#that's usually called things like 'sunburns' or 'radiation poisoning'

[sidereon-spaceace]

Concept: an upper limit to how much magic you can use to heal someone

Like how desperately chugging gallons of water in a span of minutes will kill you, how eating far too much food than you're used to can make you sick- in similarly extreme cases, casting too much magic to heal someone from serious injury can cause more problems than you're trying to fix.

Sudden onset of fever and chills, burns, after a certain point the body may just outright reject the magic being applied so that it has no affect.

[badbackgroundscience]

Science of “The Seven”

I watched Amazon’s The Boys this week. So instead of the usual 60′s Marvel fare, here’s some tangential science relating to the superpowers featured in the show:

1. Homelander can’t see through zinc.

This is obviously a play on Superman not being able to see through lead, but the switch brings up some problems with the physics involved. X-rays - light with wavelengths ranging between 0.01 and 10 nm* - can’t travel through a lump of lead because lead is super dense. It’s nearly the heaviest non-radioactive element, with (usually) 208 protons+neutrons and 82 electrons. And its atoms pack very closely together.**

Combining that density with the fact that lead atoms are also very good at attenuating x-ray light (meaning the amount of x-ray photons that can penetrate a certain thickness of lead drops exponentially as that thickness increases), it makes sense that Superman’s x-ray vision’s weakness is lead.

But zinc is a smaller atom (usually 64 protons+neutrons and 30 electrons) and its atoms don’t pack as tightly; it’s about 1.5 times less dense than lead. It’s X-ray attenuation is generally lower, but not too different, from lead (compare this graph vs this one). Together, this makes it easier for x-rays to penetrate zinc than lead.

So why can’t Homelander see through zinc, but (supposedly) see through lead? It could be that the x-rays he emits correspond to a wavelength that zinc absorbs more than lead does. Annoyingly, the absorption spectra I can find all seem to be dealing with zinc compounds (e.g. ZnO, ZnS) instead of pure zinc metal. So I can’t tell you exactly what wavelength that would need to be.

Sorry.***

2. The Deep has torso gills

Fish are ectotherms, meaning their body temperature is regulated by their environment. Mammals - including cetaceans (i.e. whales, porpoises, and dolphins) - are endotherms. We generate our own body heat. Kevin presumably does, too.

This means that a man needs more oxygen than a man-sized fish does. About 15 times the oxygen, in fact. It’s the gills’ job to extract oxygen from water and pump it into the fish’s bloodstream; bigger fish have bigger gills, but a 75-kg man needs gills 15 times the size of a 75-kg fish’s. Not necessarily in length, but in collection area. And that’s assuming you’re not doing any physical activity that ups your oxygen requirements.

But on top of that, oxygen is far less abundant in water than it is in air - about 20 times less for the same volume. If an average human needs a quart**** of oxygen per minute, their gills would need to strain 51 gallons of water every minute to meet that requirement.

Combining these two factors, designer and material scientist-dabbler Jun Kamei is developing a set of artificial gills, and claims the final device will have a surface area of 32 square meters (344 square feet).

The human lung surface area is somewhere around 75 square meter range, so if you’ve got gills that can pack as efficiently as lungs do, you probably could fit them into your abdomen. Maybe not Chase Crawford’s abdomen, but a stockier human’s abdomen.

The real problem here is that Kevin’s doing himself no favors by covering the gills up while he’s underwater. Water rushing through the gills is the whole point, and you’ve just made it 1000% harder.

3. A-Train (and Popclaw) booms and bu(r)sts

According to the race announcer that one episode, A-Train can reach speeds over 1000 miles per hour. Assuming that’s true and not a horrible exaggeration, as soon as he passes the speed of sound (767 mph at sea level), A-Train would create sonic booms. Not a single boom. Constant booms for as long as he’s going fast enough. You (as a single individual) only hear one, but that’s only because you’re not moving.

We never see him do this, so we must conclude he’s not a complete idiot and only goes this fast when he’s far away from people and architecture. (If I read the screen right, he only clocks in at 371 in his race.)

