maroun younan

Whenever cars, ambulances, trains or aeroplanes go past you notice the changes that the sound makes from a high pitch sound to a low pitch sound. Example if a sound wave is coming from a siren of an approaching ambulance or police officer the sound waves are produced by the siren repeating for then one time. The change in a wave length and a pitch is known as a Doppler effect. Christian doppler described it in 1842 researching what it mainly meant. Doppler effects also happen in light but firstly there is a change in its colour instead of its pitch change. scientist use a device known as spectrometer and they use this device to view various of colours or the light change of them. Edwin Hubble studied the position of dark lines within the spectrum light that was emitted by stars and galaxies. Stars that are moving away at a great speed or rate with spectrum moving towards the red end of the light is called a redshift. The example of the ambulance mainly moves away from us and the faster it goes the louder the sound gets.

RED SHIFT
Light from stars and more distant galaxies is not featureless but has spectral features and many characteristics of the atoms that are in the gases around the stars. When these spectra are researched or examined they are found to be shifted toward the red end of the spectrum. While that shift is called a Doppler shift and it basically outlines that in a fast amount of time all the galaxies are moving away from us.

This led Hubble to the fact that the red shift (recession speed) is proportional to distance and it is mainly called the Hubble’s Law that can be used as a distance-measuring tool itself.

sorry sir i couldn’t do it by yesterday friday because my computer was not working:

Research more about the Hubble Space Telescope. Gather information about
a) Hubble’s involvement in space research

Hubble research on the space has changed our understanding of the space and hubble has contributed to research on subjects as the Solar System to the structure of the most distant galaxies. His involvment has had a big impact in the astronomy from the research of the deep space to the origin of the universe. 

b) What the space telescope does
Hubble Space Telescope known as (HST) is a large space based on observatory which has revolutionized astronomy by providing a deep and clear views of the earths Universe.
c) Where it is

Hubble is located or is found 600 km or (375 miles) above the earths surface. Hubble in comparison is around 384400 or 238860 miles away from the moon.
d) What Hubble’s constant is

Hubbles constant is found mainly by the laws he had which were V=H*R while V symbolizes the galaxy R is the distance away from the earth and H was called the hubble constantand had units known as units of KM/SEC or KM/s?Mpc The hubble constant is used to orbit the universe and is able to find out the age of the universe.