Something We Don't Know?

Happy Valentine's Day! Another nod to the wondrous Kea, who has also shown great patience with the world. She points out a new paper by Spanish physicists Antonio Ranada and Alfredo Tiemblo, The Pioneer Anomaly as a Quantum Cosmological Effect. See the post from September 007 about this anomaly, Pioneers. Ranada and Tiemblo explain the anomaly as a change in the rate of time. Change in the rate of time is mathematically equivalent to a changing speed of light!

The new issue of ASTRONOMY magazine puts Pioneer on the cover while asking, "Is There Something We Don't Know About Gravity? Spacecraft flybys and the Moon's orbit aren't following predictions. Whatever is causing this could usher in a new theory of gravity."

In addition to Pioneer, ASTRONOMY points to evidence that the Astronomical Unit, the distance from Earth to the Sun, appears to be growing. Estimates of planetary distances have many sources of error, so researchers make multiple measurements. Astronomers Georgij Krasinsky, Victor Brumberh and Elena Pitjeva of St. Petersurg compiled 204,000 observations to conclude that the AU was growing at about 15 meters per century. If the speed of light were slowing, the AU would appear to grow almost exactly as observed.

The ASTRONOMY article also points to lunar laser ranging. As readers of this blog know, an anomaly in the Moon's orbit is one clue that the speed of light is slowing down. The Lunar Laser Ranging Experiment has measured the Moon receding from Earth at 3.82 ± .07 cm/yr. Geology and paleontology can tell more precisely how the Moon’s orbit has changed. According to Bills and Ray, the Moon has been receding at 2.9 ± 0.6 cm/yr. As with Mercury, small discrepancies in orbits can be very significant. When the Moon appears to recede 1/3 faster than geology says, it is a serious anomaly.

If the speed of light slows, that would increase the time for light to return each year, making the Moon appear to recede faster as seen by LLRE.

Start with GM = tc^3

c(t) = (GM)^{1/3} t^{-1/3}

cdot(t) = (-1/3) (GM)^{1/3} T^{-4/3}

cdot/c = -1/3t

Given an estimated age of the Universe t = 13.7 Gyr, cdot/c is -1/(41.1 Gyr)

Multiplied by the Moon’s distance of 384,402 km, that distance will appear to increase an additional 0.935 cm per year. An anomaly in the Moon’s outward drift is precisely accounted for, indicating that c is slowing to this day.

Venturing out into the Universe forces us to change old ideas. The Pioneer anomaly has led to many theories, including changes in c. Apparent growth in the Astronomical Unit may be another indicator of change. The Lunar Laser Ranging Experiment may indicate that c is still slowing. There is also evidence from Type Ia supernovae and the "Faint Young sun." Science may be opening to change, even in the speed of light.

Another Happy Valentine from the new Carnival of Space!