What evidence is there to show that our universe is changing?

i'm doing some science coursework in school and i am unable to find the answer i'm looking for..



if you could tell me a little about red shift %26amp; microwaves as well it would be a big help as i get more marks %26amp; if you could describe the evidence that our universe is changing.



thanks.What evidence is there to show that our universe is changing?Start your search with Edwin Hubble.

He was the first to prove that the universe is not static, but

is expanding, with galaxies moving away from us in every

direction. This link will take you to him, and the article will

give you more information on the significance of %26quot;red shift%26quot;.



http://en.wikipedia.org/wiki/Edwin_Hubbl鈥?/a>
What evidence is there to show that our universe is changing?
What evidence that the universe is changing could be more unquestionable than the fact the sun and stars are burning and therefore getting inevitably smaller ?



Ours is not the only sun .
What evidence is there to show that our universe is changing?
evidence is the observation of galaxys.



the light we see from the furthest galaxies we can see in a sense is looking into the past. the further the object is the longer the light from it takes to reach us.



take that and compare it nearby galaxies and you can study the evolution of the universe
Edwin Powell Hubble (November 20, 1889 鈥?September 28, 1953) was an American astronomer who profoundly changed our understanding of the universe by demonstrating the existence of galaxies other than our own, the Milky Way. He also discovered that the degree of %26quot;Doppler shift%26quot; (specifically %26quot;redshift%26quot;) observed in the light spectra from other galaxies increased in proportion to a particular galaxy's distance from Earth. This relationship became known as Hubble's law, and helped establish that the known universe is expanding.



In physics (especially the physics of astronomical objects), redshift happens when light seen coming from an object is proportionally shifted to appear %26quot;redder%26quot;. Here, the term %26quot;redder%26quot; refers to what happens when visible light is shifted toward the red end of the visible spectrum. More generally, where an observer detects electromagnetic radiation outside the visible spectrum, %26quot;redder%26quot; amounts to a technical shorthand for %26quot;increased in electromagnetic wavelength%26quot; 鈥?which also implies lower frequency and photon energy in accord with, respectively, the wave and quantum theories of light.



Redshifts are attributable to three different physical effects. The first discovered was the Doppler effect, familiar in the changes in the apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles; an observed redshift due to the Doppler effect occurs whenever a light source moves away from an observer. Cosmological redshift is seen due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase of their distance from Earth. Finally, gravitational redshifts are a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blue shift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field.



Hubble's law describes the observation in physical cosmology that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us. The law was first formulated by Edwin Hubble in 1929 after nearly a decade of observations. The recession velocity of the objects was inferred from their redshifts, many measured much earlier by Vesto Slipher (1917) and related to velocity by him. It is considered the first observational basis for the expanding space paradigm and today serves as one of the pieces of evidence most often cited in support of the Big Bang model.



The law is often expressed by the equation v = H0D, with H0 the constant of proportionality (the Hubble constant) between the distance D to a galaxy and its velocity v. The SI unit of H0 is s-1 but it is most frequently quoted in (km/s)/Mpc, thus giving the speed in km/s of a galaxy one Megaparsec away. The reciprocal of H0 is the Hubble time.



The most recent observational determination of the proportionality constant obtained in 2009 by using the Hubble Space Telescope (HST) yielded a value of H0 = 74.2 卤 3.6 (km/s)/Mpc. The results agree closely with an earlier measurement of H0 = 72 卤 8 km/s/Mpc obtained in 2001 also by the HST. In August 2006, a less-precise figure was obtained independently using data from NASA's Chandra X-ray Observatory: H0 = 77 (km/s)/Mpc or about 2.5脳10^鈭?8 s^鈭? with an uncertainty of 卤 15%. NASA summarizes existing data to indicate a constant of 70.8 卤 1.6 (km/s)/Mpc if space is assumed to be flat, or 70.8 卤 4.0 (km/s)/Mpc



In 1964, Arno Penzias and Robert Wilson accidentally discovered the cosmic background radiation while conducting diagnostic observations using a new microwave receiver owned by Bell Laboratories. Their discovery provided substantial confirmation of the general CMB predictions鈥攖he radiation was found to be isotropic and consistent with a blackbody spectrum of about 3 K鈥攁nd it pitched the balance of opinion in favor of the Big Bang hypothesis. Penzias and Wilson were awarded a Nobel Prize for their discovery.



During the first few days of the Universe, the Universe was in full thermal equilibrium, with photons being continually emitted and absorbed, giving the radiation a blackbody spectrum. As the Universe expanded, it cooled to a temperature at which photons could no longer be created or destroyed. The temperature was still high enough for electrons and nuclei to remain unbound, however, and photons were constantly %26quot;reflected%26quot; from these free electrons through a process called Thomson scattering. Because of this repeated scattering, the early Universe was opaque to light.



When the temperature fell to a few thousand Kelvin, electrons and nuclei began to combine to form atoms, a process known as recombination. Since photons scatter infrequently from neutral atoms, radiation decoupled from matter when nearly all the electrons had recombined, at the epoch of last scattering, 379,000 years after the Big Bang. These photons make up the CMB that is observed today, and the observed pattern of fluctuations in the CMB is a direct picture of the Universe at this early epoch. The energy of photons was subsequently redshifted by the expansion of the Universe, which preserved the blackbody spectrum but caused its temperature to fall, meaning that the photons now fall into the microwave region of the electromagnetic spectrum. The radiation is thought to be observable at every point in the Universe, and comes from all directions with (almost) the same intensity.



The accelerating universe is the observation that the universe appears to be expanding at an increasing rate. In 1998 observations of Type Ia supernovae suggested that the expansion of the universe is accelerating since around redshift of z~0.5.



I hope these quotations from wikipedia are of some help!