Skip to main content

Reset your password

Please enter the e-mail address you used to register to reset your password

Note: The verification e-mail to change your password should arrive immediately. However, in some cases it takes longer. Don't forget to check your spam folder.

If you haven't received the e-mail in 24 hours, please contact customerservices@ioppublishing.org

Registration complete

Thank you for registering with Physics World
If you'd like to change your details at any time, please visit My account

Close
Constants and units

Constants and units

Physicists measure the fine structure constant directly for the first time

09 Dec 2022
Angle of rotation: A light source (left) sends a beam of light through a topological insulator with an intrinsic magnetic field (centre), changing the direction of polarization by an angle that is given by the fine structure constant. (Courtesy: Tatiana Lysenko / TU Wien)
The value of the fine structure constant – perhaps the most important constant in nature as it dic

You’ve reached the limit of what you can view on Physics World without registering

If you already have an account on Physics World, then please sign in to continue reading

If you do not yet have an account, please register so you can

  • Access more than 20 years of online content
  • Choose which e-mail newsletters you would like to receive

Tim Wogan is a science writer based in the US
Read previous

Spaghettified star ripped apart by a black hole lights up with a relativistic jet
Read next

Electrochemical cell could detect airborne SARS-CoV-2

Discover more from Physics World

Related jobs

Related events

Copyright © 2024 by IOP Publishing Ltd and individual contributors