Hello. I'm not very educated in the field of physics but I do like to let my mind wander at times and contemplate the nature of gravity and the speed of light. I had this thought today over morning coffee and thought I would share it with someone who has a much better understanding of these things Has anyone ever accelerated an object to near the speed of light and detected an actual increase in it's mass? Just curious because Einstein states that any object with mass that is accelerated to the speed of light would gain infinite mass requiring infinite energy. However, is it all relative to the observer? To an outside observer doing the math, the object would appear to gain infinite mass, but to an observer inside the object, perhaps the rest of the universe appears to lose all mass, allowing for instantaneous travel anywhere. The universe losing all mass to the observer inside the object seems no more bizarre than the object gaining infinite mass to the outside observer. Be kind and explain my fallacy. Thanks ahead of time.