Why is no one talking about the Earth’s Orbit being changed by War!?

[Rhea]

Okay, a little fun hyperbole, but hear me out:


We talk about changing asteroid orbits by blasting bombs into the side of them.
But here we are on earth, carring out most of our explosive device wars on one side of the planet, and doing it mostly during the day. nd doing it mostly during the northern summer. So, THOUSANDS of explosions all on the inner side of the orbit, on one side of the sun.

How many explosions does it take to shove earth into just a little wider orbit, hmmm?

 

[steve_bank]

For a rough paper napkin estimate without gravity from the Sun and other planets

Force = Mass * Acceleration

Earth mass = 5.972 × 10^24 kg

Acceleration is meters/second^2

Acceleration 1 meter/year = 1/(3.154e+7)^2

How much energy is in a nuclear bomb in joules?
The atomic bomb exploded over Hiroshima released about 1.5x10^13 joules of energy. How many Hiroshima bombs would one have to explode simultaneously to equal the amount of energy released in a single magnitude 8.5 earthquake?

clear
clc
t_year = 3.154e+7   //seconds 1 year
mass_earth = 5.972 * 10^24  //kg
accel = 1/(t_year^2)  // 1 meter/s^2
newtons = mass_earth *accel
work = newtons * 1  //work-energy to move earth 1 meter
disp(work)

I come up with 6.0034e+09 Joules to move the Earth 1 meter in 1 year compared to the release at Hiroshima of 1.5000e+13 Joules. Assuming all of the energy goes in the same direction.

How many joules does a bomb produce?
The explosion of one ton of TNT releases approximatly 4.2 × 10 12 joules of energy; for comparison, it takes almost 6.0 ×10 4 joules to warm up a cup of coffee. The Trinity test, a plutonium fueled bomb had an estimated yield of 21 kilotons, and left a crater 2.9 meters deep and 335 meters wide.

What is the energy of a conventional bomb?
The explosion of one ton of TNT releases approximatly 4.2 × 10 12 joules of energy; for comparison, it takes almost 6.0 ×10 4 joules to warm up a cup of coffee.

Plug magnitude values of 5.0, 6.0, and 7.0 into the equation above. The energy released by an M5 earthquake is about 2.8 x 1012 joules. An M6 earthquake releases 7.8 x 1013 joules, and an M7 radiates 2.1 x 1015 joules.

Earthquakes can affect wobble through discernment of mass. I watched a report about massive amounts being pumped across Libya from an underground reservoir affecting wobble.

For a conventional high explosive bomb the damage is done by the rate of the burn, not a high amount of energy in Joules. When a bomb penetrates a building and goes off it is the expanding gasses and heat that does the damage. Low explosives have a lower rate of burn.

There are routine massive explosions in surface mines. I think operators are supposed to make international notifications, the explosions can trigger nuclear detonation seismic alarms around the globe.

Plus the solar system is in a dynamic equilibrium. I think if the Earth is perturbed there might be a damped osscilation and it would go back to equilibrium.

 

[Loren Pechtel]

You can only alter the orbit if you throw mass at above local escape velocity. Easy to do if you're trying to move an asteroid around. Exploding a nuke inside atmosphere, though--the energy goes into the atmosphere and is normally too diffuse to throw it above escape velocity.

The big blockbusters (think Tsar Bomba) actually can toss off some atmosphere that's above them--but when you get into that energy level you also find very little increase in the damage radius as the bomb gets bigger. The blast wave separates from the ground and simply shoves air around. Thus there's almost no reason to build one that big. (They do have a potential use as orbital weapons--EMP or thermal pulse. A gigaton bomb in low orbit fries pretty much all electronics to the horizon and lights fires to the horizon. And note how far away the horizon is when you're in low orbit.)

 

[bilby]

Okay, a little fun hyperbole, but hear me out:


We talk about changing asteroid orbits by blasting bombs into the side of them.
But here we are on earth, carring out most of our explosive device wars on one side of the planet, and doing it mostly during the day. nd doing it mostly during the northern summer. So, THOUSANDS of explosions all on the inner side of the orbit, on one side of the sun.

How many explosions does it take to shove earth into just a little wider orbit, hmmm?

One.

This question is a variation on the old saw "What happens when an irresistible force meets an immovable object?"; The answer, as Newton showed, is that there's no such thing as an immovable object, and all forces are irresistible.

Any force applied to any object will accelerate that object.

