Spoiler alert: At the end of the movie, Jack freezes to death in the icy water. It is the ultimate sacrifice as he clings to a raft carrying Rose, his love, because the plank cannot h0ld the both of them.
According to Cameron, amateur physicists on the Internet had done the math - plugging in the weights of two actors to calculate the force of buoyancy - and found the answer to be inconclusive.
Maybe, just maybe, Jack and Rose could have shared the plank and gone on to live happily ever after….
So Sunday, Cameron turned to Adam Savage and Jamie Hyneman of the popular show "Mythbusters," on which they test common myths.
"These thousands of fans think I got it wrong," Cameron told Savage and Hyneman. "That the board could have supported them both. So this is what I want you to test."
First, Savage and Hyneman tried the theory out in a bathtub with small Jack and Rose dolls. (The dolls sank.) Then, they tried it out in the open water.
They calculated how much time Jack and Rose would have had to swim in 28-degree water before hypothermia set in. They concluded that if they could get 80 percent of their bodies out of the water, both could have made it until rescue came.
By lashing a life preserver, which was available, underneath the plank, the guys on "Mythbusters" found that Jack and Rose would have both been kept high and dry.
"Based on that," the duo said during the show, "it's plausible [that] Rose and Jack could have survived."
But Cameron pointed out that sometimes the laws of drama trump the laws of physics.
"I think you guys are missing the point," he said. "The script says Jack died. He has to die."