In several movie classics we have seen how villains (or even heroes) find their death falling on lava or molten steel. Hollywood shows us this person sinking in a glorious way, but the reality is that dying in this way is something much more horrible than the movies show us.
Everything has to do with the density of things. The reality is that for a human being it is basically impossible to sink into a lava river, because the density of these molten rocks is much greater than that of a person's organism, or basically any living being.
The head of the YouTube channel Nerdist explains in a great video why the way in which Gollum died in The Lord of the Rings: The Return of the King is not accurate, much less the way in which Terminator says goodbye the Connor family in their second movie.
The theory explains that any object that has a higher density than a liquid will sink into it, while that with a lower density will float on it.
These are the two most mythical scenes in cinema in which an important character dies to fall on lava or molten steel:
The human being has a density quite similar to that of water, which is 1,000 kilograms per cubic meter. The lava, on the other hand, has a density of about 3,000 kilograms per cubic meter. This means that any human being falling on lava will actually float on it, it will not sink.
In the case of molten steel is the same, since it has a density of about 7,500 kilograms per cubic meter, so any human (or even Terminator, which according to the film is made of a metal much lighter than steel) will float about this.
The fact that both lava and molten steel are liquid is not to say that a person is going to sink into them. In the case of the Gollum ring itself, because the density of gold is 19,300 kilograms per cubic meter, six times higher than that of lava.
Now, what does this mean?
The fact that a human body (or humanoid, in the case of Gollum) does not sink but "floats" on the lava means that it will not melt almost immediately when surrounded by it, but rather the effect will be Just put your hand on a pot or griddle at a temperature between 700 and 1,200 degrees Celsius and let it melt slowly until it reaches the bone and eventually melt completely. That, but in the whole body.
No wonder Hollywood does not show it this way.
This is the original video in which Nerdist explains:
