The Science of Soccer from 11 a.m. to 2 p.m. Saturday at The MIT Museum, 265 Massachusetts Ave. Free with museum admission, which is $10 for adults, $5 for visitors under 18, students and seniors and free for children under age 5. RSVP here.

In preparation for the 2014 FIFA World Cup in Brazil, the Massachusetts Institute of Technology and MIT-Brazil present this collection of soccer-themed events starting with an Embaixadinha soccer ball-juggling competition with Adidas World Cup Brazuca soccer balls as a prize. At noon, institute professor John Bush will talk about the physics behind soccer; at 1 p.m. is a musical performance by Receita De Samba, husband and wife Bill Ward and Anna Borges, with Brazilian refreshments. Information is here.

Mobilia Gallery spotlight exhibitions from 10 a.m. to 5 p.m. Saturday at Mobilia Gallery, 358 Huron Ave., Huron Village. Free.

This 36-year-old gallery is bringing together small collection of artists’ new works in short spotlight exhibitions, with the current half-dozen meshing into a pretty cohesive tour of small treasures led by Mariko Kusumoto’s Translucent Explorations and Arline Fisch’s Hanging Gardens.

Kusumoto, a metalsmith, works with fabric here to update the ancient technique of Tsumami Zaiku, origami-like flower hair ornaments worn with kimonos. Translucent Explorations is at the gallery through June. Fisch is a jeweler and metalsmith now exploring turning delicate, colored copper wire into organic forms. Her Hanging Gardens leave May 31.

Also at the gallery are Shane Fero’s delightful colored glass Birds from A-Z until May 31; Shinji Nakaba’s surreal, slightly spooky Glyptic Art and Carved Sculptural Jewelry until May 31; Kaz Robertson & Donna Barry’s friendly wearable art in resin, soft metals and semi-precious stones, through June; and Jee Hye Kwon’s architectural jewelry, which stands out among the collections as crystalline and mainly monochromatic, tending toward silver and Shakudo, also at the gallery through June. Information is here.

US Air Guitar qualifier round at 4 p.m. Saturday at T.T. the Bear’s Place, 10 Brookline St., Central Square. Entry is $10.

Okay, guys, this is serious. The winner of this US Air Guitar contest will be sent to Oulu, Finland, to compete for the world air guitar title – but it all starts with these regional qualifier rounds. Whether you want to compete or just get a glimpse at the faux-guitar god that might take the gold in Finland, you’ll want to be at T.T.’s. Get information and sign up here.

As the organizers put it: “US Air Guitar is devoted to taking our nation’s unofficial pastime out of the bedroom and putting it up on the world stage … In a time when U.S. political, economic, military and athletic dominance faces unprecedented challenges around the world, it is our belief that air guitar represents one endeavor our country can dominate without controversy.”

Family: A Benefit Performance for the 2014 Jean Appolon Summer Dance Institute in Port-Au-Prince from 8 to 9:30 p.m. Saturday at The Dance Complex, 536 Massachusetts Ave., Central Square. Tickets are $25 for one or at the door, or $20 for two or more in advance.

This benefit performance features the Haitian contemporary dancers of Boston-based Jean Appolon Expressions as well as guest performers in modern dance, urban dance, African dance and African drumming. Information is here.

The Freedom Cypher hip-hop gathering from 6 to 9 p.m. Sunday in the Rosa Parks room of The Democracy Center, 45 Mount Auburn St., Harvard Square.

This monthly event provides a glimpse at the area’s vibrant hip-hop scene and a chance to hear the best, most creative emcees, singers, beatboxers, musicians and DJs as they come together to support a featured music producer. This mobile sound lab also showcases local merchants (after its founding at Park Street in Boston, the Cypher was hosted for a while by Harvard Square’s Kulturez shop), visual artists and broadcasters. It’s an open studio environment that lets participants try out ideas and engage in unique collaborations. Background on the event is here.