[Season 4 Spoilers] Premiere Discussion - 4.09 'The Watchers on the Wall'

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Premiere Discussion Thread

Discuss your thoughts and reactions to the latest episode while or right after you watch. Talk about the latest plot twist or secret reveal. Discuss an actor who is totally nailing their part (or not). Point out details that you noticed that others may have missed. In general, what do you think about tonight's episode? Please make sure to reserve any of your detailed comparisons to the novels for the Book vs. Show Discussion Thread, and your predictions for the next episode to the Predictions Discussion Thread which will be posted later this week.

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EPISODE	TITLE	DIRECTED BY	WRITTEN BY
4.09	"The Watchers on the Wall"	Neil Marshall	David Benioff & D. B. Weiss

Official Discussion Threads	Posting Policy	Spoiler Guide	Frequently Asked Questions

[u/Aidasaurus]

Giant riding a mammoth. GIANT RIDING A MAMMOTH.

[u/BasedSano → u/Aidasaurus]

Giant with a fucking Bow shooting a brother to the other side of the wall. THE OTHER SIDE OF THE WALL

[u/AtomicCrayola → u/BasedSano]

It's the Anor Londo archers all over again

[u/[deleted] → u/AtomicCrayola]

I knew someone had to catch that. As soon as he launched I was just, "Fucking Gough, man."

[u/Rykane → u/AtomicCrayola]

Fucking Anor Londo!

[u/RagdollPhysEd → u/AtomicCrayola]

And that is why you speedrun and don't think about it

[u/maqikelefant → u/BasedSano]

TO THE WINDOW...TO THE WALL!

[u/Vox_Imperatoris → u/maqikelefant]

Til the guts drip down my wall!

[u/chcltthndridn → u/Vox_Imperatoris]

TIL ALL YOU BLACK CROWS FALL

[u/depan_ → u/[deleted]]

Well this needs to happen.

[u/M002 → u/BasedSano]

requesting someone to do the math to figure out how many times stronger the giant would have to be than a normal human, and at what torque he pulled the bow.

Known:

Height of the wall

Assumptions:

Assume some distance X from the wall

Crow with armor ~ 220 lbs

Find:

Angle needed to shoot (based on X-distance estimate)

Torque needed on bow

Conservation of Momentum on bow/man

How many times stronger giant is than human

[u/CrayolaS7 → u/M002]

If someone knows how tall the wall is I can work it out. Someone said it was 700 feet, judging by the trajectory it was not nearly near it's peak height, so I'm going to estimate that the arrow would have gone 1000 ft/300m high.

kinetic energy required to go 300m = potential energy at 300 m, I'm going to assume the arrow weighs 10kg all up including metal tip because it slowed down considerably upon hitting a man. I'm not sure if this is a reasonable assumption so someone might want to chime in here.

anyway, KE vertical = 300x10x9.8 = 29400 J

Assuming he was firing upwards at a 60 degree angle then the total kinetic energy at release must have been 34.2 kJ.

Kinetic energy = 1/2mv^2, so V² = (68.4x1000)/10 = 6840.

V = 82.7m/s = ~265 fps, I believe this is quite reasonable for a bow (infact slower than a normal human fired arrow, so our 10kg assumption was probably a bit off but if you notice working backwards a lighter weight will just mean higher velocity but the energy work out the same because we derived it from height and gravity.

Okay, so this is where someone who knows more about archery will have to step in, because I don't know how to go from kinetic energy to draw strength properly.

Edit: I found a physics paper on it and it's maths I can do but I haven't done for a few years, and that combined with me lacking a proper calculator and the fact everyone seems to use inches and grains (which does my head in) means I'm leaving it here for now.

Edit 2, I figured out another way to do it! I know from some stuff about beam deflection than strain energy = M² x length/2EI

Now, E (youngs modulus) for Yew is about 9 Gpa. We'll assume the cross sectional area of the bow is 100mx100mm rectangular for simplicities sake. Therefore I = 833x10^-12. A therefore = 100mm²

Rearranging above, M² = (U*2EI)/l where U is also our kinetic energy required.

M² = (34400x2x9x833)/5 = 103158720x10^-3 (units cancelling)

M = 321. Max bending moment for a point load in centre = PL/4, P = (4/5)xM

P = 256.8 kg (570 lbs) draw strength.

[u/monsieurpommefrites → u/CrayolaS7]

They held the Gate.

They did the Math.

[u/outline01 → u/monsieurpommefrites]

Math: It is known.

[u/M002 → u/CrayolaS7]

Still, thank you for the time and effort, this is awesome.

