The Great wall .. Background radiation (read Details please)?

Question

the other day i read something about how it was possible to conclude the distance and speed of some far away astronomic objects from the emission lines of hydrogene being present in the spectrum.
These objects were Quasars and it was determined that they move away from us at a good percentage of the speed of light, due to the expansion of space.
Now i thought .. has anybody ever tried pulling a spectrum from the background ?
was it even possible ?
as far as i know its some glob radiating around at just 4 Kelvin, but i do not really have an idea how it was possible to figure at which speed its moving away from us.
soo .. was there any test ? does anyone know something ?

thanks for explaining Doppler-effect and redshift, but actually that wasn't what i was asking.

Answer 1

I read your details, but I'm not completely clear about which question you really want answered, but let's get started:

Background radiation: Spectroscopy has been done. In fact, that's what leads to the 4 Kelvin description. The spectrum is consistent with blackbody radiation of objects at 4deg K. It is called background radiation because there is no identifiable point of origin. In other words, directional sensors pick up the same signal level when aimed at any point in the sky. The source is believed to be vastly red-shifted radiation emanating from the big bang. More info here: http://en.wikipedia.org/wiki/Background_radiation

Speed & distance determination: Speed estimates are based on 'red shift'. This term refers to the measured Doppler shift in the spectral absorption signature (lines) of known elements. Hydrogen is very frequently used because it is so common. Doppler shift, of course, is the phenomenon that changes the apparent frequency/wavelength of a received signal due to relative motion between the source and the receiver. In the case of sound waves, a train whistle will sound higher than the 'true' pitch as the train approaches a stationary listener. It drops to a lower apparent pitch as the train moves away from the listener. Does the actual pitch of the whistle change? No. The apparent pitch perceived by the stationary listener is all that changes. Faster trains result in a greater pitch changes. In the case of light, spectral lines appear shifted toward the red end of the spectrum when observing rapidly receding sources. The faster the object, the greater the shift. Hubble's constant is used to relate the amount of measure red shift to a distance. The relationship of red shift to distances seems to apply to many classifications of deep sky objects. More info @ http://en.wikipedia.org/wiki/Doppler_shift
& http://en.wikipedia.org/wiki/Hubble%27s_constant

Answer 2

Redshift...

In physics and astronomy, redshift occurs when the electromagnetic radiation, usually visible light, that is emitted from or reflected off of an object is shifted towards the red end of the electromagnetic spectrum. More generally, redshift is defined as an increase in the wavelength of electromagnetic radiation received by a detector compared with the wavelength emitted by the source. This increase in wavelength corresponds to a decrease in the frequency of the electromagnetic radiation. Conversely, a decrease in wavelength is called blue shift.

Any increase in wavelength is called "redshift", even if it occurs in electromagnetic radiation of non-optical wavelengths, such as gamma rays, x-rays and ultraviolet. This nomenclature might be confusing since, at wavelengths longer than red (e.g., infrared, microwaves, and radio waves), redshifts shift the radiation away from the red wavelengths.

A redshift can occur when a light source moves away from an observer, corresponding to the Doppler shift that changes the perceived frequency of sound waves. Although observing such redshifts, or complementary blue shifts, has several terrestrial applications (e.g., Doppler radar and radar guns), spectroscopic astrophysics uses Doppler redshifts to determine the movement of distant astronomical objects. This phenomenon was first predicted and observed in the 19th century as scientists began to consider the dynamical implications of the wave-nature of light.

Another redshift mechanism is the expansion of the universe, which explains the famous observation that the spectral redshifts of distant galaxies, quasars, and intergalactic gas clouds increase in proportion to their distance from the observer. This mechanism is a key feature of the Big Bang model of physical cosmology.

Sorry, you want to know if you can determine the speed of the cosmic background radiation away from us using this method... I don't think so because the CMB permeates all of space-time since it was created during the big bang itself.
Probes have mapped variations in the CMB.

I hope that helps.

Answer 3

If you have the spectrum of something, it's usually easy to calculate the (relative) speed at which it's moving. That's because of the dopler shift, in which frequencies of a wave appear to change as things move toward or away from you. Like a freight train's whistle or an ambulence's siren as comes towards you and then goes away..... it's pitch (frequency) seems to you to change, but in fact it's constant. Similarly, by looking at a spectrum, we can recognize familiar lines, representing the known frequencies of hydrogen and other materials as they emit radiation when excited, but the peaks are usually displaced a little, representing an apparent change in frequency. The change is proportionate to the relative speed of the object. Voila. Look up 'dopler shift' for more info.

Answer 4

How I see it is that The Agnostic Position is merely an interim learning period for a final conclusion !!! It is clear what the bible says that God always existed but when think about something has to always exist; atheist like say "Well Who Created God Then But They Always Turn Around & Say The Same Thing About Something In Their Theories, Just Look M Theory, The Brane World Always Existed, Or Look at Eternal Inflation Theory (The Inflation Always Existed), Or Simply Look At The Quantum Field (Hell Yeah It Always Existed Fot Atheists). BUT AH NOW; POOR GOD HE CAN'T EXIST EVEN IF THE BIBLE CLAIMS THAT HE DOES, HOW SIMPLY UNFAIR & UNTRUE !!! How Can Something Be Illogical Based On A Bias & Unfair Argument ?