Discover what a jiffy actually is
About this idea
Learn that a 'jiffy' is an actual unit of time—it's the time light takes to travel one femtometer (10^-15 meter). That's about 3 × 10^-24 seconds! This quick physics lesson reveals the real science behind this casual expression.
On this page
How to get started
STEP 1
the definition (2 minutes)
- Jiffy (physics): Time for light to travel one femtometer
- Femtometer: 10^-15 meters (quadrillionth of meter)
- Light speed: 299,792,458 m/s
- One jiffy: ~3 × 10^-24 seconds
- That's:
- - 0.000000000000000000000003 seconds
- - Septillionth of a second
- - Unimaginably brief
STEP 2
other jiffies (2 minutes)
- Multiple scientific definitions:
- Light-foot (above)
- - 3 × 10^-24 seconds
- Electronics:
- - 1/60 second (US)
- - 1/50 second (Europe)
- - One AC cycle
- Computing:
- - 10 milliseconds
- - Or one tick of system timer
- Casual use:
- - 'Very short time'
- - No exact definition
- Context determines meaning!
STEP 3
origin OF the word (2 minutes)
- Word 'jiffy':
- - First recorded ~1780s
- - Origin uncertain
- - Possibly from lightning ('giffy')
- - Or from 'jiff' (glance/moment)
- Became casual term for brief moment
- Scientists co-opted for precise measurements
- Multiple fields defined it differently
- Now has several meanings
STEP 4
PERSPECTIVE (2 minutes)
- In one second:
- - 10^24 jiffies (light-femtometer)
- - More jiffies than seconds since Big Bang!
- Shows:
- - Time can be divided infinitely small
- - Our perception is coarse
- - Subatomic world operates on different scale
- Next time someone says 'be there in a jiffy':
- - Ask which jiffy they mean!
- - Probably the casual one
- - Not the physics one
What you’ll need
- none
Recommended resources
Progress milestones
Track your progress with these key achievements:
1
3 minutes
Learn what a jiffy is
2
5 minutes
Understand different definitions
3
8 minutes
Appreciate the scale
Common challenges
Every beginner faces obstacles. Here's how to overcome them:
Numbers too small to comprehend
Solution: That's the point! The subatomic world operates on time scales we can't intuitively grasp. Light is unimaginably fast, and distances between particles are incomprehensibly small, so jiffies are appropriately tiny.
Share your progress
Celebrate your achievements and inspire others:
- • Share this word origin fact
- • Appreciate scientific precision
- • Understand different time scales