Zodiacal Light 2022

In 2022, the best dates and times for observing the zodiacal light are listed in the calendar below. The sky must be very clear with little or no light pollution. The specific times listed are for Dodgeville, Wisconsin (42° 58′ N, 90° 08′ W).

Here’s a nicely-formatted printable PDF file of the zodiacal light calendar:

January 2022
SUN MON TUE WED THU FRI SAT
            1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19
Zodiacal Light 6:36 – 6:38 p.m. West
20
Zodiacal Light 6:37 – 7:37 p.m. West
21
Zodiacal Light 6:38 – 7:38 p.m. West
22
Zodiacal Light 6:39 – 7:39 p.m. West
23
Zodiacal Light 6:40 – 7:40 p.m. West
24
Zodiacal Light 6:41 – 7:41 p.m. West
25
Zodiacal Light 6:42 – 7:42 p.m. West
26
Zodiacal Light 6:43 – 7:43 p.m. West
27
Zodiacal Light 6:44 – 7:44 p.m. West
28
Zodiacal Light 6:46 – 7:46 p.m. West
29
Zodiacal Light 6:47 – 7:47 p.m. West
30
Zodiacal Light 6:48 – 7:48 p.m. West
31
Zodiacal Light 6:49 – 7:49 p.m. West
         

February 2022
SUN MON TUE WED THU FRI SAT
    1
Zodiacal Light 6:50 – 7:50 p.m. West
2
Zodiacal Light 7:04 – 7:51 p.m. West
3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18
Zodiacal Light 7:10 – 7:51 p.m. West
19
Zodiacal Light 7:12 – 8:12 p.m. West
20
Zodiacal Light 7:13 – 8:13 p.m. West
21
Zodiacal Light 7:14 – 8:14 p.m. West
22
Zodiacal Light 7:15 – 8:15 p.m. West
23
Zodiacal Light 7:16 – 8:16 p.m. West
24
Zodiacal Light 7:18 – 8:18 p.m. West
25
Zodiacal Light 7:19 – 8:19 p.m. West
26
Zodiacal Light 7:20 – 8:20 p.m. West
27
Zodiacal Light 7:21 – 8:21 p.m. West
28
Zodiacal Light 7:22 – 8:22 p.m. West
         

March 2022
SUN MON TUE WED THU FRI SAT
    1
Zodiacal Light 7:24 – 8:24 p.m. West
2
Zodiacal Light 7:25 – 8:25 p.m. West
3
Zodiacal Light 7:26 – 8:26 p.m. West
4
Zodiacal Light 8:14 – 8:27 p.m. West
5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
Zodiacal Light 8:47 – 8:59 p.m. West
20
Zodiacal Light 8:48 – 9:48 p.m. West
21
Zodiacal Light 8:49 – 9:49 p.m. West
22
Zodiacal Light 8:51 – 9:51 p.m. West
23
Zodiacal Light 8:52 – 9:52 p.m. West
24
Zodiacal Light 8:53 – 9:53 p.m. West
25
Zodiacal Light 8:55 – 9:55 p.m. West
26
Zodiacal Light 8:56 – 9:56 p.m. West
27
Zodiacal Light 8:57 – 9:57 p.m. West
28
Zodiacal Light 8:59 – 9:59 p.m. West
29
Zodiacal Light 9:00 – 10:00 p.m. West
30
Zodiacal Light 9:02 – 10:02 p.m. West
31
Zodiacal Light 9:03 – 10:03 p.m. West
   

April 2022
SUN MON TUE WED THU FRI SAT
          1
Zodiacal Light 9:05 – 10:05 p.m. West
2
Zodiacal Light 9:11 – 10:06 p.m. West
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

May 2022
SUN MON TUE WED THU FRI SAT
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31        

June 2022
SUN MON TUE WED THU FRI SAT
      1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30    

July 2022
SUN MON TUE WED THU FRI SAT
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31            

August 2022
SUN MON TUE WED THU FRI SAT
  1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25
Zodiacal Light 3:33 – 4:11 a.m. East
26
Zodiacal Light 3:35 – 4:35 a.m. East
27
Zodiacal Light 3:36 – 4:36 a.m. East
28
Zodiacal Light 3:38 – 4:38 a.m. East
29
Zodiacal Light 3:39 – 4:39 a.m. East
30
Zodiacal Light 3:41 – 4:41 a.m. East
31
Zodiacal Light 3:42 – 4:42 a.m. East
     

September 2022
SUN MON TUE WED THU FRI SAT
        1
Zodiacal Light 3:44 – 4:44 a.m. East
2
Zodiacal Light 3:45 – 4:45 a.m. East
3
Zodiacal Light 3:47 – 4:47 a.m. East
4
Zodiacal Light 3:48 – 4:48 a.m. East
5
Zodiacal Light 3:49 – 4:49 a.m. East
6
Zodiacal Light 3:51 – 4:51 a.m. East
7
Zodiacal Light 3:52 – 4:52 a.m. East
8
Zodiacal Light 3:57 – 4:54 a.m. East
9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
Zodiacal Light 4:14 – 5:14 a.m. East
25
Zodiacal Light 4:16 – 5:16 a.m. East
26
Zodiacal Light 4:17 – 5:17 a.m. East
27
Zodiacal Light 4:18 – 5:18 a.m. East
28
Zodiacal Light 4:19 – 5:19 a.m. East
29
Zodiacal Light 4:21 – 5:21 a.m. East
30
Zodiacal Light 4:22 – 5:22 a.m. East
 

October 2022
SUN MON TUE WED THU FRI SAT
            1
Zodiacal Light 4:23 – 5:23 a.m. East
2
Zodiacal Light 4:24 – 5:24 a.m. East
3
Zodiacal Light 4:25 – 5:25 a.m. East
4
Zodiacal Light 4:27 – 5:27 a.m. East
5
Zodiacal Light 4:28 – 5:28 a.m. East
6
Zodiacal Light 4:29 – 5:29 a.m. East
7
Zodiacal Light 4:30 – 5:30 a.m. East
8
Zodiacal Light 5:28 – 5:31 a.m. East
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23
Zodiacal Light 4:48 – 5:12 a.m. East
24
Zodiacal Light 4:50 – 5:50 a.m. East
25
Zodiacal Light 4:51 – 5:51 a.m. East
26
Zodiacal Light 4:52 – 5:52 a.m. East
27
Zodiacal Light 4:53 – 5:53 a.m. East
28
Zodiacal Light 4:54 – 5:54 a.m. East
29
Zodiacal Light 4:55 – 5:55 a.m. East
30
Zodiacal Light 4:56 – 5:56 a.m. East
31
Zodiacal Light 4:57 – 5:57 a.m. East
         

November 2022
SUN MON TUE WED THU FRI SAT
    1
Zodiacal Light 4:59 – 5:59 a.m. East
2
Zodiacal Light 5:00 – 6:00 a.m. East
3
Zodiacal Light 5:01 – 6:01 a.m. East
4
Zodiacal Light 5:02 – 6:02 a.m. East
5
Zodiacal Light 5:03 – 6:03 a.m. East
6
Zodiacal Light 4:35 – 5:04 a.m. East
7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22
Zodiacal Light 4:21 – 5:21 a.m. East
23
Zodiacal Light 4:22 – 5:22 a.m. East
24
Zodiacal Light 4:23 – 5:23 a.m. East
25
Zodiacal Light 4:24 – 5:24 a.m. East
26
Zodiacal Light 4:25 – 5:25 a.m. East
27
Zodiacal Light 4:26 – 5:26 a.m. East
28
Zodiacal Light 4:27 – 5:27 a.m. East
29
Zodiacal Light 4:28 – 5:28 a.m. East
30
Zodiacal Light 4:29 – 5:29 a.m. East
     

December 2022
SUN MON TUE WED THU FRI SAT
        1
Zodiacal Light 4:30 – 5:30 a.m. East
2
Zodiacal Light 4:31 – 5:31 a.m. East
3
Zodiacal Light 4:32 – 5:32 a.m. East
4
Zodiacal Light 4:33 – 5:33 a.m. East
5
Zodiacal Light 4:41 – 5:34 a.m. East
6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31

The best nights to observe the zodiacal light at mid-northern latitudes occur when the ecliptic plane intersects the horizon at an angle of 60° or steeper. The dates above were chosen on that basis, with the Sun at least 18° below the horizon and the Moon below the horizon being used to calculate the times. An interval of time of one hour either before morning twilight or after evening twilight was chosen arbitrarily because it is the “best one hour” for observing the zodiacal light. The zodiacal light cone will be brightest and will reach highest above the horizon when the Sun is 18° below the horizon (astronomical twilight), but no less.

