As an extension to my question about the "phonetic languages" I'd like to open a topic about the writing systems. As far as I understand the Chinese writing system has literally no connection at all with the pronunciation of the words and practically it is like mathematical symbols that have the same meaning in every language (for instance "empty set / nothing - ∅", "sum - ∑", "not equal - ≠", "for all - ∀"...). So I'm curious if it is possible a writer A who knows only language A to write a text using Chinese symbols (or even Egyptian hieroglyphs) and a reader B who knows only language B to read (and understand) the text?
Chinese characters work very well for Chinese – but that is a tautology because they evolved as a way to represent Chinese and can thus be said to be designed for Chinese. This not necessarily applies only to Mandarin Chinese but also to many other flavours of Chinese that developed from a common Old or Middle Chinese ancestor. However, once you start using Chinese characters to represent a language that is not Chinese or morphologically very similar to Chinese you run into a number of problems.
As soon as you want to write a text using Chinese characters in a non-Chinese language you will have to decide how to render features that your non-Chinese language has but Chinese doesn’t. Some of these may be trivial. Chinese has a character that can essentially serve as some kind of of so you can try using that as a marker for English genitive-s. But in German, the genitive is realised by inflection of the noun (and adjective/article, where applicable) and it could stand either before or after the noun it belongs to (die Sprachen Chinas or Chinas Sprachen). So how do you unambiguously show what is meant in a text?
Then there are less clear choices you have to make. Suppose I am trying to write Finnish using Chinese characters, then I would need to find a clear way to represent at least 10 of the 15 cases using methods that original Chinese doesn’t really have or need. I suspect that distinguishing nominative, accusative and partitive cases would be the hardest. There may also be a problem with different verb forms. While different grammatical persons could be distinguished by using pronouns, how would one distinguish the English leaves, is leaving and has left?
There are two general ways to overcome these problems. One would be to radically simplify or sinify one’s origin language to make it better fit the Chinese characters. But then, you are no longer writing in English or Russian, you would be writing a form of Pidgin that relies heavily on understanding of the Chinese grammar. The other would be what Japanese has done: take the writing system and adjust it in multiple ways to fit your own language, but that comes at the cost of no longer being properly understandable to another language.
Knowing only Chinese characters (even when knowing only the forms used in Japan which differ slightly from their counterparts in Taiwan/Hong Kong/Macao and strongly from their counterparts in mainland China) can give you a basic understanding of the concepts of a Japanese text but to actually understand what is going on you need to know Japanese grammar and also learn the Japanese syllabaries that are used to supplement what kanji cannot easily describe. Crucially, without knowing the syllabaries or Japanese grammar, you would not be able to distinguish whether a sentence is positive or negative as that is implemented by verb inflection in Japanese.
While Chinese writing isn't a universal writing in the sense of the question, there were attempts to create such writing systems, e.g., Bliss symbolics. They are generally known as pasigraphies.
Some more information on pasigraphies is available from the sister site on Constructed Languages in these questions and their answers: How to describe a purely symbolic writing system? and Are there any “unspeakable” languages?