Red hot lava basalt
Not that I spend a lot of time thinking about red hot lava pits every day, but after reading Erik Klemetti’s article on the viscosity of lava, I find myself thinking of it differently. Evidently, the viscosity of lava is such that if you or I were to fall into one of the fiery red hot lava pits around the world, we wouldn’t sink beneath the surface and die quickly. Instead, we would float atop the surface while it slowly devoured us in its heat.
There are two reasons why we would be forced to suffer such a tragic fate. The first is the difference of density between the human body and lava. Think about jumping in water. Think about floating in water. Why do we sink down through water so easily? Things float because they have a lower density than the fluid they displace. As the density of the fluid increases, the floating object will float higher. Salt water is noticeably denser than fresh water and people float more easily in it. I have been snorkeling in warm salt water areas where I could float, motionless, atop the surface for quite a while — sometimes to the point of boredom, or occasionally a large wave would roll over me, filling my nose and mouth with salt water! Some bodies of water on the planet, like the Dead Sea, have such high levels of salt that people go there specifically to float atop the water while bathing in the rich minerals it is reputed to contain. So, floating occurs when the liquid has a lower density (is more dense) than the object that is floating. Now, think about lava. Molten lava is liquid basalt (a rock). The human body isn’t anywhere near the density of basalt, so, the lava is not displaced when we enter it. It is nearly impossible to sink in lava.
The second reason is viscosity. Viscosity (the resistance to flow) causes a liquid like water, which has a low viscosity, to get out of the way when we enter it, but a liquid with high viscosity like corn syrup, or even higher viscosity, like lava, doesn’t displace itself for the human body.
The more I think about this, the more it causes my empathic nerves to shriek. I recall stories of young virgins being brought to the edge of the volcano’s mouth, then, being thrown inside as a sacrifice to the gods. They weren’t enveloped quickly in fiery hot lava and put out of their misery. Instead, they would’ve probably hit the burning hot surface and been roasted and assimilated within the flow itself.
I googled some photographs of lava taken by independent photographers around the world. One of them had some great close-ups of small foot-wide flows of lava in action. A commentor asked him if the smoke in the area was due to the heat. He responded by saying the paint on his camera lens literally peeled away due to the extreme heat he experienced there. Now that’s hot!
Mind Whimsy 