Sleep

Difficulty falling asleep and interrupted sleep is often associated with pain and anxiety and other stresses.  Disabled people fear, probably correctly, that not getting eight hours only makes their underlying health issues worse.  A related condition, obstructive sleep apnea, is a serious health issue on its own.

Today we think that 8-hours of sleep is the normal pattern.  There are sleep studies that measure our sleep--light sleep, deep sleep, and REM (rapid eye movement) sleep as well as oxygen saturation.  

However, historically, 8-hours of sleep was not necessarily the usual experience.

The episode on light in the PBS series, How We Got to Now:

http://video.pbs.org/program/how-we-got-now/ described that a common sleep pattern up until the late 17^th century was four hours of sleep, followed by a waking period of one or two hours and then another four hours of sleep.

This online article goes into more details: http://www.bbc.com/news/magazine-16964783

See also, At Day's Close: Night In Times Past by A. Roger Ekirch, pp. 300-312, 405 ff., NY (2005).

Below is the answer to the puzzle posted on October 30, 2015.

1 B

2 G

3 A

4 S

5 A

6 A

7 A

8 P

9 B

10 I

11 L

12 L

13 A

A

C

P

14 B

A

B

B

O

15 A

F

E

E

16 F

E

D

E

17 R

A

L

D

I

S

18 T

R

I

C

T

19 T

A

C

T

I

C

20 A

A

T

C

21 L

H

E

22 S

C

O

23 A

24 H

A

A

25 R

L

E

M

26 S

27 E

28 I

29 A

L

M

30 S

31 D

R

E

32 A

D

M

33 I

N

I

S

T

34 R

A

T

I

35 V

36 E

37 S

N

U

M

38 E

O

E

39 G

E

V

40 A

41 A

P

P

42 E

43 A

L

S

C

44 O

45 U

N

C

I

L

46 E

I

G

47 S

A

I

L

48 O

L

E

49 F

50 B

51 L

I

K

E

52 S

53 P

L

T

54 S

55 A

A

A

56 O

I

C

57 H

58 E

R

R

59 A

60 N

61 D

62 R

E

C

63 O

N

S

I

D

64 E

R

A

T

I

O

N

65 A

D

E

E

66 T

O

T

E

S

67 A

D

N

A

68 D

A

Y

S

69 S

N

V

S

70 S

E

E

S