Origin of the Universe Bell work: Pick up handouts Cut “Origin” one out around solid lines. Grab your spiral

What is the universe? Space and all the matter and energy in it What energy form do scientists study to learn about the universe? Electromagnetic radiation from visible light

What large scale structures make up the universe? Star cluster – stars held together by gravity Smallest Galaxy cluster – Lots of galaxies Largest Galaxy – million to billion stars - 3 types Super cluster- Hundreds of galaxies Solar System

Current Theory of Origin Big Bang Theory Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something After its initial appearance, it apparently inflated (the "Big Bang"), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe. It continues to expand and cool to this day

Evidence supports the Big Bang Theory 1.Light Element Abundance Study stars Look at spectral lines emitted by elements in stars Compare element % to those present at Big Bang Hydrogen most abundant

Evidence supports the Big Bang Theory 2. Red shift Discovered by Edwin Hubble Galaxies move away Far away = fast moving Shift of a wavelength Doppler effect Light in a wavelength stretches out when moving away to the red spectrum

Evidence supports the Big Bang Theory 3. Cosmic Wave Background Thermal radiation left over from the time of the recombination of the Big Bang cosmology

Age of the universe? Estimated using expansion Measure on how fast galaxies move away from Earth Look at spectral data Red shifts Current data = expansion Estimate age = 13 to 15 billion years old

Open Your Textbook to Page 326 Follow along as we fill in important contributions made by the following 5 scientists. When finished. You can glue, staple, or tape both of today’s note taking items into your spiral.