Time Dilation Calculator

Einstein's Special Relativity

Calculate how velocity affects the passage of time using Einstein's Special Relativity. Essential for understanding relativistic effects, space travel, and modern physics.

Examples

Click on any example to load it into the calculator.

GPS Satellite

GPS Satellite

Time dilation for a GPS satellite moving at orbital velocity.

Velocity: 3874 m/s

Reference Time: 86400 s

Speed of Light: 299792458 m/s

Fast Spaceship

Fast Spaceship

Time dilation for a spaceship traveling at 10% of light speed.

Velocity: 29979245.8 m/s

Reference Time: 3600 s

Speed of Light: 299792458 m/s

Relativistic Particle

Relativistic Particle

Time dilation for a particle moving at 90% of light speed.

Velocity: 269813212.2 m/s

Reference Time: 1 s

Speed of Light: 299792458 m/s

Commercial Airplane

Commercial Airplane

Time dilation for a commercial airplane at cruising speed.

Velocity: 250 m/s

Reference Time: 3600 s

Speed of Light: 299792458 m/s

Other Titles
Understanding Time Dilation: A Comprehensive Guide
Explore Einstein's Special Relativity, how velocity affects time, and the fascinating implications for our understanding of space, time, and the universe.

What is Time Dilation?

  • Einstein's Revolutionary Discovery
  • The Speed of Light as a Universal Constant
  • The Relativity of Simultaneity
Time dilation is one of the most counterintuitive predictions of Einstein's Special Theory of Relativity. It states that time passes more slowly for objects moving at high velocities relative to a stationary observer. This effect becomes significant only when velocities approach the speed of light.
The Fundamental Principle
Einstein's Special Relativity is based on two fundamental postulates: the laws of physics are the same in all inertial reference frames, and the speed of light in vacuum is constant for all observers, regardless of their motion relative to the light source.
The Mathematics of Time Dilation
The time dilation formula is: t = t₀/√(1 - v²/c²), where t is the dilated time, t₀ is the reference time (proper time), v is the velocity of the moving object, and c is the speed of light. The factor γ = 1/√(1 - v²/c²) is called the Lorentz factor.

Key Concepts:

  • Time slows down for moving objects
  • The effect is negligible at everyday speeds
  • GPS satellites must account for time dilation

Step-by-Step Guide to Using the Time Dilation Calculator

  • Understanding Your Inputs
  • Choosing the Right Parameters
  • Interpreting the Results
This calculator helps you understand how velocity affects the passage of time according to Einstein's Special Relativity. Follow these steps to calculate time dilation for various scenarios.
1. Determine the Velocity
Enter the velocity of the moving object relative to the observer. This should be in meters per second. Remember that the velocity must be less than the speed of light (299,792,458 m/s). For everyday objects, the effect is extremely small.
2. Set Your Reference Time
Enter the time interval as measured by a stationary observer (the reference frame at rest). This is your proper time, and the calculator will show you how much time passes for the moving object relative to this reference.
3. Choose Your Speed of Light
The speed of light is typically kept at the default value of 299,792,458 m/s. This is the universal constant that defines the maximum possible velocity in the universe.

Calculation Steps:

  • Enter velocity (must be less than light speed)
  • Specify reference time interval
  • Calculate dilated time and Lorentz factor

Real-World Applications of Time Dilation

  • GPS Navigation Systems
  • Particle Physics Experiments
  • Space Travel and Interstellar Missions
Time dilation has practical applications in modern technology and scientific research. Understanding these effects is crucial for accurate measurements and predictions in various fields.
GPS and Navigation
GPS satellites orbit Earth at high velocities and experience both special relativistic time dilation and general relativistic gravitational time dilation. Without accounting for these effects, GPS would accumulate errors of several kilometers per day.
Particle Accelerators
In particle accelerators like the Large Hadron Collider, particles are accelerated to velocities very close to the speed of light. Time dilation effects are crucial for understanding particle lifetimes and decay rates.
Space Travel
For future interstellar travel, time dilation could allow astronauts to reach distant stars within their lifetimes, even though the journey would take much longer from Earth's perspective.

Practical Examples:

  • GPS satellites gain 38 microseconds per day due to time dilation
  • Muons created in the upper atmosphere reach Earth's surface due to time dilation
  • Astronauts on the ISS experience slightly slower time than Earth observers

Common Misconceptions and Correct Methods

  • The Twin Paradox Explained
  • Absolute vs. Relative Motion
  • The Role of Acceleration
Time dilation is often misunderstood, leading to common misconceptions about how relativity works and what it means for our understanding of time and space.
The Twin Paradox
The famous twin paradox involves one twin traveling at high speed and returning to find the other twin has aged more. This is not a paradox but a real effect, though it requires acceleration to return, which involves general relativity.
Relative Motion
Time dilation is always relative. Each observer sees the other's clock running slow. This apparent contradiction is resolved by the relativity of simultaneity - different observers disagree about which events happen at the same time.
Acceleration and General Relativity
Special relativity deals with inertial reference frames (no acceleration). When acceleration is involved, general relativity must be used, which also includes gravitational time dilation effects.

Important Clarifications:

  • Time dilation is symmetric between observers
  • Acceleration breaks the symmetry
  • Both special and general relativity affect time

Mathematical Derivation and Examples

  • Lorentz Transformations
  • The Time Dilation Formula
  • Numerical Examples and Calculations
The time dilation formula can be derived from the Lorentz transformations, which relate space and time coordinates between different inertial reference frames moving at constant velocity relative to each other.
Lorentz Transformations
The Lorentz transformations are: x' = γ(x - vt), t' = γ(t - vx/c²), where γ = 1/√(1 - v²/c²) is the Lorentz factor. These transformations preserve the speed of light and the spacetime interval.
Deriving Time Dilation
Consider a clock at rest in the moving frame. For this clock, Δx' = 0. Using the time transformation: Δt = γΔt', where Δt is the time interval in the stationary frame and Δt' is the proper time in the moving frame.
Numerical Examples
For a velocity of 0.5c (half the speed of light), γ = 1/√(1 - 0.25) = 1.155. If 1 hour passes in the moving frame, 1.155 hours pass in the stationary frame. For everyday velocities like 1000 m/s, the effect is negligible (γ ≈ 1.000000000006).

Mathematical Insights:

  • Lorentz factor approaches infinity as velocity approaches light speed
  • Time dilation becomes significant at velocities above 10% of light speed
  • The effect is quadratic in velocity for small velocities