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!