Robert also sent in a link to this story at Https://phys.org/news/2021-05-space-voyager-plasma.html … Voyager One, launched 44 years ago, now the most distant human made object in space, is still sending back information to NASA. It has passed through the heliosphere, the border between our solar system and further space, and is trawling through the interstellar medium. It has detected a constant drone of plasma waves, a persistent hum. Voyager is the mission that keeps on giving, even outside the influence of our sun.
At https://phys.org/news/2021-05-scientists-magnetic-action-sun-photosphere… … scientists catch magnetic waves in action on the Sun's photosphere – as in plasma waves [also known as Alfven waves]. Seems like Alfven is being readmitted into the mainstream fold. However, Alfven predicted this back in 1947 – over 70 years ago. These waves have the ability to transfer energy over very long distances. It may help explain the extreme heat of the solar atmosphere.
The press release comes from Queen Mary University in London -but seven other institutes were involved [including the Italian Space Agency].
On the subject of waves we have 'internal waves' that possibly sank an Indonesian submarine – see https://phys.org/news/2021-05-internal-possibly-sank-indonesian.html …where we learn that internal waves exist all around us, in the atmosphere and the oceans. Airplane turbulence is one of the effects. In this instance they are looking at the sinking of an Indonesian submarine. In the ocean internal waves are generated, they say, by hills on the sea floor. Thisa creates currents which concentrate wave energy in an up and down motion. They can be hundreds of metres high and several kilometres in length, travelling rapidly. Not only that but sea mounts off Indonesia are known to have caused problems at other times.
Even on the surface of the earth there are waves created by hills and mountains, we are told. These are generated by wind rather than currents.