To explain Kuhn to the HN reader, I'd like to make an analogy between an established enterprise, and a disruptive startup.
The startup is disruptive, because it has re-thought a problem, and uses a different basic model to solve it.
This affects the language used to describe the problem and the solution. For example you still 'call' an Uber, but you actually don't call it anymore, you click on your phone screen to order it. So when a cab company and Uber talk about 'calling', they might have trouble agreeing what 'calling' really means (e.g., in Uber it already entails agreeing on a price, with a cab it doesn't). This is how I understand what Kuhn means with 'incommensurability'.
As the article points out too, it is not two completely separate languages. Rather, the shift in the underlying model also shifts the language, so that supporters of one model mean different things than supporters of the other model, when they make a statement.
This affects the language used to describe the problem and the solution. For example you still 'call' an Uber, but you actually don't call it anymore, you click on your phone screen to order it. So when a cab company and Uber talk about 'calling', they might have trouble agreeing what 'calling' really means (e.g., in Uber it already entails agreeing on a price, with a cab it doesn't). This is how I understand what Kuhn means with 'incommensurability'.
As the article points out too, it is not two completely separate languages. Rather, the shift in the underlying model also shifts the language, so that supporters of one model mean different things than supporters of the other model, when they make a statement.