Quantum theory pioneer Niels Crossword Clue

We have the 4-letter answer for Quantum theory pioneer Niels crossword clue, last seen in the Universal Crossword May 18, 2026 puzzle. Let us help you solve the crossword clue that has you stumped so you can finish the puzzle.

Quantum theory pioneer Niels Crossword Answer

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Helpful Hints

(noun)
1. Danish physicist who studied atomic structure and radiations; the Bohr theory of the atom accounted for the spectrum of hydrogen (1885-1962)

Hint 2: Clue Definitions

PIONEER (verb)
1. take the lead or initiative in; participate in the development of
2. open up an area or prepare a way
PIONEER (noun)
1. someone who helps to open up a new line of research or technology or art
2. one of the first colonists or settlers in a new territory
THEORY (noun)
1. a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena
2. a belief that can guide behavior

More Universal Crossword (5/18/2026) Answers

Across

1. Loose-knit fabric

9. Scholar in a synagogue

14. Highest of highs

15. Weapon for an athlete who's en garde

16. On guard

17. Tie to a dock

18. Gradually withdraw

19. Bygone Russian rulers

20. *Early-stage startup funder

23. Conjunction that kids sometimes snicker at

24. "Talk" in all caps

25. What a spider spins

28. Coordinates, as devices

30. In an unsettling way

32. Score 100% on

34. *Anonymous author

37. Bummer

39. Confucian philosophy

40. 'Yikes!'

41. *Saja Boy's rival in a blockbuster 2025 movie

46. Guy

47. 'Same!'

48. Make snarky remarks

50. French denial

51. No __ no glory

54. Biz bigwig

55. Meditation or mindfulness, e.g. ... or what the starred clues' answers could engage in?

61. Dominant theme

63. Deserve

64. Thrill ride cry

65. Choose via ballot

66. Car window shading

67. Slick

68. Sub sandwiches

69. Roughly

70. Courts

All Answers

Down

1. Common first word

2. Biz major's subject

3. Pollution that worsens air quality

4. "I ___ declare ..."

5. Cast a spell on

6. Unlocked

7. Weighty

8. "Not My Fault" singer Rapp

9. Snake named for its warning noise

10. In addition

11. "Hang on a sec"

12. "I'm so cold!"

13. Word often wrongly apostrophized

21. Respiratory organ

22. Whole lot

26. Justice Kagan

27. "Don Juan" poet Lord ___

28. Kraken, for example

29. Lengthy presidential speech: Abbr.

31. Where Simone Biles won four golds

32. Extra ingredient

33. System of beliefs

35. ___ Francisco 49ers

36. Tater bites

38. Obtained

42. Request on a birthday party invitation

43. Daylight saving amount

44. Disney film with the song "We Don't Talk About Bruno"

45. Cambodian currency, and an anagram of "lire"

49. Native American gathering

52. Connect with

53. One of 1,665 in the Eiffel Tower

56. ___ de gallo

57. Large tea vessels

58. Home to the Browns and Reds

59. Move to a new house, for short

60. Janitors' janglers

61. *shrug*

62. World Cup cheer

All Answers