13/01/2017 Leave a comment
The Moon is a dick and we should get rid of it.
Why we should get rid of The Moon
The most obvious effect of The Moon on The Earth are the tides. Tides are a consequence of how The Moon’s gravity affects our planet. Gravity is a force that attracts objects towards each other and its strength is dependent on the objects’ mass and the distance between the objects. The closer they are, the stronger the force of attraction.
The force of gravity follows an “inverse square law”, which means that it drops off rapidly with distance. Double the distance, the force of gravity is reduced to a quarter. At 10 times the distance, the force of gravity is reduced by a factor of 100.
This means, because we’re close to The Moon, that whichever side of The Earth is facing it experiences a noticeably stronger gravitational effect than the far side. This causes the sea to rise up at the side nearest to The Moon. It also pulls on The Earth more than it does the sea on the far side, so we have two high tides per day.
(This isn’t to scale – that would be a fairly catastrophic high tide if it were.)
Tides are rubbish and we should do without them. It’s annoying when you go to the beach and it’s high tide and there’s nowhere to sit. It’s also annoying if the sea is too far away. Get rid of The Moon and you have a happy medium and every beach is just right. Have you ever spent time and effort, erecting the perfect sand castle, only to have it destroyed by The Moon? Destroy The Moon and our sand castles live on forever.
The Moon is making days longer
The presence of The Moon is actually slowing The Earth’s rotation. This is because the bit of the Earth that is closest to the Moon, be it land or sea, bulges up due to The Moon’s gravity. The bulge goes back down slowly such that the bulge is always a little bit past where The Moon is. The Moon’s gravity pulls back on the bulge, slows The Earth’s rotation and makes days longer. Do you think when days are 30 hours long, we’ll still have an eight hour working day and be allowed six more hours in bed? Of course not:
The Moon’s plan is to increase the length of your working day.
Incidentally, if you have ever wondered why the same side of The Moon always faces The Earth, it is for the same reason. With our superior gravity we have already done this to The Moon to such an extent that we stopped its rotation altogether. Ha!
The Moon ruins the beauty of the night sky
When The Moon isn’t around, the night sky looks like this:
The Moon is arrogant
The Moon considers itself on a par with The Sun (no, not the newspaper – it is on a par with that). The Sun spends its time quietly fusing hydrogen together to make helium, which gives out heat and light. This makes our planet just the right temperature for life, allows plants to photosynthesise and, in short, allows all of the life on our planet to exist. In comparison, The Moon destroys sandcastles.
Further still, there are at least 176 moons in our solar system alone and an unimaginably huge number in the universe as a whole. As far as we know, NONE of these other moons have had the arrogance to call themselves “The Moon”. The Sun, despite all the great stuff it does, has never been arrogant enough to call itself, “The Star”. Donald Trump is the most arrogant human, but even he has never had the audacity to rename himself, “The Homo Sapien”.
The Moon is the most arrogant object in the known universe.
In addition to these arguments, we should also destroy The Moon because it would be a bit of a laugh.
How do we destroy The Moon?
I’ve had a look into this and it’s actually harder than you might think and the problem, again, is gravity.
Suppose we were to blow up the moon with enough energy to scatter out all the bits a few miles. Gravity would cause the expanding fragments to slow, then stop, then start coming back together and then stick together to make the moon again. This eventuality must be avoided at all costs, as it would be a significant blow to our morale.
So when we destroy the moon (and I think we’re all now in agreement that it’s a when, not an if) we need to supply sufficient energy for the fragments to overcome the force of gravity and never collapse back into The Moon again.
The energy we need to supply is called the gravitational binding energy and we can calculate it using the equation:
U = 3GM² / 5R
Where G is the gravitational constant (6.67 × 10-11 m3 kg-1 s-2), M is the mass of the moon (7.35 × 1022kg) and R is the radius of the moon (1,737,000m)
Plugging this into our equation tells us that we need 1.25 × 1029 Joules of energy to blow up the moon and stop it coming back together again. Great, now we know – what are our options?