If you are interested in calculating the angle the ecliptic makes with your horizon for any date and time, you can use the following formula:

\cos I = \cos \varepsilon \sin \phi-\sin \varepsilon \cos \phi \sin \theta

where I is the angle between the ecliptic and the horizon, ε is  the obliquity of the ecliptic, φ is the latitude of the observer, and θ is the local sidereal time (the right ascension of objects on the observer's meridian at the time of observation).

Here’s a SAS program I wrote to do these calculations:

References
Meeus, J. Astronomical Algorithms. 2nd ed., Willmann-Bell, 1998, p. 99.

Scrooge

Alastair Sim in Scrooge (1951)

The iconic novella by the great English writer Charles Dickens (1812-1870), A Christmas Carol. In Prose. Being a Ghost Story of Christmas, was first published in 1843. There have been many film adaptations since, the first being in 1901. But I can’t imagine a better one than the 1951 British black & white film Scrooge. Even if you don’t celebrate Christmas, you should watch this movie.

Even after repeated viewings, I still can’t get through it without becoming teary-eyed at various points in the movie. The film score for Scrooge was written by English composer Richard Addinsell (1904-1977), and it is unquestionably a vital part of what makes this movie so good, along with the performances of all the actors—especially Alastair Sim (1900-1976) as Ebenezer Scrooge.

Experiencing this movie, you can’t help but be reminded of the following:

  • Bittersweet and very sad episodes in your own life (the older we get, the more of these we have to look back upon), especially now from a perspective of hindsight. What would you have done differently, knowing what you know now?
  • Much of what you thought was important has been a distraction from what really is important in “a life well lived”.
  • It is never too late to change the focus of your attentions and endeavors.

Timeless themes, to be sure.

Meteor Shower Calendar 2022

Here’s our meteor shower calendar for 2022.  It is sourced from the IMO’s Working List of Visual Meteor Showers (https://www.imo.net/files/meteor-shower/cal2022.pdf, Table 5, p. 25).

Each meteor shower is identified using its three-character IAU meteor shower code.  Codes are bold on the date of maximum, and one day either side of maximum.

Some additional events have been added to the calendar from Sources of Possible or Additional Activity, Table 6a, p. 27). I used the following abbreviations for the Table 6a events that do not have a standard three-character meteor code:

GY2 = 2006 GY2
209 = 209P/LINEAR
CK1 = C/1852 K1

Here’s a printable PDF file of the meteor shower calendar shown below:

Happy meteor watching!

January 2022
SUN MON TUE WED THU FRI SAT
            1
DLM QUA
2
DLM QUA
3
DLM QUA
4
DLM QUA
5
DLM QUA
6
DLM QUA
7
DLM QUA
8
DLM QUA
9
DLM QUA KCA
10
DLM QUA GUM KCA
11
DLM QUA GUM KCA
12
DLM QUA GUM
13
DLM GUM
14
DLM GUM
15
DLM GUM
16
DLM GUM
17
DLM GUM
18
DLM GUM
19
DLM GUM
20
DLM GUM
21
DLM GUM
22
DLM GUM
23
DLM
24
DLM
25
DLM
26
DLM
27
DLM
28
DLM
29
DLM
30
DLM
31
DLM ACE
         
February 2022
SUN MON TUE WED THU FRI SAT
    1
DLM ACE
2
DLM ACE
3
DLM ACE
4
DLM ACE
5
ACE
6
ACE
7
ACE
8
ACE
9
ACE
10
ACE
11
ACE
12
ACE
13
ACE
14
ACE
15
ACE
16
ACE
17
ACE
18
ACE
19
ACE
20
ACE
21 22 23 24 25
GNO
26
GNO
27
GNO
28
GNO
         
March 2022
SUN MON TUE WED THU FRI SAT
    1
GNO
2
GNO
3
GNO
4
GNO
5
GNO
6
GNO
7
GNO
8
GNO
9
GNO
10
GNO
11
GNO
12
GNO
13
GNO
14
GNO
15
GNO
16
GNO
17
GNO
18
GNO
19
GNO
20
GNO
21
GNO
22
GNO
23
GNO
24
GNO
25
GNO
26
GNO
27
GNO
28
GNO
29 30 31    
April 2022
SUN MON TUE WED THU FRI SAT
          1 2
3 4 5 6 7 8 9
10 11 12 13 14
LYR
15
PPU LYR
16
PPU LYR
17
PPU LYR
18
PPU LYR
19
ETA PPU LYR
20
ETA PPU LYR
21
ETA PPU LYR
22
ETA PPU LYR
23
ETA PPU LYR
24
ETA PPU LYR
25
ETA PPU LYR
26
ETA PPU LYR
27
ETA PPU LYR
28
ETA PPU LYR
29
ETA LYR
30
ETA LYR
May 2022
SUN MON TUE WED THU FRI SAT
1
ETA
2
ETA
3
ELY ETA
4
ELY ETA
5
ELY ETA
6
ELY ETA
7
ELY ETA
8
ELY ETA
9
ELY ETA
10
ELY ETA
11
ELY ETA
12
ELY ETA
13
ELY ETA
14
GY2 ARI ELY ETA
15
GY2 ARI ETA
16
GY2 ARI ETA
17
ARI ETA
18
ARI ETA
19
ARI ETA
20
ARI ETA
21
ARI ETA
22
ARI ETA
23
ARI ETA
24
209 ARI ETA
25
209 ARI ETA
26
209 ARI ETA
27
ARI ETA
28
ARI ETA
29
ARI
30
TAH ARI
31
TAH ARI
       
June 2022
SUN MON TUE WED THU FRI SAT
      1
TAH ARI
2
ARI
3
ARI
4
ARI
5
ARI
6
ARI
7
ARI
8
ARI
9
ARI
10
ARI
11
ARI
12
ARI
13
ARI
14
ARI
15
ARI
16
ARI
17
ARI
18
ARI
19
ARI
20
ARI
21
ARI
22
JBO ARI
23
JBO ARI
24
JBO ARI
25
JBO
26
JBO
27
JBO
28
JBO
29
JBO
30
JBO
   
July 2022
SUN MON TUE WED THU FRI SAT
          1
JBO
2
JBO
3
CAP
4
CAP JPE
5
CAP JPE
6
CAP JPE
7
CAP JPE
8
CAP JPE
9
CAP JPE
10
CAP JPE
11
CAP JPE
12
CAP SDA JPE
13
CAP SDA JPE
14
CAP SDA JPE
15
CAP SDA PAU
16
CAP SDA PAU
17
PER CAP SDA PAU
18
PER CAP SDA PAU
19
PER CAP SDA PAU
20
PER CAP SDA PAU
21
PER CAP SDA PAU
22
PER CAP SDA PAU
23
PER CAP SDA PAU
24
PER CAP SDA PAU
25
PER CAP SDA GDR PAU
26
PER CAP SDA GDR PAU
27
PER CAP SDA GDR PAU
28
PER CAP SDA GDR PAU
29
PER CAP SDA GDR
30
PER CAP SDA GDR PAU
31
PER CAP SDA GDR PAU
           
August 2022
SUN MON TUE WED THU FRI SAT
  1
PER CAP SDA PAU
2
PER CAP SDA PAU
3
KCG PER CAP SDA PAU
4
KCG PER CAP SDA PAU
5
KCG PER CAP SDA PAU
6
KCG PER CAP SDA PAU
7
KCG PER CAP SDA PAU
8
KCG PER CAP SDA PAU
9
KCG PER CAP SDA PAU
10
KCG PER CAP SDA PAU
11
KCG PER CK1 CAP SDA
12
KCG PER CK1 CAP SDA
13
KCG PER CK1 CAP SDA
14
KCG PER CAP SDA
15
KCG PER CAP SDA
16
KCG PER SDA
17
KCG PER SDA
18
KCG PER SDA
19
KCG PER SDA
20
KCG PER SDA
21
KCG PER SDA
22
KCG PER SDA
23
KCG PER SDA
24
KCG PER
25
KCG
26 27
28
AUR
29
AUR
30
AUR
31
AUR
     
September 2022
SUN MON TUE WED THU FRI SAT
        1
AUR
2
AUR
3
AUR
4
AUR
5
SPE AUR
6
SPE
7
SPE
8
SPE
9
DSX SPE
10
STA DSX SPE
11
STA DSX SPE
12
STA DSX SPE
13
STA DSX SPE
14
STA DSX SPE
15
STA DSX SPE
16
STA DSX SPE
17
STA DSX SPE
18
STA DSX SPE
19
STA DSX SPE
20
STA DSX SPE
21
STA DSX SPE
22
STA DSX
23
STA DSX
24
STA DSX
25
STA DSX
26
STA DSX
27
STA DSX
28
STA DSX
29
STA DSX
30
STA DSX
 
