Want to watch the sun safely with a large group? Get a disco ball

The upcoming solar eclipses and the present excessive sunspot exercise means it is a good time to watch the sun. Eclipses additionally imply that enormous teams of individuals will probably be collectively to view these occasions. Nonetheless, rule #1 for astronomy is to by no means take a look at the sun with unprotected eyes, particularly with a telescope or binoculars.

So, how are you going to safely present the altering sun to a big group of individuals with out having them line up perpetually to look via a telescope with a solar filter, or having lots of tools?

A gaggle of astronomers have an answer: Get a disco ball.

In case you arrange a disco ball in a sunlit room, they are saying, it should venture tiny pictures of the sun onto the partitions, just like how a pinhole camera works. However a disco ball can present the state of a solar eclipse or the presence of sunspots, and permit dozens of individuals to see it concurrently.

“Business disco balls present a protected, efficient and instructive means of observing the sun,” a gaggle of astronomers from a number of universities wrote in a pre-print paper published on arXiv. The paper explores the optics of solar projections with disco balls, and the researchers discovered that whereas sunspot observations are difficult, the solar disk and its modifications throughout eclipses are “straightforward and enjoyable to watch.”

In addition they discover the disco ball’s potential for observing the moon and different shiny astronomical phenomena.

The astronomers word that easy pinholes have been used to watch the sun since antiquity, together with different generally used instruments for projecting eclipses, resembling pinhole projectors, colanders, or tree canopies.

In contrast to extra conventional solar projection instruments like pinhole projectors and colanders, the disco ball spreads its solar pictures throughout a room, producing recognizable solar disks from distances of about two meters and onwards, the researchers mentioned.

“However a disco ball is ready to operate for giant crowds as a result of it doesn’t merely work on the realm the place it casts its shadow, however throughout the whole illuminated hemisphere, which may venture solar pictures throughout a complete room or courtyard,” they wrote.

Throughout March-Could 2023, the astronomers examined out a transportable disco ball as a part of a everlasting exhibition at a college observatory in Potsdam, Germany, with guests in teams of all ages. When illuminated by the sun, the ball was common with guests, “specifically, kids loved the chance of spinning the ball and watching the mirrored pictures transfer throughout the partitions,” they mentioned.

The researchers argue the disco ball is extra accessible instrument for bigger or socially distanced teams. It is usually potential to watch giant sunspots with a disco ball with sufficiently small mirror segments. In addition they examined out observing the moon and its phases, however that “requires a darker atmosphere than we’ve got but been capable of obtain.”

The record of benefits of a disco ball goes on: “Moreover, it doesn’t have to be pointed or moved to venture the sun, as new segments get illuminated because the sun strikes out of the older ones. Because of this it is sufficient to merely place a disco ball near a window in an effort to fill a big a part of the space with solar projections. The truth is, the disco ball encourages a crowd to disperse, as they stroll in the direction of the partitions to have a look at the projected pictures.”

With the annular eclipse arising on October 14, 2023 and a total solar eclipse on April 8, 2024, the astronomers mentioned a disco ball is a protected means for bigger teams of individuals to view these occasions and share them collectively.

“We imagine that the disco ball is a flexible and interesting instrument for instructional functions,” the researchers wrote, “deserving wider use each for classroom demonstrations and for public occasions.”