Presented by group 2

1. MICROWAVE BACKGROUND
RADIATION

2. 1-a. What is The Electromagnetic
Spectrum
● It is the range of all types of EM radiation
● It includes Radio wave, Microwave,
Infrared, Visible Light, Ultra-Violet Ray,
X-Rays and Gamma Rays
● From lowest energy/longest wavelength
(at the top) to highest energy/shortest
wavelength (at the bottom).

3. 1-b. What are Microwaves?
● It is a form of EM radiation
● It’s wavelengths ranging from one meter to one millimeter
● It’s frequencies between 300 MHz and 300 GHz.
- Communications and radar
- Microwave heat sources
- Natural Microwaves Sources

4. 1-c. What is meant by cosmic microwave
background radiation?
● Electromagnetic radiation from the big bang.
● I tells us that the universe was once much smaller, hotter and denser
than it is today.
● Is redshifted photons that have freely streamed from an epoch when
the Universe became transparent for the first time to radiation.

5. 2-a. How was the microwave background
radiation discovered?
● Sensitive radio telescope shows a faint background
noise, or glow, almost isotropic, that is not
associated with any star, galaxy, or other object.

6. 2-b. Who discovered it and when?
● Discovered by Arno Penzias and Robert
Wilson (Communication engineer)
● May 20,1964 it was discovered.
● first predicted in 1948 by Ralph Alpher and
Robert Herman.
● Robert Dicke and Jim Peebles they check the
prediction in 1960.

7. ● In New Jersey there’s a
loud buzzing sound
● Eliminate all possible
sources of Interference
removing some pigeons
that nesting the
antenna.
HOLMDEL HORN ANTENNA

8. 2-c. Why is it considered evidence in support of the
bigbang ?
● It Represents heat left from the big bang
explosion.
● The universe is still expanding until now.
● Any atoms were broken apart into small
particles.
● Radiation from CMB scattered off the
electrons.

9. 3. What additional internet resources did you use?
Justify your choice. Why do you think it is reliable?
● https://www.space.com/25945-cosmic-microwave-background-discovery-50th-
anniversary.html
● https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
● http://theconversation.com/the-cmb-how-an-accidental-discovery-became-the-
key-to-understanding-the-universe-45126
● Because many people rely on this sites because it answers their questions.
And because of its visitors count and reliability.It has also proofs or evidences
in a given situation. There is an author.

10. References
https://www.livescience.com/50259-microwaves.html
https://en.wikipedia.org/wiki/Cosmic_background_radiation
https://www.scientificamerican.com/article/what-is-the-cosmic-microw/
https://www.space.com/25945-cosmic-microwave-background-discovery-50th-anniversary.html
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html http://theconversation.com/the-
cmb-how-an-accidental-discovery-became-the-key-to-understanding-the-universe-45126
http://www.darvill.clara.net/emag/emagmicro.htm
https://socratic.org/questions/why-is-the-big-bang-theory-considered-a-theory-and-not-a-fact