Speaking on Morning Joe on Wednesday, Game Change author John Heilemann did not hold back in his blistering criticism of President Trump's tweet that taunted North Korea over the unimpressive size of its nuclear button. Trump "is not merely being cavalier with a threat about nuclear war," said Heilemann. "He's being cavalier in a way that makes him seem demented and deranged."

Heilemann had also pointed out that neither Republican nor Democratic presidents in the past have ever before treated the nuclear threat in a "cavalier" way. Trump's comments make none "of our serious allies or adversaries around the world think he's a serious person talking in this way about the most serious threat that the world ever faces," Heilemann insisted. Watch his comments below, and read more responses to Trump's tweet here. Jeva Lange

Children are spending more time than ever in front of a screen, and it doesn't necessarily bode well for their futures.

In 1997, babies and toddlers age 0-2 got an average of 1.32 hours of screen time each day, Axios reports via a Monday report from JAMA Pediatrics. By 2014, that number had doubled to three hours per day, and more of that time is spent in front of the TV than ever before.

Using data from a previous child development study, JAMA researchers found that children age 2 and under spent 43 percent of their screen time in front of a TV in 1997. The rest of the time was spent with video games and computers, the study showed. By 2014, the definition of screen time expanded to include cell phones and tablets, CNN notes. Still, TV had still skyrocketed to take up 86 percent of the youngest age bracket's screen exposure, or more than 2 and half hours each day. Screen time for kids age 3-5 didn't increase much overall, but the portion of time spent watching TV grew from 48 to 78 percent.

The data stops in 2014 because that's when the "real acceleration of decline in kids TV started," a children's tech CEO tells Axios. "Prolonged screen time can increase risks of obesity in children and can be linked to poorer performance on developmental screening tests," Axios also notes via past research. Yet one pediatrician wants to ensure different kids of devices and content are "thought of differently," she tells CNN. For example, learning devices aren't the same as cartoons on TV. Read more about the study at CNN. Kathryn Krawczyk

If you're flying east today, you're in a whole lot of luck: The jet stream, that funny little channel of high-altitude air that flows over the United States and northern Atlantic, is moving at unheard-of speeds, delivering commercial jets to their destinations nearly an hour ahead of schedule, The Washington Post reports. In fact, one Virgin Atlantic flight traveling from Los Angeles to London notched a speed of 801 miles per hour over Pennsylvania — which, had it been on the ground, would have been faster than the speed of sound.

Thankfully for the passengers on board, the plane itself didn't actually break the speed of sound because, as the Post puts it, "it was embedded in the swiftly moving air," so only its horizontal speed over the land, or ground speed, crossed the 767-mile-per-hour speed-of-sound threshold. The plane's true "airspeed," or speed at which air was passing over the wings, would have been much lower.

Still, the speed is impressive, and is thought to be a record for a Boeing 787-9 Dreamliner, which has a usual cruising speed of 561 miles per hour.

Other flights have also been catching an extra boost from the high winds: A 737 traveling from Chicago to New York hit a ground speed of 700 miles per hour on Tuesday morning, with that route's estimated travel time down to one hour and 24 minutes from the usual two hours.

If you're flying west, alas, the jet stream won't be quite as fun: The Post expects westward flights out of New York and New England to see up to an extra 30 minutes of travel time. Jeva Lange

Fox just last week denied reports that Jussie Smollett would ever be written off Empire. But a lot has changed since then.

The Fox show is reportedly in the process of cutting Smollett scenes from upcoming episodes, TMZ and Deadline are both reporting. The drama series is currently in production, but Deadline reports that Smollett will be "a rare presence" on set this week and that "upcoming episodes have seen serious rewrites" to minimize his role. TMZ similarly reports that scripts have "undergone multiple revisions" and that scenes where he's the focus are being removed. But Deadline says there aren't plans to cut Smollett out of episodes that had already been shot.

Smollett has alleged he was the victim of a hate crime and that two men attacked him in Chicago, specifically targeting him because of his role on Empire and screaming "This is MAGA country" at him while they beat him, covered him in bleach, and tied a rope around his neck. Since then, questions have emerged about his account, with two local Chicago news stations reporting last week that police now suspect that Smollett staged the attack himself, something he has strongly denied. One report suggested he may have done so because he was in danger of being written off Empire.

