Please forward this error screen to sharedip-1601531662. Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail. The following is a list of unsolved problems grouped into broad solved problems on open channel flow pdf of physics.

Why does time have a direction? Why are CP violations observed in certain weak force decays, but not elsewhere? Are CP violations somehow a product of the Second Law of Thermodynamics, or are they a separate arrow of time? Are there exceptions to the principle of causality?

Is there a single possible past? Is the present moment physically distinct from the past and future, or is it merely an emergent property of consciousness?

What links the quantum arrow of time to the thermodynamic arrow? Interpretation of quantum mechanics: How does the quantum description of reality, which includes elements such as the superposition of states and wavefunction collapse or quantum decoherence, give rise to the reality we perceive? Another way of stating this question regards the measurement problem: What constitutes a “measurement” which apparently causes the wave function to collapse into a definite state? Theory of everything: Is there a theory which explains the values of all fundamental physical constants?

Is there a theory which explains why the gauge groups of the standard model are as they are, and why observed spacetime has 3 spatial dimensions and 1 temporal dimension? Do “fundamental physical constants” vary over time? Are any of the fundamental particles in the standard model of particle physics actually composite particles too tightly bound to observe as such at current experimental energies?

Are there fundamental particles that have not yet been observed, and, if so, which ones are they and what are their properties? Are there unobserved fundamental forces? Mills theory with a finite mass gap exist?

This problem is also listed as one of the Millennium Prize Problems in mathematics. Physical information: Are there physical phenomena, such as wave function collapse or black holes, which irrevocably destroy information about their prior states? How is quantum information stored as a state of a quantum system? What is the minimum number of dimensionless physical constants from which all other dimensionless physical constants can be derived?

Are dimensional physical constants necessary at all? Fine-tuned Universe: The values of the fundamental physical constants are in a narrow range necessary to support carbon-based life.

Is this because there exist other universes with different constants, or are our universe’s constants the result of chance, or some other factor or process? Problem of time: How can time be reconciled with general relativity? Cosmic inflation: Is the theory of cosmic inflation correct, and, if so, what are the details of this epoch? What is the hypothetical inflaton field giving rise to inflation?