Immutable objects are thread safe, but why?

Question

Lets say for example, a thread is creating and populating the reference variable of an immutable class by creating its object and another thread kicks in before the first on

Answer 1

Immutability doesn't imply thread safety.In the sense, the reference to an immutable object can be altered, even after it is created.

//No setters provided
class ImmutableValue
{

     private final int value = 0;

     public ImmutableValue(int value)
     {
          this.value = value;
     }

     public int getValue()
     {
          return value;
     }
}

public class ImmutableValueUser{
  private ImmutableValue currentValue = null;//currentValue reference can be changed even after the referred underlying ImmutableValue object has been constructed.

  public ImmutableValue getValue(){
    return currentValue;
  }

  public void setValue(ImmutableValue newValue){
    this.currentValue = newValue;
  }

}