Hubble tried to estimate age of universe by looking at other galaxies. Andromeda closest to Milky Way: estimated they wil col ide in 3 bil ion years. know because of Doppler ef ect, works by looking at sound waves going away Red shifted, moving quickly) from or coming toward you (Blue winded, low frequency)
Checking luminosity & speed is a way to measure how fast.
Cosmic standard candles distance galaxy is away. Hubble calculated universe 13bil ion years old. Others said 12-18bil ion years.
infinitely bright @night then the universe is not infinite in space and time. If infinite in space, there would be an infinite # of spheres which would make the sky infinitely bright even if 1 quantum of dark mat er in each sphere would stil be bright. Either hasn’t existed forever or isn’t infinite in space.
Smal star 3.5 SMU:
white dwarf to brown dwarf to black dwarf. Before white dwarf star is
nova(energy from the outside is used, sun is a smal star). Alpha processes only to carbon. Medium star: 3.5-20SMU. More gravity, mat er, and energy. Red giant explodes into supernova. Lastly becomes neutron star(pulsar). Alpha process up to
Mg24.Large stars: 20SMU greater. Becomes red giant when helium burning complete. Red giant col apses into a black hole, a dead star. Alpha process up to Fe56.
Historical dating- figure out age of something by comparing to something in history w/ known date. People: Ramses2: 1225BC, Alex the great: 384-322BC,
Cyrus the Great: 600-529BC, Darius:521-486BC, Julius Ceasar: 100-44BC, Buddha: 563-483, Conficius: 551-479.
Dendrochronology: tree-ring dating.”Dendros” tree, “Chronos” time. Developed @ the university of Arizona, dates wood to exact year far as 10,000 years. Every year new ring grows adjacent to the bark,
show what the climate conditions of year. Long growing season w/a lot of moisture=wide
ring, drought= nar ow ring.
14C produced in upper atmosphere (4N2+solar energy> 14C+proton +energy). Al living organisms produce carbon while alive after stops. 14C half life of 5583±30years, can determine amount of 14C and
thus the date. Radiometric dating tedious often checked using other methods (ex. tree ring dating). K/Ar dating:K-35,K-40,K-41:K-40 decays, nonradioactive.K-40 decays 40Ca(89%), 40Ar(11%). Date things 50,000-4bil ion years b/c of its 1.3bil ion half life.
Sequencing dif erent b/c uses living organisms. Principle: an
enzyme built from primary structure to secondary structure to tertiary shape. The shape built for one specific substrate & binding site. Enzyme changes shape cannot catalyze reaction. Binding site is critical to amino acids.
Mutations not binding site critical occur over time, neutromutations build up. Dif erences
proportional to amount related. More dif erences=less related. Molecular clock how often neutral mutations occur, too rapid critical mutations result in death and not go to next generation. Structure proteins not critical, have much more rapid build up of changes than hemoglobin which is critical
Clade group of organisms
w/ single common ancestor and al the descendants of that ancestor. Also considered monophyletic group, cladogram(how they are related),a diagram of the organism in the form of a tree.