Question 1 of 12Correct: 0
Why were 10 days removed from the calendar?
Is it true that people rioted, demanding that the days be returned?
What kept the zipper from catching on for eighty years?
Who used the zipper first?
When did alarm clocks become widespread?
Who woke workers before clocks became cheap?
Why could the mold stop the bacteria in the dish?
What turns a strange experimental result into an invention?
What task did the network grow out of?
How is the internet different from the web?
Why can a large portion stay cold in the middle?
Why does the plate usually heat less than the food?
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Why 10 Days Were Removed from the Calendar0/2Why the Zipper Took So Long to Catch Onin the app0/2Who invented the alarm clock?in the app0/2Famous Things That Were Invented by Accident0/2How the Internet Began0/2How radar helped invent the microwavein the app0/2
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Answers and explanations12 questions
- Why were 10 days removed from the calendar? To align the calendar with Earth's movementThe old calendar counted the year as slightly longer than it really was.From “Why 10 Days Were Removed from the Calendar”
- Is it true that people rioted, demanding that the days be returned? Historians find no evidence of such riotsThe discontent concerned rent deadlines, interest, and holidays.From “Why 10 Days Were Removed from the Calendar”
- What kept the zipper from catching on for eighty years? Early versions jammed and split openOne incident of a fastener splitting open on a customer was enough to make people never use it again.From “Why the Zipper Took So Long to Catch On”
- Who used the zipper first? The military and shoe manufacturersA large order gave manufacturers enough volume to make zippers cheap enough to interest clothing makers.From “Why the Zipper Took So Long to Catch On”
- When did alarm clocks become widespread? When scheduled shift work appearedWhile people lived by the sun, no one needed to wake up at an exact time.From “Who invented the alarm clock?”
- Who woke workers before clocks became cheap? People paid to tap on windowsThe profession lasted until the middle of the 20th century and disappeared when mechanisms became cheaper.From “Who invented the alarm clock?”
- Why could the mold stop the bacteria in the dish? It was cool first, then it warmed upThe cool weather gave the mold a head start, and it warmed up once the mold could already interfere with the bacteria.From “Famous Things That Were Invented by Accident”
- What turns a strange experimental result into an invention? Saving, repeating, and explaining the effectChance becomes an invention when someone notices it, tests it, and develops it into something useful.From “Famous Things That Were Invented by Accident”
- What task did the network grow out of? Sharing expensive computersResilience to breaks was a feature of packet switching, not the project's purpose.From “How the Internet Began”
- How is the internet different from the web? The internet is a network and a set of transmission rules; the web is one service built on top of itEmail and file transfers worked twenty years before the web appeared.From “How the Internet Began”
- Why can a large portion stay cold in the middle? The wave penetrates shallowly, then conduction heats itThe microwave enters food only a couple of centimeters, while heat travels more slowly deeper in - by conduction.From “How radar helped invent the microwave”
- Why does the plate usually heat less than the food? Water in food turns in the field, but plate material barely doesWater molecules turn in the oscillating field and heat the food, while glass and porcelain usually don't.From “How radar helped invent the microwave”