One of them arguments was that in a vacuum, absent of any container or gravity, a liquid’s shape is that of a sphere.
Another one was that depending on the definition of liquid, liquids might or might not have a shape. This ranged from definitions of liquid based on atomic structure of molecules up to phenomenological definitions (asphalt and glass are liquids, according to some definitions e.g.). It also varies depending on the definition of the attribute shape itself.
The point of the exercise was to challenge the notion of objective truth in science.
Without gravity it’s a sphere, or in free fall without air drag it’s a sphere (if it has sufficient surface tension anyway, which is what makes lava or molasses flow that way, in combination with its viscosity).
But in a vacuum it will boil off until the vapor pressure is high enough to eliminate the vacuum. But then it’s not in a vacuum anymore.
Really a fluid or liquid will always try to minimize its surface area while fighting gravity.
It’s a definitions problem that a lot of people who think there aren’t “objective truths” in science.
Exactly, remember the point was not to be right. But to have the discussions. It wasn’t the physics we were interested in, but in the ways to construct knowledge. Definitions and models are human constructs. The universe doesn’t care that we do or do not have neat words and models of its workings. However, language and knowledge, as human endeavors, require human interaction.
An interesting one way to illustrate this point was: An hermit, all alone in the wilderness, by sole virtue of reasoning acquires absolute objective truth of the fundamental laws of the universe. Way beyond any current scientific knowledge. However, he doesn’t tell anyone. Has any knowledge been gained? If he dies, not telling anyone what he discovered, has any knowledge been lost?
Isn’t part of the definition of liquid that it takes the form of its container?
I need another epistemological argument like I need another hole in my head.
One of them arguments was that in a vacuum, absent of any container or gravity, a liquid’s shape is that of a sphere.
Another one was that depending on the definition of liquid, liquids might or might not have a shape. This ranged from definitions of liquid based on atomic structure of molecules up to phenomenological definitions (asphalt and glass are liquids, according to some definitions e.g.). It also varies depending on the definition of the attribute shape itself.
The point of the exercise was to challenge the notion of objective truth in science.
Without gravity it’s a sphere, or in free fall without air drag it’s a sphere (if it has sufficient surface tension anyway, which is what makes lava or molasses flow that way, in combination with its viscosity).
But in a vacuum it will boil off until the vapor pressure is high enough to eliminate the vacuum. But then it’s not in a vacuum anymore.
Really a fluid or liquid will always try to minimize its surface area while fighting gravity.
It’s a definitions problem that a lot of people who think there aren’t “objective truths” in science.
Exactly, remember the point was not to be right. But to have the discussions. It wasn’t the physics we were interested in, but in the ways to construct knowledge. Definitions and models are human constructs. The universe doesn’t care that we do or do not have neat words and models of its workings. However, language and knowledge, as human endeavors, require human interaction.
An interesting one way to illustrate this point was: An hermit, all alone in the wilderness, by sole virtue of reasoning acquires absolute objective truth of the fundamental laws of the universe. Way beyond any current scientific knowledge. However, he doesn’t tell anyone. Has any knowledge been gained? If he dies, not telling anyone what he discovered, has any knowledge been lost?