October 2022
SUN MON TUE WED THU FRI SAT
            1
STA DSX
2
ORI STA DSX
3
ORI STA DSX
4
ORI STA DSX
5
ORI STA OCT DSX
6
ORI STA DRA OCT DSX
7
ORI STA DRA OCT DSX
8
ORI STA DRA DSX
9
ORI STA DRA DSX
10
ORI DAU STA DRA
11
ORI DAU STA
12
ORI DAU STA
13
ORI DAU STA
14
ORI EGE DAU STA
15
ORI EGE DAU STA
16
ORI EGE DAU STA
17
ORI EGE DAU STA
18
ORI EGE DAU STA
19
LMI ORI EGE STA
20
NTA LMI ORI EGE STA
21
NTA LMI ORI EGE STA
22
NTA LMI ORI EGE STA
23
NTA LMI ORI EGE STA
24
NTA LMI ORI EGE STA
25
NTA LMI ORI EGE STA
26
NTA LMI ORI EGE STA
27
NTA LMI ORI EGE STA
28
NTA ORI STA
29
NTA ORI STA
30
NTA ORI STA
31
NTA ORI STA
         
November 2022
SUN MON TUE WED THU FRI SAT
    1
NTA ORI STA
2
NTA ORI STA
3
NTA ORI STA
4
NTA ORI STA
5
NTA ORI STA
6
LEO NTA ORI STA
7
LEO NTA ORI STA
8
LEO NTA STA
9
LEO NTA STA
10
LEO NTA STA
11
LEO NTA STA
12
LEO NTA STA
13
NOO LEO NTA STA
14
NOO LEO NTA STA
15
NOO AMO LEO NTA STA
16
NOO AMO LEO NTA STA
17
NOO AMO LEO NTA STA
18
NOO AMO LEO NTA STA
19
NOO AMO LEO NTA STA
20
NOO AMO LEO NTA STA
21
NOO AMO LEO NTA
22
NOO AMO LEO NTA
23
NOO AMO LEO NTA
24
NOO AMO LEO NTA
25
NOO AMO LEO NTA
26
NOO LEO NTA
27
NOO LEO NTA
28
PHO NOO LEO NTA
29
PHO NOO LEO NTA
30
PHO NOO LEO NTA
     
December 2022
SUN MON TUE WED THU FRI SAT
        1
PUP PHO NOO NTA
2
PUP PHO NOO NTA
3
HYD PUP PHO NOO NTA
4
GEM HYD PUP PHO NOO NTA
5
DLM GEM HYD MON PUP PHO NOO NTA
6
DLM GEM HYD MON PUP PHO NOO NTA
7
DLM GEM HYD MON PUP PHO NTA
8
DLM GEM HYD MON PUP PHO NTA
9
DLM GEM HYD MON PUP PHO NTA
10
DLM GEM HYD MON PUP NTA
11
DLM GEM HYD MON PUP
12
DLM COM GEM HYD MON PUP
13
DLM COM GEM HYD MON PUP
14
DLM COM GEM HYD MON PUP
15
DLM COM GEM HYD MON PUP
16
DLM COM GEM HYD MON
17
DLM URS COM GEM HYD MON
18
DLM URS COM GEM HYD MON
19
DLM URS COM GEM HYD MON
20
DLM URS COM GEM HYD MON
21
DLM URS COM
22
DLM URS COM
23
DLM URS COM
24
DLM URS
25
DLM URS
26
DLM URS
27
DLM
28
DLM QUA
29
DLM QUA
30
DLM QUA
31
DLM QUA

The Enemy Below

Robert Mitchum and Curt Jürgens in The Enemy Below (1957)

I don’t normally watch war movies, but the 1957 classic The Enemy Below is a war movie for people who don’t like war movies. It is best if you don’t know anything about the story or plot before you see it, so I won’t share any details here, but I will say that even if you are a pacifist (as I am), you will probably like this movie.

Some interesting facts:

  • The German actor Curt Jürgens, who played the German U-boat commander, was critical of Hitler and the Nazis and was sent to an internment camp in Hungary in 1944. He became an Austrian citizen after World War II.
  • The USS Whitehurst, an active-duty ship first used during World War II, was utilized for this movie.
  • Many of the sailors on the American ship in this movie were actual crewmen of the USS Whitehurst and not actors.
  • The main actors on the German submarine were born in Germany and Austria.
  • This is the film debut for (Albert) David Hedison (Jr.) as Lt. Ware, and he went on to a starring role in the television series Voyage to the Bottom of the Sea (1964-1968) as Captain Lee Crane.
  • The excellent 1966 first-season Star Trek episode Balance of Terror was influenced by this movie and closely parallels it.

Highly recommended!

Globulars Galore

So far, a total of 162 globular clusters have been discovered in our Milky Way galaxy.

Many of the recent globulars that have been discovered are either heavily obscured by intervening interstellar matter at visible wavelengths (and thus detectable only in the infrared), or they are so diffuse that they are difficult to detect against the field stars.

Here’s a list of the 88 constellations, and how many globulars have been found in each.

Milky Way Globular Clusters

46 of the 88 constellations harbor globulars (52%). Sagittarius contains the most globular clusters, 36, representing nearly 22% or about 1/5 of the total. This is perhaps not surprising as the center of our Milky Way galaxy (Sgr A*) is located at a distance of 26,673 ± 72 ly from our Solar System in the direction of Sagittarius near the Sagittarius-Ophiuchus-Scorpius border.

Only two other constellations host more than 5 globular clusters: Ophiuchus is in 2nd place with 25, and Scorpius comes in 3rd with 20. Together these three adjacent constellations, Sagittarius, Ophiuchus, and Scorpius, contain a total of 81 globular clusters, exactly half (50%) of all the known Milky Way globulars! Truly, then, the Sagittarius+Ophiuchus+Scorpius region can be called the “Realm of the Globulars”.

The northernmost globular cluster is Palomar 1 (Cepheus, α2000 = 3h33m19s, δ2000 = +79°34’55”), and the southernmost globular cluster is IC 4499 (Apus, α2000 = 15h00m19s, δ2000 = -82°12’50”).

Apus
NGC 6101
IC 4499

Aquarius
NGC 6981 (M72)
NGC 7089 (M2)
NGC 7492

Aquila
NGC 6749
NGC 6760
Palomar 11

Ara
NGC 6352
NGC 6362
NGC 6397
ESO-SC06
FSR 1735

Auriga
Palomar 2

Boötes
NGC 5466

Canes Venatici
NGC 5272 (M3)

Capricornus
NGC 7099 (M30)
Palomar 12

Carina
NGC 2808

Centaurus
NGC 5139 (Omega Centauri)
NGC 5286
Ruprecht 106

Cepheus
Palomar 1

Cetus
Whiting 1

Chamaeleon
ESO 37-01 (E3)

Columba
NGC 1851

Coma Berenices
NGC 4147
NGC 5024 (M53)
NGC 5053

Corona Australis
NGC 6541

Crater
Crater (Laevens 1)

Delphinus
NGC 6934
NGC 7006
Laevens 3

Eridanus
Eridanus

Hercules
NGC 6205 (M13)
NGC 6229
NGC 6341 (M92)
Palomar 14

Horologium
NGC 1261
Arp-Madore 1

Hydra
NGC 4590 (M68)
NGC 5694
Arp-Madore 4

Lepus
NGC 1904 (M79)

Libra
NGC 5897

Lupus
NGC 5824
NGC 5927
NGC 5986

Lynx
NGC 2419

Lyra
NGC 6779 (M56)

Musca
NGC 4372
NGC 4833
Van den Bergh-Hagen 140 (BH 140)

Norma
NGC 5946
FSR 1716
Lynga 7
RLGC 1

Ophiuchus
NGC 6171 (M107)
NGC 6218 (M12)
NGC 6235
NGC 6254 (M10)
NGC 6266 (M62)
NGC 6273 (M19)
NGC 6284
NGC 6287
NGC 6293
NGC 6304
NGC 6316
NGC 6325
NGC 6333 (M9)
NGC 6342
NGC 6355
NGC 6356
NGC 6366
NGC 6401
NGC 6402 (M14)
NGC 6426
NGC 6517
IC 1257
HP 1
Palomar 6
Palomar 15

