# Adams, Ashley Hamer, Mohammed Chiffon discussed on Curiosity Daily

|

### Automatic TRANSCRIPT

What's a second? Someone couldn't have just made a moving object look at ticking hand and a and said sixty ticks is one minute and sixty minutes is an hour and so on. So who decided what a second is? Well, before we divided time into seconds. We divided time into days and hours historians credit. The Egyptians with being the first to divide the day into equal parts while the counting system. We're familiar with his base ten you have ten fingers after all the ancient Egyptians had a base twelve system. They counted on their finger joints using their thumbs a pointer, cool, right? As a result, they divided the day into twelve parts and the night into twelve parts, which we know from seeing the sun dials. They left behind the subdivision of each hour into sixty minutes in each minute into sixty seconds started. With the Babylonians who had a base sixty counting system. You are gonna be counting to sixty using body parts, of course, but that's does have mathematical advantages. I don't have time to get into. Anyway, that definition of a second a sixtieth of a sixtieth of twenty fourth of a day or one eighty six thousand four hundred of the average solar day, which is the time. It takes the sun to come back to the same place in the sky continued to be the standard measure of a second until the twentieth century. See the average solar day actually changes length. So this definition wasn't exact enough for science. So in one thousand nine hundred they were like, okay instead of making it a fraction of the average solar day will make it a fraction of the specific solar day on January first nineteen hundred well that didn't really help things. You can't exactly go back and measure the length of that day. Still that definition lasted until nineteen sixty seven when the second got really specific scientists used their knowledge of the atom. To define a second. As get ready. Nine billion one hundred ninety two million six hundred thirty one thousand seven hundred and seventy periods of the radiation for a cesium one thirty three atom wolf that sounds way more complicated than counting to sixty on your body parts, I know, but scientists can make that measurement anywhere anytime, regardless of the amount of daylight this time of year, and that's key for ideal precision. A scientists has to be able to check their measurements in the lab not against some abstract concept like how long the day was in one thousand nine

## Coming up next

### Adams, Ashley Hamer, Mohammed Chiffon discussed on Curiosity Daily

Curiosity Daily 1 year ago

### NFL Commissioner Roger Goodell says "we were wrong" amid protests

KYW 24 Hour News 6 hrs ago

### Massive peaceful protests fill the streets of Washington, D.C.

NPR News Now 6 hrs ago

### Buffalo, New York cops plead not guilty in protester shoving

Scott Sloan 8 hrs ago

### Biden secures enough delegates to clinch Democratic nomination

KYW 24 Hour News 7 hrs ago

### George Floyd memorial service held in North Carolina

WBZ Afternoon News 13 hrs ago

### Cuomo: "We have a moment here where we can make change"

10 10 WINS 24 Hour News 15 hrs ago

### Garcetti makes nomination for director of civil and human rights department

Leo Laporte 16 hrs ago

### Prince William has been anonymously helping out on a crisis helpline

10 10 WINS 24 Hour News 17 hrs ago

### Seattle-area protests: Demonstrators hit the streets for ninth day of action after George Floyd’s killing

Talking Real Money with Don McDonald and Tom Cock 14 hrs ago

### Families of officer-involved shooting victims in Houston decline to release of body camera footage

Texas Home Improvement 15 hrs ago