Reasons to Believe

Distance to Double Pulsar Tests Cosmic Creation Models

Space-time theorems prove a supernatural Agent must've created the universe of space, time, matter, and energy. These theorems are true, however, only if general relativity reliably describes the dynamics of bodies within the universe. Thus, the greater the degree to which astronomers can verify the dependability of general relativity, the greater the confidence we can all have that an Agent beyond space, time, matter, and energy (a.k.a. the God of the Bible) created the universe.

Astronomers' measurements of the orbital characteristics of binary neutron stars have given rise to the most definitive tests for the reliability of general relativity. A neutron star is a supergiant star that collapses under its own gravity down to a size only about seven miles (twelve kilometers) in diameter. The compression that occurs is so great that protons and electrons are fused into neutrons. A neutron star is a solid lattice crystal of neutrons touching one another from the surface of the star down to its center. A single level teaspoonful of neutron star material weighs in at over two billion tons.

A binary neutron star is a system composed of two neutron stars that closely orbit one another. The gravitational forces these stars exert on one another can be a million times stronger than those astronomers measure in our solar system. Because of the extraordinary gravitational forces manifested in binary neutron stars, these systems yield for astronomers the most definitive tests for the reliability of general relativity.

Astronomers have discovered eight binary neutron star systems. Only one of them, J0737-3039A/B, is a system in which both neutron stars are visible as pulsars. A pulsar is a highly magnetized rotating neutron star that emits a focused beam of electromagnetic radiation. Each rotation of the pulsar brings the beam into Earth's view. The observed periods of the beam pulses range from about one millisecond to nearly ten seconds.

J0737-3039A/B exhibits the shortest revolution period. It takes just 2.5 hours for one of the pulsars to orbit about the other. Since the manifested gravitational force increases with the inverse square of the distance between two objects orbiting each other, J0737-3039A/B provides the best possible opportunity, by far, for testing the reliability of general relativity.

What limits the precision of general relativity tests by J0737-3039A/B is the need to determine the contribution of kinematic effects (movements of the pulsar binary system relative to Earth) to the measured timings of the pulsar pulses. This determination requires an accurate distance to J0737-3039A/B as well as measurements of its transverse motions. Until this past month, the best distance measurement to J0737-3039A/B was accurate to a factor of only two. Moreover, this evidence was gained through an indirect method.

Now, a precise, direct measurement of the distance to J0737-3039A/B has been achieved. A team of radio astronomers used the Australian Long Baseline Array, an array of radio telescopes stretched across the Australian continent, to measure the distance to J0737-3039A/B and its transverse movements employing the same trigonometric method taught in high school geometry classes.1 In that method, if one knows the length of the base of an isosceles triangle, then measurements of the angles at either end of the base will deliver the distance to the vertex of the triangle. For determining the distance to J0737-3039A/B, the team used as the base of the triangle the diameter of Earth's orbit around the Sun (about 185,912,076 miles or 299,195,741 kilometers).

The team determined the distance to J0737-3039A/B to be 3,750 ± 620 light-years. This measurement is three times superior to the previous best. Better yet, the team can continue using their array (and even bigger ones elsewhere) to dramatically improve the precision of both their distance measurement and of their determinations of the transverse motions of J0737-3039A/B.

Already, general relativity ranks as the most exhaustively tested and best-proven principle in physics. Thanks to the efforts of the Australian radio astronomy team and other such teams that will join in their quest, it will not be long before astronomers can add at least another factor of ten to their capacity to prove the reliability of general relativity. Such added proof will make the grip of the space-time theorems even more secure than it is today. Consequently, we can look forward to a far more compelling conclusion that the God of the Bible must have created the universe.

An added bonus to the team's efforts is that their measurements of the rate at which the two pulsars are spiraling inward toward a merger event will reveal much about the character of gravitational radiation. Such knowledge will help cosmologists determine exactly what kind of inflationary hot big bang model best explains the cosmic creation event. We can anticipate that a more detailed cosmic creation model will yield additional evidence for the supernatural design of the universe for the benefit of all life and for humanity in particular.

  1. A. T. Deller, M. Bailes, and S. J. Tingay, "Implications of a VLBI Distance to the Double Pulsar J0737-3039A/B," Sciencexpress Report (February 5, 2009), http://www.sciencexpress.org/5 February 2009/10.1126/science.1167969 (accessed May 6, 2009).

Subjects: Big Bang, Einstein / Relativity, Origin of the Universe

Dr. Hugh Ross

Reasons to Believe emerged from my passion to research, develop, and proclaim the most powerful new reasons to believe in Christ as Creator, Lord, and Savior and to use those new reasons to reach people for Christ. Read more about Dr. Hugh Ross.