Pavo
NGC 6752

Pegasus
NGC 7078 (M15)
Palomar 13

Puppis
NGC 2298

Pyxis
Pyxis

Sagitta
NGC 6838 (M71)
Palomar 10

Sagittarius
NGC 6440
NGC 6522
NGC 6528
NGC 6540
NGC 6544
NGC 6553
NGC 6558
NGC 6569
NGC 6624
NGC 6626 (M28)
NGC 6637 (M69)
NGC 6638
NGC 6642
NGC 6652
NGC 6656 (M22)
NGC 6681 (M70)
NGC 6715 (M54)
NGC 6717
NGC 6723
NGC 6809 (M55)
NGC 6864 (M75)
2MS-GC01
2MS-GC02
Arp 2
Van den Bergh-Hagen 261 (BH 261)
Djorgovski 2 (Djorg 2)
Palomar 8
Sagittarius II (Laevens 5)
Terzan 5
Terzan 7
Terzan 8
Terzan 9
Terzan 10
Terzan 12
UKS 1
VVV-CL001

Scorpius
NGC 6093 (M80)
NGC 6121 (M4)
NGC 6139
NGC 6144
NGC 6256
NGC 6380
NGC 6388
NGC 6441
NGC 6453
NGC 6496
Djorgovski 1 (Djorg 1)
ESO 452-SC11
FSR 1758
Liller 1
Terzan 1
Terzan 2
Terzan 3
Terzan 4
Terzan 6
Tonantzintla 2 (Ton 2)

Sculptor
NGC 288

Scutum
NGC 6712
Mercer 5
RLGC 2

Serpens (Caput)
NGC 5904 (M5)
Palomar 5

Serpens (Cauda)
NGC 6535
NGC 6539
IC 1276

Sextans
Palomar 3

Telescopium
NGC 6584

Tucana
NGC 104 (47 Tuc)
NGC 362

Ursa Major
Palomar 4

Vela
NGC 3201

Virgo
NGC 5634

References

Fundamental parameters of Galactic globular clusters (as of May 2021)
https://people.smp.uq.edu.au/HolgerBaumgardt/globular/
Accessed: November 29, 2021

A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty
The GRAVITY Collaboration, R. Abuter, A. Amorim, M. Bauböck, J. P. Berger, H. Bonnet, W. Brandner, Y. Clénet, V. Coudé du Foresto, P. T. de Zeeuw
A&A, 625 (2019) L10

Korngold & The Prince and the Pauper

Robert J. Mauch and Errol Flynn in The Prince and the Pauper, 1937

Sometimes you hear a piece of film music that is so good that it makes you want to see the film. That is certainly what brought me to the 1937 film adaptation of Mark Twain’s The Prince and the Pauper. Erich Wolfgang Korngold (1897-1957) wrote the film score for The Prince and the Pauper. Here is the Main Title:

André Previn and the London Symphony Orchestra (Deutsche Grammophon 289 471 347-2)

Korngold reused this theme in his wonderful Violin Concerto of 1945:

André Previn and the London Symphony Orchestra; Gil Shaham, violin
(Deutsche Grammophon 439 886-2)

Erich Wolfgang Korngold was a Viennese compositional wunderkind whose father was the overbearing Julius Leopold Korngold (1860-1945), chief music critic for the Neue Freie Presse and the most influential music critic in all of Vienna during Erich’s formative years. (Another Leopold was also an overbearing father to another extraordinarily talented child prodigy whose middle name was Wolfgang.) Undoubtedly molded by his father’s extreme distaste for atonal modernism, young Erich developed a style that was tonal and melodic. However, the classical music world was “evolving” away from tonality and Romanticism, and as often happens with composers who write new music using an old idiom, they are largely ignored or, worse yet, forgotten. Fortunately, Erich Wolfgang Korngold was discovered by Hollywood where his tonal music was appreciated, and he went on to write scores for sixteen Hollywood films to great acclaim. He also wrote a great deal of classical music not associated with films that has been neglected for decades and only recently is receiving a fresh hearing and long-overdue appreciation.

The Prince and the Pauper, starring Billy & Bobby Mauch, Errol Flynn, Claude Rains, Phyllis Barry, and many other notable actors, is a delightful movie suitable for the entire family. Highly recommended!

Reinventing the Global Economy

I watched a new thought-provoking documentary last night, Going Circular, about the need to reinvent our local and global economic systems to eliminate waste and save our planet’s resources.

Mother Nature has had a 4-billion-year head start in figuring out how to build a sustainable ecosystem where nothing is wasted and we have much to learn from her.

Little or nothing should be going into the landfill. As much as possible should be recycled, reused, and repurposed. Everything possible should be manufactured so that it can be repaired and upgraded, rather than thrown away and replaced with something completely new.

This is especially important considering that world population is nearing 8 billion and much of the world is rapidly adopting the wasteful lifestyle of the United States and other developed nations. We need to rapidly pivot to a more sustainable economic system or risk catastrophic damage to the global ecosystem and unimaginable human suffering. With so many people, we face the very real possibility of trashing the world’s environment in a single generation.

I don’t know how you accomplish the needed changes fast enough without strong and competent involvement and regulation by the world’s governments. Sure, we can have reasoned debates about the exact roles that governments will play, but all parties should be onboard with the common goal that tax money should be spent wisely and that government should run efficiently. This is no time for “small government” but it is time for better government.

Excessive military spending across the world is tying up valuable resources that could be used to help transform our economies and save the planet. The United States is one of the worst offenders. “With an annual defense budget of $733 billion, the U.S. spends more than three times what China does and 12 times as much as Russia.”1

To end this short article on a hopeful note, think how satisfying it would be both personally and collectively if much of our labor force had jobs directly involved with reducing waste, reusing materials, producing products that last as long as possible, and repairing and upgrading products rather than seeing them thrown away.

Watch the film, please. Though Going Circular is currently only available through Curiosity Stream, which is a subscription service, hopefully it will be more generally available soon. I’d like to see this documentary aired on PBS.

1The Week, November 19, 2021, p. 13

An Almost-Total Partial Lunar Eclipse

Tonight, half of the world—including the U.S.—will be treated to a partial lunar eclipse that is so deep that it is almost total. At mid-eclipse, which occurs at 3:02:56 a.m. CST, only about 45 arcseconds of the Moon’s south-southeastern limb (as seen in the sky) will extend beyond the Earth’s umbral shadow into the penumbral shadow. This is extraordinary. Tonight’s eclipse will be the longest partial lunar eclipse since February 18, 1440, and a partial lunar eclipse this long won’t occur again until February 8, 2669.

Here is the time for each important event during the eclipse, given in Central Standard Time, and—allowing for time zone corrections—the same everywhere the eclipse is visible, plus local circumstances for Dodgeville, Wisconsin.

Time (CST)EventAltitude
12:02:09 a.m.Penumbral Eclipse Begins65˚
1:18:43 a.m.Partial Eclipse Begins58˚
3:02:56 a.m.Greatest Eclipse42˚
4:47:07 a.m.Partial Eclipse Ends24˚
5:19:03 a.m.Astronomical Twilight Begins18˚
5:52:45 a.m.Nautical Twilight Begins12˚
6:03:44 a.m.Penumbral Eclipse Ends10˚
Partial Lunar Eclipse of Friday, November 19, 2021

The Moon is in the constellation Taurus for this eclipse, and you’ll enjoy seeing the Pleiades star cluster nearby become increasingly visible as the eclipse progresses towards maximum. Enjoy!

Animation courtesy of Shadow & Substance
https://www.shadowandsubstance.com

DNA Genealogy

DNA sequencing is revolutionizing the study of human origins and prehistory, but also genealogy.

The number of ancestors you have at each preceding generation is given by 2n, where n = 1, 2, 3, and so on (parents, grandparents, great-grandparents, etc.). The total number of ancestors you have back to any preceding generation is given by 2n+1 – 2. The number of ancestors for the first seven generations is shown in the following table.

GenerationnGeneration AncestorsCumulative Ancestors
Parents122
Grandparents246
Great-Grandparents3814
2G-Grandparents41630
3G-Grandparents53262
4G-Grandparents664126
5G-Grandparents7128254

It is natural to wonder, is there a point at which you don’t receive any distinguishable1 DNA from an ancestor? As an example, looking at your 128 great-great-great-great-great-grandparents, what are the chances that any one of them contributed no DNA to you? The answer is about 0.5%. You would expect, on average, that 128×0.005 = 0.64 ancestors at this generation has contributed nothing to your DNA. In other words, either 127 or 128 of your 5G-grandparents contributed to your DNA. As we go even further back in time, the number of ancestors at each preceding generation that did not contribute to your DNA rapidly increases, as shown in the following table.

