Expansion speeding up

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Re: Expansion speeding up

Postby david48 » Fri Sep 18, 2015 6:51 pm

dave.b wrote:LOL!
The Wikipedia article about the Lyman-Alpha Forest is clear enough; hydrogen absorption lines occur at many places in the observed spectrum from the distant source due to red shift. And when the source is so far removed and therefore it's light, as seen here on earth, started out a very long time ago it has so many absorption lines that a good chunk of its spectrum is knocked out, which appears as a trough in a plot of its spectrum.

It is incorrect to think of light as being solely a particle. It is not! Light exhibits both wave like and particle like properties simultaneously. A photon is best thought of as being a pulse of electromagnetic energy arising from the shift of an electron between energy states. Electromagnetic radiation exhibits a field with a frequency and a spin or phase. The frequency places the EMF on a spectrum of frequency of which visible light is just a small part. White light is what we perceive when a spread of visible light emf frequencies are detected by our eyes rather than just a narrow band, which we would see as a particular colour. Polarised light occurs when the spin or phase of the EMFs are in agreement.

Spectral absorption occurs when a photon (being a packet of emf energy) strikes an electron in an atom and is absorbed by it, causing the electron to shift to a new energy level.

Dave B.


Thanks Dave B. Your post is extremely lucid. It excellently sums up present ideas.

May I ask the following questions:

I. You say "the photon is best thought of as being a pulse of electromagnetic energy arising from the shift of an electron between energy states." Now doesn't that imply that:

The photon isn't a real particle. But the electron is an actual, real particle. It seems implicit. Would you agree?

2. You refer to the EMF as being a spectrum of frequency of which visible light is just a small part. OK, Suppose that's so. The Electromagnetic Spectrum is a continuous spectrum. Which extends all the way from Radio Waves, to Microwaves, to Infra-Red, Visible Light, Ultra-Violet, X-Rays, and Gamma Rays. They're just differing frequencies.

Then could we produce a single device, a kind of omnivisual telescope, which could "tune along" all these frequencies, like a radio set tuning into different frequencies?
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Re: Expansion speeding up

Postby dave.b » Fri Sep 18, 2015 10:24 pm

1. Interference wouldn't occur with particles. The double slit experiment makes this very clear.

2. Yep, that's it.

3. Sounds plausible, but currently not practical and it currently takes a range of detectors to cover the entire emf spectrum. There are false colour pictures where infra red, visible, ultra violet, and x-ray days have been overlaid and combined. In effect the producers of the picture have compressed a wide band of the light spectrum into just that of the visible light spectrum.

Regards
Dave B.
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