According to Wikipedia, 1000kg of TNT releases 4.2 billion Joules of energy. Nice.
That means we just need… gimme a sec…
30 billion trillion kg of TNT.
I’ll be honest, that sounds like a little more than I was hoping for. The maximum payload of a space shuttle was 25,000kg. So we need about 1.2 quintillion space shuttle missions to deliver the TNT to the moon. If we do one mission a day, we should be able to destroy The Moon in about 3.3 quadrillion years. That’s far too long for me – TNT is rubbish and we’re going to need something bigger.
Back to Wikipedia – the most powerful nuke ever detonated was the Tsar Bomba, which the Soviets detonated in a test in 1961. The resulting mushroom cloud was over seven times the height of Mount Everest (show offs).
The Tsar Bomba released the equivalent energy of 57 million tons of TNT. This means we only need… gimme a sec…
526 billion Tsar Bombas
That’s better but there is quite a big catch in that the Tsar Bomba weighed 27,000kg, which is over our max space shuttle payload. Let’s suppose that increasing the max payload of a shuttle from 25,000kg to 27,000kg is achievable. At one mission per day we are still looking at 1.4 billion years to blow up the moon. Better but still far too long – we’re going to need something bigger.
How could The Earth possibly destroy The Moon? Yeah, it’s gravity again. If we were able to halt The Moon’s orbit it would plummet to Earth, and before it hit, it would move steeply up that gravity curve we mentioned before, such that the near side experienced a much stronger gravitational pull compared with its far side. At about 18,000km out, The Moon would be ripped apart by The Earth’s gravity! Go The Earth!
The problem here is how to stop the orbit, in order to make it fall down (I’ll neglect the problem that we have a destroyed Moon plummeting towards us at catastrophic speed). The kinetic energy of the moon can be calculated as:
E = GMm/2R
Where G is the gravitational constant, R, is the radius of the moon’s orbit around the earth (384,400,000m,) M is the mass of The Earth (5.972 × 1024 kg) and m is the mass of the moon (7.34767309 × 1022). (Do note that in the equation, the big M is given to the mass of the Earth and the little m is the mass of the moon. How do you like them apples, The Moon?)
So the kinetic energy of the moon is 4.8 × 1028J and we just need to apply as much energy in the opposite direction to The Moon’s motion in order for us to stop it in its tracks and let it plummet to Earth. Get the Tsar Bombas ready, we just need….
200 billion Tsar Bombas
We are getting closer but we’re still a long way off. We’re going to need something bigger.
While the Tsar Bomba sounds scary, The Sun is on another scale. Through nuclear fusion, The Sun gives out a whopping 3.8 × 1026 Joules of energy every second. If we could direct all of that at The Moon we would reach our goal of 1.25 × 1029 Joules in less than six minutes! The Sun is a badass.
Now, we can’t easily focus all of The Sun’s energy on The Moon but we can do something that helps out a bit. You know that if you take a magnifying glass and focus The Sun’s rays on a small point, you can properly burn it? Imagine that on a bigger scale, that’s what we’re going to do – a giant lens in space.
The Moon is going to spend half of its time behind The Earth and we definitely do not want to be hitting The Earth with our giant sunbeam. So let’s say that we have a window of 14 days to do this. If we were to put a very big lens at around the orbit of Mercury and point it at The Moon, how big would it need to be to do the deed in 14 days?
The orbit of Mercury is, at its closest, 47 million km from The Sun. The surface area of a sphere is 4πr2, so the surface area of a sphere at this distance from The Sun is 2.8× 1022 m2. That means that we’re getting 13,700 J per m2 every second, or 1.2 billion Joules per day per m2. In order to shoot 1.25 × 1029 J at The Moon in 14 days, our lens needs to have a diameter of…
1.5 million km
… or approximately 121 times the size of The Earth.
Oh dear. What are we going to need to build that?
A “can do” attitude? …Most likely.
But I think I might need to admit defeat here. I really thought that, given the circumstances, The Sun would be a little more help than this.
The Sun is a dick. Maybe we should get rid of it.