With the aid of recently emerged metamaterials offering extraordinary properties unattainable in nature, transformation optics (TO) and transformation acoustics (TA) utilize coordinate transformations to arbitrarily control the propagation paths of optical and acoustic waves, which is of fundamental significance in wave physics and has great application potential in diverse scenarios. The cover shows the distorted space made by TO/TA and metamaterials can curve light and sound into desired trajectories and give rise to versatile unconventional effects such as producing optical/acoustic illusions or mimicking celestial phenomena.

With the aid of recently emerged metamaterials offering extraordinary properties unattainable in nature, transformation optics (TO) and transformation acoustics (TA) utilize coordinate transformations to arbitrarily control the propagation paths of optical and acoustic waves, which is of fundamental significance in wave physics and has great application potential in diverse scenarios. The cover shows the distorted space made by TO/TA and metamaterials can curve light and sound into desired trajectories and give rise to versatile unconventional effects such as producing optical/acoustic illusions or mimicking celestial phenomena.