Carl Sagan said in the first Cosmos: "Absence of evidence is not evidence of absence." What greater "absence" is there than something critically relevant being forever beyond our direct measurements on an individual basis? This challenge can apply on a very small scale, or on a scale as large as the multiverse.
There are indirect work-arounds that can help us "see the unseeable." This strategy for finding truth was well expressed by Arthur Conan Doyle, creator of Sherlock Holmes: "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." He also said: "It has long been an axiom of mine that the little things are infinitely the most important." (brainyquote.com)
The history of science is filled with established error passing as comfortable fact, and with new truth being opposed as heresy. English philosopher Bertrand Russell put it this way: "The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd."
Those who chose to burn Giordano Bruno at the stake in 1600 were good people in their own minds, protecting Truth against disruptive heresy. Bruno's real crime was envisioning life on planets around stars in the sky. Today's technology is just approaching what Bruno visualized over 400 years ago. In the future our instruments are likely to confirm what he visualized.
In Bruno's case we are talking about seeing the conditional unseeable, as a matter of time and technology. Neither time nor technology allows us mortals to directly see and/or measure forever unseeables. The lesser can never fully know the greater, and our powers of observation are definitely less than the majesty of all that is.
There are distances outward, and distances inward. Both directions inflict limits on our scientific technologies. We can never see all the way to the end of our universe, and beyond. Equally, we can hardly see below the level of atoms at 10^-10 m, and are a long way from directly observing corpuscular entities approaching Planck's dimension (10^-35 meters), below which no laboratory technology can measurably penetrate. Nevertheless, that's where the most exciting science lies!
There is one instrument that can penetrate the super-small, as well as the super-large. It is the human mind, following the trail of logic and visual imagination. The purely imaginary world is full of attractive ideas and theses (some of which are developed into religions), and nearly all of which are likely in error, due to an intellectual version of the Pauli exclusion principle. Even conventional elementary physics is in crisis today, whether admitted or not. How can we move forward?
Conventional physics has built its reputation on testable phenomena, some of which have been repeatedly tested and verified. The area of possible verification still represents only a small percentage of all phenomenal dimensions.
Scientists happily induce experimental findings to everything else within their chosen theory. However, neither induction nor deduction is flawless, no matter how apparently verifiable any experiment has been.
Ideas appear to come in six flavors: impossible, possible, probable, untestable, testable, tested, and verified:
* Some ideas are easily eliminated, such as "impossible" being self-contradictory.
* The "possible" is more important than "probable," as ultimately we cannot put a probability value on any possible unknown.
* "Untestable" is equivalent to unseeable.
* "Testable" ideas are good to have, if we can design and execute a valid test of general value which is repeatable.
* Just because something has been repeatedly "tested," it is not necessarily true. Misunderstanding what it is we are testing, even if we think we know the forces, can lead to the right conclusion for the wrong reasons in the everyday world. This was Einstein's primary error.
In the everyday world, where we can discuss and utilize "forces" of nature, physics works just fine. It is only when we go very large, or very small, that the neat and tidy everyday ideas are stressed. It is within extreme dimensions that a general paradigm lives or dies for all dimensions.
General Relativity DIES when it fails to explain gravity data relating to supercluster trains. Another theory, shadow gravity, elegantly and operationally explains what happens. In this case, GR has misrepresented shadow gravity measured in smaller everyday dimensions as general proofs of GR in all dimensions.
The chain of logic is only as strong as its weakest link. That's why Einstein wrote to a friend one year before his death that he feared his continuous structures would soon be overthrown: "In that case, nothing remains of my entire castle in the air, gravitation theory included, and of the rest of modern physics." Albert Einstein. (Pais, A. 1982. Subtle is the Lord: The Science and the Life of Albert Einstein, Oxford U. Press, Oxford, UK, p. 467.)
There are theoretical astrophysicists, and there are experimental astrophysicists. Each needs the other. Theory needs to be developed, and then tested. If there were nobody to design and execute experiments, theories would proliferate like weeds. We see this in the many flavors of string theory, which cannot be independently verified by testing.
String theory cosmologists have a lot of sophisticated calculus to "back up" their ideas. However, nobody can win a string theory argument, because there can be no experimental verification. Additionally, there is no way for the math by itself to verify any theory. No abstract statement by itself proves any version of string theory is false or true, as long as it is internally consistent. String theory is something of a mutation of Einstein's GR; so when GR falls, so too does string theory.
An aspect of string theory is supersymmetry. Whereas super-symmetric particles are not branes, they are part of the overall multi-dimensional architecture. Ironically, the Large Hadron Collider was supposed to find a zoo of supersymmetric particles, and it did not. Other experiments have likewise failed to support the idea. If we are not able to rely on GR and string theory, what's left, as Sherlock Holmes might ask?
On the macro scale, shadow gravity works exceptionally well. On the sub-nano scale it works too, except not below the graviton level. Below that level push gravity is replaced by primary electromagnetism, which dialectically shifts into secondary/polar EM at dimensions larger than Planck scale. Thus, all verifiable EM experiments have been of secondary EM, and not of primary EM.
The closest we can come to experimental verification of energy/matter within the Planck dimension (10^-35 m) is to construct a theory or theories that elegantly allow for the emergence of phenomena we can observe and measure on the collective scale. We are talking about the forever unseeable foundation (at 10^-40 m) elegantly supporting the superstructure of increasingly larger dimensions of matter and energy.
To the degree that we can reverse engineer experiments involving collective nano-phenomena, we can thereby make reasonable and elegant hypotheses about the much smaller energy/matter corpuscles we cannot see and measure. This luminous method is important for developing all-dimensional paradigms. In short: Go at the unseeable with all-dimensional theory, and with testing of the seeable; then hypothesize about the unseeable in mass form according to the Law of Parsimony. From the collective we can deduce the individual unseeables.
In contrast, verifying theory on the scale of hundreds of millions of light years is not like doing an experiment near the sub-Planck level: First, one checks for a theoretical/logical consistency, which is supplied by the modern version of shadow gravity correcting Le Sage's mistakes. Second, one checks the data supplied by the COBE satellite, as verified by red shifts seen in Digital Sky Survey images. When all this checks out, and it does, we can say that the "experiment" is complete. To challenge/verify it, we need only re-check the data, and try to propose a superior theoretical model, of which there is none to date.
Einstein's trepidations in 1954 have come true. It just took sixty years for the right data to euthanize his continuous structures fantasy. Combine the COBE and DSS gravitational data along supercluster chains of galaxies, with the Large Hadron Collider not being able to support supersymmetry, and you have the makings of a complete transformation of accepted modern cosmology.
In a Kurosawa movie featuring samurai in Japan's medieval period, a warrior is stabbed once in the belly by an enemy sword. He shouts out to his attacker, "You have killed me!" The stabbed samurai initially seems quite alive, except for that festering mortal wound. Such is the fate of standard cosmology.
A final thought for those who think elemental astrophysics is just a game for nerds: "Ninety-nine percent of who you are is invisible and untouchable." R. Buckminster Fuller. (brainyquote.com)