Classroom Aid - Gravitational Redshift Test

In this segment of the “How Fast Is It” video book, we cover the effects of general relativity and how they differ from what Newton’s gravity predicts. Our first effect is the orbit of Mercury that precesses more than Newtonian gravity predicts. To understand the non-Euclidian space that Mercury orbits in, we introduce the Schwarzschild metric and compare it to the Minkowski metric for flat space-time. We illustrate the positive curvature around the Sun using concentric circles with shrinking circumferences. We then show how this slight difference in curvature produces additional movement in the precessing perihelion of Mercury’s orbit that exactly fits the measured number. Our next effect is the bending of light. We cover Arthur Eddington’s famous measurement during a total eclipse of the Sun and show how the amount of starlight bending matched Einstein’s calculations better than Newton’s. We extend this bending effect to show how Einstein Rings and gravitational lensing work. And we show how this effect tips over light cones and changes world-lines. Our third effect is gravitational time dilation. We show how it works and cover how our GPS uses it. We also cover the Pound-Rebka experiment used the Mossbauer Effect to showed how this time dilation impacts gravitational redshift. We also illustrate how this effect resolves the Twin Paradox we introduced in the Special Relativity segment.
Music
Music

@01:17 Mozart - Flute Concerto No. 2 in D Major: Kurt Berger, Vienna Mozart Ens; from the album “50 Must-Have Adagios Masterpieces” 2013

@12:03 Grieg - Holberg Suite, Sarabande (Andante): Gothenburg Symphony Orchestra; from the album “For the Hopeless Romantic” 2005

@19:47 Korsakov - Capriccio Espagnol: Royal Philharmonic Orchestra; from the album “Rimsky-Korsakov: Scheherazade” 2009

[Greg_Chase]

As a race car or firetruck (siren) moves away, the same sound waves - the same frequency - is being emitted from the source.

What appears to change is this. Since higher frequencies have greater energy (that is true for sound waves and electromagnetic waves: the energy content in the wave increases with increasing frequency) -

- even though the same frequency is emitted from the race car exhaust or firetruck siren, the wave travels a greater distance if the source of the wave is moving away from you.

That means the same energy wave, as it has to travel an increased distance to reach you, is attenuated by a greater bulk of matter (the air molecules).

EXAMPLE
- you stand next to the firetruck, its siren on, and it's parked - the sound waves travel through a mass of M = m1
- now, the truck passes you at 60mph - the sound waves travel through a greater air mass of M = m2

Since m2 > m1, there is more material (more matter, in the form of air molecules) to 'dampen' or attenuate, ie. absorb the energy of the sound wave.

So the wave loses greater energy traveling through m2 than through m1.

And the decline in wave energy requires an increase in wavelength.
This is the way I've reasoned it out.
.

[woody]

This is the kind of information that should be taught in schools, unfortunately school kids today can’t even tell time on an analog clock…not kidding

[woody]

It boggles the mind that an object, ie light, with zero mass can be influenced by gravity in any way..?