Why can’t the calvin cycle run if the light reactions don’t occur?

Because the Calvin cycle is dependent on the the product from light reaction.

Explanation:

The Calvin cycle is the light independent phase of photosynthesis during which carbon is fixed. This step requires energy generated during the light dependent phase of the photosynthesis.

Hence, if the light dependent reaction does not occur, the required energy to drive carbon fixation will be lacking and the Calvin cycle will not be able to proceed.

mechanics (greek   is that area of science concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment. the scientific discipline has its origins in ancient greece with the writings of aristotle and archimedes[1][2][3] (see history of classical mechanics and timeline of classical mechanics). during the early modern period, scientists such as galileo, kepler, and newton laid the foundation for what is now known as classical mechanics. it is a branch of classical physics that deals with particles that are either at rest or are moving with velocities significantly less than the speed of light. it can also be defined as a branch of science which deals with the motion of and forces on objects. the field is yet less widely understood in terms of quantum theory.

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