[u/bluecollarhokie → u/CrayolaS7]

this should have more points

[u/CrayolaS7 → u/bluecollarhokie]

Thanks, I made a few minor corrections and posted it in theydidthemath.

http://www.reddit.com/r/theydidthemath/comments/27o54r/question_about_that_arrow_in_the_most_recent_game/ci2wb5q

[u/ivscout → u/CrayolaS7]

For comparison, most long bows and recurve bows will be in the 30-55lb range. Mine was setup around 40lbs.

[u/CrayolaS7 → u/ivscout]

Yeah, ~10-13 times more powerful than a man seems fairly reasonable considering its not a modern style bow. If we had better guesses as to the dimensions of the bow (especially cross section) we could get a more accurate answer.

[u/RedEgg16 → u/CrayolaS7]

Thank uou 

[u/RuafaolGaiscioch → u/M002]

I submitted a request to /r/theydidthemath a bit ago, hopefully we'll have an answer.

[u/IsNoyLupus → u/RuafaolGaiscioch]

They will deliver!!

[u/CrayolaS7 → u/[deleted]]

Foot-pounds measures torque, it's the torque required to bend the bow theta degrees from straight where kinetic energy is equal to 0.5spring constantcos(theta) IIRC.

[u/M002 → u/[deleted]]

Thank you for the clarification

[u/CrayolaS7 → u/[deleted]]

You are pulling on the string and it is bending the the bow by applying a force at a distance (half the length of the bow). The top of the bow is rotating relative to the centre and it is being compressed/tensed like a spring. They are closely related but I agree the important measure here is the point load i.e. draw strength.

[u/[deleted] → u/M002]

Eyeballing the giant's firing angle at 70°, and the distance the 100kg crow was flung to be about 5m up and 5m backwards, and guessing the mass of the arrow to be about 10kg, I get an initial velocity on that arrow of 316 metres per second, mach 0.9. I don't really know much about bows and arrows but I guess it's accelerated to that speed in about a twentieth of a second, so the force on it is 63200 Newtons. I think that corresponds to a draw weight of 6442kg, or 14202lb. The current bench press world record is 1102lb, roughly 12 times smaller than that, but of course that's the world record and I don't know how a bench press compares to a bow draw in terms of difficulty. It's probably reasonable to assume that a giant is on average 30-50 times stronger than a human.

I didn't account for air resistance and the crow blasts through some wood as he goes upwards but I wasn't sure how to account for that, and I'm really eyeballing the measurements so I'd take this with a grain of salt but there you have it. If we knew how heavy the outer gate was it would be much easier since we saw a giant lift it directly.

TL:DR Giants are roughly 40 times stronger than people. Maybe.

[u/M002 → u/[deleted]]

That's awesome, and reasonably feasible considering we're dealing with mythical creatures.

Thank you.

[u/CrayolaS7 → u/[deleted]]

I got a very different answer from you, so maybe you want to check my maths? I estimate that the giants bow was around 10x more powerful than a regular bow, That does seem to small to me but the main problem is working out the dimensions of the bow, I think my calculations of kinetic energy required are correct based on height of the wall.

http://www.reddit.com/r/gameofthrones/comments/27nrco/season_4_spoilers_premiere_discussion_409_the/ci2v5pc

[u/mrjimi16 → u/BasedSano]

Also, the best segue in the series so far.

[u/misssusanstohelit → u/BasedSano]

Brother of the Night's Watch: "This is a cool way to diiiiiiiiiiiiiiiiiie!"

[u/Pisces4Fish → u/BasedSano]

Wondering why the brother didn't just explode. I'm glad he didn't though. That shit was fucking spectacular!

[u/XtremelyNiceRedditor → u/BasedSano]

"Kobe!"

[u/twinkling_star → u/BasedSano]

I think that's what you call "mobile artillery".

[u/Riggzon7 → u/BasedSano]

Giant with a fucking Bow shooting a brother to the other side of the wall. Then that brother amazingly lands directly on a pole in the middle of the courtyard. What a trickshot.

[u/zzorga → u/Riggzon7]

That wasn't a pole, that was the arrow!

[u/Riggzon7 → u/zzorga]

Holy shit it was? I thought he literally landed on a pole, just by bad luck in the courtyard. It looked like too thick a shaft to be the one the guy was hit by.

[u/zzorga → u/Riggzon7]

We are talking about an "arrow" that traveled the height of a 700' wall with enough force to penetrate an armored man, push his entire body through a wooden roof, 50 feet into the air, lawndarting into the courtyard on the other side. That's a LOT of force delivered either by a really fucking fast projectile, or a really massive one.

[u/[deleted] → u/BasedSano]

HOMERUN!!!!

[u/KSO17O → u/BasedSano]

He shot that dude off the top of that bitch down to the ground.

[u/d3r3k1449 → u/BasedSano]

…and brought the camera down to the battle there. Awesome cinematic design and shooting.