Richard Shotwell/AP

Bill Belichick hit the books and defended the New England Patriots in a Deflategate press conference last week, claiming that the footballs used in the AFC Championship game were underinflated because they were simply affected by climactic conditions. Belichick said that when the footballs were taken out of a controlled environment and introduced to the cold, the footballs lost at least one pound of air pressure.

A number of actual scientists aren’t buying that explanation.

Bill Nye ‘The Science Guy’ called out Bill Belichick’s shoddy science on national television Sunday, and on Monday astrophysicist Neil deGrasse Tyson explained exactly why the story doesn’t check out.

So either Belichick is full of hot air, or the footballs are.