How Do We Know?

How Do We Know? a song by The Pop Ups on Soniditos

Shadow by The Pop Ups , Secret Agent 23 Skidoo ,
Time by The Pop Ups ,
Inventors by The Pop Ups ,
Synthesizer by The Pop Ups ,
Meteor Dinosaur by The Pop Ups ,
Space Adventure by The Pop Ups ,
Cave of Wonders by The Pop Ups ,
Holding Up A Mirror To A Mirror by The Pop Ups ,
How Do We Know? by The Pop Ups ,
Science of Sleep by The Pop Ups ,