I shouldn't have left my previous statement without any elaboration — that was a pretty inflammatory comment to make and I apologise.

When I say "gravity is a social construct", part of what I'm getting at is that the natural world is distinct from scientific knowledge we create when attempting to model the natural world, and that our scientific knowledge is, by necessity, socially mediated.

I like gravity as an example of this because of how fundamental it is: even animals have some level of intuitive understanding of gravity — they don't need to understand what parabolic motion is to be able to demonstrate it when they jump over things.

But also, our understanding of gravity has vastly changed over the years. In the 1800s, astronomers had measured Mercury's orbit so precisely that they found it to be inconsistent with what Newton's Law of Universal Gravity would predict, so they figured there had to be another planet closer to the Sun. Turns out there wasn't though, and it was only after Einstein's theory of relativity that Mercury's weird orbit could be explained.

They had good reason to guess that another planet was responsible for Mercury's orbit though, because the same guy who made that guess (a French astronomer, Urbain le Verrier) had actually predicted the existence of Neptune just a few years earlier; he had used Newtonian gravity to analyse the orbit of Uranus and found that it was slightly off from what observers had been measuring, and deduced that there must be another planet that nobody had seen yet that was causing these perturbations.

These two examples show two different ways that we can respond to experimental observations not matching with our theoretical understanding: sometimes it's productive to assume our current theory is correct and that our observations are wrong or insufficient in some way, and sometimes we fix the disparity between what we see and what we know by amending our theories, like we did when we learned the limits of Newtonian gravity. Choosing which hypothesis to investigate is how science (and scientific knowledge) is socially constructed.

Disclaimer: I'm a biochemist, not an astrophysicist, so talking about gravity isn't my primary domain. Many of these ideas are articulated far better in this video essay by Dr Fatima (and I suspect some of my phrasing is subconsciously borrowed from this video — this is bad citation practice on my part)