Thursday, October 17, 2019

News You Can Use—After London Commuters Physically Drag Climate Protestors From Roof of Train: How To Glue Yourself to the Roof Using Science

First up, ITV London's deputy news editor:
HT: ZH

And from Popular Mechanics:

How to Glue Yourself to a Plane, According to Science
A protester did it. We can do it better.
Popular Mechanics HQ was predictably spellbound yesterday when news reports trickled out concerning a protester who glued himself to the top of a British Airways plane at London City Airport. 

On top of that, the protester, identified as a man named James Brown, is a partially visually impaired former Paralympic runner and cyclist. Meet your new Most Interesting Man in the World.

While we’d like to reach out to Brown to ask him some questions—actually, all the questions—what’s complicating matters is the small fact that he may or may not be in jail at the moment. Brown was acting on behalf of Extinction Rebellion, a London-based environmental group known for theatrical gestures of protest, when he bought a ticket for a flight, went through security, proceeded up the steps of the BA Embraer 190 jet, and propelled himself on top, according to The Sun.

“Here I am on top of a f****** aeroplane at City Airport,” Brown said in a video he posted online during the stunt. “I hate heights, I’m s******* myself, I managed to get on the roof. I am so shaky.”
Security soon approached Brown, and not a moment too soon. “Oh good,” Brown said after a few impassioned rally cries against government inaction on climate change, “security are coming. I hope they don’t take too long, because this is f****** scary.”

Brown was eventually removed, and we await more information about his status.
There’s lots to unpack here, like, say, how exactly a partially visually impaired man was able to climb on top of a twin-engine jet airliner. Seems pretty hard! But we were mostly curious about how you’d go about gluing yourself to a plane. Since airport security pulled Brown off the jet with relative ease, he honestly couldn’t have tried very hard.

So. Let’s say you actually wanted to do this thing the right way. We won’t ask why. But you’re dead-set on sticking to a plane, dammit, and that’s all that matters. Where do you start? 

Master the Physics
“The first order of business,” says Giles Dillingham, Ph.D., the CEO and chief scientist at BTG Labs, a materials science company that performs research in surface science, surface treatments, and adhesion, “is to determine the load we are asking the bond to withstand.”

In this scenario, imagine you’re 170 pounds. This is your load. If you try to stick yourself to the bottom of a plane, you’ll put the adhesive bond (the glue) into too much tension, and the forces will probably fail it, Dillingham says. But go to the top of the plane and your weight will compress the bond instead. In that case, the only thing that could fail the bond is the shear stress that results from the drag of the airflow on your body.

Your bond will have to resist the force of wind, says Dillingham, so you’ll need an estimate of that force. “A skydiver who is facing straight down has a terminal velocity of about 200 mph,” he says. “At that speed, the force of gravity pulling the body down is just equal to the force of the wind on the body.” Let’s assume, then, that your bond has to survive a speed of 200 mph and withstand a 170-pound load.

You’ll want to maximize the entire bonded area, of course. If you only glue your hand to the plane, your entire load—your weight, plus the drag from the airflow—must be supported by the spot on your skin that’s actually bonded. Bond a large area, however, and the force per unit area will be low, Dillingham says. 

In other words, spread that glue all over your body, and leave no patch of skin unturned. 

Nail the Chemistry...
....MUCH MORE 
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