Where does this come from, and can I check it?

Bright light before the clock's low point advances its timing by up to an hour a day. The figure is taken from NIGMS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a human body fact?

Yes. It sits on the Human Body shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Morning light shifts the body clock earlier

Bright light before the clock's low point advances its timing by up to an hour a day The retina sends light information to the suprachiasmatic nucleus, which adjusts its phase according to when light arrives. Light in the morning pulls the clock earlier, while light late at night pushes it later. This is why a few days of camping can reset a delayed sleep pattern. It sits in Mondo's human body collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NIGMS

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Science trivia

More facts like this

Cortisol hormone levels peak in the morning to promote wakingDiurnal adrenal hormone cycles help regulate energy availability and mood The suprachiasmatic nucleus controls internal body clock rhythmsTiny cluster of hypothalamic cells uses light input to sync biological timing A sudden twitch can strike just as sleep beginsHypnic jerks are brief muscle jolts that often arrive with a sensation of falling The hippocampus replays the day to build memoriesDuring sleep, it reactivates recent patterns and passes them to the cortex The pineal gland regulates daily sleep rhythms with melatoninLight exposure signals the brain to adjust hormone production for sleep The brain paralyzes major muscles during REM dream sleepMotor neuron inhibition prevents acting out vivid dream sequences physically

Tags: light, circadian, sleep

Morning light shifts the body clock earlier: the short answers

Where does this come from, and can I check it?: Bright light before the clock's low point advances its timing by up to an hour a day. The figure is taken from NIGMS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a human body fact?: Yes. It sits on the Human Body shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.