Fox pushed back on that report, saying that the idea that Smollett "has been, or would be, written of Empire is patently ridiculous," with the network adding, "we continue to stand behind him." But since then, police have said that the case's "trajectory" has changed, and CNN is reporting that cops believe he paid the two men to attack him and that the men are cooperating with law enforcement. Fox is now declining to comment, which The New York Times' Sopan Deb notes is a "stark contrast" to their position just days ago. Brendan Morrow

New York Times v. Sullivan has set the standard for libel for the last 70 years. Supreme Court Justice Clarence Thomas thinks it's time for that to change.

In 1964, the Supreme Court ruled public officials would have to prove a publication made a defamatory statement with "actual malice" when suing for libel. But in a concurring opinion regarding sexual assault accusations against Bill Cosby on Tuesday, Thomas suggested Times v. Sullivan and subsequent press-protecting rulings were "policy-driven decisions masquerading as constitutional law."

The Tuesday case regarded Cosby accuser Katherine McKee, who said "Cosby's lawyer leaked a letter that distorted her background and damaged her reputation," NBC News notes. The court decided against hearing McKee's case, and Thomas alone wrote a concurring opinion questioning Times v. Sullivan. "If the Constitution does not require public figures to satisfy an actual-malice standard in state-law defamation suits, then neither should we," Thomas said, mentioning the infamous term coined in 1964.

Thomas' language reflects past statements from President Trump, who has constantly said he wants to "open up" and "change" libel laws and make it easier to sue the press. Read Thomas' whole opinion at CNN. Kathryn Krawczyk

Patience is, indeed, a virtue.

Major League Baseball's stagnant winter — during which the sport's biggest news was about how a top prospect was electing to play another sport — finally began to thaw today when All-Star third baseman Manny Machado, fresh off a career-best year on offense in which he hit .297 with 37 home runs, agreed to sign with the San Diego Padres on Tuesday. The 26-year-old's 10-year, $300-million deal is the largest free agent contract in the history of American sports, per ESPN.

Machado's saga seemed like it would never end, as his free agency stretched into the early stages of spring training. It appeared that Machado and his agent, Dan Lozano, would fall well short of their lofty contract goals, based on a brutal winter market for other free agents and a surprising lack of interested teams. Only four teams — San Diego, the Philadelphia Phillies, the Chicago White Sox, and the New York Yankees — were known to have expressed legitimate interest in the former longtime Baltimore Oriole (Machado played briefly for the Los Angeles Dodgers last year, as well.) But Lozano's decision to play the waiting game paid off and then some.

It's a surprising turn of events for the Padres, a normally frugal franchise that did not enter the Machado sweepstakes until late January when General Manager A.J. Preller and company realized that the interest in Machado was lighter than anticipated. San Diego finished last in the National League West last season, but boasts one of the league's top minor league systems.

With Machado off the board, attention will turn mainly to outfielder Bryce Harper, who remains on the open market and could potentially make Machado's record-setting deal a short-lived one. Tim O'Donnell

Nothing makes you say awww, shucks quite like realizing you've misplaced 15 gallons of radioactive uranium ore right beside your popular taxidermy exhibit.

Yet in 2018, the museum at Grand Canyon National Park reportedly discovered that for 18 years, they'd accidentally been storing three 5-gallon containers of uranium right by where unsuspecting tourists and school groups were admiring dioramas of stuffed mountain lions and mule deer. The dangerous buckets of ore could have remained within proximity to the public for much longer, too, if it weren't for the fact that "the teenage son of a park employee who happened to be a Geiger counter enthusiast ... brought a device to the museum collection room," the Arizona Republic reports.

The museum's safety, health, and wellness manager Elston "Swede" Stephenson confirmed that "if you were in the Museum Collections Building between the year 2000 and June 18, 2018, you were 'exposed' to uranium by OSHA's definition." Worryingly, one of the buckets was apparently so full of uranium that the lid wouldn't close. Children would have been exposed to unsafe levels of uranium in as little as three seconds, and adults in less than half a minute.

Technicians have since removed the uranium from the Grand Canyon museum, although "lacking protective clothing, they purchased dish-washing and gardening gloves, then used a broken mop handle to lift the buckets into a truck," the Republic notes.

Stephenson said that as of now, there is "no current risk to the public or park employees." The Grand Canyon is one of the most popular parks in the country, with more than 4 million visitors a year. Jeva Lange