Protection of the Electromagnetic Spectrum

The electromagnetic spectrum is a finite and important societal and scientific resource. The American Physical Society calls for actions to increase and update protections placed on the electromagnetic spectrum, to balance the needs of science, national security, industry and the public interest in the presence of an evolving technology landscape.

Such actions include

• Implementing policies to govern the spectrum that recognize that specific frequencies in the spectrum correspond to atomic or molecular transitions necessary for science and medicine, and
  protect these frequencies from other use, such as commercial telecommunications.
• Improving efficiency within existing commercial and government allocated bands through policies promoting temporal and spatial band sharing.
• Promoting designs to minimize terrestrial light pollution while respecting safety concerns.
• Developing and requiring satellite design standards to minimize light reflected towards the Earth and electromagnetic interference.
• Recognizing that electromagnetic spectrum conflicts are increasingly international in nature and engaging with and developing further both international bodies and agreements to address these conflicts.

Context

The electromagnetic spectrum includes all forms of light, from the visible light seen by human eyes to higher frequencies (ultraviolet light, x-rays, and gamma rays) and lower frequencies (infrared light, microwaves, and radio waves). Scientists often rely on exquisitely sensitive instruments that use this spectrum to inform our understanding of the Universe, the Earth’s atmosphere, the human body, the microscopic world, and a great many other wonders. However, in many cases the efficacy of these instruments is under threat.

The rapid expansion of wireless communications, including satellite-based networks, endangers the balance among the various societal uses of light. For instance, the current expansion of 5G bands poses a threat to satellite water vapor column measurements at 23.8 GHz, a band critical to weather forecasting. Radio and microwave astronomical observations are similarly harmed by interference from wireless networks, and restrictions on out-of-band transmission by these networks can be insufficient given the sensitivity of these astronomical telescopes. On a terrestrial level, wireless communications can interfere with technologies ranging from aircraft altimeters to medical devices.

Visible light pollution presents a similar challenge. Night-time light pollution arising from the growth of human-made lighting has been found to have detrimental effects on plants and wildlife. It now also hides the Milky Way from almost a third of humanity. Similarly, satellites that are not designed to minimize their Earth-ward reflection can outshine the brightest stars. The number of satellites is expected to grow to over a hundred thousand in coming years, making them an increasing threat to astronomy and night-sky viewing.

These challenges are not insurmountable. Organizations and institutional frameworks to address some of these problems already exist, including the FCC, NTIA and NSF, which collectively manage the radio and microwave spectrum in the US, and UN institutions including the ITU and UNOOSA, which coordinate the use of spectrum internationally. However, new laws, agreements and institutions will have to be developed, especially with regards to space and shorter wavelengths. In all cases thoughtful oversight in the presence of an ever-changing landscape will be required to protect the public good provided by the electromagnetic spectrum.

The review process for any statement may be started at any time if deemed necessary by the Panel on Public Affairs, and at least once every five years.