This statement is not true and the basis of Mach principle
Mach's principle is a hypothesis. It doesn't predict our observation of the universe as well as relativity, and what's more, it doesn't predict phenomena that relativity does, such as the lifetime of radioactive elements as a function of speed.
This need to look for an approximate alternative theory, out of rejection of academic science, is irrational.
I have been Reading scientific work, papers, articles and journals for many years. I have talked to many scientists across those years. Very very very few of them were open minded enough to even accept an alternative viewpoint. It's not about who is right or wrong but about the ability to open up to new ideas even if they come from the "fringe".
This point of view is totally arbitrary and contrary to the facts, in my opinion due to a misunderstanding of why scientists hold a certain number of current theories to be the best and others to be false or insufficient.
On the other hand, they are totally open to new ideas as long as they are relevant, i.e. verify observations. If they weren't open, Einstein would never have been able to put forward relativity, which shocked everyone at the time and was nevertheless adopted.
This openness can also be seen in scientists' ability to question their own theories - I've already mentioned this in connection with relativity - and to search for a "new physics", because they are perfectly aware of the limitations of the current theories. Do a Google search for "new physics", and you will see that all physicists are looking for it. Seriously, do you think you're the only ones who know that scientific theories have limits and want to look beyond them?!
This closed-mindedness of those who believe themselves to be open-minded can be seen everywhere in FE, particularly in the rejection of any scientific theory because it is beyond them. Some people here challenge relativity when they don't understand it at all - they've only read a vague popularization of it. How can you criticize something you don't understand?
I am addressing them.
Denying what you don't understand, refusing to acknowledge facts that are different from what you'd like to see, falsifying and reducing the world to simple beliefs, demand an absolute Truth but inventing imaginary realities like FE machines that no one has, has always been the lot of believers. They believe that what they don't understand is false, that the world should be reduced to what they do understand or dream, and that it should be rewritten to suit the childishness of children railing against their teachers or great minds.
When mankind is equipped with your "free energy" machines, you'll be able to teach scientists a thing or two. For the moment, it's thanks to them that you have energy, that you can communicate here, so thank them, show some modesty, lean on them to go beyond, and before condemning what's beyond you, try to learn to think straight or you will always be as bad as today in the creation of a new technology useful to humanity.