Scientific theories are explanations that are developed through repeated observation and testing, and can be proven true or false. The Hubble Expansion Theory shows that the universe is expanding, with galaxies moving away from each other at a speed calculated by the Hubble Law. This theory has been tested and observed by scientists over many years, including Edwin Hubble's 1929 measurements showing that nearly all galaxies are receding from Earth, indicating the universe is expanding overall. Astronomers have also used parallax to measure distances to stars and further confirm the expansion of space between galaxies.

1. OUR EXPANDING UNIVERSE
By Ofori Boateng

2. SCIENTIFIC THEORY
A scientific theory is a explanation about something that has been developed
through processes and methods. it is something that has been repeatedly
observed and tested. A scientific theory can be true or false.

3. PROCESSES THAT A THEORY
GOES THROUGH
Normally a scientific presentation to be accepted has to go through a various series of tests that
will determine whether is wrong or right.
To be proven right scientific tests have to be made and these have to be unbiased and reliable. By
unbiased and reliable we mean something that is without prejudice, impartial and that can also be
repeatable in time.
Once done these tests findings and results have to be compared with other existing studies, to
show similarities and contrasts.
A scientific theory also has to be peer-reviewed which: “is the evaluation of work by one or more
people of similar competence to the producers of the work”. (1)
To have an accurate theory the size of the study is much relevant. A large research will obviously
give better and more accurate results than a small study.

4. THE HUBBLE EXPANSION
THEORY
The theory of the Hubble Expansion shows that “...the Universe is
expanding, with galaxies moving away from each other”.
This theory also shows that the Universe is expanding at a certain speed which
is calculated by following the Hubble Law (v = H*r) (2)
By relying on this theory we can come out with our own hypothesis which in
this case could be: The Universe is growing and expanding rapidly.

5. METHODS AND PROCESSES
There have been many tests and observations made by scientist to show how real this theory is,
and there have been methods and process used to prove this.
For example in 1929 the astronomer Edwin Hubble measured the velocities of a large selection
of galaxies. He began with the expectation that equal numbers of galaxies would be moving
toward and away from us, but instead he found out that almost every single galaxies is moving
away from us.
Since then scientists and astronomers with better equipment have proved that galaxies are really
moving away from us, which means the Universe is expanding. Galaxies seem to be receding from
us because the whole Universe is changing by getting larger. The space in between the galaxies is
stretching, and the farther away a galaxy is the more space there is to stretch so the faster the
galaxy appears to move away from us.
Astronomers have also found how to calculate how far a star is by a method called parallax. With
this method astronomers can measure the distance between stars, even though this is just possible
once every six months as stars move away from each other. (3)

6. REFERENCES
1. http://en.wikipedia.org/wiki/Peer_review Wikipedia, accessed on 3nd
October 2014
2. http://astro.berkeley.edu/~mwhite/darkmatter/hubble.html, scientific
website, accessed on 2nd October 2014
3. http://lcogt.net/spacebook/parallax-and-distance-measurement,
scientific website, accessed on 2nd October 2014
4. Universe Image: http://someinterestingfacts.net/is-the-universe-expanding/,
scientific website, accessed 2nd October 2014