Eric Hessels

{{Short description|Canadian physicist}}

Eric A. Hessels is a Canadian physicist, currently a Canada Research Chair and Distinguished Research Professor at York University in Toronto, Ontario.{{Cite web |url=http://www.physics.yorku.ca/index.php/who-we-are/all-faculty/66-hessels |title=Eric Hessels |publisher=yorku.ca |access-date=February 24, 2017 |archive-url=https://web.archive.org/web/20170224212319/http://www.physics.yorku.ca/index.php/who-we-are/all-faculty/66-hessels |archive-date=February 24, 2017 |url-status=dead }}{{Cite web |url=http://vpap.info.yorku.ca/awards-and-recognition/distinguished-research-professors/ |title=Distinguished Research Professors |publisher=yorku.ca |access-date=February 24, 2017}}{{Cite web |url=http://www.chairs-chaires.gc.ca/chairholders-titulaires/profile-eng.aspx?profileId=1125 |title=Canada Research Chair |date=29 November 2012 |publisher=gc.ca |access-date=February 24, 2017}}{{Cite web |url=https://www.aps.org/programs/honors/prizes/prizerecipient.cfm?last_nm=Hessels&first_nm=Eric&year=2003 |title=Prize |publisher=aps.org |access-date=February 24, 2017}} In September 2019, Hessels et al. measured the Lamb shift for hydrogen to measure the radius of a proton and demonstrated that it is consistent with the value obtained for muonic hydrogen. This proved that the supposed discrepancy known as the proton radius puzzle did not exist.{{Cite web|url=https://www.quantamagazine.org/physicists-finally-nail-the-protons-size-and-hope-dies-20190911/|title=Physicists Finally Nail the Proton's Size, and Hope Dies|last=Wolchover|first=Natalie|website=Quanta Magazine|date=11 September 2019 |access-date=2019-09-18}}