Science Explains Fantasy: Weaknesses

Even the mightiest of us have our weaknesses.  Superman, the embodiment of physical superiority, is reduced to a position of humility in the presence of kryptonite.


Many characters in fiction have their own personal kryptonite:  werewolves and silver, vampires and sunlight… the list goes on.  Below is a picture from Serkworks that highlights the weaknesses of several famous movie monsters and villains.  Hoodies and t-shirts featuring this design are available here.

How to kill monsters

Kryptonite may not be real, but it has become synonymous with weakness.  But can we have our own personal kryptonite?  The concept of having a personal weakness is far more commonplace than you might think.


Allergies are so common that this segment hardly needs any introduction.  It is estimated that 15 million Americans suffer from food-related allergies alone, which marks a 50% increase from those estimated in 1997.  Although it remains unclear why allergies are on the rise in general, it’s no mystery of how they develop in an individual.

Your body’s immune system is really great at fighting off invading germs. That’s because your body has trained itself to recognize the chemical signature of the germs and send out a squadron of antibodies custom-designed to attach to the surface of each different invader. Those chemical signatures on the germs that your body recognizes as harmful are called “antigens,” and when an antibody attaches to an antigen, the germ can be easily destroyed by the body.

However, sometimes your body can get a little overambitious.  There is a particular type of antibody that helps defend your body against parasites called Immunoglobulin E, or IgE for short.  In some individuals, for reasons which are currently not understood, the body misinterprets some ingested food (like milk or peanuts) as an invading antigen, and it sends out the IgE antibodies to attack (see picture below).

How Allergies Work

The unfortunate news is that IgE doesn’t float around freely in your body for long.  Eventually, it binds to mast cells in your bloodstream, and then things become a lot more uncomfortable for you.  You see the next time you eat that same food (milk, peanuts, etc.), the IgE will still be sitting on those same mast cells, and when they bind to the food “antigen,” they will instruct the mast cells to release histamine (the “powerful chemicals” in the diagram above) into your body, which causes itching, sneezing, or even inflammatory swelling, which could lead to death if it happens near the throat.  The reason for the itching and swelling is because IgE is mainly used to eliminate parasites from your body, and the human body’s method of choice for this process is inflammation.

So, what does any of this have to do with fantasy?  Well, allergies aren’t restricted to pollen and food.  You can also become allergic to a whole host of materials such as…

Silver Bullets

As the legend goes, a werewolf can only be killed with silver.  This piece of myth likely stems from the metal’s long association with good luck and the moon; however, you don’t need to be a werewolf to have a bad reaction to silver.

It’s not uncommon for people to experience allergic reactions to nickel in the form of skin rashes upon contact with metal jewelry.  Such reactions are called acute contact dermatitis, and an example is shown below.

The rash is in the shape of the pendant’s surface, which is the cause of the allergy.

What does this have to do with silver?  Most silver jewelry contains nickel, either in large quantities to cheapen the cost of silver jewelry, or as trace impurities left over from the silver purification process.  As a result, many people who believe that they are allergic to silver may, in fact, actually be allergic to nickel instead.

Researchers believe that dietary nickel [1] plays an important role in the development of this allergy, and nickel can be found in the most surprising places.  Although most people won’t die from exposure to silver or nickel like a werewolf might, some extreme cases of the condition do cause anaphylactic shock, which will lead to death if not treated immediately.


In last week’s post, I talked about a medical condition known as porphyria, which causes skin lesions in individuals who are exposed to sunlight.  Vampires have an extensive list of weaknesses, but after sunlight, perhaps the most famous is garlic.

Garlic has been viewed as a medicinal plant in large areas of Eastern Europe, and as such, it has been rumored to be able to ward off evil spirits such as demons and vampires.  However, just like with other edible plants, people can develop food allergies to garlic as well.

Although allergies to garlic are not widespread, scientists have isolated antibodies associated with garlic [2].  Just like any other food allergies, allergies to garlic would cause itching, sneezing, and inflammation – possibly leading to death.  Perhaps what’s more interesting is that upon ingesting large quantities of garlic, no existing allergy is even required to experience these symptoms.  Exposure to large quantities of allicin, a principle component of garlic, will trigger a similar response even in individuals who are not sensitive to garlic.