GenerationnGeneration AncestorsLikelihood of inherited DNA
Parents12100%
Grandparents24100%
G-Grandparents38100%
2G-Grandparents416100%
3G-Grandparents532100%
4G-Grandparents66499.99%
5G-Grandparents712899.5%
6G-Grandparents825696%
7G-Grandparents951284%
8G-Grandparents10102464%

So you can see that of your 1,024 G-G-G-G-G-G-G-G-grandparents, you will not have received any DNA from about 1024×0.36 = 369 of them.

Another question you might have relates to cousins. What is the probability that you and a cousin share DNA? That is shown in the following table.

RelationshipLikelihood of a DNA Match
Sibling100%
1st Cousin100%
2nd Cousin100%
3rd Cousin98%
4th Cousin71%
5th Cousin32%
6th Cousin11%
7th Cousin3.2%

As you can see, beyond your 3rd cousins, there’s a reasonably good chance you have no distinguishable DNA in common.

DNA Tests

The usual DNA test that most folks get is an autosomal DNA test. It is that test that we are referring to in the sections above.

There are two other DNA tests you might want to consider. The Y-DNA test and the mtDNA test, which allow you to trace your patrilineal (father) and matrilineal (mother) lines, respectively.

Y-DNA Tests

A Y-DNA test looks at the Y-chromosome, which only men have. The Y-chromosome is passed down from father to son generation after generation virtually unchanged. So if you are male and took the Y-DNA test, and another male also took the Y-DNA test, if they matched you would know that you are both descended from the same common ancestor along male lines, whether it could be proved by records or not. I’ll use myself as an example.

I have been able to trace my male line ancestors back to my 7G-grandfather.

AncestorRelationship
Andreas Oesper (?-1721)7G-Grandfather
Andreas Oesper (1709-1776)6G-Grandfather
Zacharias Oesper (1744-1792)5G-Grandfather
Johann Georg Oesper (1780-?)4G-Grandfather
Johann Peter Oesper (1817-1890)3G-Grandfather
Ernst William Oesper I (1846-1918)2G-Grandfather
Ernst William Oesper II (1874-1951)Great-Grandfather
Ernst William Oesper III (1904-1976)Grandfather
Ernst William Oesper IV (1928-1997)Father
David Oesper (1956-)Self

Any male that descended along the male line from any of these ancestors (or unknown earlier generations) would have a Y-DNA match with me. They probably also have the surname Oesper, but not necessarily for a variety of reasons.

Though we haven’t both taken a Y-DNA test, my 2nd cousin once removed Pete Oesper and I would have matching Y-chromosomes. Pete is descended along the male line from my great-great-grandfather Ernst William Oesper I.

mtDNA Tests

A mitochondrial DNA (mtDNA) test looks at the mitochondria, which both males and females have. Mitochondrial DNA is passed down from a mother to her children generation after generation virtually unchanged. So if you and another person took a mtDNA test, if they matched you would know that you are both descended from the same female ancestor along mother-lines, whether it could be proved by records or not. I’ll again use myself as an example.

I have been able to trace my female line ancestors only back to my great-grandmother, or perhaps my great-great-grandmother, but all we have for her is a first name and perhaps not even that.

AncestorRelationship
Mary? (?-?)2G-Grandmother
Katherine Curtin (1855-1931)Great-Grandmother
Sarah Geneva Smith (1896-1992)Grandmother
Carla Mary Pieroni (1929-1985)Mother
David Oesper (1956-)Self

My great-grandmother Katherine Curtin and her brother and sister were orphaned at a young age in New York City. We know that her parents immigrated from Ireland, but nothing more for certain. If I were to take a mtDNA test and could find someone in Ireland who is a mtDNA match, they would likely have descended along the female line from the same female ancestor as me, presumably my great-great-great grandmother, or her mother, grandmother, etc. See how it works?

1 All humans have about 99.5% identical DNA. The half percent that differs between us is what we might call traceable or distinguishable DNA. When you see the term DNA in this article, we are always referring to the portion of the human genome that is distinguishable between individuals, present and past.

References

What is genetic inheritance?
https://www.ancestry.com/cs/dna-help/matches/inheritance
Accessed: November 17, 2021

Y-DNA, mtDNA, and Autosomal DNA Tests
https://support.ancestry.com/s/article/Y-DNA-mtDNA-and-Autosomal-DNA-Tests?language=en_US
Accessed: November 17, 2021

Acknowledgements

I’d like to thank Paul Martsching for emails he sent to me that I utilized in the writing of this article. I alone am responsible for any errors or inaccuracies herein, so please let me know if you find anything in need of correction.

Great Courses, Great Episodes

The Great Courses offers a number of excellent courses on DVD (also streaming and audio only). Here are my favorite episodes. (Note: This is a work in progress and more entries will be added in the future.)

Course No. 153
Einstein’s Relativity and the Quantum Revolution: Modern Physics for Non-Scientists, 2nd Edition – Richard Wolfson
Lecture 8 – Uncommon Sense—Stretching Time
“Why does the simple statement of relativity—that the laws of physics are the same for all observers in uniform motion—lead directly to absurd-seeming situations that violate our commonsense notions of space and time?”
Lecture 9 – Muons and Time-Traveling Twins
“As a dramatic example of what relativity implies, you will consider a thought experiment involving a pair of twins, one of whom goes on a journey to the stars and returns to Earth younger than her sister!”
Lecture 12 – What about E=mc2 and is Everything Relative?
“Shortly after publishing his 1905 paper on special relativity, Einstein realized that his theory required a fundamental equivalence between mass and energy, which he expressed in the equation E=mc2. Among other things, this famous formula means that the energy contained in a single raisin could power a large city for an entire day.”
Lecture 16 – Into the Heart of Matter
“With this lecture, you turn from relativity to explore the universe at the smallest scales. By the early 1900s, Ernest Rutherford and colleagues showed that atoms consist of a positively charged nucleus surrounded by negatively charged electrons whirling around it. But Rutherford’s model could not explain all the observed phenomena.”
Lecture 19 – Quantum Uncertainty—Farewell to Determinism
“Quantization places severe limits on our ability to observe nature at the atomic scale because it implies that the act of observation disturbs that which is being observed. The result is Werner Heisenberg’s famous Uncertainty Principle. What exactly does this principle say, and what are the philosophical implications?”
Lecture 21 – Quantum Weirdness and Schrödinger’s Cat
“Wave-particle duality gives rise to strange phenomena, some of which are explored in Schrödinger’s famous ‘cat in the box’ example. Philosophical debate on Schrödinger’s cat still rages.”

Course No. 730
Symphonies of Beethoven – Robert Greenberg
Lecture 11 – Symphony No. 3—The “New Path”—Heroism and Self-Expression, III
“Lectures 9 through 12 focus on Symphony No. 3, the Eroica Symphony. This key work in Beethoven’s compositional revolution resulted from his crisis of going deaf. Beethoven’s struggle with his disability raised him to a new level of creativity. Symphony No. 3 parallels his heroic battle with and ultimate triumph over adversity. The symphony’s debt to Napoleon is discussed before an analysis.”
Lecture 13 – Symphony No. 4—Consolidation of the New Aesthetic, I
“Lectures 13 through 16 examine Symphony No. 4 in historical context and in its relationship to opera buffa. Symphony No. 4 is the most infrequently heard of his symphonies. We see how it represents a return to a Classical structure. Its framework is filled with iconoclastic rhythms, harmonies, and characteristic motivic developments that mark it as a product of Beethoven’s post-Eroica period.”
Lecture 23 – Symphony No. 7—The Symphony as Dance, I
Lecture 24 – Symphony No. 7—The Symphony as Dance, II
“Lectures 23 and 24 discuss Beethoven’s Symphony No. 7 with references to the historical and personal events surrounding its composition. The essence of the symphony is seen to be the power of rhythm, and originality is seen to be an important artistic goal for Beethoven.”
Lecture 31 – Symphony No. 9—The Symphony as the World, IV
“The last five lectures are devoted to Symphony No. 9, the most influential Western musical composition of the 19th century and the most influential symphony ever written. We see how this work obliterated distinctions between the instrumental symphony and dramatic vocal works such as opera. Also discussed are Beethoven’s fall from public favor in 1815, his disastrous relationship with his nephew Karl, his artistic rebirth around 1820, his late compositions, and his death in 1827.”

Course No. 759
Great Masters: Robert and Clara Schumann-Their Lives and Music – Robert Greenberg
Lecture 8 – Madness
“In Düsseldorf, Robert was inspired to write the Symphony No. 3 in E-flat Major, along with trios, sonatas, orchestral works, and pieces for chorus and voice and piano. Robert and Clara also met Johannes Brahms there; he became a lifelong friend and source of strength for Clara. In 1854, Robert attempted to drown himself in the Rhine and was taken to an asylum. He died there two years later. Clara managed to sustain the family through her concerts but was dealt even more pain by the early deaths of several of her children.”

