Removing decimal from double?

Hello!

I've only just started learning Java, and I've just progressed from programs like "HelloWorld" and such

I've written an extremely simple and basic program, that measures time dilation when a fictive space vessle travels close to the speed of light...
It's working as I've intended, however, my ambition is to remove all decimals from the answer. For example if I get answer of 15.93848929393, I've used
Math.floor to round the double off, however now it will be displayed as 15.0 and I would like to be rid of the decimal completely.
Is there anybody who can give me a suggestion as to how to remove the decimal?
Please bear with me, I'm a complete noob at this, and there's a lot I still don't know and understand...

Here is the code:

import javax.swing.*;
import java.lang.Math;



public class TimeDilation {
public void dilation(){

double speedoflight, result, round;



speedoflight = Double.parseDouble(JOptionPane.showInputDialog("En ter lightspeed"));
result = 100*(Math.sqrt(1-(Math.pow(speedoflight, 2))));
round = Math.floor(result);






JOptionPane.showMessageDialog(null, "If you travel for 100 years on Earth " + round + " years will pass on The Magellan");


}

}

Thanks in advance for any replies!!