Asphalt.
You know, that's that wonderful tari black stuff that we put on roads and parking lots.
Asphalt was created to as a cheap way to make nice, smooth and relatively hard roads and they were pretty good.
They are pretty good.
Most of the roads that cars drive on in cities are asphalt, of course, out in the country in, in big, big countries like Russia and Canada, there are thousands of kilometers of dirt roads.
No, it's fine.
But the major highways and main arteries that trucks and cars drive on is made with asphalt.
Asphalt is relatively cheap and you can put stone into the tar mixture and depending on the stone mix, you get different qualities in the asphalt.
It's soft and if you heat it up to a low a shall we say? Not too hot temperature? It becomes viscous liquid.
It, it sort of can flow and you can move it around, but in daily ordinary temperatures it's relatively hard.
It creates problems in the summer because it absorbs heat.
So now as you walk across asphalt, the asphalt itself is hot, baking in the sun.
Now there's two other problems that it has it radiates the heat and it also reflects the heat.
So as you walk across the asphalt, not only do your feet get hot from the asphalt, but the heat is reflecting and radiating up from the asphalt to you and the air around you.
And so you get very, very hot.
This can create sort of heat cities where the city gets hotter than the countryside because of the asphalt concrete does that too.
But asphalt is probably bigger in terms of surface area.
However, these days, we have a new problem as the climate is getting hotter and hotter, it's becoming too hot for the asphalt and some of the asphalt becomes soft and the cars are sinking into it.
This is a big problem.
I'm not sure what the scientists and engineers are doing now, but they're probably hard at work trying to make asphalt that remains hard at hot temperatures because we're getting all sorts of heat waves these days.
So, be careful when you go walking across the parking lot next time because there's a lot of heat coming off that asphalt.