system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does paper light more easily on the edge rather than placing a flame directly underneath?

ELI5: Why does paper light more easily on the edge rather than placing a flame directly underneath?
gpt
On the edge, there is less area to heat up to the combustion temperature. When you light it from the middle, the heat from the flame dissipates more quickly due to the larger surface area, which makes the paper take a much longer time to heat up to a hot enough temperature.