Is "existence of cosmic dark energy" falsifiable yet? And what about dark matters? Let me rephrase it again(pardon me for my previous poor expression)-
Is there any condition discovered which can be used to determine the "existence of cosmic dark energy" is true or false without any ambiguity?
I'm not a physics guy. Just being curious.
If you are asking whether the proposition that "dark energy and dark matter are necessary to explain the experimental astrophysical observations within the framework of known physics" has been found false, the answer is no.
If you are asking whether it is possible to falsify the proposition, i.e. if new data could show that the proposition is false, this is always possible in physics explorations. New data trump old theories.
In general physics theories/models/propositions are falsifiable, i.e. open to refutation by new data, to be considered at all as viable.
Edit: With the link you provided for what you mean as "falsifiable" the answer is that the proposition "that dark energy and dark matter are necessary adjuncts of the theory to explain the astrophysical data " is yes, it has always been falsifiable, in the sense that new data may not fit the model and it will then be either falsified or superseded. It may take a long time to do so, as progress in astrophysics data needs money and patience, but of course it could be falsified.
Also a better model could do the job of making a model history, without falsifying it, just superseding it:
Take the example of the epicycles, when the model was a geocentric system. It has been superseded by the heliocentric one once it was realized that it could mathematically describe the system much better. Note that the epicycles were superseded, not falsified, since if you go into any planetarium program and plot a geocentric system the epicycles appear in all their glory. They just are a cumbersome and unnecessary now projection except for special cases, as in understanding the path of the planets in retrograde motion, when observing the night skies.
The word "falsifiable" is a philosophical term which just means that the theory can predict statements which may (or may not) conflict with available observations. This question is essentially just asking whether or not there are any predictions made by the dark energy theory which could conflict with observations that have already been made, or could be made with current technology. Thus, the answer is a simple yes, the model is currently falsifiable. The accelerating rate of expansion determines a value for the cosmological constant and this value helps determine the curvature of the universe. One would naturally predict, based upon the rate of accelerating expansion and other observations, that the universe should be nearly flat, and this is indeed observed. If the universe were curved then this theory would have been falsified.
The epicycles may be interpreted either as a mathematical device or as a 'real' representation of what's going on. Either way this theory is falsifiable if one measures the planet's positions with sufficient precision - this model cannot incorporate perturbations. Basically, any good theory is falsifiable, and every one will get falsified eventually until the final theory is found.
