The substance of our universe is pulled together, or pushed apart by these forces which are determined by the fact they do not appear to be reducible to more basic interactions between particles.
They include the gravitational and electromagnetic forces, which produce significant long-range interactions whose effects can be seen directly in everyday life.
And they also include forces known as the strong interactions and weak interactions, which produce forces at tiny, subatomic distances and govern nuclear physics.
Over the years, there have been many unsubstantiated claims of the existence of a fifth fundamental force, and as the long hunt for dark matter continues to prove fruitless, efforts to find new forces at play to help fill-in the gaps the standard model of particle physics can’t explain have increased.
Over the years, there have been many unsubstantiated claims of the existence of a fifth fundamental force, and as the long hunt for dark matter continues to prove fruitless, efforts to find new forces at play to help fill-in the gaps the standard model of particle physics can’t explain have increased.