Science Buddies: "Ask an Expert"

hello guys! google sent me to this site and forum, and i think i am in the right place for my question

Anyway, i am working on my book trilogy (dystopia-mystery-thriller- slightly sci-fi) where i stumbled upon a big problem, to which i can not find an exact solution on the web.

The point is, there is a fictional city that rests by the sea, and three lighthouses that are 10-15 kilometers away from that city. Each are distant among themselves approx 10 km. In the center of that triangle, lies a small island, upon which the dangerous alien entity is encircled with some kind of force shield. The army of that country decided to penetrate the force field and destroy the alien entity for good with a tactical nuclear missile strike. And now comes the question.

How many kilotons would that nuclear warhead needs to be, in order to keep the demolition radius at bay enough, not to reach the city walls? Have in mind that the lighthouses are safe from any possible blast or impact. They do not matter.

You would save my life if you help me out on this. In my novel, i wrote 30 KT, clean nuclear warhead without the radiation fallout.

Thank you all in advance

P.S. If you help me out on this, i think i would have another interesting question, also from the book, but first thing first

Hi nefredil,

This forum is intended to answer questions related to Grade 9-12 science fair projects.

That said, Wikipedia is a good place to start. I would not sweat the estimated payload too much since the details of the weapon technology will be speculative and you've already introduced alien physiology and a "force shield" (and may opt to neglect fallout.)

As the author you'll be deciding precisely where (and how) to depart from our current level of technology and scientific knowledge. This line can be as well-defined or as fuzzy as you like.

https://en.wikipedia.org/wiki/Nuclear_weapon_yield
https://en.wikipedia.org/wiki/Effects_o ... ast_damage

-John

Hey @jkarnes, thanks for your reply ^_^ I appreciate the suggestion you gave me, really

I think i would listen to your advice, and just throw away the mentioning of the specifics and bomb details, after all, it is sci-fi

Thank you very much!!