4 ms·
If I remember my physics classes correctly, this is a surprisingly easy phenomenon to understand. 1. Lasers heat things up. In this case, they're heating up ai
by dragontamer 3y ago
If I remember my physics classes correctly, this is a surprisingly easy phenomenon to understand.
1. Lasers heat things up. In this case, they're heating up air.
2. Hot air has lower-resistance than cool air. This is why lightning happens at all: as lightning goes through its path, it heats up the air hotter-and-hotter, which allows for more and more electricity to flow. That is, lightning itself heats up the air which makes the lightning more powerful.
3. This article talks about a device that uses lasers to heat up air ahead-of-time, where you heat up the air along pre-designated "safe" paths to provide a virtual lightning rod composed of this narrow stream of hot air... rather than a metal rod.
- euroderf 3y agoCan we add this to forest fire watchtowers ? Could it be done with a solar+battery system ? One notes that for the rangers stationed in them it would be a hair-raising experience.
- deleted 3y ago[deleted]
- onos 3y agoIf it can be directed in this way I wonder if the lightning could be harvested to charge up a battery somehow.
- _trampeltier 3y agohttps://en.wikipedia.org/wiki/Harvesting_lightning_energy https://en.wikipedia.org/wiki/Harvesting_lightning_energy No one has is really done yet. I think also in Switzerland, ETHZ tryed it some years ago, but when the lightning hit, he blew up everything.
- dragontamer 3y agoCharging up a battery requires a lot of _energy_. Lightning doesn't have much energy. Exploding something requires a lot of _power_. Lightning is very, very high power. -------- So a dam collapsing demonstrates energy vs power, for example. The floodwaters race across the land slowly, having a small amount of power. But the floodwaters move for hours-and-hours, days and days, maybe a week or longer. That's energy, the ability to move for a long-long time. Lightning is the opposite. Its an explosive amount of power, but it only lasts for a fraction of a second. Its so short that there's barely any energy involved. A power-plant (and a battery) needs both. Which is where things get tricky.
- sidpatil 3y ago> That is, lightning itself heats up the air which makes the lightning more powerful. https://en.m.wikipedia.org/wiki/Thermal_runaway https://en.m.wikipedia.org/wiki/Thermal_runaway