As fermionic observers (ie made of matter) we experience electromagnetic waves (ie bosons) as traveling at the speed of causality (mistakenly called the speed of light).
In reality, electromagnetic waves exist in an instant throughout the space dimensions everywhere like a really long stitch sewn across, and experience no time. Because they spend all their causality budget in space, they canβt spent any in the time dimension. To us slow fermionic observers, electromagnetic waves βappearβ to travel through time, but thatβs just from our own reference as green dots confined to the spokes of a wheel, where our paths cross.
A photon we perceive coming from a far away galaxy is a really long switch that existed in an instant. Bosons are confined to spend all their causality budget across space dimensions. Fermions are confined to spending their causality budget across both space and time dimensions, but to move along with the wheel, they collect near the axle. Fermions thus has a tendency to get close to the axle, where most of its movement is going to be through time (forward direction of the wheel, perpendicular to the plane it rotates over).
When a fermion is prevented from getting to the center of the axle (free fall), it must move through space to keep up with the forward motion of the wheel, and will feel an acceleration, which we call gravity. That is what happens for us at the surface of the earth, we are prevented from getting to the axle, and that push up and down the wheel as it rotates feels like gravity.