Introduction Astronomy Tools Concepts 1. Electromagnetic Spectrum 2. Atmosphere Limitations 3. Space Observations Equipment 1. Telescopes 2. Radio 3. Space Tools 4. Photography 5. Spectroscopy 6. Computers 7. Advanced Methods 8. Radio Astronomy Basic Mathematics Algebra Statistics Geometry Scientific Notation Log Scales Calculus Physics Concepts - Basic Units of Measure - Mass & Density - Temperature - Velocity & Acceleration - Force, Pressure & Energy - Atoms - Quantum Physics - Nature of Light Formulas - Brightness - Cepheid Rulers - Distance - Doppler Shift - Frequency & Wavelength - Hubble's Law - Inverse Square Law - Kinetic Energy - Luminosity - Magnitudes - Convert Mass to Energy - Kepler & Newton - Orbits - Parallax - Planck's Law - Relativistic Redshift - Relativity - Schwarzschild Radius  - Synodic & Sidereal Periods - Sidereal Time - Small Angle Formula - Stellar Properties  - Stephan-Boltzmann Law - Telescope Related - Temperature - Tidal Forces - Wien's Law Constants Computer Models Additional Resources 1. Advanced Topics 2. Guest Contributions
 Physics - Formulas - Converting Mass to Energy The equation of all equations: Everyone has seen this equation, and everyone knows this is Einstein's famous "mass equals energy" equation. But what does it mean exactly? As always, its best to see it in an example. Because Einstein's work was with light and energy, the best example is the Sun. Our Sun produces energy through fusion - the combining of 4 hydrogen atoms to make a helium atom plus a few extra parts. When comparing the mass of 4 hydrogen atoms to a helium atom, there is some mass loss: Keep in mind that this is EACH reaction. In the Sun, there are millions of these reactions occurring. Back to Top