Course No. 1257
Mysteries of Modern Physics: Time – Sean Carroll
Lecture 10 – Playing with Entropy
“Sharpen your understanding of entropy by examining different macroscopic systems and asking, which has higher entropy and which has lower entropy? Also evaluate James Clerk Maxwell’s famous thought experiment about a demon who seemingly defies the principle that entropy always increases.”
Lecture 15 – The Perception of Time
“Turn to the way humans perceive time, which can vary greatly from clock time. In particular, focus on experiments that shed light on our time sense. For example, tests show that even though we think we perceive the present moment, we actually live 80 milliseconds in the past.”
Lecture 16 – Memory and Consciousness
“Remembering the past and projecting into the future are crucial for human consciousness, as shown by cases where these faculties are impaired. Investigate what happens in the brain when we remember, exploring different kinds of memory and the phenomena of false memories and false forgetting.”
Lecture 20 – Black Hole Entropy
“Stephen Hawking showed that black holes emit radiation and therefore have entropy. Since the entropy in the universe today is overwhelmingly in the form of black holes and there were no black holes in the early universe, entropy must have been much lower in the deep past.”
Lecture 21 – Evolution of the Universe
“Follow the history of the universe from just after the big bang to the far future, when the universe will consist of virtually empty space at maximum entropy. Learn what is well founded and what is less certain about this picture of a universe winding down.”

Course No. 1280
Physics and Our Universe: How It All Works – Richard Wolfson
Lecture 1 – The Fundamental Science

“Take a quick trip from the subatomic to the galactic realm as an introduction to physics, the science that explains physical reality at all scales. Professor Wolfson shows how physics is the fundamental science that underlies all the natural sciences. He also describes phenomena that are still beyond its explanatory power.”
Special Note: This entire series is outstanding! I will eventually be adding many of the episodes of this course as I rewatch them. (I watched this series before I began keeping track of “best” episodes.)

Course No. 1360
Introduction to Astrophysics – Joshua Winn
Lecture 5 – Newton’s Hardest Problem
“Continue your exploration of motion by discovering the law of gravity just as Newton might have—by analyzing Kepler’s laws with the aid of calculus (which Newton invented for the purpose). Look at a graphical method for understanding orbits, and consider the conservation laws of angular momentum and energy in light of Emmy Noether’s theory that links conservation laws and symmetry.”
Lecture 10 – Optical Telescopes
“Consider the problem of gleaning information from the severely limited number of optical photons originating from astronomical sources. Our eyes can only do it so well, and telescopes have several major advantages: increased light-gathering power, greater sensitivity of telescopic cameras and sensors such as charge-coupled devices (CCDs), and enhanced angular and spectral resolution.”
Lecture 11 – Radio and X-Ray Telescopes
“Non-visible wavelengths compose by far the largest part of the electromagnetic spectrum. Even so, many astronomers assumed there was nothing to see in these bands. The invention of radio and X-ray telescopes proved them spectacularly wrong. Examine the challenges of detecting and focusing radio and X-ray light, and the dazzling astronomical phenomena that radiate in these wavelengths.”
Lecture 12 – The Message in a Spectrum
“Starting with the spectrum of sunlight, notice that thin dark lines are present at certain wavelengths. These absorption lines reveal the composition and temperature of the Sun’s outer atmosphere, and similar lines characterize other stars. More diffuse phenomena such as nebulae produce bright emission lines against a dark spectrum. Probe the quantum and thermodynamic events implied by these clues.”
Lecture 13 – The Properties of Stars
“Take stock of the wide range of stellar luminosities, temperatures, masses, and radii using spectra and other data. In the process, construct the celebrated Hertzsprung–Russell diagram, with its main sequence of stars in the prime of life, including the Sun. Note that two out of three stars have companions. Investigate the orbital dynamics of these binary systems.”
Lecture 15 – Why Stars Shine
“Get a crash course in nuclear physics as you explore what makes stars shine. Zero in on the Sun, working out the mass it has consumed through nuclear fusion during its 4.5-billion-year history. While it’s natural to picture the Sun as a giant furnace of nuclear bombs going off non-stop, calculations show it’s more like a collection of toasters; the Sun is luminous simply because it’s so big.”
Lecture 16 – Simple Stellar Models
“Learn how stars work by delving into stellar structure, using the Sun as a model. Relying on several physical principles and sticking to order-of-magnitude calculations, determine the pressure and temperature at the center of the Sun, and the time it takes for energy generated in the interior to reach the surface, which amounts to thousands of years. Apply your conclusions to other stars.”
Lecture 17 – White Dwarfs
“Discover the fate of solar mass stars after they exhaust their nuclear fuel. The galaxies are teeming with these dim “white dwarfs” that pack the mass of the Sun into a sphere roughly the size of Earth. Venture into quantum theory to understand what keeps these exotic stars from collapsing into black holes, and learn about the Chandrasekhar limit, which determines a white dwarf’s maximum mass.”
Lecture 18 – When Stars Grow Old
“Trace stellar evolution from two points of view. First, dive into a protostar and witness events unfold as the star begins to contract and fuse hydrogen. Exhausting that, it fuses heavier elements and eventually collapses into a white dwarf—or something even denser. Next, view this story from the outside, seeing how stellar evolution looks to observers studying stars with telescopes.”
Lecture 19 – Supernovas and Neutron Stars
“Look inside a star that weighs several solar masses to chart its demise after fusing all possible nuclear fuel. Such stars end in a gigantic explosion called a supernova, blowing off outer material and producing a super-compact neutron star, a billion times denser than a white dwarf. Study the rapid spin of neutron stars and the energy they send beaming across the cosmos.”
Lecture 20 – Gravitational Waves
“Investigate the physics of gravitational waves, a phenomenon predicted by Einstein and long thought to be undetectable. It took one of the most violent events in the universe—colliding black holes—to generate gravitational waves that could be picked up by an experiment called LIGO on Earth, a billion light years away. This remarkable achievement won LIGO scientists the 2017 Nobel Prize in Physics.”

Course No. 1456
Discrete Mathematics – Arthur T. Benjamin
Lecture 8 – Linear Recurrences and Fibonacci Numbers
“Investigate some interesting properties of Fibonacci numbers, which are defined using the concept of linear recurrence. In the 13th century, the Italian mathematician Leonardo of Pisa, called Fibonacci, used this sequence to solve a problem of idealized reproduction in rabbits.”
Lecture 15 – Open Secrets—Public Key Cryptography
“The idea behind public key cryptography sounds impossible: The key for encoding a secret message is publicized for all to know, yet only the recipient can reverse the procedure. Learn how this approach, widely used over the Internet, relies on Euler’s theorem in number theory.”
Lecture 16 – The Birth of Graph Theory
“This lecture introduces the last major section of the course, graph theory, covering the basic definitions, notations, and theorems. The first theorem of graph theory is yet another contribution by Euler, and you see how it applies to the popular puzzle of drawing a given shape without lifting the pencil or retracing any edge.”
Lecture 18 – Social Networks and Stable Marriages
“Apply graph theory to social networks, investigating such issues as the handshake theorem, Ramsey’s theorem, and the stable marriage theorem, which proves that in any equal collection of eligible men and women, at least one pairing exists for each person so that no extramarital affairs will take place.”
Lecture 20 – Weighted Graphs and Minimum Spanning Trees
“When you call someone on a cell phone, you can think of yourself as a leaf on a giant ‘tree’—a connected graph with no cycles. Trees have a very simple yet powerful structure that make them useful for organizing all sorts of information.”
Lecture 22 – Coloring Graphs and Maps
“According to the four-color theorem, any map can be colored in such a way that no adjacent regions are assigned the same color and, at most, four colors suffice. Learn how this problem went unsolved for centuries and has only been proved recently with computer assistance.”

Course No. 1495
Introduction to Number Theory – Edward B. Burger
Lecture 12 – The RSA Encryption Scheme
“We continue our consideration of cryptography and examine how Fermat’s 350-year-old theorem about primes applies to the modern technological world, as seen in modern banking and credit card encryption.”
Lecture 22 – Writing Real Numbers as Continued Fractions
“Real numbers are often expressed as endless decimals. Here we study an algorithm for writing real numbers as an intriguing repeated fraction-within-a-fraction expansion. Along the way, we encounter new insights about the hidden structure within the real numbers.”
Lecture 24 – A Journey’s End and the Journey Ahead
“In this final lecture, we take a step back to view the entire panorama of number theory and celebrate some of the synergistic moments when seemingly unrelated ideas came together to tell a unified story of number.”

