Below are complete images, captions, and credits for the June 2017 OPN photo essay on the March for Science. [Key to numbers]

1. Former White House science advisor John Holdren (second from right), with OSA staff members John Taylor, Rebecca Anderson and Elizabeth Rogan, at a “Stand Up for Science” reception at the American Association for the Advancement of Science, 21 April 2017. [Image: Michael D. Duncan]

2. William Phillips, Nobel laureate and OSA Honorary Member, at wears a bright blue LED clip at a pre-March for Science rally at the American Association for the Advancement of Science, 22 April 2017. [Image: Michael D. Duncan]

3. Monica Ohnsorg of the University of Minnesota, USA, holds aloft a sign proclaiming that science matters, near the U.S. Capitol at the 22 April 2017 March for Science in Washington, D.C. [Image: Becky Rodriguez]

4. OSA President Eric Mazur, at the OSA headquarters building before the March for Science, 22 April 2017, Washington, D.C. [Image: Eric Mazur]

5. One of the Vienna, Austria, march participants, Laura Silverstein (left), a research assistant at TU Wien’s Institute for Discrete and Convex Geometry, holds a sign paying homage to the march’s special guest, a walking allosaurus at the Vienna Natural History Museum. [Image: Sarah Michaud]

6. OSA Member Michael Mielke at the March for Science, San Francisco, CA, USA, 22 April 2017. [Image: Michael Mielke]

7. The 22 April 2017 March for Science in Greenland attracted a small but spirited crowd. [Image: Mike MacFerrin]

8. Philip Bucksbaum, 2014 OSA President, wearing a blue LED pin at the pre-March for Science rally at the American Association for the Advancement of Science, 22 April 2017. [Image: Michael D. Duncan]

9. Aleks Klimas and Merritt Wherry work on signs for the March for Science before the event, at OSA headquarters, morning of 22 April 2017, Washington, D.C. [Image: Michael D. Duncan]

10. A group of marchers use what they describe as a “very geeky Star Trek reference” to make a statement for evidenced-based reasoning en route to the U.S. Capitol, March for Science, Washington, D.C., 22 April 2017. [Image: Margaret Wills]

11. Participants in the March for Science in Dublin, Ireland, 22 April 2017. [Image: Conor Courtney]

12. Participants in the March for Science in Stockholm, Sweden, 22 April 2017, send the message that “Science Works!.” [Image: Erik Cronberg]

13. The French Physics Society and the European Physical Society participate together in the Paris March for Science, 22 April 2017. [Image: Luc Berge/EPS]

14. OSA volunteers and staff work on signs at OSA headquarters before the March for Science in Washington, D.C., 22 April 2017. [Image: Mary Wheeler]

15. OSA staff and volunteers en route from Washington Monument to U.S. Capitol, March for Science, 22 April 2017. [Image: Mary Wheeler]

16. Preparing to march for science on the French island of Réunion, Indian Ocean, on 22 April 2017. [Image: Natacha Nikolic]

17. The March for Science in Chicago, Ill., USA, on 22 April 2017 reportedly attracted more than 40,000 participants. [Image: Rosalind Wills]

18. Marchers at the Stockholm, Sweden, March for Science on 22 April 2017 carry a sign reads, in translation, “science, not silence”. [Image: Erik Cronberg]

19. Signmaking at OSA headquarters before March for Science, 22 April 2017, Washington, D.C. [Image: OSA]

20. Merritt Wherry, Aleks Klimas, Amy Eskilson and Lottye Lockhart at the Washington, D.C., March for Science, 22 April 2017. [Image: Kaitlyn Beisel]

21. Marchers show off their signs in Melbourne, Australia (left), and Busan, South Korea (right) at the March for Science, 22 April 2017. [Images: left, Matt Nurse/March for Science Australia; right, David Blackman/Irfan Khan]

22. Left: Marchers at March for Science event overlooking the Bernex Haute-Savoie in Thonon les Bains, France, 22 April 2017. [Image: Le Dauphiné Libéré / Virginie BORLET] Right: A future scientist shows his spirit the March for Science in Minneapolis/St. Paul, USA, 22 April 2017. [Image: Lindsey Pockl]

23. OSA staff members Michael Brown, Elizabeth Nolan, Brandy Dillingham, and Laura Koulton at OSA headquarters before the March for Science, Washington, D.C., 22 April 2017. [Image: Mary Wheeler]

24. OSA board member Amy Eskilson, right, talks with OSA staff member Sean Bagshaw before the March for Science, Washington, D.C., 22 April 2017. [Image: Mary Wheeler]

25. OSA President Eric Mazur, Jim Kakalios of the University of Minnesota, and Rebecca Thompson of the American Physical Society at OSA/APS “Physics for Superheroes” teach-in, pre-March for Science rally near Washington Monument, Washington, D.C., 22 April 2017. [Image: Michael D. Duncan]

26. OSA staff members Stephanie Scuiletti and Rebecca Robinson outside OSA Teach-in at 2017 March for Science, Washington D.C., USA. [Image: Alessia Kirkland]

27. At the March for Science in Chicago, demonstrators carried a large dinosaur puppet. [Image: Tomas Petkus/Flickr]

28. March for Science, April 22, 2017, in Rochester, N.Y., USA. [Image: Susan Houde-Walter]

29. Marchers signs seen in Melbourne, Australia (left), and Gainsville, Florida, USA (right), at the March for Science, 22 April 2017. [Images: left, Flickr/John Englart; right, Flickr/Todd Van Hoosear]

30. Marcher Amy Wright, outside of the OSA/APS “Physics for Superheroes” teach-in tent, pre-March for Science rally near Washington Monument, Washington, D.C., 22 April 2017 [Image: Michael D. Duncan]

31. Stewart Wills, Arlene Smith (Avo Photonics), Alessia Kirkland, James Kakalios (Physics of Superheroes teach-in speaker, University of Minnesota), and Kari Smith, with daughters Annika and Sophia, at 2017 March for Science, Washington D.C., USA. [Image: Alessia Kirkland]

32. OSA members and Cornell University professors Chris Schaffer and Nozomi Nishimura snap a selfie at the March for Science, Washington, D.C., 22 April 2017. [Image: Chris Schaffer]

33. Waiting to march in the Dunedin, New Zealand, March for Science, 22 April 2017. [Image: March for Science Dunedin]

34. A marcher holds up a sign at a rally in Pittsburgh, Pa., USA. March for Science, 22 April 2017. [Image: Flickr/Mark Dixon]

35. March for Science Göttingen, Germany, 22 April 2017. [Image: University of Göttingen/Jan Vetter]

36. OSA volunteers hand out ViewMaster viewers for “Physics for Superheroes” teach-in, pre-March for Science rally near Washington Monument, Washington, D.C., 22 April 2017. [Image: Michael D. Duncan]

37. A sign seen at the March for Science in Portland, Oregon, USA, 22 April 2017. [Image: Joe Frazier/Flickr]