I just took delivery of my sisyphus table 2 days ago (and wish that I had backed them 18 months ago for their kickstarter to save myself some money
their product is a glass top table that has a recessed area under the glass that houses a ring of adjustable LED lights and a soft, felt surface (much like a billiard table) that is covered with a thin layer of white sand. under the table, a raspberry pi computer controls a rotating, moveable arm with a strong magnet on the end that moves a 1/2" ball bearing through the sand to create a multitude of continuous line patterns (much like the spirograph toy of the 1960s)
the microSD memory card comes pre-loaded with over 30 designs and they have a community that not only has created a website that allows you to generate your own patterns, but you can also take vector drawings and convert them to the appropriate format to be used as well.
the mobile app (android and ios) allows you to control the brightness level of the strip of LED lighting surrounding the "playfield", ball speed as well as creating "playlists" for the drawing patterns.
at the slower speeds, it can take upwards of 2 hours to complete a design (depending on its complexity) but its rather therapeutic to watch it trudge through the mini mountains of sand, as it plows through and creates small valleys
I purchased the 3' coffee table version (they also produce a 22" dia. side table) and for people with lots of money, hand crafted 3' and 4' wooden tables
begin shameless plug:
if you are even considering purchasing one, you can use my referral link (below) to save $75 off of the purchase of a side or $100 off of the 3' coffee metal tables (which sell for $1299 and $1899 respectively). I receive an equal amount in my account that I can bank for the purchase of another table. it's definitely not a cheap table, but they are very well made and nicely constructed (and great conversational pieces
more information on the table can be found at https://sisphus-industries.com