CREWE Skyscraper

Screen Education 94 I © ATOM

ABOVE: The image used for the infamous Skyscraper poster, featuring Dwayne ‘The Rock’ Johnson as security consultant Will 36

Screen Education 94 I © ATOM

ABOVE: The image used for the infamous Skyscraper poster, featuring Dwayne ‘The Rock’ Johnson as security consultant Will 36

SCREENS IN THE CLASSROOM MY SS

Cinema Science THE LOGICAL LEAPS OF SKYSCRAPER

When the first promotional material for the 2018 Dwayne ‘The Rock’ Johnson action vehicle came out, much mirth was had on social media at the expense of the poster’s questionable trajectorial implications. But, as DAVE CREWE explores, the poster and film alike contain ample opportunities for classroom investigation into a range of physics and engineering topics, from projectile

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kyscraper (Rawson Marshall Thurber, 2018) isn’t the most original Hollywood action film.

Unapologetically crafted from the constituent parts of The Towering Inferno (John Guillermin, 1974) and Die Hard (John McTiernan, 1988) and fronted by the defining action hero of our time, Dwayne ‘The Rock’ Johnson, the film has little interest in offering anything new. For a piece of entertainment, that isn’t necessarily a problem; in fact, this ranks as one of the better entries in Johnson’s dense filmography (in large part thanks to its use of Johnson as a charismatic leading man rather than a comedian).

And, despite its filmic familiarity, Skyscraper has plenty to offer science teachers looking to enliven their classrooms.

It’s not only the film. Since its inception, Cinema Science has largely been motivated by cultural prominence, choosing films that you can expect a majority of your students to be familiar with. Skyscraper’s first act could prompt an investigation into the

engineering requirements of mega-­skyscrapers, and its second act – in which a towering skyscraper is engulfed in flames and plagued by terrorists – allows for the exploration of elevators, bridges and fire-prevention strategies. But when it comes to Skyscraper’s cultural prominence, the film itself has arguably been eclipsed by the physics-centric memes that sprung up across the internet in the wake of its first poster’s release.1 These memes humorously debate the plausibility – or lack thereof – of Johnson’s character, security consultant Will Sawyer, making an impossible-looking jump from a crane to the skyscraper.

Using memes, a contemporary language that students should be familiar with, allows for both engagement and some serious grappling with the physics of projectile motion. With time-poor teachers often unable to find time to screen a complete feature film, Skyscraper presents a rare opportunity to incorporate pop culture into the curriculum … without needing to sacrifice teaching time.

www.screeneducation.com.au

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motion to vortex shedding.

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Leap of faith These memes are a legitimate attempt to grapple with a frequent focus of Cinema Science: the realism of a spectacular stunt. A quick bit of MS Paint from Twitter user James Smythe2 soon ­inspired a series of proposals3 as to how Johnson would or wouldn’t clear the distance between the crane and the skyscraper.

Some of these were serious scientific investigations4 … others, not so much.5 This is a fantastic demonstration of how science doesn’t have to be carefully calibrated experiments and stuffy lab coats, and that it can be fun and irreverent while still motivated by scientific rigour. If I were introducing projectile motion, I’d begin by showing my students the poster by itself, prompting a class discussion about whether or not it seems likely that Johnson could successfully land inside the broken window. For the next step, I’d present the students with the series of memes before providing them with Twitter user Christian Bedwell’s calculations,6 and – assuming they’re familiar with the core concepts of projectile motion and straight-line motion equations – ask them to verify the validity of his conclusion.

The next part is where it gets really interesting. Too often, students are accustomed to assuming that the values spat out by the mathematical formulas they’re given in class are accurate and reliable. But a formula is only as good as its parameters and their associated assumptions. Bedwell’s calculations seem solid, but are reliant on some key assumptions. For instance, even if we take Google’s first result for Johnson’s height as accurate without further verification, the red box used in Bedwell’s tweet to approximate the scale of the poster is measured from Johnson’s outstretched foot to his head – potentially overestimating the distance of the jump.

There are other factors to consider, many of which are presented (not always in full seriousness) in the ensuing Twitter thread.

Perhaps the updraft from the fire is enough to buoy Johnson’s arc – sounds implausible, but certainly worthy of investigation!

Maybe the crane is not stationary, but itself moving forwards,

Too often, students are accustomed to assuming that the values spat out by the mathematical formulas they’re given in Screen Education 94 I © ATOM

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class are accurate and reliable. But a formula is only as good as its parameters and their ABOVE, FROM TOP: Memes created by Twitter users James Smythe, Galen Kehler and Christian Bedwell

associated assumptions.

meaning that Johnson’s required initial speed is reduced by however fast the crane is moving at the moment he jumps off. A more pertinent question relates to the arc posited by Bedwell, which seems to go below Johnson’s centre of mass.

