While human history is riddled with tales of vampires, the bloodsucking creatures that drain the blood of their victims, nobody has considered how the gruesome process of bloodsucking would work if they actually existed. Now, to coincide with the 85th anniversary of Universal Pictures' "Dracula," students from the University of Leicester's Department of Physics and Astronomy have released a paper that uses fluid dynamics to reveal how long it would take for a vampire to drain an average human of its blood.
The team discovered that it would take just 6.4 minutes for a vampire to drain 15 percent of the blood from the external carotid artery in a human neck. The study used 15 percent as the benchmark due to the fact that any more blood loss than this changes the heart rate, whereas less than this amount can be taken without affecting the human circulatory system.
In order to come to their conclusion, the researchers examined the velocity of blood flowing into only the common carotid artery. Although the main artery of the body, the aorta, splits into a total of five arteries, the team assumed even thickness for all of them, allowing them to calculate the velocity of blood flowing into the common carotid artery.
After determining the average blood pressure in the arteries relative to air pressure, the team obtained the pressure difference. They then determined the average blood density at room temperature, which allowed them to pinpoint the amount of blood that would be released from a puncture in a human's neck. The team assumed that if vampires existed, their fangs would possess a width of 0.5 millimeters each.
The results showed that if a vampire were to take 15 percent of blood from a human - with an average of five liters of blood per person - it would take them around 6.4 minutes.
"Every year we ask each student to write around 10 short papers for the Journal of Physics Special Topics," said Mervyn Roy, course tutor for the students who released the paper. "It lets the students show off their creative side and apply some of physics they know to the weird, the wonderful, or the everyday."
The paper was published in the Journal of Physics Special Topics, a peer-reviewed student journal run by the university's Department of Physics and Astronomy.
