Electronics № 01
Why Do Blue LEDs Need More Voltage Than Red?
Blue photons carry 0.8 eV more than red ones, yet blue LEDs need 1.45 V more. Datasheets show where the extra voltage goes and why white LEDs match blue.
Simulations
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Space Interactive Zoom out to the edge of the universe
Space Interactive What if we replace the Sun?
Space Interactive Spin a space station: artificial gravity
Space Interactive Could we terraform Mars?
Physics Interactive The muon paradox
Space Interactive How small can you squeeze it?
Physics Interactive Orbits and Kepler’s laws
Space Interactive Scale of the universe
Planets Interactive Planet and star size comparison
Planets Interactive Weight on other planets
Space Interactive Moon phases: why does the Moon change shape?
Space Interactive Why do we have seasons?
Space Interactive Solar and lunar eclipse simulator
Earth Interactive How do tides work?
Space Interactive How long does it take to get to Mars?
Space Interactive Rocket equation: why is orbit so hard?
Physics Interactive Projectile motion simulator: which angle goes farthest?
Physics Interactive Pendulum period formula and simple pendulum simulator
Physics Interactive Half-life and radioactive decay simulator
Quantum Interactive Double slit experiment: waves, particles and watching the slits
Relativity Interactive The twin paradox: how much younger does the traveller return?
Light Interactive Snell’s law: how light bends, reflects and gets trapped
Space Interactive Roche limit simulator: turn a moon into rings
Space Interactive Lagrange points simulator: L1 to L5
Space Interactive Retrograde motion simulator: Mars and Mercury
Space Interactive Gravity assist simulator: a Jupiter flyby
Space Interactive Atmospheric escape simulator: can a planet keep its gas?
Relativity Interactive Gravitational time dilation simulator: black hole clocks
Space Interactive Redshift and blueshift simulator: spectral detective
Space Interactive Exoplanet transit simulator and light curve
Space Interactive Star life cycle simulator and H–R diagram
Space Interactive Orbital resonance simulator: repeating planetary rhythms
Physics Coming soon
How body shape changes lift
Featured
Latest posts
Electronics 01
Why Is Three-Phase Power Used? The Real Reasons
Three-phase power delivers constant power and a rotating field for motors. The copper saving is real but depends on what you compare. Worked numbers here.
Electronics 02
LC Resonant Frequency Formula: Derivation, Q and Real Parts
f = 1/(2π√LC), derived from energy sloshing, with Q, bandwidth, an AM tuner worked example, and why real coils and capacitors miss the ideal number.
Electronics 03
How Do Noise Cancelling Headphones Work? The Timing Math
Noise cancelling headphones play inverted sound, but a 20° phase error leaves a third of the noise. Why ANC kills engine drone and not voices, with plots.
Electronics 04
How Does an H-Bridge Work? Decay, Dead Time, Losses
Four switches reverse a motor, but the details decide whether it works: shoot-through and dead time, brake vs coast, why an L298 loses 2.5 V and PWM ripple.
Electronics 05
How Does a Boost Converter Work? Worked 3.7 V to 5 V
How a boost converter stores energy in an inductor and releases it at higher voltage. Worked 3.7 V to 5 V design, and why D near 1 fails.
Physics 06
Could Ant-Man Really Shrink? The Physics Says No
A 1 cm Ant-Man who keeps his 86 kg is as dense as a white dwarf. Why you can't squeeze out the space in atoms, and the one trick that really shrinks them.