Can a cell phone receive a signal in a vacuum?

OK! The transmission of the signal does not need a medium, of course, it also needs a transfer station or a signal tower, and the mobile phone signal is a high-frequency electromagnetic wave, which can also be transmitted in a vacuum, and of course the signal can be received. For example, astronauts have to cross a vacuum zone to connect with Earth.

In other words, this is a bloody question that has not appeared for many years, may I ask if your Excellency is from the teacher?

Electromagnetic waves (also known as electromagnetic radiation) are electric and magnetic fields that oscillate in phase and are perpendicular to each other in the form of waves in space, and their propagation direction is perpendicular to the plane composed of electric and magnetic fields, effectively transmitting energy and momentum. Electromagnetic radiation can be classified according to frequency, from low frequency to high frequency, including radio waves, microwaves, infrared, visible light, ultraviolet light, X-rays, and gamma rays. The electromagnetic radiation that can be received by the human eye, with wavelengths between about 380 and 780 nanometers, is called visible light.

Any object whose temperature is greater than absolute zero can emit electromagnetic radiation.

The propagation of electromagnetic waves does not require a medium, and electromagnetic waves of the same frequency have different speeds in different media. When electromagnetic waves of different frequencies propagate in the same medium, the higher the frequency, the greater the refractive index, and the smaller the velocity. And electromagnetic waves can only propagate in a straight line in the same uniform medium, if the same medium is inhomogeneous, the refractive index of electromagnetic waves in it is different, and in such a medium it propagates along the curve.

When passing through different media, refraction, reflection, diffraction, scattering, absorption, and so on occur. The propagation of electromagnetic waves includes ground waves that propagate along the ground, air waves that propagate from the air, and sky waves. The longer the wavelength, the less attenuation, and the longer the wavelength of the electromagnetic wave, the easier it is to continue to propagate around obstacles.

Both mechanical and electromagnetic waves can be refracted and reflected, diffracted and interfered with because all waves are wavering. Diffraction is particle-based; Refraction, reflection, and interference are waves.

The above shows that mobile phones can receive signals in a vacuum, and the dialogue between astronauts in space during spacewalks, and the communication between satellites and the ground in space are all based on this principle.

Mobile phone signals are high-frequency electromagnetic waves.

It can also be transmitted in a vacuum, and of course the signal can be received. Here's an example.

Astronauts have to cross a vacuum zone to connect with Earth.

It shows that the propagation of electromagnetic waves does not require a medium!

It shows that the radio waves have nothing to do with air. Air affects the speed at which radio waves travel.

Astronauts are instructed by the Earth to be the same kind of thing.

OK. Our mobile phone signals are transmitted in the form of electromagnetic waves. Whereas, the propagation of electromagnetic waves does not require a medium. You can think about how our satellites communicate.

Yes, it means that the propagation of electromagnetic waves does not require a constant temperature of the medium, how to calculate the reversible expansion work.