1. Lecture 2 (cont’d): In the Beginning: Origins of the Elements 1.The Periodic Table: elements and isotopes 2.Synthesis of elements in the Early Universe 3.Stars: making the “elements of life” 4.We are made of star stuff.

2. 2 Millenium Run, Springel et al. 2006

3. * LIFE & CULTURE * JANUARY 29, 2011 If You Don't Like This Universe… Brian Greene and David Gelernter discuss alternate realities, like a cosmos with a Jets-Bears Super Bowl

4. Electron Orbits in Atoms

6. The Periodic Table

8. Electron Orbits in Atoms

9. Plots of electron density shapes of 1s, 2p and 3d orbitals:

10. The Periodic Table … in terms of electron subshells:

11. The Periodic Table … the elements of Earth life:

14. Looking Back into the Past Hot Dense Smooth Cold Thin Clumpy

15. Looking Back into the Past NASA’s WMAP mission mapped the sky in microwaves

16. Looking Back into the Past False-color map of the temperature fluctuations seen by measured by WMAP. This pattern appears to be random, but it is the superposition of waves of different size. It is like a fingerprint. The pattern seen is consistent only if 75% of H and 25% of He constitute the gas.

17. Stars like our Sun expand and disperse their envelopes It takes 3 to 10 Ga for the the synthesis of light and heavy elements in these stars. Their envelopes are rich in heavy elements - yet, especially in C, N, and O. Eventually new stars are formed from this gas. How do we know that ? a)We see the signatures of these newly synthesized elements in their light.

18. The most massive stars end their thermonuclear cycles as Supernovae Supernova 1994D: the bright explosion of a star in the outskirts of a distant galaxy. During the explosion, in a matter of minutes, hours and days, large quantities of iron and other heavy elements are synthesized.

19. The most massive stars end their thermonuclear cycles as Supernovae During the explosion, in a matter of hours and days, large quantities of iron and other heavy elements are synthesized. How do we know that ? a)We see the signatures in the light from the explosion; b)Computer models reproduce measured isotopic ratios in Solar System objects and other stars.

20. We are made of star stuff By mass - Human body: H = 10%, He = 0%, C = 18%, N = 3%, O = 65%, Ca = 2%, Fe = 0.004%. Earth’s crust: H = 1 %, He = 0%, C = 2%, N = 0%, O = 47%, Si = 26%, Ca = 3%, Fe = 5% Sun & stars: H = 71%, He = 27%, all other elements = 2% (with O most abundant).

21. The Periodic Table … the elements of Earth life:

22. Main points to take home: 1) Elements: def. by protons in atom (90 stable); Isotopes: def. by neutrons in atom (266 stable); The Periodic Table of the Elements allows the analytical description of all species of mineral or biological origin. 2)There are 2 main sources of their origin: a) H, He, & Li were synthesized ~13.7 Ga ago in the Early Universe; b) stars transform H & He into all the rest. 3) Planets and life are here thanks to many past generations of stars.

24. The Periodic Table

25. We are made of star stuff By mass - Human body: H = 10%, He = 0%, C = 18%, N = 3%, O = 65%, Ca = 2%, Fe = 0.004%. Plants: H = 10%, He = 0%, C = 3%, N = 0.3%, O = 79%, Ca = 0.1%, Fe = 0.02%. Earth’s crust: H = 1 %, He = 0%, C = 2%, N = 0%, O = 47%, Si = 26%, Ca = 3%, Fe = 5% Sun & stars: H = 71%, He = 27%, all other elements = 2% (with O most abundant).