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TOPS June 21, 2001 - Origins?

TOPS June 21, 2001 - Origins?. Where did all this stuff come from?. (What astronomy has to say about it?) Jeff Kuhn, IfA kuhn@ifa.hawaii.edu. Substance?. Molecules, compounds Atoms, elements Fundamental atomic constituents. Forces for change. Thermodynamics Chemistry Life.

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TOPS June 21, 2001 - Origins?

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  1. TOPS June 21, 2001 - Origins?

  2. Where did all this stuff come from? (What astronomy has to say about it?) Jeff Kuhn, IfA kuhn@ifa.hawaii.edu

  3. Substance? • Molecules, compounds • Atoms, elements • Fundamental atomic constituents

  4. Forces for change • Thermodynamics • Chemistry • Life

  5. Building blocks Electrons

  6. Elements

  7. Nuclear building blocks and “patterns”

  8. Cosmic abundances

  9. Solar system abundances

  10. Very local abundances Most common compound: Water! CNO Fe Pb Most common elementary particle: Neutron, almost same as protons, IDENTICAL number of electrons

  11. Element origins • Where does it start (Big Bang?) • Did it all come from the first 3 minutes? • Can stars play a role?

  12. A brief history

  13. Epochs

  14. BB works for light elements • Even oldest generations of stars have a lot of Helium… • “Hot soup” model works

  15. Making He in the sun...

  16. Heavy Stars

  17. Evidence of heavy element production

  18. Heavy elements require more... • Higher densities and temperatures… • Above Iron need something special to happen…

  19. Heaviest elements from cosmic explosions (Supernovae) • SN1987A was the first Supernovae in hundreds of years that was visible by eye

  20. Molecule problems... • Collisions aren’t frequent enough to get atoms to stick…Need a way to collect atoms so they can combine… • Cosmic dust is the answer...

  21. Molecules and solids?

  22. We see dust/molecules around giant stars Dust and gas are always found together! ISO image of HD97300

  23. Where did we come from then?

  24. Summary • Light elements formed in the first 3 minutes • Heavies formed in stars later and now • Dust (grains) formed in cool parts of giant stars • Molecules formed on dust grains • Planets condensed from stellar environment • Biological processes differentiated elements

  25. Web resources • www.pbs.org/deepspace/timeline/index.html • Big Bang, classroom activities, screen savers • howstuffworks.lycos.com/atom.htm • activities, atoms, general science, *links* • micro.magnet.fsu.edu • higher level science, movies, Electricity/Mag • www.lbl.gov/abc/wallchart/index.html • Nuclear science intro • www.iso.vilspa.esa.es/science/ • btc.montana.edu/ceres/html/stars1.html#lessonplans • helios.gsfc.nasa.gov/nucleo.html#nucactys • www.ncsa.uiuc.edu/Cyberia/Bima/SolSys.html • www.eng.rpi.edu/~napolj/Origins • this power point presentation at hubble.ifa.hawaii.edu, anonymous ftp on directory INCOMING named topsorigins.ppt

  26. Activities • Concepts • Atoms as product of matter subdivision • Atoms mostly space, nucleus+electrons • Fission requires high density and temperature • “Cross-section” concept • protons and neutrons different cross-sections • Molecules built from atoms • Local constituents result from “fractionation”

  27. Activities • Making atoms, 10cm paper strip cut 31 times… • Make cardboard atom target. Rice grain nucleus, 3’ diameter circle • Proton and neutron target practice, making He • Atomic differentiation, rice and bb’s for H and Fe

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