14 DAY TRIAL // The results of a new scientific study indicate that our planet indeed remains of the same size at all times. Researchers proposed some time ago that the world was contracting and expanding periodically, but the latest NASA-led investigation proved them wrong.
Experts first proposed the expanding Earth hypothesis while famed evolutionary biologist Charles Darwin was still alive. They were arguing that – even if solid – the planet underwent cycles of expansion and contractions that could be measured.
In fact, until the discovery of tectonic plates and the development of associated theories to explain their motions, this was the prevailing view in the international scientific community. However, even after these theories were established, some continued to propose the existence of such cycles.
Scientists who still argued for such a scenario proposed a variety of explanations to underly the phenomena. However, the new study demonstrates that neither of these scenarios is correct. The work is detailed in a recent issue of the top scientific journal Geophysical Research Letters.
In order to arrive at the new conclusions, investigators used a combination of space measurement tools with a new data calculation technique. This enabled them to search for statistically-significant expansions or contractions of the planet. No such events were discovered.
The study was carried out by an international collaboration of researchers, led by investigator Xiaoping Wu. The scientist is based at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California.
Experts from the Institut Geographique National, in Champs-sur-Marne, France, and Delft University of Technology, in The Netherlands, were also a part of the research. The team's goal was to evaluate the accuracy of the International Terrestrial Reference Frame, a group analyzing our planet's expansion.
“Our study provides an independent confirmation that the solid Earth is not getting larger at present, within current measurement uncertainties,” Wu explains.
“The team applied a new data calculation technique to estimate the rate of change in the solid Earth's average radius over time, taking into account the effects of other geophysical processes,” NASA scientists say in a press release.
“The previously discussed geodetic techniques (satellite laser ranging, very-long baseline interferometry and GPS) were used to obtain data on Earth surface movements from a global network of carefully selected sites,” the statement adds.
The end result of the new study was that Earth's radius is changing by about 0,1 millimeters (0.004 inches) per year, which is the equivalent of a human hair. Such a small measure is considered statistically insignificant.