Earth and Space ScienceEarth in space and time

Objectives and Expectations:

TEK Objective 4: The student knows how Earth-based and space-based astronomical observations reveal differing theories about the structure, scale, composition, origin, and history of the universe.

Student Expectations: • evaluate the evidence concerning the Big Bang model such as red shift and

cosmic microwave background radiation and current theories of the evolution of the universe, including estimates for the age of the universe;

• explain how the Sun and other stars transform matter into energy through nuclear fusion; and

• investigate the process by which a supernova can lead to the formation of successive generation stars and planets.

The Origin and History of the Universe

THE BIG BANG THEORYORIGINS OF THE UNIVERSE

• How did our universe begin?

• How old is our universe?

• How did matter come to exist?

• What is our place in the universe?

Homo neanderthalensis

Galileo

True to the nature of science, a majority of these answers have only led to more intriguing and complex questions. Perhaps, science is all about finding the next question, instead of the answers!

STRUCTURES AND ORGANIZATION IN SPACE

Universe

Galaxy

Star, or Stellar System

Planetary, or Solar Systems

The universe is commonly defined as the totality of everything that exists,[

including all space, time, matter, energy, planets, stars, galaxies, and intergalactic space

A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas, dust, and dark matter. Our galaxy is the Milky Way, and it is a spiral galaxy.

Messier 100 (M100) Spiral Galaxy

A star system or stellar system is a small number of stars which orbit each other, bound by gravitational attraction.

A solar system consists of one or a number of stars, surrounded by a number of planets and planetary bodies held by gravitation.

Universe had no beginning or end…it was truly infinite

With the Big Bang theory, universe is “finite”:

• 15 billion years ago, huge explosion which started the expansion of the universe.

• all matter, and energy of space was contained at one point.

• this explosion filled all of space with the particles of the young universe rushing away from each other.

Edwin HubbleObserved the universe expanding in every direction and that a galaxy’s velocity is proportional to its distance from us.Ex: galaxies that are twice as far from us, move twice as fast

THE RED SHIFT

This movement would tend to make objects (or galaxies) that are most distant to appear “reddish”

This is the name given to the phenomenon of galaxies moving farther away from each other.

As light approaches Earth from different galaxies, the space between that distant galaxy and Earth increases. This leads to wavelengths of the light being stretched.

Why red???

The Electromagnetic Spectrum

Remember…the longer wavelengths of the visible light spectrum include the reds and oranges. The shorter wavelengths of the visible light spectrum include the indigos and violets, so the farther away the stars become, the “more red” they appear

CMBRCosmic Microwave Background Radiation

is thermal radiation filling the observable universe almost uniformly. It is radiation left over from an early stage in the development of the universe, and its discovery is considered proof of the Big Bang model of the universe.

Scientists use very small radio telescope arrays to listen to CMBR.Listen to the Big Bang

THE SUN’S ENERGYThe sun represents a source of light and heat upon which all living things depend for their survival.

This light and heat radiated by the sun is the result of fusion energy.

Fusion converts matter to energy. Fusion is the joining of two small elements to form one larger one. In the process, energy is lost, in the form of light and heat.

The main fuels used in nuclear fusion are deuterium and tritium, both heavy isotopes of hydrogen.

This energy, once it reaches the Earth, is then utilized by plant life to build tissue, and repair injury, as well as maintain homeostasis.

Then animals and microscopic consumers eat the plants, delivering the energy to their bodies. Consumers use this energy for the same purposes as plants.

SupernovaA supernova is a stellar explosion that is more energetic than a nova. It represents the “death” of a star.The explosion expels much or all of a star's material[ at a great velocity driving a shock wave into the surrounding space. The explosion sends much or all of a star's material . This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant.

It is this remnant, or stellar “dust” which has the potential to form new stars and even planets.

Lab One: Light and Temperature…How are they related?

Question: How can we use the amount of radiant energy emitted by a star to determine the relative surface temperature of that star?For today, you are going to investigate the properties of the visible light spectrum, otherwise known as “ROYGBIV”.

You will be given a tool known as a diffraction grating. It takes visible light we usually see as white, and breaks it down into the various component wavelengths of light.

A display of colors and lines called a spectrum is produced. Using this you will look in the direction of the sun, but not directly at the sun. What do you see? Make your observations. Use markers to sketch what you see.