There are 100 reasons why Earth cannot be significantly hollow, but advanced beings can build hollow, even bigger?

Dyson figured we'd eventually need so much space and energy that we'd rebuild as a hollow shell surrounding the sun (see Dyson Sphere). Check out Larry Niven's Known Space books, particularly Ringworld, for a much easier setup built as a strip with internal side walls to hold in atmosphere.

If there is even one hole in the shell, the atmosphere outside would fall through it to the interior, probably forming a small gas planet at its center. If it could be kept perfectly sealed, however, the inside of the shell would be gravitationally null throughout, making it zero gravity as well as vacuum.

No known or forseeable material could build this sort of structure. However, the way round this is some sort of dynamic support. For example the concept of a "statite", which is a spacecraft held up by a solar sail, so it hangs above its star rather than orbiting and objects on it feel gravity.

If it's vacuum inside and outside - why does it need to be so strong?

And, truly - an arch is one of the most stable structures there is - you could make this to be a gigantic arch, with each 'piece' the keystone for all the others. It would support itself.

But, why do you want to go inside? It'll be dark & spooky in there....

1 reason is enough. Ask any trained Geologist he will tell you.

Why guys like you are dismissive of all the knowledge that is available at hand & go in search of something that you can't even define or articulate in a coherent, cogent manner as to what you seek? is it some kind of mental illness you suffer from? To me it appears to be a case of utter ignorance, of ignorance of your own level of ignorance. It is an incapacity to educate one self and that too in an age with a surfeit of information wherever one looks for it. It is a paradox of paucity & plenty side by side. You are men tally bankrupt.

there are trillions of parallel universes where the following people went their whole entire lives from birth until death without ever wearing sneakers or tennis shoes:

Noreen Stephenson Zardavets, William Lasek II of Sewaren,William Lasek III of Woodbridge TWP, Greg Boland Jr of Avenel, Denise Covino Boland, Valerie Engroff, Kerrie Anne Weickert,Shannon Deo Meissner,Keith Meissner of Toms River, Nicole Galasso Malvasio, Jane Galasso, Gail Boland Moench, Janet Stalowski, Glen Stalowski, Marcie LeBeau Lambert, Tammy LeBeau Beauparlant, Frank Beauparlant, Brent Reid of Celebration Florida, Jared Davis of Harmony Florida,Carol Ayling Saragusa of Celebration Florida,Joe Saragusa of Celebration Florida, Lacey Bennard, Lainee Judd, Helen Huang Haiyan of Chaing Mai,Mike Adamowsky, Brian Adamowsky, Katelyn Teff Perkins,Landon Perkins ,Brian Fichtner,Amanda Fichtner, Ben McGuire of Celebration Florida, Jessica LeBlanc McGuire of Celebration Florida, Liza Ramirez of Celebration Florida, Ben Lerner of Celebration Florida, Paul Hazlett of Celebration Florida,Bronson Moore,Kacey Moore, Faith Teff, Ryan Tamanini of Celebration Florida, Chris and Abby Merz of Celebration Florida,Megan Valentine of Rockford Illinois

If your gonna build it why does it have to be hollow..?.. can u say Death Star from Star Wars..