Perhaps a more pertinent (and much more difficult) question would be whether the forces on the Earth due to warfare are significant. Forces that are entirely contained within a system cannot accelerate the system as a whole, and the vast majority of the forces due to explosives used in war are contained within the planetary boundary. The only component that is effecting long term change is the minuscule amount of matter accelerated above escape velocity, and not subsequently re-captured by the damping effects of the atmosphere. This may amount to nothing at all; Certainly at most its going to cause a tiny differential from the status quo in the number of molecules of atmospheric gases that depart the top of the atmosphere with sufficient velocity to escape the Earth's gravitational well.

As there's already a sizeable flux of such escaping gases, and as this flux has far larger influences, both from insolation raising the temperature of the day-side, and from solar wind stripping atmosphere in the countervailing direction (away from the Sun); And as such other external influences as the Solar Wind, and meteoric impacts (both of which also have significant biases in the day-side/night-side direction) are likely many orders of magnitude larger, I am going to go out on a limb and suggest that this effect probably isn't big enough to be measurable within the lifespan of the species Homo Sapiens.

Particularly not if that lifespan is limited by that species's tendency towards warfare.

 

[Swammerdami]

This question is a variation on the old saw "What happens when an irresistible force meets an immovable object?"; The answer, as Newton showed, is that there's no such thing as an immovable object, and all forces are irresistible.

I often learn physics by watching YouTubes, especially Sabine Hossenfelder or Veritasium. But there's a blue-eyed lecturer who covers the topic bilby mentions.

 

[steve_bank]

The old goofy trippy British show Space 1999.

Space: 1999 - Wikipedia

en.wikipedia.org

Space: 1999 is a British science-fiction television programme that ran for two series from 1975 to 1977.[2] In the opening episode, set in the year 1999, nuclear waste stored on the Moon's far side explodes, knocking the Moon out of orbit and sending it, as well as the 311 inhabitants of Moonbase Alpha, hurtling uncontrollably into space.

 

[SIB]

Okay, a little fun hyperbole, but hear me out:


We talk about changing asteroid orbits by blasting bombs into the side of them.
But here we are on earth, carring out most of our explosive device wars on one side of the planet, and doing it mostly during the day. nd doing it mostly during the northern summer. So, THOUSANDS of explosions all on the inner side of the orbit, on one side of the sun.

How many explosions does it take to shove earth into just a little wider orbit, hmmm?

thats funny.

sometimes its the questions we ask ...

 

[robnisch]

IIRC dam construction in 19th and 20th centuries had an effect on the rotation of the earth. Like milli seconds.

 

[bilby]

IIRC dam construction in 19th and 20th centuries had an effect on the rotation of the earth. Like milli seconds.

Yeah, but that's an angular momentum thing - building dams causes mass to move away from the centre of the Earth (as water that would otherwise be moving towards sea level is halted at higher elevations), and so slows the planet's rotation in accordance with the conservation of angular momentum.

I guess wars would have the opposite effect, as buildings are flattened, bringing their mass closer to sea level; But the masses involved are far lower, and the distances that mass moves are typically far less, too.

 

[Jimmy Higgins]

Earth is moving 30,000 meters per second, with a mass of 6x10²⁴ kg. If my math is right, that is a kinetic energy of around 10^33 joules. A 100 megaton nuke is around 10^17 joules. Need about 10^16 (a metric fuckton) of those bad boys to equal the kinetic energy of the earth. This isn't exactly apples to apples, just indicating the relative energies involved.

 

[Shadowy Man]

Earth is moving 30,000 meters per second, with a mass of 6x10²⁴ kg. If my math is right, that is a kinetic energy of around 10^33 joules. A 100 megaton nuke is around 10^17 joules. Need about 10^16 (a metric fuckton) of those bad boys to equal the kinetic energy of the earth. This isn't exactly apples to apples, just indicating the relative energies involved.

But the question wasn’t about stopping the earth completely but altering its orbit. The main response is that the orbit will only be perturbed by debris that can carry momentum off the planet. Anything that doesn’t escape the gravity of earth will fall back down and the orbit will be conserved.

 

[TomC]

But the question wasn’t about stopping the earth completely but altering its orbit.

Really, the question was "How important are humans and their doings to planet Earth?"
Answer "Not very".

I once heard an environmental biologist point out something important. If a person blew on a cold marble, the resulting mist on the marble would be greater, in relation to the mass of the marble, than the biosphere is to the planet.

Put some things in perspective.
Tom