Every time a science fiction epic such as “The Martian” and “Gravity” hits the big screen, we can count on Neil deGrasse Tyson to take to Twitter to nitpick the science. Tyson’s purpose is twofold. First, he tries to use popular culture to impart some lessons about physics to a wide audience. Second, Tyson takes the opportunity to show off his awe-inspiring brilliance.

Now, Dr. Tyson has branched out into high fantasy. He has just finished binge-watching the latest season of “Game of Thrones” and has some observations about the physics of dragons (which sounds like it would be a neat title of a popular science book.

How do GOT dragons work according to physics?

It turns out, according to Tyson, that the “Game of Thrones” dragons work pretty well according to known laws of physics. The wingspans are just the right size to keep a creature of that size airborne. He even noted that the dragons had forfeited their forelimbs like birds and bats. Tyson also suggests that the fire breathed by the blue, zombie dragon had to be three times as hot as the one from a regular dragon.

On the negative, nitpicky side, Tyson suggests that using chains to pull the zombie dragon out of the lake made no sense. He tweeted, “Pulling a dragon out of a lake? Chains need to be straight, and not curve over hill and dale.”

But what are the physics of a magical universe?

Tyson no doubt has congratulated himself once again at using pop culture to be both an educator and burnish his self-defined role as a science icon.

However, in one sense he is a little off base. It doesn’t matter what the wingspans of the dragon are or how hot (or cold) their fire is. Dragons are magical creatures in a universe where ordinary physics can be bent to the will of anyone who understands wizardry. Describing the physics of dragons flying is just as useful as trying to say that no one could ride a broom through the air as in the “Harry Potter” stories.

One can just wait until the good Dr. Tyson delves into the stories of the boy wizard.

Magic has its own internal rules, but they tend to be made up by the author to fit the plot and the necessities of world-building in the stories. Dragons fly and breath fire because George R.R. Martin needed them to do so for all of those cool scenes of the beasts setting entire armies on fire. If the wings made sense, it is because the special effects people know a little bit of biology and physics and like Tyson enjoy showing off.