Sine wave using Date.now()

sine.js

var d = Math.sin(Date.now() * frequency) * amplitude);

xample.css

body{
  margin: 30px;
}

.container{
  perspective: 500px;
  position: absolute;
  width: 50px;
  height: 50px;
}

.disc{
  background-color: lightblue;
  position: relative;
  top: 0;
  left: 0;
  width: 50px;
  height: 50px;
  border-radius: 25px; 
}

xample.html

<div class="container">
  <div class="disc"></div>
</div>

xample.js

var frequency = 0.005,
    amplitude = 50,
    elem = document.querySelector('.disc'),
    update = function(){
      elem.style.transform = 'translateZ(' + (Math.sin(Date.now() * frequency) * amplitude) + 'px)';
      requestAnimationFrame(update);
    };
update();