how to destroy the world jacob schwartz, society of physics students, week 10, fall 2011

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!