Wouldn't 24th century bras have dual antigrav suspensors and hyperbolic field containment matrices under independent multiphasic control units? Presumably they'd be dynamically reconfigurable by the wearer, from maximum hysteretic control when going to a business meeting to minimum hysteresis (i.e. bouncy) for more social occasions. I only hope they make them respond to voice commands so that they're easier to take off. Instead of having to say things like, "No, no, this one unfastens in the front" women of the future will be saying, "My mammary protrusion suspension unit's access code is 3-4-beta, unlock."