How to destroy the world

1. How to destroy the world Jacob Schwartz, Society of Physics Students, Week 10, Fall 2011

2. Acknowledgements • http://qntm.org/destroy

3. Scope/Goals • To make The Earth no longer be a planet

4. Definitions IAU definition: Planet: a celestial body that • 1. is in orbit around the Sun • 2. has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, • 3. has cleared the neighborhood around its orbit

5. Ways not to destroy earth • Hurling it into interstellar space, • Moving it into orbit around a gas giant • Moving it into a solar orbit whose neighborhood is not cleared • These don’t count!

6. Information on Earth • Radius: 6371 km • Mass: 5.9722 x 10^24 kg • = 5972200000000000000000000 kg ball of rock and iron • Semi-major axis of orbit: 149,598,261 km • Average orbital speed: 29.78 km/s

7. Calculations • Rotational Angular Momentum: Assuming constant density, spherical earth L = I w = 2/5 M R2w = 7.05 x 1033 T_rotation = ½ I w^2 = 2.56 x 1029  Energy output of sun over 11 minutes

8. Calculations • Orbital angular momentum: • L = mrv = 2.66 x 1040 J s • Orbital Kinetic Energy: • T= ½ m v2 = 2.658 x 1033 J • For comparison: Mean solar output = 3.846×1026W •  80 days of sun’s entire output

9. Method 1: Annihilated by Antimatter Earth • You will need: An entire planet Earth made from antimatter E= (2m) c2 = 1.07 x 1042 Joules  89 million years of sun output

11. Method 1: Annihilated by Antimatter Earth • Feasability: 2/10 • Earth’s final resting place: gamma rays

12. Method 2: Fissioned • You will need: a universal fission machine (e.g. a particle accelerator), an unimaginable amount of energy • Method: Take every single atom on planet Earth and individually split each one down to become hydrogen and helium.

13. Method 2: Fissioned • Solar wind carries H, He away • Planet essentially evaporates

14. Method 2: Fissioned • Feasability: 2/10 • Earth’s final resting place: gas cloud

15. Method 3: Sucked into a microscopic black hole • You will need: a microscopic black hole, mass > Mount Everest or so • Method: Drop black hole into earth, wait

17. Method 3: Sucked into a microscopic black hole • Feasability: 3/10 • Earth’s final resting place: A black hole orbiting the sun

18. Method 4: Cooked in a solar oven • Surface area of Earth: 5.112 * 1014m2 • Black-body temperature of Earth: ~287 K • Power radiated by Earth: ~1.966 * 1017 kg m2 s-3 • Black-body temperature of Earth after being completely boiled: ~3134K • Power radiated by Earth at this temperature: ~2.796 * 1021 kg m2 s-3 • Ratio of these two powers: 1 to ~14,000

19. Method 4: Cooked in a solar oven • Need to have 14000 * Earth’s surface area worth of mirrors : 1.80 * 1018 m2

20. Method 4: Cooked in a solar oven

21. Method 4: Cooked in a solar oven • Feasability: 3/10 • Earth’s final resting place: gas cloud

22. Method 5: Overspun • Increase rotation speed until Earth flies apart : centrifugal force > gravity • r w2 > 9.8 m/s2 • w > 0.00124 or Period of rotation < 84 minutes • Increase rotational kinetic energy by 7.4*1031 J •  2 days of solar output

23. Method 5: Overspun

24. Method 5: Overspun • Feasability: 4/10 • Earth’s final resting place: A new asteroid belt

25. Method 6: Destroyed by Antimatter Bomb • Gravitational Binding Energy of Earth: • U = 3/5 G M2 / R = 2.24 * 1032 • Need enough antimatter to overcome this • m c^2 = U • Only need half of that! • m = 1.25 * 1015 kg of antimatter! ~ 200 Mt Everest • Sun’s energy output over one week

27. Method 6: Destroyed by an Antimatter Bomb • Feasability: 4/10 • Earth’s final resting place: a new asteroid belt around the sun

28. Method 7: Sucked into a giant black hole • You will need: a black hole, extremely powerful rocket engines. • Nearest black hole: ~1600 light years from earth

30. Method 7: Sucked into a giant black hole • Feasibility rating: 6/10. • Earth’s final resting place: Part of the black hole

31. Method 8: Deconstructed • You will need: a mass driver • Method: Dig up a chunk of earth, launch it at escape velocity or more A million tonnes per second 189,000,000 years. Note that Earth’s mass increases at ~~~ 1000 tons/day

33. Method 8: Deconstructed • Feasibility: 6/10 • Earth’s final resting place: Scattered throughout the solar system

34. Method 9: Pulverized • You will need: Something large and heavy • Method: Smash it into earth • Example: • 5,000,000,000,000-tonne asteroid at 90% of light speed • Note that a Mars-sized object once hit Earth … this led to the moon.

36. Method 9: Pulverized • Feasibility: 7/10 • Earth's final resting place: a variety of roughly Moon-sized chunks of rock

37. Method 10: Hurled into the Sun • You will need: Earthmoving Equipment • Solar sails, giant rockets, large asteroid, gravity assist

39. Method 10: Hurled into the Sun • Feasibility: 9/10 • Earth's final resting place: a small globule of vaporized iron sinking slowly into the heart of the Sun.

40. Method 11: Tidal Forces • Move Earth close to the Sun / Jupiter • Tidal forces rip it apart.

41. Method 11: Tidal Forces • Feasibility: 9/10 • Earth's final resting place: lumps of heavy elements, torn apart, sinking into the massive cloud layers of Jupiter, never to be seen again.

42. Thanks!