As for the secret girlfriend he murdered, there are several species of amphibians that can stick their own bones out through their skin to use as weapons. For example, species of frog within the genus Astylosternus, and Trichobatrachus robustus (aka the hairy frog). The Spanish ribbed newt can push its ribs out through its torso; when threatened, its skin also secrets poison, turning its bones into poisonous barbs.*****

4. Translucent isn’t see-through. He’s see-around.

As the man explains to Jimmy the late night host (No, not that Jimmy the late night host...the other Jimmy the late night host), his skin can convert at will to a “carbon metamaterial” that bends light around it. 

We don’t know if there are other elements involved besides carbon, but if there aren’t, the real-world comparison is graphene -- an atom-thick layer of carbon atoms bonded to each other forming a honeycomb pattern.

Given its thickness, it’s translucent itself. [Side note: yes, “translucent” doesn’t mean invisible. However, some dictionaries (e.g. Merriam Webster and the OED) include alternative definitions identical to "transparent"...which goes against everything I ever learned. But either way, he actually is translucent when he isn’t “translucent”. Because human skin is translucent, assuming there isn’t too much melanin in it.]

A 2D sheet of graphene has a breaking strength of 42 Pa (0.0061 psi). That number seems super small, but it's actually reflecting the strongest material we know of. You'd need 4,300 pounds balanced on a pencil (pointy end on the graphene) to break through that atom-thick sheet.

Alternatively, if I did my back-of-the-envelope math right, you’d need a 50 gram .50-cal bullet traveling at ~770,000 mph (and coming to a stop in ~1 millisecond). Now, the human epidermis averages ~1mm thick. That's 3 million layers of graphene. 

However, if you manage to put a crack into your graphene, it becomes brittle on par with a ceramic.`*

As for being able to electrocute Translucent because carbon is “highly conductive”, graphene is indeed so; however, other carbon compounds aren't (e.g. diamonds). It all depends on the positioning of electrons within the solid (moving electrons = flowing charge). Since we don’t know what Translucent’s metamaterial is, we’ll have to take the show at its word.

Though here’s some bonus info: metamaterials are all synthetic. Which would mean that Translucent had this skin installed somehow. Or, it’s a very subtle dig at Compound V being used to create superheroes that only I caught.

The one thing that the season left bugging me about Translucent was his eyeballs. Somehow those are see-through.

5. Starlight pushes it real good

Our newest member of the Seven can use concentrated light to knock baddies off their feet, as well as throw them several meters back. This is an exaggerated form of reality. Light can actually push stuff. 

Photons do exert a teeny tiny amount of pressure on whatever they hit. It’s called radiation pressure. The amount is sufficient for something like a solar sail (The above image is LightSail 2), but not wiping the floor with a criminal.

According to (more) envelope math, Starlight would need to emit ~30 PetaWatts to deliver a good boxer-level punch to a baddie standing ~2 meters away. That's the equivalent amount of energy released by 7.2 million tons of TNT exploding, in 1 second. 

Also, given the color of the light she emits, she’s probably emitting a spectrum identical to our Sun, meaning she’s emitting a ton of light that normally gets blocked by our atmosphere, including x-rays and ultraviolet radiation.

She’s definitely given someone a melanoma at some point during her life. Or at least a very bad sunburn.

Bonus: Ice Princess shatters wangs

Final back-of-the-envelope math, calculating how fast that guy's (presumably erect) penis would freeze being enveloped by an ice vagina at -346 °F (-210 °C). A combination of calculating the heat lost per second via conduction, and the amount of energy lost as body-temp water cools and converts to ice.

Came out to 0.1 seconds. 

Faster than I expected...

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* Visible light is ~400-700 nm

** There are several (nonradioactive) metals more dense than lead, but more rare/expensive, like gold and iridium. 

*** Also, brass can be up to 45% zinc. Does that mean Homelander can only sort of see through brass?

**** Get out of here with your imperial units, self...

***** Fun fact: it can regenerate lost limbs, heart tissue, brain cells, and its spinal cord

`* Butt cracks don’t count.

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Image credits:

Zinc - CC BY 3.0

gills By Chris 73, CC BY-SA 3.0

frog claws from Barej et al 2010

sonic boom By I, Melamed katz, CC BY-SA 3.0

graphene By U.S. Army Materiel Command, CC BY 2.0

lightsail 2 By Josh Spradling / The Planetary Society CC BY-SA 3.0

ice by Ian Mackenzie CC BY 2.0