title: Observables created at time interval
body: <p>I was looking at the RxScala observables which are created at a given time interval:</p>
  
  <pre><code>val periodic: Observable[Long] = Observable.interval(100 millis)
  
  periodic.foreach(x =&gt; println(x))
  </code></pre>
  
  <p>If I put this in a worksheet, I get this result:</p>
  
  <pre><code>periodic: rx.lang.scala.Observable[Long] = rx.lang.scala.JavaConversions$$anon$2@2cce3493
  
  res0: Unit = ()
  </code></pre>
  
  <p>This leaves me confused: What do the elements of <code>periodic</code> actually contain?</p>
  
  <p>Do they contain some index?
  Do they contain the time interval at which they were created?</p>