1. Antimatter And Annihilation

2. Remember Photons? What are photons?

3. What can Photons do? When photons come close to an atom, they can do a few things: 1) NOTHING- it just sails by and doesn’t hit anything

4. What can Photons do? When photons come close to an atom, they can do a few things: 2) It can hit an electron and make it go up a level…

5. What can Photons do? When photons come close to an atom, they can do a few things: 3) It can knock an electron loose (Remember the photoelectric effect?)

6. What can Photons do? When photons come close to an atom, they can do a few things: 4) If it had A LOT of energy, it can spontaneously turn into matter! Poof! e- e+ BIG PHOTON

7. What can Photons do? But not just anything….. The huge photon can spontaneously create an electron and a positron. Poof! e- e+ BIG PHOTON electron positron

8. MATTER What can Photons do? Electrons are regular electrons. Positrons are special particles that are called ANTIMATTER! (Like the Red Matter in the Star Trek Movie)

9. Positrons Positrons are created very rarely and don’t live very long. They are exactly like an electron BUT, they have a positive charge! (They even have the same mass as an electron)

10. Positrons So… ElectronsPositrons Mass 9.11E-31kg 9.11E-31kg Charge Neg (-)Pos (+) MatterAntimatter e-e+

11. Einstein’s Equation So how much energy does the photon need to be in order to create these two particles? Einstein figured it out…

12. Einstein’s Equation Energy Needed Total mass created Speed of light squared

13. Example What is the minimum energy needed for a photon to create an electron-positron pair? Recall the mass of both particles is 9.11E-31kg.

14. Example What is the minimum energy needed for a photon to create an electron-positron pair? Recall the mass of both particles is 9.11E-31kg. m electron =9.11E-31kg m positron =9.11E-31kg

15. Example What is the minimum energy needed for a photon to create an electron-positron pair? Recall the mass of both particles is 9.11E-31kg. m electron =9.11E-31kg m positron =9.11E-31kg

16. Antimatter So when you get a lot of high energy photons, you have a chance of creating some matter and antimatter both at the same time. HOWEVER…. If antimatter runs into regular matter after its’ created, something else happens….

17. Antimatter Matter Antimatter

18. Matter Antimatter

19. Matter Antimatter

20. Matter Antimatter

21. KABOOM!! BIG EXPLOSION: All the energy that was needed to create the particles in the first place is released all over again. This KABOOM is called Annihilation.

22. Example How much energy is released when.005kg of dirt annihilates with.005kg of anti-dirt. Anti- dirt is just dirt made up of antimatter particles.

23. Example How much energy is released when.005kg of dirt annihilates with.005kg of anti-dirt. Anti- dirt is just dirt made up of antimatter particles. m total =.005kg+.005kg=.010kg

24. Example How much energy is released when.005kg of dirt annihilates with.005kg of anti-dirt. Anti- dirt is just dirt made up of antimatter particles. m total =.005kg+.005kg=.010kg

25. Practice Complete the worksheet on antimatter creation and annihilation.