Astronomers suggest that an alternative concept of gravity, known as modified Newtonian dynamics, could explain orbital inconsistencies that have previously pointed to the existence of a ninth planet in the solar system.
  • Dandroid@dandroid.app
    10·
    1 year ago

    I have thought this for a long time. How do we know it’s not dark matter?

    Edit: Well, I just read the article, and they are saying that an alternative theory to dark matter could explain the gravity instead of what I was saying, that dark matter could explain it.

    Though I’m confused by this part:

    Isaac Newton’s second law states that gravity tugging on an object is inversely proportional to the distance between the object and the object that is pulling it, meaning that gravity gets weaker as the distance between the two objects increases. But MOND tweaks this and suggests that past a certain distance, the gravitational pull is directly proportional to the distance, meaning the strength of the gravitational pull does not drop off as quickly at greater distances.

    Wouldn’t “the gravitational pull is directly proportional to the distance” mean that gravity gets stronger as it gets further away rather than dropping off less quickly? I thought gravity was actually inverse squared. Did they mean inverse squared becomes inverse instead of inverse becomes direct?