Showing posts with label National Park Service. Show all posts
Showing posts with label National Park Service. Show all posts

Sunday, July 5, 2026

Liberty literally cracked up in 1846, fifteen years before the whole country did



 
... No one recorded when or why the Liberty Bell first cracked, but the most likely explanation is that a narrow split developed in the early 1840s after nearly 90 years of hard use. In 1846, when the city decided to repair the bell prior to George Washington's birthday holiday (February 23), metal workers widened the thin crack to prevent its farther spread and restore the tone of the bell using a technique called "stop drilling". The wide "crack" in the Liberty Bell is actually the repair job! Look carefully and you'll see over 40 drill bit marks in that wide "crack". But, the repair was not successful. The Public Ledger newspaper reported that the repair failed when another fissure developed. This second crack, running from the abbreviation for "Philadelphia" up through the word "Liberty", silenced the bell forever. No one living today has heard the bell ring freely with its clapper, but computer modeling provides some clues into the sound of the Liberty Bell. ...
 

Friday, September 3, 2021

The absolute number of nuclear warheads matters but their hard-target kill capability matters more, and we don't have it against the Chicoms

All presidents since Reagan/Bush have failed to prioritize US hard-target kill capability, including Trump, so our enemies both in Russia and China have been compensating for that.

Eroding the certainty of destruction erodes deterrence.

The Chicoms haven't been emphasizing concrete manufacturing just to build vacant buildings and roads to nowhere.

Mark B. Schneider:

In 1985, then-Chairman of the Joint Chiefs of Staff General John Vessey briefed President Ronald Reagan about the need for improved hard-target kill capability, including the need for 100 MX (Peacekeeper) ICBMs. We actually got 50. Of the three U.S. hard target capable systems created by the Reagan administration, two (the Peacekeeper ICBM and the Advanced Cruise Missile) were eliminated by the George W. Bush administration. This left only the high-yield WW-88 Trident warheads. Reportedly, the U.S. produced only 400 of the high-yield WW-88 warheads for the Trident II missile. Obviously, they can’t all be used against Chinese silos even if one makes a number of best-case assumptions. Moreover, it is not clear that the 1990 accuracy of the Trident II will be adequate if the Chinese are building silos based upon the new 30,000 psi super concrete now commercially available. The 1970 accuracy of a Minuteman III, while a great achievement in 1970, is hardly the same today against really hard targets. Unfortunately, the Minuteman III life extension program did not aim to upgrade the accuracy of the Minuteman.[8] It is not comparable to the Peacekeeper. There are plenty of important targets, including hard targets, the Minuteman III can cover, but super hard targets are not among them.

Even before the discovery of the new Chinese silos, a case could be made from a targeting standpoint for a strategic nuclear force of 2,700-3,000 nuclear warheads. There is a great difference between target coverage (assigning a warhead to a target) and damage expectancy (the probability of target destruction). Claims by Minimum Deterrence advocates, such as the Global Zero "Commission" report that a small nuclear force can do effective counterforce targeting are bogus. Regarding China, the report’s targeting plan involved “(85 warheads including 2-on-1 strikes against every missile silo), leadership command posts (33 warheads), war-supporting industry (136 warheads).” With the new Chinese silos, this targeting approach would require almost 1,000 warheads. Moreover, the approach itself is flawed because it ignores the Underground Great Wall, which protects the Chinese mobile ICBM force, the Chinese Navy and Air Force, and the large Chinese force of nuclear-capable theater-range missiles. The Global Zero report also assigned two warheads against every Russian silo. The report talked about target coverage, not damage expectancy, because its recommended force structure would likely have performed very badly against the facilities it targeted.

Against the very deep hard, and deeply targets (HDBTs) [sic; should read "very hard deeply-buried targets] there is essentially zero chance that they can be destroyed with a single U.S. nuclear warhead. The 2018 U.S. Nuclear Posture Review only partially reversed the Obama administration’s decision to eliminate the two most effective U.S. bombs against HDBTs, the B61 Mod 11 and B-83. These bombs will be retained longer than planned but not be life extended. Once again, numbers matter, and we no longer have the numbers. Conventional weapons have little and declining capability against HDBTs.[9] As one report stated, “One GBUJ-57A/B [Massive Ordnance Penetrator] can only penetrate 8 meters of 10,000 psi rock or concrete. This could drop to 2 meters of 30,000 psi material.” 

More.

Monday, March 15, 2021

Trend for Tanana River Ice-Outs 1917-2020 continues to show them occurring much earlier after 104 years

This is a corrected chart and supersedes all previous iterations. Data in the chart has been double-checked again against printed versions of the data available from the Nenana Ice Classic. One or two dates were incorrectly shown in previous versions of my chart through 2018. 

The overall trend earlier in those charts remains unchanged, however, and has been reinforced by the record-setting early Ice-Out in 2019 on April 14. This is because of the preponderance of relatively earlier Ice-Outs April 30 through May 7, of which there are forty-five. With or without the record early Ice-Out on April 14, 2019 and the relatively early 2020 Ice-Out on April 27, the median date remains the same: May 4. Half the Ice-Outs occur before that date, half after.

Otherwise from April 14-29 there are 27 early Ice-Outs vs. May 8-20 with 32 late Ice-Outs:

April 14-21: 3
April 22-29: 24
April 30-May 7: 45
May 8-15: 29
May 16-20: 3.

Is "global warming" at work?

If you back out all data from the year 2000 onward, here's what you get:

April 14-21: 2
April 22-29: 14
April 30-May 7: 37
May 8-15: 28
May 16-20: 2.

Median date: May 5.

Obviously the biggest impact since 1999 has been on the week April 22-29, adding ten early Ice-Outs, moving the median date earlier by one day after 20 years.

Another thing it does, however, is balance out the data surrounding April 30-May 7, which otherwise was weighted heavier later, with far more Ice-Outs in the second week of May than the last week of April. It could be that over the long course of history prior to 1917 we're missing a lot of early Ice-Outs which recent warming has only now supplied.

For example, we know early 20th century temperatures were warm enough for Roald Amundsen famously to make it through the Northwest Passage from east to west in his small wooden herring ship between 1903-1906. He finally traversed the western half of the Canadian island archipelago during 1905 after being ice bound in the heart of it for two winters. In August 1905 he put in at Herschel Island 5 miles off the north coast of Canada due to ice. From there he skied 500 miles south to Eagle, Alaska, in order to send a message by telegraph wire of the news of his singular achievement. The wire was sent on December 5, 1905. Amundsen spent two months in Eagle before skiing back to his ship and sailing on to Nome in 1906, where his ship then remained until 1972. 

Eagle, AK, incidentally, is about 200 miles due east of the Fairbanks Area, which includes Nenana. The mean average temperature for the Fairbanks Area since 1999 is 28.6 vs. 26.3 1904-1999.

The data for Ice-Outs since 1999 is what it is, evidence of warming.