Statutory Interpretation - When Interpreted in Light of Changing Technology and Science. Telus Communications Inc. v. Federation of Canadian Municipalities
In Telus Communications Inc. v. Federation of Canadian Municipalities (Fed CA, 2023) the Federal Court of Appeal considered 'when' statutory text should be interpreted, in terms of changing technical and scientific contexts:
 The appellant similarly contends that the words "“transmission line”" should be interpreted in a dynamic and evolving way, and claims that the meaning ascribed to these words by the CRTC is frozen in time. There is no doubt that legislation must be interpreted in light of changing circumstances. This is particularly true of constitutional and quasi-constitutional statutes, because they are meant to endure over time and are difficult to amend. That being said, care must be taken to refrain from amending legislation in the name of interpreting it. Navigating between these equally important concerns is obviously a delicate exercise.
 The Supreme Court provides some guidance in that respect. In Perka v. The Queen,  2 S.C.R. 232, 1984 CanLII 23 (at pp. 264-265) [Perka], for example, the Court started with the proposition that the words of a statute must generally receive the meaning they had at the time of enactment. As the Court recognized, this is not to say that all terms in all statutes must always be confined to their original meanings. Broad statutory categories and "“open-textured”" legislative language, for example, must be capable of growth to take into account changing circumstances. The Court has since cautioned that even where constitutional documents are involved, the starting point must always be the text of the provision: see Quebec (Attorney General) v. 9147-0732 Québec Inc., 2020 SCC 32, 451 D.L.R. (4th) 367 at paras. 8-10; British Columbia (Attorney General) v. Canada (Attorney General),  2 S.C.R. 41, 1994 CanLII 81 at p. 88. In Perka, the Court explicitly cautioned against giving a technical term a new meaning that would stray from Parliament’s intention at the time of enacting the statute:
(...) But where, as here, the legislature has deliberately chosen a specific scientific or technical term to represent an equally specific and particular class of things, it would do violence to Parliament’s intent to give a new meaning to that term whenever the taxonomic consensus among members of the relevant scientific fraternity shifted…
Perka at p. 265. See also R. v. D.L.W., 2016 SCC 22,  1 S.C.R. 402 at para. 61; Canada v. Cheema, 2018 FCA 45,  4 F.C.R. 328 at para. 74