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
The study of physical laws as they operate across the four dimensions of spacetime, treating time not as a separate parameter but as a full coordinate alongside space. In 4D physics, objects are understood as four-dimensional worldlines—complete trajectories through spacetime from beginning to end. A person isn't a 3D object that moves through time; they're a 4D object—a spacetime worm—with their entire existence laid out like a path. 4D physics explains why time seems to flow (we're just moving along our worldline), why the past feels fixed (it's just the part of the worm behind us), and why you should have paid attention in relativity class (because your GPS needs 4D corrections to work). It's the physics of block universes, where past, present, and future all coexist, and your sense of "now" is just a local illusion.
Text fits
Save
Cancel