Electromagnetic Waves

Maxwell’s Equations Maxwell’s Equations Lorentz Force

Displacement Current Flowing current generates a magnetic field, but what about inside a capacitor where current doesn’t flow? I B A changing electric field also generates a magnetic field. E I

Wave Propagation in 3-D Plane Waves - Crests of the 3 dimensional wave lie in a plane. Intensity remains constant. Faraday’s Law Solution is Ampere’s Law

Properties of EM Waves E & B fields satisfy the same wave equation. EM waves travel at velocity, E & B fields are perpendicular to each other and to the direction of travel. Magnitude of E & B fields obey EM waves obey the superposition principle.

Polarization Electric Wave Preferential orientation of the wave’s electric field vectors. v Magnetic Wave Randomly Oriented Light Vertically Polarized Intensity of polarized light from incident unpolarized light is 50%.

EM Spectrum Radio waves Microwaves Infrared Light (IR) Visible Light Ultraviolet Light (UV) X-Rays Gamma Rays Decreasing Wavelength Increasing Frequency Speed - 3.0 × 108 m/s

Energy in an EM Wave Poynting vector - Rate at which energy flows through a unit surface perpendicular to the flow. (Units, W/m2) Wave Intensity Electric Wave v WLW of Cincinnati was the first 500,000 Watt station. It was ordered to reduce its output to 50,000 Watts Mar. 1, 1939. Magnetic Wave

Radiation Pressure Light has no mass; however, it does have momentum. For complete absorption of light (inelastic collision), the pressure is For complete reflection of light (elastic collision), the pressure is

Sloan Digital Sky Survey Doppler Shift For sound waves For light Light has no medium of propagation +v is motion towards the observer Star Spectra Sloan Digital Sky Survey Remember:

Evidences for IBB Hubble Constant Nucleosynthesis Microwave Background 73% H, 24% He, 3% other Microwave Background Large Scale Structure Evidence of Dark Matter

Young Creation Models How does distant light get to us? Light created in transit. Speed of light is slowing down. White hole cosmology Non-uniform properties of space Responses to the inflationary big bang model arise because it is difficult to remove the 13 billion year old universe prediction from the model itself. Also if the universe is really as big as it seems, then how does light travel a distance of billions of light years. Light created in transit (Mature creation) model states that the physical objects were created as well as the light between them. If the light between them was not there, then we would not comprehend the magnitude of the creation. Speed of light slowing down was proposed by Setterfield and is based on observation of the speed of light ranging back to the late 1700’s. The objection to this model is that we don’t want to change fundamental parameters of the universe. White hole cosmology is a recent model proposed by Russ Humphreys. He holds to a Big Bang type model with the earth at the center. The proposal is that when the earth went through the event horizon of the a white hole, time transpired at different rates by general relativity. When only a day transpired on earth, the cosmos aged billions of years. The objection to this model is that we do not want to put the earth in a unique position within the universe. Also there are problems with local phenomena not showing a distinctive difference than distant phenomena. A final possibility is that space has more complexity to it than currently assumed and this complexity provides conditions for super-luminal speeds of light.

Big Bang Critique Quintessence Exotic Dark Matter Laws of Thermodynamics Inflation Exceed speed of light by 1024× Not constrained enough “...supporters of Big Bang cosmology gain for themselves a large bag of free parameters that can subsequently be tuned as the occasion may require.” (Burbidge, Hoyle, & Narlikar) Composition of the Universe: 5% atoms, 26% dark matter, 69% dark energy

Kepler Mission Description Results as of Nov. 2013 Launched March 2009 View 145,000 stars near Cygnus Observe planet transits Stabilization failed May 2013 Results as of Nov. 2013 3538 candidate planets 10 earth sized in habitable zone Nearest maybe 12 light years away Number of stars in the galaxy – 300 billion Results from Kepler mission as of Nov. 8th, 2013. Kepler had a failure in its steering mechanism this year. View 145,000 main sequence stars in a fixed view. Looked at 3538 candidate planets in the constellation Cygnus. (Looking at direction of sun’s motion relative to the galactic center. Therefore, they are in the same galactic habitable zone.) 647 are earth sized (1 – 2 earth sizes) 104 are in the habitable zone 10 meet both criteria Nearest planet is 12 lightyears away. Using transit methods. Therefore, could be 100x more planets that just are being observed. Stars like ours (our sun and red dwarves) having earth-like planets is estimated to be 22 +- 8%.