Here's why:

* It's a gas: Natural gas exists as a gaseous mixture of hydrocarbons, primarily methane. Gases are not solid or liquid and don't have a fixed shape or volume.

* It's underground: Natural gas is extracted from the Earth, where it exists in underground reservoirs. You can't directly touch or hold it.

* We store and transport it: We store natural gas in pressurized containers or pipelines and transport it as a compressed or liquefied gas. These containers and pipelines are tangible, but the natural gas itself is not.

However, the energy derived from natural gas is tangible. When we burn natural gas, we release heat energy that we can use to heat homes, generate electricity, or power vehicles. This energy is measurable and has a tangible effect.

So, while natural gas itself isn't something you can touch, the energy it provides is very real and tangible.