diff --git a/src/constants.h b/src/constants.h
index ccb3271..9d90ca3 100644
--- a/src/constants.h
+++ b/src/constants.h
@@ -24,4 +24,4 @@
 */
 
 const double PI = acos( -1.0 );
-const double SPEED_OF_LIGHT = 2.99792458e+8;
\ No newline at end of file
+const double SPEED_OF_LIGHT = 299792458.0;
\ No newline at end of file
diff --git a/src/graphicsellipseitem.cpp b/src/graphicsellipseitem.cpp
index 7972223..e58e738 100644
--- a/src/graphicsellipseitem.cpp
+++ b/src/graphicsellipseitem.cpp
@@ -148,6 +148,7 @@ void GraphicsEllipseItem::calculateProbePath(QPointF startPoint) {
 
 double GraphicsEllipseItem::getMasse(double speed) {
 	if(speed < SPEED_OF_LIGHT/10.0) return masse;
+	if(speed >= SPEED_OF_LIGHT) speed = SPEED_OF_LIGHT - 1e-8; //fuer v>=c nehme v (etwas)<c an
 	else {
 		return masse / (sqrt(1- ( (speed/SPEED_OF_LIGHT)*(speed/SPEED_OF_LIGHT))));