Maybe it's time we stopped using the light years to determine astronomical distances

In a study published in Astronomy & Geophysics, Keith Atkin, a retired associate professor of physics at the University of Sheffield, United Kingdom, argues that perhaps we should stop using certain measures in astronomy that he considers periclited.

While the professional field of astronomy has moved away from the imperial units of miles, pounds and degrees Fahrenheit, "this transition has not been complete," according to the summary of his study. The use of units such as light years (the distance covered by light in a year: 9.5 billion kilometers) and astronomical units (the average Earth-Sun distance: 150 million km) persists.

More logical units

Atkin argues that simpler logical units would help both in the field of astronomy and, above all, in multidisciplinary research.

Atkin It focuses primarily on distance measurement units, not only warning of the seemingly random and often redundant nature of the units unique to the astronomical field, but also sometimes their strange construction.

Your solution? "To encourage the use of SI length units in all astronomical work: all distances and lengths should be based on, and simply be related to, the meter. The meter is defined as the length of the path traveled by light in a vacuum over a time interval of 1/299 792 458 of a second. "

Therefore, he argues, all astronomical distance units, from astronomical units to the parsec (equivalent to 3.26 light years), can really be expressed in meters, with the appropriate SI prefix.

For example, Atkin proposes that the megameters (Mm, 106m), gigameters (Gm, 109m) and terameteros (Tm, 1012m) are used for scale distances of the planetary and solar system, thus making the radius of the Earth 6.37 mm and su distance from the sun, 150 Gm.

For larger distances, it suggests petameters (Pm, 1015m) and exameters (Em, 1018m) within our galaxy, and zettameters (Zm, 1021m) and yottameters (Ym, 1024m) for extragalactic distances.

In this regime, Next CentauriFor example, it is about 40 Pm (instead of 4 light years) away, the Milky Way is 1 Zm wide and Andromeda is 20 Zm away. The proto-galaxy UDFj-39546284, one of the oldest and most distant objects detected to date, would be located at a distance of 126 Ym.

Atkin extends its argument to other units of measurement: Why use kilograms or solar masses if we can use grams? He also argues that units such as arc minute and arc second should be eliminated. Atkin proposes to measure all angles in terms of decimal degrees or radians.

While difficult to implement in the short term, these changes "will surely benefit understanding and communication within astronomical circles and between astronomy and related sciences."