Background

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. The strong equivalence principle says that this binding energy will still react gravitationally as if it were mass. Virtually all alternatives to General Relativity hold that it will not.

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.

“We have made some of the most accurate measurements of masses in astrophysics,” says Anne Archibald of the Netherlands Institute for Radio Astronomy and one of the authors of the study. “Some of our measurements of the relative positions of the stars in the system are accurate to hundreds of meters.” Archibald led the effort to use the measurements to build a computer simulation of the system that can predict its motions.

The NRAO’s Scott Ransom adds: “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.”

The scientists’ observational program used the National Science Foundation’s Green Bank Telescope, the Arecibo radio telescope in Puerto Rico, and the Westerbork Synthesis Radio Telescope in the Netherlands. They also studied the system using data from the Sloan Digital Sky Survey, the GALEX satellite, the WIYN telescope on Kitt Peak, Arizona, and the Spitzer Space Telescope.

  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 10 • Views: 1,362 • Replies: 7
No top replies

 
ehBeth
 
  1  
Reply Mon 6 Jan, 2014 07:51 pm
@edgarblythe,
Quote:

The NRAO’s Scott Ransom adds: “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.”


the more we learn, the more there is to learn

fantastic!

thanks edgarb
0 Replies
 
farmerman
 
  2  
Reply Mon 6 Jan, 2014 08:12 pm
@edgarblythe,
YIPPEEE, Newton may be rehabbed . WE gotta hose down the pigeon **** all over Sir Isaac's statue.
The differences between newton and Einstein are substantial . The use of gravity as a geophysical tool is heavily dependent upon Newtonian physics which has the "CENTER of differing masses as the important feature in the force.

Wow, I smell Nobel Prize.
Joe Nation
 
  1  
Reply Mon 6 Jan, 2014 09:53 pm
So, like six years before there's a paper and another fifteen before the prize is announced?

I'm just trying to get my head to understand how three objects were orbit each other.

Joe(what a dance!)Nation
Setanta
 
  1  
Reply Tue 7 Jan, 2014 03:15 am
Cool, EB . . . thanks for keeping us up to date.
0 Replies
 
Lordyaswas
 
  2  
Reply Tue 7 Jan, 2014 03:44 am
@farmerman,
farmerman wrote:

YIPPEEE, Newton may be rehabbed . WE gotta hose down the pigeon **** all over Sir Isaac's statue.



The pigeons residing near Sir Isaac's statue are no longer making deposits on him, as they have heard the rumour that a new Statesperson is due to be commemorated by means of a statue to be erected nearby. They are therefore saving up a substantial contribution for when it is unveiled.




Site of proposed statue for Margaret Thatcher, next to Sir Isaac in their home town of Grantham.....

http://news.bbcimg.co.uk/media/images/69430000/jpg/_69430857_statuesitting.jpg
farmerman
 
  2  
Reply Tue 7 Jan, 2014 05:08 am
@Lordyaswas,
I love when these potentially big brain things happen in science.Ive been getting so sick of the "religion" of string theory and how gravity is not really a force.
Course, I haven't had my coffee yet, but, I gotta say that Newtonian gravity works just fine in small arenas (like geophysics) and weve always been given a "pass" as those somehow luddite dowsers who
really don't understand, poor boys they.

The field equations for magnetics and gravity are dimensionally equivalent and we can model one in terms of the other. That fact always annoyed the hell out of me as "Stringies" took over the entire discussion on basic forces in order to "shoe horn" their pet hypothesis.

0 Replies
 
rosborne979
 
  1  
Reply Tue 7 Jan, 2014 06:13 am
@Joe Nation,
Joe Nation wrote:

I'm just trying to get my head to understand how three objects were orbit each other.

The pulsar contains most of the mass of the system and the other two are just slightly larger than gas giant planets. So the orbital pattern probably looks like two glowing planets orbiting one super-dense star.
0 Replies
 
 

Related Topics

New Propulsion, the "EM Drive" - Question by TomTomBinks
The Science Thread - Discussion by Wilso
Why do people deny evolution? - Question by JimmyJ
Are we alone in the universe? - Discussion by Jpsy
Fake Science Journals - Discussion by rosborne979
Controvertial "Proof" of Multiverse! - Discussion by littlek
 
  1. Forums
  2. » Three Star System
Copyright © 2022 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.03 seconds on 05/23/2022 at 03:24:32