Course No. 1802
The Search for Exoplanets: What Astronomers Know – Joshua Winn
Lecture 4 – Pioneers of Planet Searching

“Chart the history of exoplanet hunting – from a famous false signal in the 1960s, through ambiguous discoveries in the 1980s, to the big breakthrough in the 1990s, when dozens of exoplanets turned up. Astronomers were stunned to find planets unlike anything in the solar system.”
Special Note: This entire series is outstanding! I will eventually be adding most of the episodes of this course as I rewatch them. (I watched this series before I began keeping track of “best” episodes.)

Course No. 1830
Cosmology: The History and Nature of Our Universe – Mark Whittle
Lecture 3 – Overall Cosmic Properties

“The universe is lumpy at the scale of galaxies and galaxy clusters. But at larger scales it seems to be smooth and similar in all directions. This property of homogeneity and isotropy is called the cosmological principle.”
Lecture 4 – The Stuff of the Universe
“The most familiar constituents of the universe are atomic matter and light. Neutrinos make up another component. But by far the bulk of the universe—96%—is dark energy and dark matter. The relative amounts of these constituents have changed as the universe has expanded.”
Lecture 6 – Measuring Distances
“Astronomers use a ‘distance ladder’ of overlapping techniques to determine distances in the universe. Triangulation works for nearby stars. For progressively farther objects, observers use pulsating stars, the rotation of galaxies, and a special class of supernova explosions.”
Lecture 8 – Distances, Appearances, and Horizons
“Defining distances in cosmology is tricky, since an object’s distance continually increases with cosmic expansion. There are three important distances to consider: the emission distance, when the light set out; the current distance, when the light arrives; and the distance the light has traveled.”
Lecture 10 – Cosmic Geometry – Triangles in the Sky
“Einstein’s theory of gravity suggests that space could be positively or negatively curved, so that giant billion-light-year triangles might have angles that don’t add up to 180°. This lecture discusses the success at measuring the curvature of the universe in 1998.”
Lecture 11 – Cosmic Expansion – Keeping Track of Energy
“Has the universe’s rate of expansion always been the same? You answer this question by applying Newton’s law of gravity to an expanding sphere of matter, finding that the expansion was faster in the past and slows down over time.”
Lecture 12 – Cosmic Acceleration – Falling Outward
“You investigate why the three great eras of cosmic history—radiation, matter, and dark energy—have three characteristic kinds of expansion. These are rapid deceleration, modest deceleration, and exponential acceleration. The last is propelled by dark energy, which makes the universe fall outward.”
Lecture 13 – The Cosmic Microwave Background
“By looking sufficiently far away, and hence back in time, we can witness the ‘flash’ from the big bang itself. This arrives from all directions as a feeble glow of microwave radiation called the cosmic microwave background (CMB), discovered by chance in 1964.”
Lecture 22 – The Galaxy Web – A Relic of Primordial Sound
“A simulated intergalactic trip shows you the three-dimensional distribution of galaxies in our region of the universe. On the largest scale, galaxies form a weblike pattern that matches the peaks and troughs of the primordial sound in the early universe.”
Lecture 24 – Understanding Element Abundances
“The theory of atom genesis in the interiors of stars is confirmed by the proportions of each element throughout the cosmos. The relative abundances hardly vary from place to place, so that gold isn’t rare just on earth, it’s rare everywhere.”
Lecture 27 – Physics at Ultrahigh Temperatures
“This lecture begins your investigation of the universe during its first second, which is an immense tract of time in nature. To understand what happened, you need to know how nature behaves at ultrahigh energy and density. Fortunately, the physics is much simpler than you might think.”
Lecture 29 – Back to the GUT – Matter and Forces Emerge
“You venture into the bizarre world of the opening nanosecond. There are two primary themes: the birth of matter and the birth of forces. Near one nanosecond, the universe was filled with a dense broth of the most elementary particles. As temperatures dropped, particles began to form.”
Lecture 30 – Puzzling Problems Remain
“Although the standard big bang theory was amazingly successful, it couldn’t explain several fundamental properties of the universe: Its geometry is Euclidean, it’s smooth on the largest scales, and it was born slightly lumpy on smaller scales. The theory of cosmic inflation offers a comprehensive solution.”
Lecture 31 – Inflation Provides the Solution
“This lecture shows how the early universe might enter a brief phase of exponentially accelerating expansion, or inflation, providing a mechanism to launch the standard hot big bang universe. This picture also solves the flatness, horizon, and monopole problems that plagued the standard big-bang theory.”
Lecture 33 – Inflation’s Stunning Creativity
“All the matter and energy in stars and galaxies is exactly balanced by all the negative energy stored in the gravitational fields between the galaxies. Inflation is the mechanism that takes nothing and makes a universe—not just our universe, but potentially many.”
Lecture 34 – Fine Tuning and Anthropic Arguments
“Why does the universe have the properties it does and not some different set of laws? One approach is to see the laws as inevitable if life ever evolves to ask such questions. This position is called the anthropic argument, and its validity is hotly debated.”

Course No. 1866
The Remarkable Science of Ancient Astronomy – Bradley E. Schaefer
Lecture 10 – Origins of Western Constellations
“The human propensity for pattern recognition and storytelling has led every culture to invent constellations. Trace the birth of the star groups known in the West, many of which originated in ancient Mesopotamia. At least one constellation is almost certainly more than 14,000 years old and may be humanity’s oldest surviving creative work.”

Course No. 1878
Radio Astronomy: Observing the Invisible Universe – Felix J. Lockman
Lecture 5 – Radio Telescopes and How They Work
“Radio telescopes are so large because radio waves contain such a small amount of energy. For example, the signal from a standard cell phone measured one kilometer away is five million billion times stronger than the radio signals received from a bright quasar. Learn how each of these fascinating instruments is designed to meet a specific scientific goal—accounting for their wide variation in form and size.”
Lecture 7 – Tour of the Green Bank Observatory
“The Green Bank Observatory is located within the 13,000-acre National Radio Quiet Zone straddling the border of Virginia and West Virginia. Come tour this fascinating facility where astronomers discovered radiation belts around Jupiter, the black hole at the center of our galaxy, and the first known interstellar organic molecule, and began the search for extra-terrestrial life.”
Lecture 8 – Tour of the Green Bank Telescope
“At 17 million pounds, and with more than 2,000 surface panels that can be repositioned in real time, this telescope is one of the largest moveable, land-based objects ever built. The dish could contain two side-by-side football fields, but when its panels are brought into focus, the surface has errors no larger than the thickness of a business card. Welcome to this rare insider’s view.”
Lecture 9 – Hydrogen and the Structure of Galaxies
“Using the laws of physics and electromagnetic radiation, astronomers can ‘weigh’ a galaxy by studying the distribution of its rotating hydrogen. But when they do this, it soon becomes clear something is very wrong: A huge proportion of the galaxy’s mass has simply gone missing. Welcome to the topsy-turvy world of dark matter, which we now believe accounts for a whopping 90 percent of our own Milky Way.”
Lecture 10 – Pulsars: Clocks in Space
“In the mid-1960s, astronomers discovered signals with predictable periodicity but no known source. In case these signals indicated extraterrestrial life, they were initially labeled LGM, Little Green Men. But research revealed the source of the pulsing radiation to be neutron stars. Learn how a star with a diameter of only a few kilometers and a mass similar to that of our Sun can spin around hundreds of times per second.”
Lecture 11 – Pulsars and Gravity
“A pulsar’s spin begins with its birth in a supernova and can be altered by transfer of mass from a companion star. Learn how pulsars, these precise interstellar clocks, are used to confirm Einstein’s prediction of gravitational waves by observations of a double-neutron-star system, and how we pull the pulsar signal out of the noise.”
Lecture 12 – Pulsars and the 300-Foot Telescope
“Humans constantly use radio transmission these days, for everything from military communications to garage-door openers. How can scientists determine which signals come from Earth and which come from space? Learn how the 300-foot telescope, located in two radio quiet zones, was built quickly and cheaply. It ended up studying pulsars and hydrogen in distant galaxies, and made the case for dark matter.”
Lecture 16 – Radio Stars and Early Interferometers
“When radio astronomers discovered a sky full of small radio sources of unknown origin, they built telescopes using multiple antennas to try to understand them. Learn how and why interferometers were developed and how they have helped astronomers study quasars—those massively bright, star-like objects that scientists now know only occur in galaxies whose gas is falling into a supermassive black hole.”
Lecture 18 – Active Galactic Nuclei and the VLA
“The need for a new generation of radio interferometers to untangle extragalactic radio sources led to the development of the Very Large Array (VLA) in New Mexico. With its twenty-seven radio antennas in a Y-shaped configuration, it gives both high sensitivity and high angular resolution. The VLA provided a deeper and clearer look at galaxies than ever before, and the results were astonishing.”
Lecture 19 – A Telescope as Big as the Earth
“Learn how astronomers use very-long-baseline interferometry (VLBI) with telescopes thousands of miles apart to essentially create a radio telescope as big as the Earth. With VLBI, scientists not only look deep into galactic centers, study cosmic radio sources, and weigh black holes, but also more accurately tell time, study plate tectonics, and more—right here on planet Earth.”
Lecture 20 – Galaxies and Their Gas
“In visible light, scientists had described galaxies as ‘island universes’. But since the advent of radio astronomy, we’ve seen galaxies connected by streams of neutral hydrogen, interacting with and ripping the gases from each other. Now astronomers have come to understand that these strong environmental interactions are not a secondary feature—they are key to a galaxy’s basic structure and appearance.”
Lecture 21 – Interstellar Molecular Clouds
“In the late 1960s, interstellar ammonia and water vapor were detected. Soon came formaldehyde, carbon monoxide, and the discovery of giant molecular clouds where we now know stars and planets are formed. With improvements in radio astronomy technology, today’s scientists can watch the process of star formation in other systems. The initial results are stunning.”
Lecture 22 – Star Formation and ALMA
“With an array of 66 radio antennas located in the high Chilean desert above much of the earth’s atmosphere, the Atacama Large Millimeter/submillimeter Array (ALMA) is a radio telescope tuned to the higher frequencies of radio waves. Designed to examine some of the most distant and ancient galaxies ever seen, ALMA has not only revealed new stars in the making, but planetary systems as well.”
Lecture 23 – Interstellar Chemistry and Life
“Interstellar clouds favor formation of carbon-based molecules over any other kind—not at all what statistical models predicted. In fact, interstellar clouds contain a profusion of chemicals similar to those that occur naturally on Earth. If planets are formed in this rich soup of organic molecules, is it possible life does not have to start from scratch on each planet?”
Lecture 24 – The Future of Radio Astronomy
“Learn about the newest radio telescopes and the exhilarating questions they plan to address: Did life begin in space? What is dark matter? And a new question that has just arisen in the past few years: What are fast radio bursts? No matter how powerful these new telescopes are, radio astronomers will continue pushing the limits to tell us more and more about the universe that is our home.”

