Time is One of the Great Mysteries
From VOA Learning English, this is Science in
the News. I'm June Simms.
Our program today is about a mystery as
old as time1. Bob Doughty and Sarah Long tell about the
mystery of time.
If you can read a clock, you can know the time
of day. But no one knows2
what time itself3 is. We cannot see it. We cannot touch it4. We cannot hear5 it. We know it only6 by
the way7 we mark its passing8.
For all our success in measuring9
the smallest parts10 of time, time remains11
one of the great mysteries of the universe.
One way to think about time is to imagine a
world without12 time.
There could be no movement13, because time and
movement cannot be separated.
A world14 without
time could exist only as long as there were no changes15. For time and change are linked16. We know that time has passed when something
changes.
In the real world -- the world with time --
changes never stop. Some changes happen17
only once in a while18, like an eclipse of the
moon. Others happen repeatedly19,
like the rising and setting of the sun20. Humans always have noted natural events that
repeat themselves. When people began
to count such events21, they began to measure22
time.
In early23 human history,
the only changes24 that seemed to repeat
themselves25 evenly26 were the movements of
objects in the sky. The most
easily seen result27 of these movements was the difference
between light and darkness28.
The sun rises in the eastern29
sky, producing light. It moves
across the sky30 and sinks31 in the
west, causing darkness. The appearance
and disappearance of the sun was even and unfailing32. The periods of light and darkness it created
were the first accepted periods of time.
We have named each period of light and darkness -- one day.
People saw33 the sun
rise higher34 in the sky during the summer35
than in winter36. They counted the days that passed from the
sun's highest position until37 it returned to that
position. They counted 365 days. We now know that is the time Earth38
takes to move once39 around the sun. We call this period of time a year.
Early humans also40 noted
changes in the moon. As it moved across
the night sky, they must have wondered41. Why did it look different42 every
night? Why did it disappear? Where did it go?
Even before43 they learned the answers to these questions, they developed a way44
to use the changing45 faces of the moon to
tell time.
The moon was "full46"
when its face was bright and round47. The early humans counted the number of times
the sun appeared between full moons.
They learned48 that this number always remained
the same49 -- about50 29 suns. Twenty-nine suns equaled one moon. We now know this period of time as one month.
Early humans hunted51 animals
and gathered52 wild plants53. They moved in groups or tribes from
place to place54 in search of food. Then, people learned to plant seeds55
and grow crops56. They learned to use animals to help them
work, and for food.
They found57 they no
longer needed58 to move from one place to another59
to survive.
As hunters, people did not need a way to
measure time. As farmers, however60, they had
to plant crops in time to harvest61
them before winter. They had to know
when the seasons62
would change. So, they developed
calendars.
VOCABULARY
1. as old as time = tão velho quanto o tempo
2. no one knows = ninguem sabe
3. itself = em si proprio
4. We cannot touch it = não conseguimos toca-lo
5. hear = ouvir
6. only = somente
7. way = forma
8. passing = passagem
9. success in measuring = sucesso em medir
10. the smallest parts = as menores partes
11. remains = permanece
12. without = sem
13. There could be no movement = não poderia haver nenhum movimento
14. world = mundo
15. as long as there were no changes = contanto que não houvesse nenhuma mudança
16. linked = ligados
17. happen = acontecer
18. once in a while = as vezes
19. repeatedly = repetidamente
20. rising and setting of the sun = nascer e por do sol
21. began to count such events = começou a contar tais eventos
22. measure = medir
23. early = primitivo
24. the only changes = as unicas mudanças
25. seemed to repeat themselves = pareciam repetir a si mesmos(as)
26. evenly = uniformemente
27. The most easily seen result = o resultado mais facilmente visto
28. darkness = escuridão
29. eastern = oriental
30. moves across the sky = move-se através do céu
31. sinks = mergulhar
32. even and unfailing = uniforme e infalível
33. saw = viam
34. higher = mais alto
35. during the summer = durante o verão
36. winter = inverno
37. until = até
38. Earth = Planeta Terra
39. once = uma vez
40. also = também
41. they must have wondered = eles devem ter se perguntado
42. look different = parece diferente
43. Even before = mesmo antes
44. developed a way = desenvolveram um maneira
45. changing = variavel
46. full = cheio(a)
47. bright and round = brilhante e arredondada
48. learned = aprenderam, descobriram
49. remained the same = permanecia o mesmo
50. about = aproximadamente
51. hunted = caçavam
52. gathered = reuniam, juntavam
53. wild plants= plantas silvestres
54. from place to place = de lugar a lugar
55. seeds = sementes
56. grow crops = cultivavam plantações
57. found = descobriram
58. no longer needed = não precisavam mais
59. from one place to another = de um lugar para outro
60. However = contudo
61. harvest = colher
62. seasons = temporadas, estações
