Dr. Glen Jeffery

I wish that was the case.

In all of those people, and I have to say we've done similar experiments on flies, on mice, on humans.

It's five days.

It lasts five days.

Five days.

It's a solid five-day effect.

So something very fundamental that is conserved across evolution

is playing a role here.

And I have to say that to a first approximation, anything I find in a fly, I find in a mouse.

Anything I find in a mouse, I find in a human.

I can't find a big disjuncture between those things.

So it lasted five days.

And the real big point to take on board is it's a switch.

There's not a dose response curve here.

You put enough energy in at a certain wavelength of light and it goes bang and click.

And then five days later, it goes chunk and stops.

Pretty much anything works to a rather similar extent at 670 going upwards.

When you go below 670 towards 650, the effects tend to be somewhat reduced.

I'm a big, big fan of natural sunlight because life's evolved for billions of years under sunlight.

It's only recently changed.