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based in Lee County Alabama

How Long Does The Rotation of the Earth Take?

How long would you say that it takes for the earth to rotate one time on its axis? Some of us would say 24 hours (plus or minus a few seconds due to aberrations in the rotation which are periodically resolved by the integration of “leap seconds.”) National Institute of Standards and Technology What Is A Leap Second, accessed 12/01/2025, https://www.nist.gov/pml/time-and-frequency-division/leap-seconds-faqs#:~:text=A%20leap%20second%20is%20a,that%20it%20is%20gradually%20slowing.

Well, the answer of 24 hours plus or minus is incorrect. In addition to the actual rotation of the earth on its axis, the orbit of our planet around the sun must also be accounted for in global timekeeping. We use 24 hours as our nominal day length (which more or less accounts for both the rotation of the earth on its axis as well as its orbit of the sun). This 24-hour period is referred to as a “Solar Day.” But the portion of that Solar Day attributable to the rotation of the earth is only about 23 hours 56 minutes and 4 seconds (a so-called “Sidereal Day”). The other (approximately) four minutes is added to deal with the planet’s orbit around the sun. This constitutes one whale of a trivia question.

Not to split hairs, but there are a couple other associated considerations:

1) The time of rotation of the earth is not constant. In the long term, the rotation is slowing for several reasons.  Chief among these is the tidal drag of the moon. However that gradual slowing is, from time to time, punctuated by other changes in the rate the result of other factors. For example recently, factors such as melting polar ice caps and large earthquakes have acted to increase the rate of rotation. BBC Science Focus The Earth’s rotation is changing speed: should we be worried?, accessed 12/01/2025, https://www.sciencefocus.com/planet-earth/earth-rotation-speed.

2) The whole “Leap Seconds” thing is on its way out. In a 2022 meeting of Bureau International des Poids et Mesures, or BIPM it was resolved to fully phase Leap Seconds out by 2035. Scientific American, Should We Abandon the Leap Second? Accessed 12/01/2025, https://www.scientificamerican.com/article/leap-seconds-may-be-abandoned-by-the-worlds-timekeepers/

Tidbits from Recent Meetings!

November 27, 2025 – We had great attendance at our meeting this morning!  And it’s Thanksgiving Day.  We all considered how thankful we are for our blessings and for each other.  Richard – WA4IWD is on the beach for the holiday and reported a radon level there of only of 0.18 pCi/L. Bob – KD4PK pointed out that high levels of radon are often associated with areas underlain by granite rock which is not common near the beach. Gail – KB4JAA read one of her wonderful poems to us.  It was a Thanksgiving poem and it reminded us of our younger days at home on Thanksgiving with our families. Thanks to Mike – KI4TWB for sharing our wonderful turkey background.  And also Mike thanks for reminding us for that popular old ballad so commonly remembered for its Thanksgiving talking blues song,, “Alice’s Restaurant” by Arlo Guthrie

November 20, 2025 – Some interest was again sparked in the LoRa mesh technology, so we discussed it briefly. Mike – KX4YZ sent out an email to all with some basic information. We compared chain saws and fuel for a few minutes. Bob – KD4PK explained that he has moved to electrically driven technology for his lawn maintenance equipment. John – NK4N reported that the leaf color in the mountains of North Carolina has mostly passed, but tourist traffic remains strong. Mike – KI4TWB provided a report on the completion of the Ultimate Pool championship which he attended in Cherokee, North Carolina with his son Dustin. According to Dayne – K8CHY, as hurricane Melissa approached Jamaica last month, the strongest hurricane wind ever recorded by a dropsonde (252 miles per hour) was observed. A NOAA Hurricane Hunter airplane dropped a dropsonde which parachuted down streaming data as it went. Just before landing in the ocean, it this record wind speed. No one in attendance today was able to shed any light on who Auburn’s new football coach will be. A wide net has been cast.

November 13, 2025 – We had full attendance this morning at our meeting! Mike – KI4TWB was traveling in North Carolina but joined from his hotel room at the Harrah’s Cherokee Casino Resort. Mike is there with his son Dustin who is competing in The National Open pool tournament this week. Mike indicates only a minimum investment in the casino itself thus far. Dayne – K8CHY and Richard – WA4IWD spent a few minutes comparing notes on the famous Convair B-36 Peacemaker which first flew on August 8, 1946. The B-36 was a mammoth airplane as can be seen in the image available by clicking on this link wherein one is parked beside a B-29 Superfortress. The recent appearance of auroras in the southern states was also a topic and the discussion included the impact on radio wave propogation. Several members indicated that the effects were significant.

November 6, 2025 – An interesting discussion took place related to the Mouse House (Bldg. 9210) which existed until 2021 on the premises of the Oak Ridge National Laboratory in Tennessee. Dayne – K8CHY recently met a ham who was involved in the demolition of the facility at that time. John – NK4N clearly remembers this building having utilized its facilities in the past. An interesting paper on the facility can be found HERE. Radon level in Opelika remains at 0.67 pCi/L per Richard – WA4IWD.  NK4N also reports that the first significant snowfall of the season occurred on Mount Le Conte on 10/30/2025 when 3 to 4 inches accumulated.

LINK TO OLDER TIDBITS

Areas of Special Interest to Heart of Dixie Amateur Radio Society Members

Friendship
Technology
FT8
WSPR
RTTY
Fun
CW

We are friends with many other amateur radio organizations including the following local organizations:

W4LEE The East Alabama Amateur Radio Club W4LEE.ORG
W4CVY The Columbus Amateur Radio Club W4CVY.ORG
AB4KE The LaGrange Amateur Radio Club LAGRANGERADIOCLUB.ORG
K4YWE The Lake Martin Amateur Radio Club FACEBOOK.COM/K4YWE
W4AP The Montgomery Amateur Radio Club W4AP.ORG

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