By Derek Caney (@stax920)

Digit of the day:

1.91 seconds

Katie Ledecky of the United States celebrates after setting a new world record. REUTERS/Marcos Brindiccir 

In other Olympic news:

• Michael Phelps collected his 19^th gold medal, as part of the 4x100 relay team. He swims again tonight in the 200-meter butterfly.
• The U.S. women's gymnastics team topped the table in the team all-around qualifiers. The team final is tomorrow night.
• Argentine Juan Martin del Potro defeated the world's top-ranked men's tennis player, Novak Djokovic. Next Del Potro, ranked #141 in the ATP World Tour, plays Portugal's Joao Sousa, who is ranked #36 in the world.

In the Olympics today:

• Tennis: Serena Williams represents the United States in women's singles. Spain's Rafael Nadal plays Italy's Andreas Seppi in Round 2 of the men's singles.
• The men's gymnastics finals are tonight. China edged out the United States in the qualifiers. Russia came in third.
• The men's U.S. basketball team plays Venezuela as the preliminaries continue, after punishing China over the weekend.

Around the world

• Japanese Emperor Akihito said he's getting too old for this.

Quote of the day:

Akihito stopped short of saying outright that he wanted to abdicate, which could be interpreted as interfering in politics. Once considered divine, the emperor is defined in the constitution as a symbol of the state and the unity of the people. He has no political power.

• An Australian and an American were kidnapped in Kabul. The pair, believed to be affiliated with a Kabul university, was taken by four or five gunmen from a nearby road late last night. We don't know who did it.
• A suicide bomber killed at least 45 people and wounded dozens more in Pakistan in an attack on mourners gathered at a hospital in Quetta. The bomber struck as more than 100 mourners, mostly lawyers and journalists, crowded into the emergency department to accompany the body of a prominent lawyer, who had been shot and killed in the city earlier in the day.

Around the country

• All Delta Air Lines flights have been grounded due to a nationwide system outage. We're waiting for updates.
• Republican presidential nominee Donald Trump is expected to propose allowing parents to deduct spending on childcare from their income taxes today at a speech for the Detroit Economic Club. His Democratic opponent Hillary Clinton has pledged that no family should pay more than 10 percent of its income on childcare. She has called for a tax cut to help middle-class parents cope with rising childcare costs and an expansion of a federally funded program that provides education and health services to low-income families with young children.
• Pennsylvania Attorney General Kathleen Kane goes on trial today on charges that she illegally leaked grand jury information to embarrass a rival, closing out a four-year term dominated by a web of allegations that have roiled the state government. Kane, 50, says she has broken no laws and is expected to offer a vigorous defense against perjury and obstruction charges.

Around Wall Street

• China's exports and imports fell more than expected in July in a rocky start to the third quarter, pointing to further weakness in demand.
• Japan's Fair Trade Commission raided Amazon's offices on suspicion of pressuring retailers to offer products at lower prices than on rival sites, Nikkei reported. Amazon Japan's website booked net sales of $8.3 billion last year, equivalent to 7.7 percent of Amazon.com's worldwide net sales. By comparison, main rival Rakuten recorded e-commerce revenue in Japan of $2.9 billion in the same period. Amazon's practices toward retailers and e-commerce partners have also come under scrutiny in Europe.
• Gawker Media Group is engaged in preliminary talks with the former professional wrestler Hulk Hogan to reach a settlement over a $140 million court judgment that led the company to file for bankruptcy protection, the Wall Street Journal reported.

Today's reason to live

Iris DeMent – Broad Gold