Daily Archives: 2010年5月20日

How does Google suggests for "rheology"?

Study showed recently that Google search suggestions may be misleading. The study took the word “nanotechnology” for example and showed that Google frequently directs searcher of this word to topic of health impact of nanotechnology. News reporters said this means that Google may scramble our perception of science reality.

Although I don’t buy the logic that not knowing any topic about the health impact of nanotechnology at all is helpful for a positive public image of nanotechnology, I am still interested what Google suggests for “rheology”. There is a relatively new tool in Google search — the wonder wheel. When searching for “rheology”, you can start a wonder wheel of it and explore the second-order wheel of each suggestion to “rheology”.

wonder wheel.jpg

To my surprise, “thixotropic” seems much more suggestible than “viscoelastic”. Does this mean people want to know about the former more frequently than the latter? Also more suggestible than “viscoelastic” is the simpler concept “viscosity”. “Viscoelastic” is even not in the suggestion list.

“Viscoelastic” does appears in wider list of suggestion, though.

related searches.jpg

Viscoelasticity is a fundamental concept in rheology. The study of this property started from the very beginning of the history of rheology until today. However, many that are new to rheology find it much harder to accept than the concept of viscosity or even thixotropy.

The concept of viscosity is simple. The famous Newtonian definition appears exclusively in every textbooks. And starting from this, it is quite easy to understand what is non-Newtonian. Indeed, the Newtoinan/non-Newtonian type of classification is very convenient for fluids — things that can flow, but most rheological problems is concerned by things with fluidity that depends. The abyss most students of rheology really struggling against is things that cannot be properly characterized by only viscosity but need to intorduce the measures of G‘ and G”. I have been asked too many times about the “real, real meaning” of these moduli. Even experienced materials science researchers may not understand why bother uses this complicated framework of measure to characterize a piece material.

No bother indeed, in the practical context. There are two rheometers in my research group. Colleagues from other collages or institutes often find me for rheometry. 90% of the cases are requests for simple viscosity vs shear rate curves. Only when a requester wants to “add more plots and depth” to his/her paper would he/she asked for dynamic, that is, G‘/_G_” tests. In industry, a viscosity curve gives enough information for production in most cases.

The also popular “thixotropy” should thank the industry, too. Thixotropy is hard to characterize in a scientific way (ready for structural modeling) till even today, but materials of this property are essential for the existence of the paint industry, where an ad hoc thixotropic loop test is enough in most cases. More interestingly, while the concept of viscosity cannot meet the cases where the fluidity of materials is dependent, the concept of thixotropy is just about the duality of “flow/don’t flow”, somewhat complementing the former. In the practical sense, it seems that simple extreme concept like flow and not-flow (i.e. Newtonian vs Hookian) is enough in dealing rheological problems. That’s why Google does not suggest “viscoelastic” when searched for “rheology”. This may be misleading, however, when the user wants to know about rheology academically.

怀念Constance Holden

Random Samples栏目页眉

Random Samples栏目页眉

直到她不幸去世,我才知道她,尽管她的名字一直写在每一期Science的这一页上。作为Random Samples栏目的长期读者,听到她去世的消息,心里感到这个世界又失去了一个宝贵的心灵。

也许跟许多关注Random Samples栏目的中国朋友一样,我是从前几年的华南虎事件知道这个栏目的。记得当时国内的媒体纷纷打上诸如“美国《科学》杂志刊登华南虎存疑照片”,让当时打虎的网友们好不振奋,以为美国一个大名鼎鼎、“德高望重”的一个不知道啥过来为他们撑腰了,士气大增。现在仍然能找到当年在新华网的报道。我在当时想到的问题是,中国各大报章肆无忌惮地把Science的一整页截图贴到自己的报道里,是不是都向Science索取了版权许可了?现在我想到的问题是,截图上“Edited by Constance Holden”的字样赫然可见,同为媒体界的中国记者和编辑是否有谁向Constance去信了解当初为什么为自己的栏目选择这样的题目。反正现在我已经无法问到了。

我实在很难用语言去描述Random Samples是一个怎样的栏目,在网上也无法找到这个栏目的介绍,了解不到办这一栏目的宗旨。当时华南虎事件上这一栏目之后,有一些中国网友泼冷水说Random Samples只是一个讽刺性的栏目,不是Science刊登研究论文的地方。但“讽刺”这个词对于Random Samples来说不仅过火,而且不全面。诚然,栏目里经常有含蓄的幽默体现在对一些研究上。这种幽默的火候要比Improbable Research要小得多,它并不是为了让你笑在脸上,而是让你笑在心里;但幽默并不是Random Samples的全部,在这里还常常有悲悯的温情。在我博客上能找到的记录有两个,一个是一只等待屠杀的幼年锄猩猩,另一个是被洪水冲走了的大象研究。还有一个我至今记得,但是找不到原文的文章,介绍了一个考古发现的远古墓地,一个成年女子的骸骨与幼儿的骸骨同时在一个坑里被发现。从骨架的姿势来看,这两人当初可能是被活埋,成年女子至死都抱着这个幼儿。文章旁附上了照片。

Science无疑是中国人熟知的外国杂志。我觉得,如果Random Samples这一栏目在中国读者中的印象仅仅是“刊登了华南虎照片”,实在太对不起Constance。因此我有必要在这里这下这篇文字以表怀念之情。

Constance的讣告除了刊登在最后一期由她编辑的Random Samples栏目中外,还在Science杂志网站上。上面放出了她的一些作品,包括油画作品。此外,还有Science员工对她的哀思。