This question originally appeared on Quora: What would happen if Google were to shut down for 30 minutes? Answer by Ashish Kedia, who works at Google.
In August 2013, Google and all of its services came down briefly for 2-3 minutes. And the whole internet traffic went down by a massive 40%. 
A similar incident also occurred in May 2009. 
Note that it was just for 2 minutes. Imagine 30 minutes. It's highly unlikely but here is what I think will happen.
- First few minutes people will check their Internet connection. Some will even call their Service Provider. Some may even check for hardware failures on their side - which is still more likely than a 30 minute outage
- People will then realise that it's true. There will be a period of disbelief. People will desperately try to reload Google's homepage.
- People all around the world will start taking screenshots of the Google Server Error Page. [Likely 500]
- Your Facebook Newsfeed will be full of "OMG Can't believe", "I witnessed something astonishing" along with several images from the previous point.
- People will search for alternate search engine ~ but how? Most of them don't even know that there are alternate search engines.
- Bing and Yahoo will get huge traffic surge.
- DuckDuckGo ( Page on duckduckgo.com ) will start trending on Twitter. People will realise it's good. (That's a search engine that doesn't track you by the way.)
- Many other internet apps - that uses Google Services in the backend will also come down. Without Gmail, for 30 minutes the productivity across the whole world will drop by a huge margin.
- I can't even imagine the revenue loss - not just for Google but for all the companies throughout the world that uses Google.
- Android users will be stranded on the roads and iPhone users will be lost in the lanes if Google Maps stopped working for 30 minutes.
- Among all this fiasco Internet life in China will remain unaffected.
- People at other competitive companies will enjoy and sing songs.
After the outage is fixed and services are restored:
- Google will release their statement to press - explaining the cause (maybe)
- Tech savvy people around the world will try to dig deep in search for the cause of the outage.
- Many will speculate that a group of hackers are responsible. People will then approach many hackers regarding their opinion
- Media will call experts and try to analyse situation themselves.
- Many bloggers will write a post about "How we are too dependent on Google? - A reality check". Even media will do it.
- Quora would be full of questions - "Why did it happen ?", "What do you think about the outage ?", "Can it happen again ?", "Was my data leaked?", "Is it true that Google was hacked ?", etc.
- A lot of users will switch from Google services to alternates.
- BuzzFeed and ScoopWhoop will have articles like "Google went down for 30 minutes. You won't believe what happened next." and "10 things to do when Google goes down the next time" *.
- People will find this answer and realise that many of it are actually happening.