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| Lightning |
 Title text: Maybe you should wear one too? I guess I'm taller than you, so as long as I have one we're fine. |
Explanation
An anti-static wrist strap is a device worn by people working with sensitive electronic devices. The strap is connected to a "ground", so any static charge will be neutralized rather than accumulating and discharging to the device, potentially causing damage. Many electrical devices are grounded by conductors in their power cords, protecting the devices (and their users) from electrical faults.
Lightning is a release of static electricity that occurs when there's a large charge difference between a cloud and the Earth or between two clouds. In the comic, Cueball has once again confused how anti-static devices work β rather than protecting a device from static in the person, he thinks it will protect the person from static in the lightning. In fact, wearing a strap that conducts electricity will make it fractionally more likely that he will be struck by lightning (by bringing the typical 'ground' anode marginally closer to the cloud's cathode, bypassing the usually greater electrical impedance of his body), and then the strap is far too small to protect him from the electricity in the lightning strike once this happens.
He may think that the anti-static device works like a lightning rod, attracting the lightning that would have struck his body, and diverting it away from it. The reason they work is because lightning takes the easiest path. If a tall structure is going to be hit by a lightning strike, it's better to have that strike not go via more resistive materials that can be easily damaged or destroyed. A proper lightning conductor is designed to conduct the large amount of energy of lightning safely to the bottom, unlike a wrist-strap cable that is only made to leak away much smaller static buildups and could not contain a sudden cloud-to-ground surge of electricity.
This is further echoed by the title text, in which he thinks that Ponytail should be safe because he's taller than she is (plus also higher up in the hill in the comic β although she could at some time easily move further up the hill than him, so relative tallness is only part of the issue), and lightning tends to be attracted to the most prominent conductor in its vicinity (e.g., lightning rods that extend above the roof of the building they're protecting). While it is true that Ponytail is less likely to be struck by lighting directly she is by no means safe: If lighting hits the ground a very large current is discharged into the earth, and will spread outwards from the impact point. Since Ponytail (like all humans) has a lower resistance than the ground, this current will travel through her feet and legs upon reaching her. Since Cueball has (by an extension of his own logic) made himself more likely to be struck he has increased the risk for Ponytail even if the grounding would protect him. (Obviously, there are better ways to be protected during a thunderstorm; see the What If on lightning.)
Additionally, merely wearing such a device has no effect at all if it isn't connected to a handy grounding point, which is unlikely to be the case if you're actively moving around, such as with the two characters here who seem to be hiking during the storm. You'd possibly even need a couple of grounding-wires, always one secured to some suitable 'earthing point' even while the other is being unclipped from where you've just been and reclipped to slightly ahead of where you're going. Close examination of the 'protected' individual shows that there is a loop of some dangling wire going from their wrist to their body. If that's all it does, then it's practically useless. There is some vague possibility, however, that the wire goes down the torso (ideally in an insulated manner, to avoid both electrical and thermal transference in the event of a lightning strike passing through it) and splits to connect down each leg and towards a grounding-plate/spike on the sole of each foot. This would technically create a dynamic 'always active' form of lightning-rod protection (ignoring the discrepancy between the height of the figure's wrist and the possibility that the higher crown of the head might be struck by lightning more in the first instance) where the act of walking will always create a protective connection to the ground β so long as Cueball does not attempt to run or (even momentarily) make any jumping movements. And it still relies upon an effective lightning-conductor connection that is rated sufficient to carry a strike's charge properly, without creating additional surface effects to the skin/clothing it passes down along. This is one of the rare situations in which wearing a tin foil hat might actually be of some benefit, assuming that it was connected to ground via a conductor, all sufficiently heavy-duty to carry the current.
Randall also shows Cueball's incorrect views on lightning in 795: Conditional Risk, in that case confusing statistics.
Transcript
- [Lightning overhead. Cueball and Ponytail (the latter holding a walking stick) are standing on a hill at night with various shrubbery on it, watching the lightning.]
- [In the sky, by the lightning:]
- BOOOOM
- Cueball: Don't worry, I'm wearing an anti-static wrist strap
Trivia
There was indeed a brief period, starting in France in 1778, when lightning rods were incorporated into clothing. Its effectiveness is debatable. One would need data about how many people wearing such clothing were struck by lightning but unhurt because of the rods, and there's no way to know how many people wearing such clothing weren't struck at all, but would have been struck if they hadn't been wearing it.
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