The Universe and Electromagnetic SpectrumState Objectives 2e. and 4.f.

WHAT ARE ELECTROMAGNETIC WAVES?*Form of _______________ that travels at the speed of ________________ (3000,000 km/s)

*Uses _______________ and _____________________ fields

*Can travel through a ____________________ (empty space)

*Two Characteristics

-_____________________ - distance between two points on a wave.

- _____________________-number of waves that pass a point in one second.

*Electromagnetic _________________ is a collection of EM waves of all known frequencies.

Properties of Waves

Electromagnetic Spectrum

Gamma Rays

*__________________ : carry the most energy

*____________________ wavelength & __________________ frequency

*Produced by _______________ objects in universe

*_______________ living cells

*Used to _________________ medical equipment, _____________ bacteria in food, and

_____________ cancer

X-Rays

*_________- high energy through soft tissue & matter; but lower energy in hard tissue & matter.

*Can damage or kill __________________________, so precautions must be taken

*Used in ___________________ imaging and security screening ___________________

Ultraviolet Rays

*___________________; has both ________________ and _______________ effects on living

organisms.

*Helps produce ______________________ in the skin and causes _____________________.

*Prolonged exposure causes ___________________ and _______________________.

*Most UV radiation is blocked by the _______________________.

*Can be used to ___________________ objects and in “_____________________”.

Visible Light

*________________; the only part of the spectrum that is ________________ by the human eye

*__________________ wavelength & _____________________ frequency than UV-rays

*Allows us to see different ___________________

*Objects __________________ the color of the spectrum you see and _____________ the other colors

*Order from _________________ wavelength to __________________

*___________, ______________, _________________, ___________, ____________, ___________,

_____________

*_____________________________

Infrared Rays

* ______________________: cannot be seen by humans but is felt as _____________.

*Wavelengths ________________ than visible and have frequencies which are _____________ than

visible

*Used in thermal imaging cameras (__________________), and _____________ remote controls

*Can be used to observe faint objects in ________________

Microwaves

*Pass easily through earth’s _____________________ so they can be used to transmit ______________

(TV broadcasts)

*Also used to ________________, in ____________________________, & ________________________

*_________________ ovens work by causing water and fat molecules to ________________.

*Some scientists believe prolonged exposure to microwaves though cells phones and other devices can

lead to __________________________.

Radio Waves

*________________ ; carry the _______________ amount of energy

*_________________ wavelength & __________________ frequency

*Main use is ________________________.

*Different frequencies

Place the appropriate letter in the blank.

_____1. Radio A. Prolonged exposure can harm skin

_____2. Microwaves B. Only part of the spectrum the human eye can detect

_____3. Infrared C. Used to transmit information

_____4. Visible light D. Humans release this in the form of heat

_____5. Ultraviolet E. Kills living cells

_____6. X-rays F. Used in cell phones and to cook food. Might cause cancer.

_____7. Gamma rays G. Damaging to soft tissue, but is used with precaution for

medical imaging.

Parts of the Universe

*The __________________is all space, matter, and energy that exists.

*The exact size is ____________________, but it is believed to still be ___________________ outward.

*Stars group together in ______________.

*Clusters group together in _________________.

*Galaxies group together in ______________.

*Galaxy groups group together in __________________________.

Galaxies

*Huge collection of ___________, __________, & ____________ held together by ________________.

*3 types of galaxies______________, ______________________ & ______________________.

Galaxy Groups

*The __________________ (our galaxy) is located in the __________________________.

*The Local Group contains ______________ galaxies.

*The Local Group is part of the ____________________________________(at least 100 galaxies).

The Milky Way

*From the side, the Milky Way appears to be a narrow ___________ with a ____________ in the

middle. The galaxy’s spiral structure is visible only from ______________ or _______________.

Stars

*Stars are objects made of ____________ which produce ___________ and ___________ from

_____________ reactions inside the star.

*Smaller stars fuse ______________________ into ___________________.

*Larger stars form & end their life in ________________.

Nebulae

*__________________ are large clouds of gas, plasma & dust within a ______________.

*Typically a few light-years wide.

*_____________________ is the distance light travels in one year (about 9.5 trillion km)

Life Cycle of a Star

How far away are stars?

*________________: apparent shift in the position of an object when view from two different locations.

*Can be used to measure the _________________ of stars from Earth that are relatively close.

*______________________: closest star to earth

*(4.3 light years away -40 trillion km)

The Expanding Universe

*All distant galaxies are moving rapidly ______________ from our galaxy and from each other.

*________________: occurs when a star or other object is moving away from Earth.

*________________: occurs when a star or other object is moving toward Earth.

Origins of the Universe

*______________________ : states that all matter and energy were once packed into a tiny particle

smaller than a speck of dust.

*The particle began to expand and matter and energy moved rapidly ______________ it in all directions.

*The matter _________________ and ________________ to form stars, galaxies, nebulae, and planets.

*Most scientists believe the universe is about _____________________ years old.

Telescopes

*________________ are instruments that collect and focus light or other forms of electromagnetic

radiation.

*Many telescopes use ______________ to collect light form space.

*Space telescopes in orbit provide clearer pictures because __________________________________

___________________________________________________________________________________.

Four Views of Crab Nebula

*Different types of telescopes collect electromagnetic radiation at different ______________________.

*Astronomers are able to learn a great deal about the Crab Nebula examining these different images.

Hubble Space Telescope

*Launched in _________.

*One of NASA’s most successful missions.

*Orbits _________ miles above the Earth

*Completes one orbit every _________ minutes.

Chandra X-ray observatory

*Launched in _______.

*Detects x-rays from the ____________ regions of the universe.

*Orbits Earth at an altitude of ___________________.

*Has observed the ____________________ at the center of the Milky Way and discovered several other

black holes.

Spitzer Space Telescope

*Launched in __________.

*Observes ______________ radiation.

*_____________________ (sun-centered) obit.

*Parts of the telescope must be kept at -450 degrees Fahrenheit so as not to interfere with infrared

detection.

James Webb Telescope

*Currently being built to replace Hubble

*Scheduled to launch in 2018

*Will observe radiation in _______________ and ______________ light.

*Will be able to see galaxies that have shifted beyond visible spectrum.