Hi John, I'm not a rheologist (had to look that one up). I am a science writer, though, and materials science is one of my favorite topics. I thought the definition of thixotropy had some funny literal connotations, hence the blog name. I poked around your blog--interesting interesting reading. Thanks for posting. I'm happy to now know what a rheologist is! best, Molly
While it is commonly thought that there is a big difference between liquids and solids, the border between them can be very fuzzy at times and that is what rheologists study.
Take Silly-Putty as an example. When you first take it out of its plastic egg, it has the shape of that egg, and so you would assume that it is a liquid, a very thick viscous liquid, but a liquid nonetheless. Yet if you roll the Silly-Putty into a ball, you can bounce it like it is a solid. So Silly Putty is both a liquid and a solid.
The reason for the dichotomy is the observation time. In the first case, we saw the liquid-like behavior over a long period of time - it took minutes and hours for it to flow. In the second case, we saw what happened over a very short period of time - a fraction of a second - as the ball bounced.
Most food is rheologically interesting too. Tomato juice has some elasticity in it. Stir some in a cup in one direction and then quickly stop. You will see the juice initially flow in the opposite direction.
Pastes, gels, paints... the list goes on and on. It's a never ending subject and a lot of fun.
Oh, and there is a company called Thixotropic Networks that I wrote about last year that thought the thixotropic concept was applicable to computer networks.
Awesome--some ideas are so compelling that they must be thought of for the first time many times. And, I love the internet for being so good at connecting disparate yet like-minded people.
I was very interested in the idea of something (or someone) having different properties "when shaken or disturbed." Physics is rife with terminology that seems to also apply to humanity/poetry/spirituality.
4 comments:
Hi,
Just saw your blog and wondered about the name. Are you a rheologist by chance or know any rheologists?
John, a rheologist
Hi John,
I'm not a rheologist (had to look that one up). I am a science writer, though, and materials science is one of my favorite topics. I thought the definition of thixotropy had some funny literal connotations, hence the blog name. I poked around your blog--interesting interesting reading. Thanks for posting. I'm happy to now know what a rheologist is!
best,
Molly
While it is commonly thought that there is a big difference between liquids and solids, the border between them can be very fuzzy at times and that is what rheologists study.
Take Silly-Putty as an example. When you first take it out of its plastic egg, it has the shape of that egg, and so you would assume that it is a liquid, a very thick viscous liquid, but a liquid nonetheless. Yet if you roll the Silly-Putty into a ball, you can bounce it like it is a solid. So Silly Putty is both a liquid and a solid.
The reason for the dichotomy is the observation time. In the first case, we saw the liquid-like behavior over a long period of time - it took minutes and hours for it to flow. In the second case, we saw what happened over a very short period of time - a fraction of a second - as the ball bounced.
Most food is rheologically interesting too. Tomato juice has some elasticity in it. Stir some in a cup in one direction and then quickly stop. You will see the juice initially flow in the opposite direction.
Pastes, gels, paints... the list goes on and on. It's a never ending subject and a lot of fun.
Oh, and there is a company called Thixotropic Networks that I wrote about last year that thought the thixotropic concept was applicable to computer networks.
Awesome--some ideas are so compelling that they must be thought of for the first time many times. And, I love the internet for being so good at connecting disparate yet like-minded people.
I was very interested in the idea of something (or someone) having different properties "when shaken or disturbed." Physics is rife with terminology that seems to also apply to humanity/poetry/spirituality.
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