One-eighth of the world's population is headed for the polls, and it's all happening in one country. India is starting its marathon elections on Thursday, a marathon because the voting process is spread out over five weeks to the tune of half a billion dollars.

India's general election is a mammoth undertaking. The numbers speak for themselves.

Nearly 900 million people are eligible to vote. Reaching them is a logistical challenge, because election guidelines say no voter should be more than two kilometers away from a polling station.

About one million polling stations are being set up, from urban centers to highland jungles. Then comes the legion of workers to oversee operations.

More than 11 million election officials and security forces are being mobilized around the country by boats, rail, roads and even elephants, which is still not enough for one day.

So voting will take place in seven phases, spreading out over the course of more than a month, which allows workers to be redeployed, and to ensure the integrity of the vote.

But the most incredible thing is that after a five-week process, vote counting for all the ballots in every constituency will be done in a single day, May 23, with results to India's 2019 elections due that evening.