Course No. 1884
Experiencing Hubble: Understanding the Greatest Images of the Universe – David M. Meyer
Lecture 5 – The Cat’s Eye Nebula – A Stellar Demise
“Turning from star birth to star death, get a preview of the sun’s distant future by examining the Cat’s Eye Nebula. Such planetary nebulae (which have nothing to do with planets) are the exposed debris of dying stars and are among the most beautiful objects in the Hubble gallery.”
Lecture 7 – The Sombrero Galaxy – An Island Universe
“In the 1920s, astronomer Edwin Hubble discovered the true nature of galaxies as ‘island universes’. Some 80 years later, the telescope named in his honor has made thousands of breathtaking pictures of galaxies. Focus on one in particular—an edge-on view of the striking Sombrero galaxy.”
Lecture 8 – Hubble’s View of Galaxies Near and Far
“Hubble’s image of the nearby galaxy NGC 3370 includes many faint galaxies in the background, exemplifying the telescope’s mission to establish an accurate distance scale to galaxies near and far—along with the related expansion rate of the universe. Discover how Hubble’s success has led to the concept of dark energy.”
Lecture 10 – Abell 2218 – A Massive Gravitational Lens
“One of the consequences of Einstein’s general theory of relativity is evident in Hubble’s picture of the galaxy cluster Abell 2218. Investigate the physics of this phenomenon, called gravitational lensing, and discover how Hubble has used it to study extremely distant galaxies as well as dark matter.”

Course No. 3130
Origin of Civilization – Scott MacEachern
Lecture 36 – Great Zimbabwe and Its Successors
“Few archaeological sites have been subjected to the degree of abuse and misrepresentation sustained by Great Zimbabwe in southeastern Africa. Nevertheless, this lecture unpacks the intriguing history of this urban center and the insights it can provide into the development of the elite.”

Course No. 3900
Ancient Civilizations of North America – Edwin Barnhart
Lecture 12 – The Wider Mississippian World
“After the fall of Cahokia, witness how Mississippian civilization flourished across eastern North America with tens of thousands of pyramid-building communities and a population in the millions. Look at the ways they were connected through their commonly held belief in a three-tiered world, as reflected in their artwork. Major sites like Spiro, Moundville, and Etowah all faded out just around 100 years before European contact, obscuring our understanding.”
Lecture 13 – De Soto Versus the Mississippians
“In 1539, Hernando de Soto of Spain landed seven ships with 600 men and hundreds of animals in present-day Florida. Follow his fruitless search for another Inca or Aztec Empire, as he instead encounters hundreds of Mississippian cities through which he led a three-year reign of terror across the land-looting, raping, disfiguring, murdering, and enslaving native peoples by the thousands.”
Lecture 19 – The Chaco Phenomenon
“Chaco Canyon contains the most sophisticated architecture ever built in ancient North America—14 Great Houses, four Great Kivas, hundreds of smaller settlements, an extensive road system, and a massive trade network. But who led these great building projects? And why do we find so little evidence of human habitation in what seems to be a major center of culture? Answer these questions and more.”
Lecture 24 – The Iroquois and Algonquians before Contact
“At the time of European contact, two main groups existed in the northeast—the hunter-gatherer Algonquian and the agrarian Iroquois. Delve into how the Iroquois created the first North American democracy as a solution to their increasing internal conflicts. Today, we know much of the U.S. Constitution is modeled on the Iroquois’ “Great League of Peace” and its 117 articles of confederation, as formally acknowledged by the U.S. in 1988.”

Course No. 4215
An Introduction to Formal Logic – Steven Gimbel
Lecture 8 – Induction in Polls and Science
“Probe two activities that could not exist without induction: polling and scientific reasoning. Neither provides absolute proof in its field of analysis, but if faults such as those in Lecture 7 are avoided, the conclusions can be impressively reliable.”

Course No. 7210
The Symphony – Robert Greenberg
Lecture 24 – Dmitri Shostakovich and His Tenth Symphony

“Dmitri Shostakovich was used and abused by the Soviet powers during much of his life. Somehow, he survived—even as his Tenth Symphony made dangerously implicit criticisms of the Soviet government.”

Course No. 7261
Understanding the Fundamentals of Music – Robert Greenberg
Lecture 9 – Intervals and Tunings

“Resuming our focus on pitch, we will turn once more to Pythagoras, and his investigation into what is now known as the overtone series. This paves the way for an examination of intervals, the evolution of tuning systems, and an introduction to the major pitch collections.”

Course No. 7270
The Concerto – Robert Greenberg
Lecture 13 – Tchaikovsky
“Excoriated by colleagues and critics alike, Tchaikovsky’s concerti ultimately triumphed to become cornerstones of the repertoire. This lecture explores his Piano Concerto no. 1 in B flat Minor, op. 23; Piano Concerto no. 2 in G Major, op. 44; and Violin Concerto in D Major, op. 35, arguably his single greatest work and one of the greatest concerti of the 19th century.”
Lecture 14 – Brahms and the Symphonic Concerto
“Johannes Brahms’s compositional style is a synthesis of the clear and concise musical forms and genres of the Classical and Baroque eras, and the melodic, harmonic, and expressive palette of the Romantic era in which he lived. This lecture examines in depth his monumental Piano Concerto no. 2 in B flat Major, op. 83.”

Course No. 30110
England, the 1960s, and the Triumph of the Beatles – Michael Shelden
Lecture 8 – The Englishness of A Hard Day’s Night
“In summer 1964, the cinematic Beatles vehicle A Hard Day’s Night broke almost every rule in Hollywood at the time. Professor Shelden reveals what lies underneath the film’s surface charm and musical numbers: an overall attitude of irreverence and defiance in the face of authority, and a challenge for audiences to think for themselves.”
Lecture 12 – Hello, Goodbye: The End of the 1960s
“In their last years together, all four of the Beatles seemed headed in new directions as they grew up—and apart. Nevertheless, witness how these final years brought a range of sounds, including protest songs, mystic melodies, anthems of friendship, and an iconic double album called simply, The Beatles, but better known as the ‘White Album.'”