MTL - Rebirth Daughter Against the World - Chapter 9 not very scientific

Julian Weber is an officer in the U.S. Army Corps of Engineers and a graduate of Westpoint Military Academy with a degree in civil engineering. As U.S. involvement in Afghanistan comes to an end, Lt. Julian Weber finds himself involved in a terrorist attack by the Taliban, which claims his life.

However, he quickly finds out that death is not always final as he is reincarnated into the body of a Baron’s son and heir in an alternate Earth set in Late-Medieval Europe. In an era of political turmoil and civil strife, the Baron’s young son is named Regent of the Barony of Kufstein and forced to contend with feudal powers. Will he be able to institute reforms leading his Barony into the age of industry?

Or will he succumb to the pressure of his feudal overlords and a corrupt church that seek dominion overall?

The aristocratic Lu family has produced a joke, a beautiful one, but a joke nonetheless. The daughter they have been rearing all this while turns out to be an imposter! With the real heiress returning to take her rightful place, everyone is eager to know the outcome of the imposter…Will she be able to survive in poverty after living a life of riches?Having just transmigrated, Huo Yao imagines that this experience will be pretty interesting. However, imagination and reality are always so different!Dad: “Daughter! Take this black card. It has no limit! Use it freely.”Mom: “My dear Yao Yao! If you don’t like this jewelry, I’ll get them to change it immediately.”Huo Yao: “…”Weren’t they supposed to be poor and ordinary? What is with this hidden lavish behavior?Her eldest brother, an investment company’s CEO: “Sis, inherit my company!”Her second brother, a top lawyer: “Whoever dares slander my sis will face the full brunt of the law!”The third brother, an international genius doctor: “Bullying my sister? Should I display the prowess of my scalpel?”Mysterious fourth brother: “My sis is the cutest!”Huo Yao: “…”What happened to being a good-for-nothing person who lives off her parents?A top aristocrat secretly changes into his cheap clothes and drives his crappy old car to her. “Baby, my heart is yours. Why don’t we get married to test if I’m telling the truth or not?”Everyone who knows about it, doesn’t dare say it out loud.All they can do is curse inwardly: “Bah! Keep acting! No one believes it!”

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).