The maximum wavelength that can be measured is not limited by the value of the speed of light, which is approximately 299,792,458 meters per second. In theory, there is no upper limit to the wavelength that can be measured.
However, practical limitations do exist in terms of the technology and instruments used for measuring light. Different measurement techniques and devices have their own limitations, such as the sensitivity of detectors, the accuracy of equipment, and the available frequency ranges.
For example, in the context of visible light, the longest wavelength that humans can perceive is typically around 700 nanometers (0.7 micrometers). This corresponds to the color red in the visible spectrum. However, there are light waves with longer wavelengths in the infrared region that can be measured using appropriate detectors and instruments designed for those ranges.
In summary, while the speed of light is a fundamental constant that sets an upper limit on the speed at which information can travel, there is no theoretical limit to the maximum wavelength that can be measured. However, the practical limitations of measurement techniques and instruments may impose constraints on the range of detectable wavelengths.