When contrasted with the scene from the film itself – in which the crane appears to be much closer to the building, and Will only manages to save himself by clutching onto debris hanging from the edge of the window – it certainly seems like there’s a scientifically plausible case for him making the jump. You could ask your students to present that argument, with calculations – and clearly justified assumptions – to support it.

Students could also be encouraged to question the conclusions, not just the premises. While Bedwell’s view that the jump is impossible because it requires an initial speed of 12.7 metres

There’s likely a wealth of educational material in examining this skyscraper from a design perspective, but let’s return to the realm of science. Described in an in-film promotional video as ‘a marvel of modern engineering’, The Pearl should – with the aid of some science-teacher scaffolding – provoke discussion around the engineering challenges limiting the height of modern buildings. A 2018 Syfy Wire article by Cassidy Ward provides an excellent summary of some of the major challenges facing engineers wanting to push higher and higher: specifically, weight, wind and liveability.10 Ward’s article links the weight challenges to square–cube law; expressed simply, doubling the height of a building will quadruple its surface area (two squared) but octuple (multiplying by eight, or two cubed) its volume and therefore its mass

Vortex shedding – where ‘wind hits a structure, causing alternating [vortices] to form at a certain frequency’ – presents a serious risk to buildings if the frequency of oscillations aligns with the resonant frequency per second is pretty hard to quibble with (given that, at that pace, he could cover 100 metres in under eight seconds), it is a good prompt for an investigation into the limits of human speed under different conditions. For instance, you could direct your class to a 2016 article in The Conversation entitled ‘The Maths Behind the Fastest Person on Earth (and No It’s Not Usain Bolt)’,7 which explores the effects of factors such as wind and acceleration on human velocity.

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After seeing the poster, the calculations and the footage from the film, do you think it’s realistic that Johnson would make the jump depicted?

What is the fastest speed that a human could realistically travel? Be careful to identify your conditions clearly!

Make a meme of the Skyscraper poster using your own projectile-motion calculations.

Touch the sky The first act of Skyscraper is an extended advertisement for a product that, beyond the world of the film, doesn’t exist. The centre of the action is a building called The Pearl, a 225-storey building that’s entirely self-sustainable, aesthetically admirable … and entirely fictional. Standing at an intimidating height of 1066 metres – some 236 metres taller than the current tallest building, Dubai’s Burj Khalifa8 – The Pearl is impressive purely from a design perspective. Talking to Dezeen magazine, production designer Jim Bissell succinctly summed up the challenges of creating The Pearl: The first real challenge was to make a very, very tall building with a pearl at the end, and not make it look phallic. The second [was] that, because it is so overbearing on the skyline, it’s so prominent […] I did want to try to give it some kind of real character.9

– and thus the force exerted by the building and the foundation necessary to support it. This provides a perfect context within which to introduce or explore proportionality beyond linear relationships.

The Pearl’s curved, almost sinusoidal structure is surely intended to provide a striking visual for audiences. It may also serve a utilitarian purpose, however, disrupting wind flow to prevent the dangers of vortex shedding. Vortex shedding – where ‘wind hits a structure, causing alternating [vortices] to form at a certain frequency’11 – presents a serious risk to buildings if the frequency of oscillations aligns with the resonant frequency of the structure. Skyscraper opens up the challenge of engineering super-skyscrapers as a new perspective on the significance of this phenomenon.

Equally fascinating are the mechanisms used to mitigate the dangers of vortex shedding. Many tall buildings are constructed with something called a tuned mass damper: a device designed to avoid exciting a system to its dangerous resonant frequency.

These can be used in cars, powerlines, wind turbines and, of course, buildings. Taipei 101 – briefly the world’s tallest building, until construction was completed on Burj Khalifa – houses the largest mass damper in the world, a 5.5-metre diameter sphere weighing around 600 tonnes.12 Granted, there’s no evidence to suggest that Skyscraper’s The Pearl has its own tuned mass damper, though engineer Alex Weinberg13 convincingly argues that it would have made sense for its namesake ‘pearl’ to be one – and that’s more than enough of an excuse to pivot to the science and applications of tuned mass dampers from the film.

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What are the logistical challenges of building a skyscraper as tall as The Pearl, and how can they be overcome?

Burj Khalifa doesn’t have a tuned mass damper. How is it designed to avoid the threat of vortex shedding?

