Various Discussions

First of all, I apologize for the recent instability in updates.

I've been quite busy with work lately, and there have been many unexpected tasks, so I haven't been planning my writing.

Regarding some purely technical issues that have arisen in the book review section, I would like to offer some clarifications from a purely scientific perspective.

I. Rockets and Artillery A. Power: A 155mm artillery shell weighs 45-50 kg, with a warhead of about 8 kg. The absolute lethal radius is 10 meters (regardless of armor protection or evasive maneuvers). Against exposed personnel, the lethal kill radius is about 50 meters, and the effective fragmentation kill radius can reach 150 meters.

The AR3 system and the "Shenlong" 300mm guided rocket exported by China are examples of rockets.

Diameter: 300mm.

Total weight: 840KG

Warhead: 150-200KG

It is very clear that the rocket has a superior propellant ratio.

By the way, let me correct a common misunderstanding. "One 155mm shell can cover an entire football field."

This is conditional:

1. To deal with exposed infantry targets. 2. An airburst at a height of about 20 meters, creating a fragmentation coverage, or simply a shrapnel grenade. "Coverage" is a technical term referring to the range of the "lethal element." It can kill at that distance, but not all of it, since the fragments are limited and random.

Imagine you scoop up a ladle of water and can water up to 10 meters away. The area you "cover" is about 100 square meters. But if you want to water thoroughly, you'll need to pour several buckets of water.

****

B. Flight speed: "Shenlong" 300, flight speed will not be lower than Mach 4.

The 155mm gun has a muzzle velocity of Mach 2-2.5, which decreases continuously after leaving the barrel.

C. Range: The range of the Shenlong 300 is 70-130 kilometers. This depends on the actual configuration during launch and the amount of money spent by the client.

And this is the data without any modifications.

Taking the PLZ-05, a currently serving 155mm self-propelled howitzer, as an example: its standard shells have a maximum range of 40 kilometers, while extended-range shells have a range of 70 kilometers, but with a reduced propellant charge.

In the storyline, the attack range is over 70 kilometers, exceeding the range of conventional artillery. And 155mm is already the largest caliber of land-based artillery currently in service with various countries.

D. Firing accuracy of the 155mm howitzer: The circular error probable (CEP) of ordinary ammunition (CEP: 50% of the shell's impact range) is 120-160 meters at a distance of 40 kilometers.

The CEP of guided projectiles is 5 meters or less.

"Shenlong" 300 rocket: meter-level CEP.

Guidance is essential for long-range weapons and for precision attacks. A weapon that cannot hit its target has no destructive power.

E. Firepower projection density – this goes without saying, right? Rockets were developed specifically for this purpose.

F. The traditional advantage of artillery, sustained firepower, is needed in some combat scenarios.

****

On the real battlefield, the situation is constantly changing. Both Russia and Ukraine are using drones to guide and use guided weapons to precisely kill targets, moving away from the past situation where 5,000-10,000 artillery shells were needed to kill one enemy.

Traditional artillery is now being used more as a tool for demolishing urban warfare environments.

This story does not develop land-based artillery. Electricity is available in the plot, and platinum group metals will soon be implemented. This is for ultra-high-power electronic components such as supercapacitors.

The route should be quite clear.

Second, space-based weapons are "less powerful than a single 155mm artillery shell."

I'm a little hesitant to talk about space-based weapons.

1. Criticism of the plot is welcome.

2. Clarify the technical issues.

The published paper, "Theoretical and Experimental Study on Rock Penetration and Ground Impact Effect of Ultra-High-Speed Long Rod Projectiles," also known as the one that claims the Rod of God is the true owner of the waste, states the following: A 140kg tungsten rod impacts the Gobi Desert at a speed of 4650m/s, forming a parabolic crater with a depth of 3.0m and a diameter of 4.6m.

Media reports therefore indicate that a 140kg tungsten rod is less powerful than a single 155mm sintered bullet (which can penetrate the ground to a depth of 2-3 meters).

But the question is, how many people actually read the original paper?

Are sensational headlines from the media all there is to it?

I think this should be basic common sense in modern society. The media always writes the most eye-catching articles, but if you only look at the headlines, the information you get will be 100% wrong!

A 155mm shell weighs 45-50 kg. Assuming an 8 kg Type B explosive warhead, its TNT equivalent is 12 kg. With a ground velocity of 600 m/s, its kinetic energy is equivalent to 2.1 kg of TNT, totaling 14.1 kg. Its absolute lethal radius is 10 meters.

