Yes, there have been numerous experiments and observations that support the conclusion that information cannot travel faster than the speed of light in a vacuum. This is a fundamental principle of physics known as the "speed of light barrier" or "causality constraint."
One of the most famous experiments that supports this principle is the Michelson-Morley experiment conducted in 1887. The experiment aimed to measure the relative motion of Earth through the hypothetical luminiferous ether, which was believed to be the medium through which light waves propagated. However, the experiment yielded a null result, indicating that the speed of light is constant and independent of the observer's motion.
Another significant experiment that supports the speed of light barrier is the observation of cosmic rays. Cosmic rays are high-energy particles that travel through space at speeds approaching the speed of light. When these particles collide with the Earth's atmosphere, they produce a cascade of secondary particles. The pattern of these secondary particles' arrival at detectors on the ground indicates that they are moving at speeds close to the speed of light, but not exceeding it. This observation suggests that information carried by these particles cannot propagate faster than the speed of light.
Additionally, the principles of special relativity, formulated by Albert Einstein, provide a theoretical framework that supports the limitation on information transfer. Special relativity establishes that the speed of light in a vacuum is the maximum speed at which information, energy, or causal influence can be transmitted. It is a fundamental aspect of our understanding of the universe and has been extensively tested and verified by various experiments.
While these experiments and theories strongly support the assertion that information cannot travel faster than the speed of light without a medium, it is important to note that there is ongoing scientific research to explore the boundaries of these principles and to investigate phenomena such as quantum entanglement, which can appear to violate the classical notion of causality. However, even in those cases, no information is actually transferred faster than the speed of light, as verified by rigorous experimental tests.