Really? How is a state of matter defined? These pretty much encompass the definitions I find on the internet …How many states of matter are there?
Physics professor shares his thoughts on a surprisingly difficult question
By Michelle Werdann
In middle and high school, most people learn about the three states of matter we interact with in our everyday lives: solid, liquid and gas. Some students may have even been introduced to the idea of plasma.
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Assistant professor in the Department of Physics Yafis Barlas provides his input in the debate over how many states of matter exist.
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Some people think plasma should be considered as a different state of matter, but it’s really an ionized gas.
- "Any of the different phases of matter whose properties are dependent on the motions and forces of the molecules of which they are composed."
- "One of the ways in which matter can interact with itself to form a homogeneous phase."
- "The different forms that various phases of matter take on."
- "The distinct ways certain groups of particles arrange themselves with various temperatures and forces."
- "One of the principal conditions in which matter exists."
I'd say those make plasma a state ... a very important state.
In fact, the professor apparently said that two states of matter must have distinct experimental properties. Ok. Well, gas and plasma certainly have very different properties. They two have different properties precisely because one is ionized and the other is not. So why aren't they two different states? And contrary to what the professor apparently thinks (assuming the *science communicator* who wrote this fluff piece was accurately reflecting the professors thoughts), almost every learned source one can find out there says plasma is a separate state of matter. The most common state of matter. Yet, the article, presumably quoting the physics professor, says that “If somebody walked up to you on the street and said, 'You have five seconds. How many states of matter are there?' what would you say? I would say three.”
And there, perhaps, lies the problem with modern astrophysics. Baby astrophysicists are being taught by *scholars* like Yafis Barlas that plasma isn’t really a state of matter. Even though the vast majority of sources declare it one, they don’t really believe it. So naturally they teach their students little about the most amazing properties and behaviors of plasma ... the properties that explain much of what we see going on in the universe.
And what’s also interesting is that even though most physicists are seemingly certain that dark matter exists (including the author of this article), they never ever identify it as a state of matter. He thought about that for a moment, but couldn’t make himself do it.
What it really boils down to is that this professor, whose expertise is condensed matter (https://www.unr.edu/physics/people/yafis-barlas), doesn’t appear to have written a single paper on plasma, so in my view he had no business making the statement he made about plasma ... especially in media. And if he’s been doing it to the students in his classes as well, then no wonder physics is so lost.