Transitional lighting for entraining biological rhythms

1. An illumination system comprising:

a luminaire having an adjustable spectral power distribution (SPD) and an adjustable photon flux output; and

a controller that provides electrical power and control signals to the luminaire;

wherein the control signals automatically transition the SPD gradually between a first SPD and a second SPD twice per day, while adjusting the photon flux output from a first photon flux output to a second photon flux output;

wherein the transitions and adjustments to the photon flux output correspond to changes in light that entrain a biological rhythm in a life form.

2. The illumination system of claim 1 , wherein

the SPD is transitioned at a time of and during a period of sunrise or sunset; and

the transitions further entrain a circannual or lifecycle rhythm.

3. The illumination system of claim 1 , wherein:

the first SPD alone emulates an SPD of daylight;

the second SPD alone emulates an SPD of twilight; and

the luminaire emits supplemental red, far-red or blue light before, during or after the transition.

4. The illumination system of claim 1 , further comprising a colorimeter that detects natural light and sends signals to the controller, wherein:

the first SPD in combination with the natural light emulates an SPD of daylight; and

the second SPD in combination with the natural light emulates an SPD of twilight.

5. The illumination system of claim 1 , wherein the luminaire's SPD transitions between the first SPD and the second SPD over a period of half an hour.

6. The illumination system of claim 1 , wherein:

the luminaire is oriented to deliver a portion of the light downwards onto the life form;

the system comprises a further luminaire oriented to deliver another portion of the light sideways onto the life form; and

the luminaire and further luminaire are independently controlled by the controller to provide different SPDs respectively in downwards and sideways directions.

7. The illumination system of claim 1 , further comprising:

a substrate towards which light from the luminaire is directed, and which supports root growth of a plant;

a further luminaire oriented to deliver further light towards a canopy of the plant;

wherein the luminaire and further luminaire are independently controlled by the controller to provide different SPDs respectively to the canopy and a root of the plant.

8. The illumination system of claim 1 , further comprising:

a substrate towards which light from the luminaire is directed, and which supports root growth of a plant;

a further luminaire oriented to deliver further light inside the substrate;

wherein the luminaire and further luminaire are independently controlled by the controller to provide different SPDs respectively to a canopy of the plant and a root of the plant.

9. The illumination system of claim 1 , further comprising:

a substrate towards which light from the luminaire is directed, and which supports root growth of a plant;

a sensor that monitors a status of the plant; and

a plurality of sensors that monitor environmental conditions to which the plant is subjected;

wherein the controller:

preconditions signals from all said sensors;

fuses data to emulate a response of the plant to the environmental conditions; and

adjusts either or both of the photon flux output and SPD of the luminaire based on the emulated response.

10. The illumination system of claim 1 , wherein the luminaire outputs near infrared radiation between 800 nm and 1000 nm.

11. The illumination system of claim 1 , further comprising:

a plurality of sensors that monitor environmental conditions to which animals are subjected, wherein light from the luminaire is directed onto the animals; and

wherein the controller:

preconditions signals from all said sensors;

fuses data to emulate a response of the animals to the environmental conditions; and

adjusts either or both of the photon flux output and SPD of the luminaire based on the emulated response.

12. A method for entraining a biological rhythm in a life form comprising the steps of:

orienting a luminaire with an adjustable spectral power distribution (SPD) and adjustable photon flux output to illuminate the life form from above;

connecting a controller to the luminaire so that the controller provides electrical power and control signals to the luminaire; and

sending, automatically from the controller, control signals that transition the SPD gradually between a first SPD and a second SPD twice per day, while adjusting the photon flux output from a first photon flux output to a second photon flux output;

wherein the transitions and adjustments to the photon flux output correspond to changes in light that entrain a biological rhythm in the life form.

13. The method of claim 12 , further comprising:

monitoring, with a sensor, a status of the life form;

monitoring, with a plurality of sensors, environmental conditions to which the life form is subjected;

preconditioning signals from all said sensors;

fusing data to emulate a response of the life form to the environmental conditions; and

adjusting either or both of the photon flux output and SPD of the luminaire based on the emulated response.

14. The method of claim 7 , wherein the transitions emulate changes of a sky colour and a sky irradiance between when a geometric centre of the sun is 6 degrees above a horizon and when the geometric centre of the sun is 8 degrees below the horizon.

15. The illumination system of claim 1 , wherein the transitions emulate changes of a sky colour and a sky irradiance between when a geometric centre of the sun is 6 degrees above a horizon and when the geometric centre of the sun is 8 degrees below the horizon.