There is no need for a fifth force to explain dark energy.

Even if chameleon forces exist, they are extremely hard to detect. The reason for that is that those hypothetical forces are connected with all other forces. And they are like carrier waves that are putting those other forces moving. 

There is the possibility that the fifth force is virtual. That means it could be some well-known force that has some source or form that we don't know or we haven't seen yet. 

The mythic fifth force that will connect all other forces is still unreachable. The fact is that the new evidence shows that the chameleon force is a myth. And it's not even existed. We don't need chameleon force to explain dark energy. Dark energy can be something like some kind of electromagnetic "hum". 

There is the possibility that the cosmic hum that Voyager 1 found can be the thing that explains dark energy. When that monotonic wave motion hits plasma the energy level of the particles rises until that energy can break out from the particle. That requires the energy level of the particle rises to a higher level than stressing electromagnetic radiation.

When that radiation or wave motion comes out from the particle. It impacts incoming wave motion. That causes whirls in those impact points. Whirls of wave motion are acting like real particles. So that's why those whirls are called "virtual particles". 

When wave motion travels in space there is another wave motion that impacts it. When two wave motion lines with the same frequency are impacting each other they are acting like lasers. That thing is called maser (or laser if the wave motion is visible light)-emission. That means the growth of spontaneous strength of the wave motion when energy impacts it. 

What is the chameleon force, if it exists? Possible the chameleon force is virtual, as I wrote at the beginning of this text. 

The legendary Muon G-2 anomaly stays. And that's it. But nobody knows what causes that mysterious anomaly. So could that thing happen when Muon hits the dark matter particle, or did it touch the wave of dark energy?

Chameleon force is the myth. It's the legend of the "carrier wave" that will carry all other transporter particles or force carriers. Unlike all other forces, the chameleon force would have only a wave-motion form. But then we can return to the top and say that the chameleon force does not exist as a "real" force. 

But there is one exciting possibility. And that thing is that the fifth force is the virtual effect or virtual force. That means it could be the wave motion that is left from open superstrings. Or some kind of shadow that forms when superstrings are undulating. 

But that strange fifth force doesn't explain dark energy. The thing that makes dark energy interesting is that it's dominating. But nobody sees it. And that thing makes dark energy so interesting. The fact is that dark energy doesn't require a fifth force for existence. 

Dark energy is wave motion that rips the universe into pieces. And that thing is all that we know about that strange thing. The source of dark energy is a mystery. But maybe someday we can solve that mystery. 

https://www.sciencenews.org/article/chameleon-force-new-dark-energy-experiment

https://en.wikipedia.org/wiki/Muon_g-2

https://informationnevervanishes.blogspot.com/