The paper "Research on Ultra-High-Speed Long Rods" provides data showing that the tested tungsten rod weighed 140 kg, had a ground contact speed of 4650 m/s, and its kinetic energy was equivalent to 361 kg of TNT, which is 25.6 times that of a 155mm artillery shell.

At 13.6 times the speed of sound, this 140kg test tungsten rod had a ground impact kinetic energy exceeding that of a 155mm artillery shell, including its explosion, by 25.6 times. So why did it only penetrate three meters?

This counterintuitive statistic is a fact, but it's also interesting science, as explained in detail in the main text.

In my personal opinion, a responsible report should explain the intricacies of the situation, rather than simply stating "shocking."

The original paper analyzed the relevant physical phenomena. When the projectile speed exceeds 1.5 times the speed of sound, its penetration into a hard surface becomes semi-fluid. When the projectile speed is greater than 3 times the speed of sound, the solid penetration mode changes to fluid penetration, resulting in a sharp reduction in the penetration depth of the hypersonic tungsten rod. Especially at the critical value jump, a precipitous drop occurs.

The study investigated the actual penetration effect of a metal rod launched using technical means. The data showed that as the velocity increased, the effect of the metal rod on the ground became closer to a shallow-buried explosion, or even a surface-impact explosion, releasing energy in all directions.

This is also why currently operational bunker buster bombs have an impact speed of around Mach 1. For example, the GBU-57, which "shone brightly" during the recent Lighthouse on Iranian nuclear facilities, had an impact speed of 443 meters per second, which is equivalent to Mach 1.3, lower than the critical value of Mach 1.5 for entering semi-fluid penetration.

The above content is limited to tungsten rods. Numerous published papers analyze the effects of earth-penetrating hypersonic weapons, which are quite complex and will not be elaborated here.

Returning to the 140kg tungsten rod in the paper's experiment, its 24.6 times greater explosive energy than a 155mm artillery shell didn't dissipate downwards. So where did it go? Did it simply vanish into thin air?

Due to word count limitations, I'll get straight to the conclusion.

In everyday life, if a 140kg tungsten rod traveling at 14 times the speed of sound were to run over your vicinity, it wouldn't drill a deep hole; instead, it would explode directly on the ground, releasing energy equivalent to the explosion of 25 155mm artillery shells. Approximately 30% of this energy would spread outwards in the form of a shockwave.

According to the relevant formula, please stay at least 30 meters away from it; this is the absolute lethal range, regardless of any protection, and there's no need to struggle. If you can stay more than 100 meters away, the survival rate will increase significantly, and you might even survive.

This explains why Ling Wen and the others weren't directly hit by the explosion, but were all severely injured. This also illustrates that the primary means of killing living organisms with explosive weapons on the battlefield is not shrapnel, but the shockwave.

The scenes in movies where large-caliber shells explode at very close range and survivors are impossible.

Because the internal organs of a living organism will shatter under such overpressure.

Using the extreme example of the little boy, the number of people who died on the spot in Hiroshima was 70,000 to 80,000, of which about 60 to 70% died from the shock wave, far exceeding the lethality of heat radiation and early radiation. Note that this is the data on deaths on the spot, not including the 70,000 deaths from various subsequent effects.

in conclusion:

Space-based weapons are considered inferior because of their disappointing ability to strike underground facilities. This doesn't mean they lack power; it's just that the way they deliver that power is ineffective.

If it can truly penetrate a hundred meters of rock, or even just a few dozen meters, it will be deployed no matter what.

The cost of launching into space is not really a problem, because Lighthouse are a magical country where everything is incredibly expensive, regardless of the initial cost.

According to Musk's publicly stated price, low Earth orbit costs $3,000 per kilogram, so a one-ton rod would only cost a mere $300.

A shipping cost of tens of thousands of dollars isn't worth a single keystroke from a Wall Street actuary.

In comparison, a single GBU-57 costs over $4 million. During Operation Midnight Hammer against Iran's nuclear facilities in June of this year, the Lighthouse used 125 aircraft to drop 7 GBU-57s. Despite such a large-scale operation, actual on-site measurements showed that the penetration depth into hard rock layers was less than 20 meters.

Honestly, the GBU-57 is less effective than throwing a stick.

(The GBU-57 weighs 13.6 tons and carries 2.4 tons of explosives. In Midnight Hammer, the flight cost of just seven B-2s was $38 million, and with the addition of tankers and other 118 aircraft, the direct cost is generally considered to exceed $300 million, not including subsequent maintenance and repairs. Real-life events are always more outrageous than fiction.)

Then stack armor.

Besides the paper mentioned above, this research team has published many other papers on hypersonic weapons, all of which are publicly available and in books. I have only read a very small portion of them.