full transcript

From the Ted Talk by Lina Marieth Hoyos: What is the coldest thing in the world?

Unscramble the Blue Letters


Under most circumstances, the egenry in a laser beam heats things up. But used in a very precise way, the beam’s momentum can satll moving atoms, cooling them down. That’s what happens in a device called a magneto-optical trap. Atoms are icejetnd into a vacuum chamber, and a magnetic field draws them towards the center. A laser beam aimed at the middle of the chamber is tnued to just the right fqeneucry that an atom moving towards it will absorb a photon of the laser beam and slow down. The slow down effect comes from the transfer of mtmenuom between the atom and the photon. A total of six beams, in a perpendicular arrangement, eusnre that atoms tarevilng in all directions will be ictrteenepd. At the center, where the bemas intersect, the atoms move sluggishly, as if trapped in a tihck liquid — an effect the researchers who invented it described as “optical molasses.” A magneto-optical trap like this can cool atoms down to just a few microkelvins — about -273 degrees Celsius.

Open Cloze


Under most circumstances, the ______ in a laser beam heats things up. But used in a very precise way, the beam’s momentum can _____ moving atoms, cooling them down. That’s what happens in a device called a magneto-optical trap. Atoms are ________ into a vacuum chamber, and a magnetic field draws them towards the center. A laser beam aimed at the middle of the chamber is _____ to just the right _________ that an atom moving towards it will absorb a photon of the laser beam and slow down. The slow down effect comes from the transfer of ________ between the atom and the photon. A total of six beams, in a perpendicular arrangement, ______ that atoms _________ in all directions will be ___________. At the center, where the _____ intersect, the atoms move sluggishly, as if trapped in a _____ liquid — an effect the researchers who invented it described as “optical molasses.” A magneto-optical trap like this can cool atoms down to just a few microkelvins — about -273 degrees Celsius.

Solution


  1. stall
  2. beams
  3. traveling
  4. injected
  5. intercepted
  6. frequency
  7. tuned
  8. momentum
  9. energy
  10. ensure
  11. thick

Original Text


Under most circumstances, the energy in a laser beam heats things up. But used in a very precise way, the beam’s momentum can stall moving atoms, cooling them down. That’s what happens in a device called a magneto-optical trap. Atoms are injected into a vacuum chamber, and a magnetic field draws them towards the center. A laser beam aimed at the middle of the chamber is tuned to just the right frequency that an atom moving towards it will absorb a photon of the laser beam and slow down. The slow down effect comes from the transfer of momentum between the atom and the photon. A total of six beams, in a perpendicular arrangement, ensure that atoms traveling in all directions will be intercepted. At the center, where the beams intersect, the atoms move sluggishly, as if trapped in a thick liquid — an effect the researchers who invented it described as “optical molasses.” A magneto-optical trap like this can cool atoms down to just a few microkelvins — about -273 degrees Celsius.

Frequently Occurring Word Combinations


ngrams of length 2

collocation frequency
laser beam 4
million times 3
times colder 3
outer space 2
incredibly sensitive 2
hot object 2
cool atoms 2
laser cooling 2
cold atoms 2

ngrams of length 3

collocation frequency
million times colder 3

Important Words


  1. absorb
  2. aimed
  3. arrangement
  4. atom
  5. atoms
  6. beam
  7. beams
  8. called
  9. celsius
  10. center
  11. chamber
  12. circumstances
  13. cool
  14. cooling
  15. degrees
  16. device
  17. directions
  18. draws
  19. effect
  20. energy
  21. ensure
  22. field
  23. frequency
  24. heats
  25. injected
  26. intercepted
  27. intersect
  28. invented
  29. laser
  30. liquid
  31. magnetic
  32. microkelvins
  33. middle
  34. molasses
  35. momentum
  36. move
  37. moving
  38. perpendicular
  39. photon
  40. precise
  41. researchers
  42. slow
  43. sluggishly
  44. stall
  45. thick
  46. total
  47. transfer
  48. trap
  49. trapped
  50. traveling
  51. tuned
  52. vacuum