How is The Pearl designed to be self-sustainable? Is this realistic?

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of the structure.

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THIS SPREAD, L–R: Will with The Pearl financier Zhao Long Ji (Chin Han); Will with his wife, Sarah (Neve Campbell)

Going down

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When selecting topics for Cinema Science, I tend to home in on short scenes and simple questions. That’s in part a concession to the practicalities of teaching; it’s rare that you’ll find time in a science or mathematics unit to sit down and watch an entire feature film, whereas there’s generally time to accommodate a brief clip from a well-known film. The other advantage is that scientific questions – especially simple ones – can facilitate an investigation into the principles, assumptions and laws underpinning the situation.

Here, I want to talk about the elevators connecting The Pearl’s hundreds of floors (for those who don’t want to dangle precariously outside the building, as seems to be The Rock’s preferred mode of transport). Sure, we could discuss the fact that they’re designed to, in Johnson’s character’s own words, ‘operate on electromagnetic induction’. There’s a productive vein of contemporary science to be mined through researching this realistic technology and its upcoming applications in elevators, no doubt.14 But, instead, let’s single out one short scene, in which Will has just rescued his family from villainous corporate traitors but is trapped in a building inferno. Needing to send his loved ones to safety, he shoves them into a nearby elevator and gives them the following instructions: ‘When there’s a fire, [the elevators are] held in place by a fail-safe brake […] It’s about 500 feet from here until the fire line. I want you to count to five and pull the handle.’ Leaving aside the rather pressing question of how Will’s able to accurately approximate the position of the fire line from within the building, the question you can pose to your ­students is straightforward: will Will’s family safely get past the fire line?

Posed to a class with a background in the physics of falling objects, that’s a relatively simple question: assume an initial

velocity of zero, standard gravitational acceleration and a time of five seconds, and some quick working should give a displacement of 122.5 metres. Convert your units, and an answer of roughly 400 feet would give a definite ‘depends’: depends on the accuracy of Will’s estimate, whether the air resistance in the elevator shaft (or potential magnetic resistance) is negligible and, of course, whether Will’s wife, Sarah (Neve Campbell), is able to reliably count to five seconds and pull the brake at the right time. For students not familiar with the underlying physics, that’s a productive lesson in itself.

What if we go beyond that quote and analyse the scene itself?

Grab a stopwatch and time from the moment the elevator drops to the moment Sarah pulls the brake, and you’ll record a time much longer than five seconds. I counted eighteen, though naturally that’s not considering that the editing might have overlapping chronology. Using straight-line motion equations – again disregarding air resistance, which certainly isn’t realistic for that length of time! – falling for eighteen seconds translates to a fall of just under 5 kilometres, or around 16,000 feet: a great deal further than The Pearl’s advertised height of 1.07 kilometres.

This is not just an empty experiment, but an effective illustration of the importance of acceleration. Ten metres per second may not sound like that much at first, but this example demonstrates how swiftly that turns into huge speeds and mammoth distances. It also opens up the opportunity to explore the necessity of considering air resistance under such circumstan­ ces, ­pivoting nicely into the concept of resistance forces and, specifically, terminal velocity.

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What are the advantages of electromagnetic elevators, and how do their mechanisms differ from most elevators?

How long would it take to drop an object from the top of The Pearl to the bottom?

Any film called Skyscraper is likely going to have a wide variety of applications in physics/engineering topics, and, thankfully, Thurber’s film more than delivers on this promise. Bridges may seem like an odd inclusion within a skyscraper, but one of the big set pieces early on involves Will’s family making a perilous journey over a plank that forms a makeshift passage over a severed internal bridge. Introductions to engineering concepts in junior Science often centre on bridge building, and this scene actually gives two different ways to frame the topic.

The first is to ponder the safety of simply extending a plank over a gulf. Is there a better way to ensure the stability of a bridge in such hazardous circumstances? Equally interesting is to con­ sider the solidity of more structurally sound bridges … like the one that Will’s family is forced to traverse after debris cuts a hole through its centre. As Weinberg laments, ‘the two unconnected spans magically stay[ing] standing up’ is a frequent but frustrating ‘action-movie trope’ that fails to consider how these bridges are constructed.15 You could build a practical activity around why this is unrealistic, and how you could design a stable bridge that would stay up under such circumstances.

One of the major hazards presented in Skyscraper is the raging inferno tearing through the building after the antagonists disable The Pearl’s fire-prevention system. That fire-prevention system is conventionally described by Will in the first act, as he explains that ‘The Pearl’s anti-fire measures employ a one-of-akind self-sealing ventilation system and a robust sprinkler and CO2 array which can put out a fire in a fraction of the time’. Here’s an opportunity to explore both fire prevention in general and in the context of a residential building. Specifically, you could discuss how CO2 arrays might not be the best system to install in inhabited apartments.