Remember earlier when I said that kryptonite wasn’t real?  Well, it’s only not real in the sense that there is no glowing green mineral with the same relative properties.  However, the Superman mythos has been around for 70+ years, and because it has become a cultural touchstone, many people have tried to justify the existence of kryptonite.

In 2003, the 70th anniversary of Superman comics, the Royal Society of Chemistry in Great Britain commissioned researchers at the University of Leicester to synthesize some ceremonial “kryptonite” in honor of the hero.  Considering that kryptonite is Superman’s greatest weakness, I’m not sure that they thought that idea through, but the researchers did in fact come up with a greenish, crystalline material called krypton difluoride.  This is quite an achievement, considering that real-life element krypton is largely unreactive, chemically speaking.

The chemists who synthesized the “kryptonite” suggested that perhaps the ill effects that Superman feels when in the presence of this compound are from radiation from a radioactive form of the element krypton, which may be plentiful on his home planet, but not ours.

And, of course, there was this terrific photo opportunity:

[Photo: superman with 'kryptonite']

But that’s not even the weirdest story about kryptonite that you’ll hear today.  In 2007, miners found actual kryptonite while mining in Serbia.  Here’s a picture:

The real kryptonite - Jadarite (NHM)

You’ll note the lack of green crystalline material present in the picture above.  Also, the sample isn’t radioactive.  So why is it called kryptonite?

To answer that, you have to go all the way back to 2006 and remember a scene from Brian Singer’s Superman Returns.  In one blink-and-you-miss-it scene, Lex Luthor, Superman’s archenemy, is carrying a sample of kryptonite in a case labeled “sodium lithium boron silicate hydroxide,” which just so happens to be the exact formula of the mineral unearthed in Serbia… one year after the movie hit theaters.

As of yet, the “kryptonite” – now named jadarite – does not have any commercial uses; however, scientists speculate that its lithium could be used in energy applications and its borosilicate nature may have applications in (ironically) processing radioactive waste.

The Wrap-Up

We’ve seen a review of how allergies work, in addition to silver, garlic, and kryptonite itself.  Having weaknesses is not only possible; it’s real.  Silver (okay, nickel) and garlic are only two of the many examples possible.  There are certain food and materials that could be our own personal kryptonite.  Heck, even “kryptonite” (or krypton difluoride… or jadarite…) could be our own personal kryptonite, depending on how much we’re exposed to it.  This is one of the few times where I get to say that this element of fantasy is not only plausible… it’s possible.  Thank you for reading my weekly words.


Jonathan MacGregor is a an adjunct instructor of chemistry in the SUNY system as well as a writer, currently seeking representation for his urban fantasy thriller, Blood of the Innocents.  If you have any suggestions for future installments of Science Explains Fantasy, you may tweet to him (@JDMacGregor) using the hashtag #ScienceExplainsFantasy.  Excerpts from his novel are available at his 20lines account.


[1]  Zirwas, M. and Molenda, M.  “Dietary Nickel as a Cause of Systemic Contact Dermatitis.”  J Clin Aesthet Dermatol. 2009.  2(6):  39–43.

[2]  Kao, S., et. al.  “Identification and immunologic characterization of an allergen, alliin lyase, from garlic (Allium sativum).”  J Allergy Clin Immunol.  2004.  113(1):  161-8.



Featured Image – Image courtesy of Shmuel Roiz, ©2015,

Serkworks – Image courtesy of serkworks at

Allergy Scheme – Image courtesy of NIAID at

Dermatitis – Image courtesy of Color Atlas of Pediatric Dermatology at

Superman with Kryptonite – Image courtesy of the University of Leicester at

Jadarite – Image courtesy of BBC News at

2 thoughts on “Science Explains Fantasy: Weaknesses

  1. Reblogged this on Records of the Ohanzee and commented:
    Jonathan MacGregor has a great series on Science Explains Fantasy on his blog MacGregor’s Pen. I love the concept of fantasy elements having a basis in real science so this series is one of my favorites to keep up with. Check out his latest post, on weaknesses and and be sure to explore his previous posts in the series too!


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