i mean why some people do not believe in God, angles, etc
a lot of interesting answers here: my take-----------------------------------. depending on where you live and your budget for water; copper costs more but is strong and reliable and i'd use type L. structurally stronger. i've never quite gotten used to the thought of plastic hidden in my walls. in my city it's illegal in the wall anyhow. now for drain; 2nd floor plastic whether PVC or ABS will suffice. depending on your city, some places plastic is illegal because it's considered combustible and not as structurally sound and therefore outlawed. lastly, you will hear the water rushing through the vertical mainline in the wall whenever someone flushes upstairs. with that in mind, i'd use cast iron for the verticals in the walls and for the bottom floor and ABS for everything above that.
Copper is the reference standard for residential water lines. Use it. Learn to sweat a joint. Hubless cast iron is the reference standard for drains. Lasts forever. There are (hubbed) cast iron systems in Europe that have been in continuous operation for over 500 years. Hell, the fountains at Versailles have a cast iron DWV system and it has been fine for over 300 years. --EDIT-- OK, ok. PVC for the drains. That would make it much more DIY friendly. But, there ARE advantages to hubless cast iron. It doesn't catch fire. It is almost completely soundproof. It is made from 100% recyclable material and is thus greener (nobody recycles PVC DWV pipes, no money in it and no weight to it). Cast also holds itself up, it is a structural member of the house. Cast doesn't experience deflection under load. No, you don't pack lead and oakum into cast hubs anymore. They usually don't even use hubs. Most installs are HUBLESS. They use a hubless connector. If you have the money, it will help resale value and you will love it while you live there. You owe it to yourself to at least look at the costs versus plastic.
It's basic instinct. People only believe in what they can sense be it smell, touch, taste, sight, or by hearing. They lack the faith that something may exist even if it's not tangible.
A magnetic field is part of the material world, and can be predicted, demonstrated, tested, and proved--both in its existence and its relationship to visible objects--by the same scientific principles with which one understands solid matter. Even though a magnetic field at first seems invisible, it is easily made visible and calculable. There is nothing supernatural about magnetism; rather, it is a well-understood physical phenomenon. God and angels can be seen only in entirely different ways from the ways in which we understand physical phenomena.
Because God is not prove-able. Basic science- evertything can be tested. God can not be. So you can not prove he exists or doesn't.
