Presentation on theme: "Galaxies and the Universe"— Presentation transcript:
1Galaxies and the Universe Spectra of ScienceAmole2013
2The Hierarchy Universe Galaxy Stars Solar System Planet World ContinentCountryStateCity
3The UniverseThe sum of all space, matter, and energy that exists, has existed, or will existThere is only oneYou are part of it too!We see it as it was in the pastContains many other galaxiesMost of it is empty space
4The Hubble TelescopeA reflecting telescope that was placed into orbit in 1990Sends images and measurements back to Earth electronicallyA deep image of an “empty”portion of the sky reveals thatthe universe is filled withgalaxiesThe light we see from themost distant galaxies hastraveled approximately 10 billion years to reach us
5GalaxiesFun Fact:If you counted 1,000 galaxies a night, it would take 275, 000 years!A collection of stars, dust, and gas bound together by gravityWe live in the Milky Way galaxyThere may be more than 100 billion galaxiesNot spread out evenly through space; exist in clustersClusters can join and form superclustersFun Fact:The Milky Way is part of a cluster called the Local Group.
7Galaxy Types Elliptical shaped like spheres or eggs; have almost no dust or gas between stars; contain old starsSpiralhave arms of stars, gas , and dust that curve away from the center of the galaxy in a spiral patternEx. – Milky WayIrregularfaint galaxies without a definite shape; smaller than the other types of galaxies; contain fewer stars
8The Big Bang Theory Misconception Alert: Describing this theory as Occurred billion years agoBefore there was nothingNo space; No timeOut of nothingness came an explosion of energy in all directionsThis energy gave rise to all the matter we know todayThought to have expanded within a second from something the size of a spec of dust to the size of our solar systemMisconception Alert:Describing this theory asthe “Big Bang” is a misnomerbecause there really was notan explosion, just a release ofenergy
9The Big BangAfter 3 minutes, protons and neutrons began to fuse to form the nuclei of hydrogen and helium atomsAbout 300,000 years later, temperatures were cool enough for complete hydrogen and helium atoms to formPhotons escaped from matter about the same time, and light existed for the first time
10The Big Bang After under a billion years the first stars form They live and die slowly creating heavier elementsGalaxies and clusters also begin to slowly follow
11The EvidenceEdwin Hubble determined that other galaxies exist, besides the Milky WayHe observed that galaxies were moving away from each otherHubble Law – the farther away a galaxy is, the faster it is moving away from us; supports the Big Bang Theory
12The EvidenceHubble found spectral lines shifted towards red
13The Evidence Explained by the Doppler Effect Objects that are moving away from us emit longer wavelengthsToward the red end of the spectrum
14The EvidenceArno Penzias & Robert Wilson accidentally detected faint radiation on a radio telescope in 1965Determined that the radiation was leftover thermal energy from the “big bang”
15The Fate of the Universe The universe will keep expanding foreverThe expansion of the universe will gradually slow down, and approach a limit in spaceThe universe will stop expanding and start to fall back in on itselfThe fate will depend on mass!
16The Fate of the Universe Too much = gravity will cause everything to collapse on itselfToo little = not enough gravity to stop expansionJust right = it will slow down, but never really stop
17Einstein’s Theory of Relativity Mass curves spaceThink about how a mattress reacts when you sit on itDuring a solar eclipse scientists noticed stars were in different positions than expected
18Interstellar MatterThe gas and dust located between stars and galaxies
19Quasar The most distant and radiant objects in space Discovered by the radio waves that they emitMay be infant galaxiesMay have huge central black holes
20Dark Matter Highly debated Scientists have evidence that there may be more matter than just that that is visibleAs much as 90% of universe may be dark matterCould be planets, black holes, or brown dwarfs (stars that never start fusion)
21Astronomical Unit (AU) unit of distance equal to the average spacing between the Earth and the Sunequal to about 150 million kilometers (93 million miles)light takes about eight minutes to cover this distanceThe Earth animation is not rotating in the correct direction;it should be rotating from west to east150 million km(93 million mi.)
22Light Yearthe distance that light travels in one year in a vacuum, which is about 9.5 trillion kilometers (6 trillion miles)The Milky Way Galaxy is about 100,000 light years in diameterthe speed at which light travels this distance is about 300,000 km/sec (186,000 mi/sec)Fun Fact:The second closest star to the Earth is a little over four light years away.
23Parsecunit of distance equal to about 3.26 light years (or 206,265 AU)
24Parallaxthe apparent shift in position of an object when viewed from different locationsused by astronomers to measure distanceTry This:Focus on the star to the left. Open and close your eyes in an alternating manner. What do you notice about the star’s position?