In a tutorial of Cornell University about Radiosity it is mentioned that:
A ray-traced version of the image shows only the light reaching the viewer by direct reflection -- hence misses the color effects.
However in Wikipedia:
Radiosity is a global illumination algorithm in the sense that the illumination arriving on a surface comes not just directly from the light sources, but also from other surfaces reflecting light.
The radiosity method in the current computer graphics context derives from (and is fundamentally the same as) the radiosity method in heat transfer.
And if ray tracing is capable of:
simulating a wide variety of optical effects, such as reflection (diffuse reflection) and scattering (i.e. the deflection of a ray from a straight path, for example by irregularities in the propagation medium, particles, or in the interface between two media)
Has that tutorial not considered these effects or are there radiosity methods that can be used in ray tracing in order to enable them?
If not, couldn't these optical effects simulate radiosity entirely or is the radiosity algorithm more efficient in solving the diffuse reflection problem?