Skip to main content
Dictionary
Store
Blog
World
Help
Advertise
Chat
System Status
Information Collection Notice
Trademark Concerns
reCAPTCHA Privacy
Terms of Service
reCAPTCHA Terms
Privacy Policy
Accessibility
Report a Bug
Data Request
Contact Us
Security
DMCA
© 1999–2026 Urban Dictionary ®
Mugs
Tees
Hoodies
Pro Customization
Create unique products with your own words and definitions
Preview
Personalize Your Design
Your Word
Your Definition
An idiom used to explain how a seemingly negligible or "weightless" variable can have a massive, tangible impact on an outcome. It refers to the physics concept of radiation pressure. Because light carries momentum, the sunlight hitting a city like Chicago on a clear day actually pushes down on it, adding roughly 300 lbs of physical force to the city's total weight.
Text fits
Save
Cancel