What a blast - Philly's Science Festival is back!

THERE'S science and technology in everything we see, touch, breathe, gulp and otherwise enjoy. That's the underlying theme of the fun-filled, not-just-for-nerds Philadelphia Science Festival, back (and to the future) today through May 3.

Hitting us all where we "live," more than 100 events are planned in everyday places like parks, restaurants, bars, libraries and museums for the nine days in this fourth annual celebration, presented by Dow Chemical and led by the Franklin Institute. Gizmo Guy has gone digging for the coolest happenings and is ready to share.

Except where noted, events are free. Find full details at philasciencefestival.org/calendar.

1. World's Biggest Rube Goldberg Machine: More than 350 kinetic energy tricks must be successively triggered to beat the Guinness record at today's Science Fest kickoff stunt. Knock on wood (catapults, metal chutes, string pulleys, burning candles and more).

Bossone Research Enterprise Center Atrium, Drexel University, Market Street between 31st and 32nd, 11:30 a.m.-12:30 p.m.

2. Astronomy Night: Tour the cosmos with your main squeeze or whole family, tonight at 7:30 p.m. You bring the blanket, they supply telescopes at 27 area locations, from the John Heinz National Wildlife Refuge, on Lindbergh Avenue, to Teens 4 Good Urban Farm (Poplar between 8th and 9th), and the Historic Fair Hill Burial Ground, at 2900 Germantown Ave., to MaST Charter School, 1800 Byberry Road.

3. Science Carnival After Hours: Also tonight, an adults-only party at the Franklin Institute, lubricated with Yards' official 2014 Festival beer. Scientific method demands try and try again!

Franklin Institute, 20th and the Parkway, 6:30-9:30 tonight, $15.

4. Discovery Day: That's tomorrow. Explore car hydraulics, take a nature walk, cultivate your inner scientist, watch sheep shearing and more at Hunting Park (900 Hunting Park Ave.), the Schuylkill Center (8480 Hagys Mill Road), Clark Park (4398 Chester Ave.) and Fox Chase Farm (8500 Pine Road). Free with 11 a.m. starts at all but Fox Chase Farm, which has a $3 admission and a noon opening.

5. Explorer Sunday: The hot topic of wearable tech is subject of a "Clothes of the Future" presentation at Drexel's ExCITE Center, 3401 Market St., 10:30 a.m.-12:30 p.m. Sunday.

Your body also will thank you for visiting the labs at Temple University School of Pharmacy, 3307 N. Broad St., 10 a.m.-noon Sunday, to make skin ointments.

And for mastering the butt-saving "Science of Skateboarding" (math meets physics, for real) at Paine's Skatepark next to Boathouse Row, 2-4 p.m. Sunday.

Gizmo Guy also is intrigued by "Plasma Lab: Improving TV Picture Quality and Saving Lives," though more for the latter (disease treatment, water purification), as plasma TV tech is sadly on the way out. A.J. Drexel Plasma Institute, 200 Federal St., noon-3 p.m.

6. Mess Fest: Things blow up (Alka Seltzer-powered rockets, D.I.Y. slime), brain power is explored, stories are told (like the rise and fall of planet Pluto) by physicist Paul Halpern and the Daily News' Vance Lehmkuhl.

Smith Memorial Playground & Playhouse, 3500 Reservoir Drive at Belmont Ave., 1-4 p.m. Sunday.

7. More Sunday shenanigans: Nerd Nite Brunch explains hangovers and dismisses "cures," Frankford Hall, 1210 Frankford Ave., noon-1:30 p.m., $5-$15.

"Science Crawl" through four Old City hot spots. Check in at Indy Hall, 22 N. 3rd., 4-6 p.m., $35.

"Sounds Made Up: (True) Tales From the History of Science" comically mocks bad science of yore. World Cafe Live, 3025 Walnut St., 4-6 p.m., $10 (ages 18+).

8. Tuesday Science Night at the Ballpark: A dozen hands-on activity stations set up throughout Citizens Bank Park explain baseballers' muscle power, reaction time, aerodynamics and more. Discount game tickets (Phils vs. Mets) start at $9.

And it's dollar hotdog night! (No science jokes, please.)

Info at phillies.com/science.

9. Chemical reactions: If you dare, explore "Love, Lust and Loathing: The Science Behind our Strongest Emotions," Frankford Hall, 1210 Frankford Ave., 6 p.m. Wednesday, $5-$15.

Learn what's up in your snoozing brain at "Sleep: A Bedtime Story," Franklin Institute's Fels Planetarium, 222 N. 20th St., 6:30-8:30 p.m. Wednesday, $10.

Taste and understand cheese fermentation at DiBruno Bros., 1730 Chestnut St., 6-8 p.m. Thursday, $15.

Dive into Beer Chemistry at Yards Brewing, 901 N. Delaware Ave., 7-10 p.m. Friday, $40.

10. Science Carnival on the Parkway: The festival finale is a massive, all-day show-'n'-tell with more than 150 exhibits, live entertainment and food trucks. Meet a real astronaut, pet zoo animals, sweep a crime scene for forensic evidence, launch rockets.

Ben Franklin Parkway, 10 a.m.-4 p.m. May 3, PhilaScienceFestival. org/carnival.