Finally, you might want to bring up the topic of artificial limbs.

Will loses his leg in the film’s prologue, and thereafter is fitted with a durable artificial limb. This plays a role in the film on a few occasions – for example, Will’s ex-partner Ben (Pablo Schreiber) shoots him in his artificial leg when trying (unsuccessfully) to incapacitate him; and, later, Will’s able to use the leg to jam a door open. Not only can students investigate how realistically durable the leg is, they can look into the growing fields of biomedical research regarding the design of artificial limbs, which is lucratively combining knowledge from biology and physics into a growth industry improving the lives of people in need.

Dave Crewe is a secondary school teacher and film critic based in Brisbane, Queensland. His writing can be found at SBS Movies, The Brag and Metro magazine, or his own website, <https://ccpopculture.com>. SE

Endnotes Mathew Olson, ‘This Skyscraper Poster Has People Asking: Could Dwayne Johnson Make That Jump?’, Digg, 5 February 2018, <http://digg.com/2018/skyscraper -poster-dwayne-johnson-rock-impossible-jump>, accessed 27 March 2019.

2 Post dated 3 February 2018 by Twitter user @jpsmythe, <https://twitter.com/jpsmythe/status/9595619696186 20416>, accessed 27 March 2019.

3 Post dated 6 February 2018 on The Mother of All Nerds Facebook page, <https://www.facebook.com/ TheMotherofAllNerdsPage/posts/2022752124652506>, accessed 27 March 2019.

4 Post dated 4 February 2018 by Twitter user @ChristianBedwel, <https://twitter.com/ChristianBedwel/status/95984888944 3606529>, accessed 27 March 2019.

5 Post dated 8 February 2018 by Twitter user @LeighYoungArt, <https://twitter.com/LeighYoungArt/status/961241473390 993410>, accessed 27 March 2019.

6 Post dated 4 February 2018 by Twitter user @ChristianBedwel, op. cit.

7 Christian Yates, ‘The Maths Behind the Fastest Person on Earth (and No It’s Not Usain Bolt)’, The Conversation, 12 August 2016, <https://theconversation.com/the-maths -behind-the-fastest-person-on-earth-and-no-its-not-usain -bolt-63732>, accessed 27 March 2019.

8 Though Saudi Arabia’s Jeddah Tower, unfinished at the time of writing, is expected to be the world’s first kilometretall building; see Andrea Lo, ‘Jeddah Tower: What Does the World’s Next Tallest Skyscraper Look Like Now?’, CNN Style, 17 January 2018, <https://edition.cnn.com/ style/article/jeddah-tower-saudi-arabia-new/index.html>, accessed 27 March 2019.

9 Jim Bissell, quoted in Dan Howarth, ‘“We Were Doomed for Failure in the Eyes of the Architectural Community” Says Skyscraper Movie Designer’, Dezeen, 16 July 2018, <https://www.dezeen.com/2018/07/16/interview-jim-bissell -skyscraper-movie-production-designer/>, accessed 27 March 2019.

10 Cassidy Ward, ‘Science Behind the Fiction: Skyscraper’, Syfy Wire, 9 July 2018, <https://www.syfy.com/syfywire/ science-behind-the-fiction-skyscraper-0>, accessed 27 March 2019.

11 ‘Vortex Shedding & Tall Structures – the Uncertainties of Wind Loading’, Sparta Designing Solutions website, <http://www.spartaengineering.com/vortex-shedding-and -tall-structures/>, accessed 27 March 2019.

12 ‘Wind Damper’, Taipei 101 official website, <https://www. taipei-101.com.tw/en/observatory-damper.aspx#SCROLL2>, accessed 27 March 2019.

13 Alex Weinberg, ‘What Skyscraper Doesn’t Get About Skyscrapers’, CityLab, 17 July 2018, <https://www.citylab. com/design/2018/07/what-skyscraper-doesnt-get-about -skyscrapers/565244/>, accessed 27 March 2019.

14 If you do want to head in this direction, this link might be a handy starting point: Ryan Whitwam, ‘Next-generation Elevator Will Use Magnets Instead of Cables’, Geek.com, 29 November 2014, <https://www.geek.com/news/next -generation-elevator-will-use-magnets-instead-of-cables -1610565/>, accessed 27 March 2019.

15 Weinberg, op. cit.

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Odds and ends

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