how to destroy the world jacob schwartz, society of physics students, week 10, fall 2011
TRANSCRIPT
How to destroy the worldJacob Schwartz,
Society of Physics Students, Week 10, Fall 2011
Acknowledgements
http://qntm.org/destroy
Scope/Goals
To make The Earth no longer be a planet
DefinitionsIAU 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
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!
Information on Earth
Radius: 6371 km
Mass: 5.9722 x 10^24 kg
= 5972200000000000000000000 kg ball of rock and ironSemi-major axis of orbit: 149,598,261 km
Average orbital speed: 29.78 km/s
CalculationsRotational Angular Momentum:
Assuming constant density, spherical earth
L = I w = 2/5 M R2 w = 7.05 x 1033
T_rotation = ½ I w^2 = 2.56 x 1029
Energy output of sun over 11 minutes
CalculationsOrbital angular momentum:
L = m r v = 2.66 x 1040 J s
Orbital Kinetic Energy:
T= ½ m v2 = 2.658 x 1033 J
For comparison: Mean solar output = 3.846×1026 W
80 days of sun’s entire output
Method 1: Annihilated by
Antimatter EarthYou will need: An entire planet Earth made from antimatter
E= (2m) c2 = 1.07 x 1042 Joules
89 million years of sun output
Method 1: Annihilated by
Antimatter EarthFeasability: 2/10
Earth’s final resting place: gamma rays
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.
Method 2: Fissioned
Solar wind carries H, He away
Planet essentially evaporates
Method 2: Fissioned
Feasability: 2/10
Earth’s final resting place: gas cloud
Method 3: Sucked into a microscopic
black holeYou will need: a microscopic black hole, mass > Mount Everest or so
Method: Drop black hole
into earth, wait
Method 3: Sucked into a microscopic
black holeFeasability: 3/10
Earth’s final resting place: A black hole orbiting the sun
Method 4: Cooked in a solar oven
Surface area of Earth: 5.112 * 1014 m2
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
Method 4: Cooked in a solar oven
Need to have 14000 * Earth’s surface area worth of mirrors : 1.80 * 1018 m2
Method 4: Cooked in a solar oven
Method 4: Cooked in a solar oven
Feasability: 3/10
Earth’s final resting place: gas cloud
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
Method 5: Overspun
Method 5: Overspun
Feasability: 4/10
Earth’s final resting place: A new asteroid belt
Method 6: Destroyed by
Antimatter BombGravitational 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
Method 6: Destroyed by an Antimatter BombFeasability: 4/10
Earth’s final resting place: a new asteroid belt around the sun
Method 7: Sucked into a giant black
holeYou will need: a black hole, extremely powerful rocket engines.
Nearest black hole: ~1600 light years from earth
Method 7: Sucked into a giant black
holeFeasibility rating: 6/10.
Earth’s final resting place: Part of the black hole
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
Method 8: Deconstructed
Feasibility: 6/10
Earth’s final resting place: Scattered throughout the solar system
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.
Method 9: Pulverized
Feasibility: 7/10
Earth's final resting place: a variety of roughly Moon-sized chunks of rock
Method 10: Hurled into the
SunYou will need: Earthmoving Equipment
Solar sails, giant rockets, large asteroid, gravity assist
Method 10: Hurled into the
SunFeasibility: 9/10
Earth's final resting place: a small globule of vaporized iron sinking slowly into the heart of the Sun.
Method 11: Tidal Forces
Move Earth close to the Sun / Jupiter
Tidal forces rip it apart.
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.
Thanks!