Light certainly travels from the sun to earth which is much farther than one wavelength. In fact, light will not stop propagating until something stops it.

Light travels for billions of light-years, where one light-year is 9.467E12 km.

And the wavelength of light is measured in nanometers, say 800 nm.

So yeah, EM waves can travel a lot further than their wavelength.

2.4 GHz Wi-Fi uses ~12 cm wavelength. It won't be practical to have the connexion in a radius of 12 cm around the router antenna.

The attenuation is what weakens the energy of the wave and in free space the attenuation is low.

Not only the electromagnetic waves (e.g. light) but also the mechanical waves (e.g. sound) usually travel far beyond their wavelength.

In theory a wave of any wavelength will travel for infinity.

In practice the distance traveled by the wave in dependent on its energy.

The electromagnetic force has an infinite range since the rest mass of the particle that conveys the force (a photon) is zero. By "wave" I am assuming you mean an electromagnetic wave such as light or RF, however, gravity waves also have an infinite range (the strong and weak nuclear forces have range limits, though). In practice, the divergence of a EM signal (e.g. the spreading of an RF signal from an antenna) gives rise to a power density that decays as 1/range2. This never becomes zero although will eventually grow too weak to be of any practical use. Light from distant galaxies and even the microwave cosmic background radiation are examples of EM energy having travelled to us from across the universe. Yes, waves can travel much further than their wavelengths.

An EM wave can travel to infinity. However, this wave will attenuate while travelling and beyond a certain distance it will become below your reciever's sensitivity, and hence, it won't be captured by it. The communication range will depend on the transmitted signal's power and frequency, and on both antennas' gain and the recievers sensitivity.

Perhaps the author of the question that has sparked these replies, would explain what triggered his question. It would be very helpful as all the replies are so obvious. Perhaps his question is not quite what he had in mind for his inquiry. F L Tabrah MD Honolulu.

Thanks for all the experts who answered my question. It is good to know that waves can travel as far it can. Nevertheless, the energy level would not be the same as distance increases more than its wavelength. This would be dependent also in different factors as what you answered, such as frequency, power, voltage, current, hindrances, and what not.

@ Roland Macana

While the energy density if some EM wave decreases with the distance from the emitter by 1/R², this is independent of the wavelength of this wave!! Whether the wavelength is measured in km or in mm, the same rule applies.

This decrease of energy density (energy per unit earea) has to do with simple geometrical rules: the surface of some sphere (denter at the EM wave emitter) increases with R². As the total energy does not decrease unless there is absorption, the total energy is spread over an area increasing with R², thus the energy density decreases with 1/R². Still nothing to do with the wavelength.

I understand all the answers but can't understand the question clearly regarding the comparison.

Kindly see the link below to get some important information.

https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Wavelength&grqid=EUm71PNx&hl=en-IN

With thanks