Attempts & Failures

This section is a review of some of the most important theories and experiments in the history physics that either have failed to achieve its main objective or have been disregarded by this science. This review has not been brought to expose the failures in physics but to be aware of those ways walked by some men in the past. 

Experimental

Recent

Impossibility of the measurement of the one-way speed of physical entities (emphasis on the one-way speed of light)

Physicists used to think that the measurement of physical entities was reduced to the operation of measuring a length l and the time t travelled by the physical entity and using the relation v=d/l. It has been shown that in most common experimental setups what clocks measure is actually the round trip time and therefore the round trip speeds or the harmonic mean. This also applies for the speed of light having profound implications for the testing of the second postulates of the special relativity. The second postulate is experimentally undetermined. On the experimental determination of the one-way speed of light 

Nuclear transmutation
Chemists and physicists of the previous three centuries used to think that it was possible to convert water into gold and silver and viceversa. So far, this has been impossible. The laws of quantum mechanics pose a limit to the structure matter. 

Superconductivity, Ferromagnetism and antiferromagnetism
It has been impossible to construct a theory that predicts the superconducting properties of a given material. As well it has been impossible to construct a theory that predicts the Neel and Curie temperatures of a given material. This clearly indicates that we haven't understood the deep nature of matter. 

Tetraquarks, Pentaquarks, sextuquarks, heptaquarks, octaquarks, etc.
Theoretically predicted never observed.

Tachions
 Particles traveling at superluminal speeds but never observed. It was believe that their existence would violate causality and would allow time travel within the context of relativity theory.

Magnetic monopoles
Charges have two polarities, negative and positive. A charge can be isolated and have a particular polarity. In a similar fashion, many physicists believe it is possible to isolate magnetic "charges". However, they have never been observed in nature. The search still continues.

Lorentz Gravitation
A attempt to explain gravitation with intuitive models that turned out to be  unsatisfactory.

Theoretical

Dragging aether theory of Stokes 
In the middle of the XIX century Stokes proposed the dragging aether to explain electromagnetic phenomena. The theory predicted that the one-way speed of light would be anisotropic. The phenomenon of the aberration of light and the constancy of the two-way speed of light disproved it.

Kaluza-Klein theory (5D), 6D and 7D theories
In 1917 Kaluza and Klein proposed a 5 dimensional theory (4+1) in order to unify the electromagnetic force with gravitation. Their predictions didn't match the observations, particularly the electron mass/charge ratio. 6 and 7 dimensional theories were also proposed during the following 3 decades, they all failed.  

Supersymmetry 
According to this theory ordinary particles should have supersymmetric partners. A quarks should have a s-quark, a lepton an s-lepton and so on. Experiments conducted at the LHC are disproving the theory. Rendering false in essence.