2/24/2027

Morning Announcements

Morning Meeting Agenda

Mon · Social Studies Tue · Literacy Wed · Science Thu · Math Fri · ROAR + Houses
Science of the Day

Why the yellow light exists

Traffic lights used to have only two settings: stop and go. They switched instantly, with no warning. Crashes were constant. One inventor figured out what was missing.

Portrait of Garrett Morgan Photo credit: [add if license requires]

Meet Garrett Morgan! He saw a terrible crash at a street corner and thought: I can fix this. He invented a better traffic light — the kind that gives you a warning before it changes!

You see his idea every single day. Let’s look at what each color tells us:

A traffic light showing red for stop, yellow for get ready, and green for go
Let’s talk
  • What would happen if a light went straight from GREEN to RED with no warning?
  • Where do you see traffic lights on your way to school?
  • What are some other things that keep us safe when we cross the street?
Reveal another inventionHide it
Garrett also invented a safety hood that let firefighters breathe clean air inside smoky buildings. When workers got trapped in a tunnel, he put one on and went in himself to help rescue them!
Try it

Red light, green light! I’ll call out colors. GREEN — walk in place. YELLOW — slow way down. RED — freeze! Ready?

Mystery inventor: Born in Kentucky in 1877 to formerly enslaved parents. He left school around sixth grade. He taught himself mechanics, moved to Cleveland, and called himself “the Black Edison.” He held patents on two inventions you have almost certainly encountered.

Who is he?Hide
Portrait of Garrett Morgan Photo credit: [add if license requires]
Garrett Morgan — inventor of the safety hood (a forerunner of the gas mask, patented 1914) and the three-position traffic signal (patented November 20, 1923). He sold the traffic signal rights to General Electric for $40,000. He also founded a newspaper, the Cleveland Call.

Look at the physics behind the safety hood. Smoke and hot gases rise. So Morgan ran a long tube down to floor level, where the air was still breathable.

Diagram showing hot smoke rising while cleaner air stays near the floor, with a tube drawing air from below
Let’s talk
  • Both inventions solve a problem in the in-between: the layer under the smoke, and the moment between stop and go. What does that suggest about how Morgan looked at problems?
  • In 1916 a tunnel under Lake Erie exploded. Rescuers without proper equipment died trying. Morgan put on his own hood and went in. What does that tell you about believing in your own work?
  • News coverage of that rescue frequently left his name out. Where have we seen that pattern this month?
Reveal the answersHide the answers
Morgan looked at the transitions everyone else ignored. Most people saw “smoke everywhere” and “stop or go”; he noticed the gap in each and built for it. Walking into that tunnel was also the ultimate test of an inventor’s confidence — he was betting his own life that his design worked. And yes, the pattern repeats: Gladys West waited 40 years for recognition, Zora Neale Hurston was buried in an unmarked grave, Katherine Johnson was unknown for decades. Their work was never in question. The credit was.
Try it

Find the in-between! With a partner, name something at school that switches suddenly from one state to another with no warning. Design a “yellow light” for it — a warning signal that would make the change safer or smoother.

Additional Notes/Activities

If additional activities are needed for the Morning Meeting, they will be added here.