Knocker-Uppers and Candle Clocks: Waking Up Before Alarms

Before alarm clocks, people woke up in fascinating ways! This mission explores the science behind waking up and how people used to do it.

The Big Question

How does your body’s natural clock help you wake up, and how did people wake up before alarms?

What You'll Need

• A window with natural light
• A dark room or a dark blanket/sheet
• A notebook and pencil or crayons

Mission Steps

1. Observe Light. Notice how bright it is outside your window right now. Is it sunny, cloudy, or dark?
2. Create Darkness. Go into a room and make it as dark as possible. You can close curtains or use a blanket.
3. Feel the Sleepiness. Sit or lie down in the dark room for 5 minutes. Notice if you start to feel sleepy or more awake.
4. Let in the Light. Open the curtains or uncover the window. How does the light change how you feel?
5. Record Your Day. Over the next day, jot down when you naturally feel sleepy and when you feel awake.

Talk About It

• What did you notice about how light made you feel in the dark room?
• How is the light from the sun like a natural alarm clock?
• What do you think would happen if you tried to sleep through the sunrise every day?

Take It Further

For older rangers, research other historical "wake-up devices" like sundials or water clocks. How did these rely on natural cues, and what were their limitations compared to a candle clock or a knocker-upper?

FAQ

Q: My child sleeps through anything, even sunlight. Does this mean they don't have a circadian rhythm? A: Everyone has a circadian rhythm, but it can be influenced by many things like age, genetics, and sleep habits. Your child's rhythm might just be set to wake up later. Q: Why is it harder to wake up when it's still dark outside? A: When it's dark, your brain releases melatonin, a hormone that makes you feel sleepy. Light signals your brain to stop making melatonin and wake up.