Help me understand this effect ( lemmy.world )
This is an abrasive disk, rotating at 1500 rpm. When I shine my flashlight at it, it carries the glow with it, approximately halfway around the disk. What am I seeing happen here?
![](https://kbin.pithyphrase.net/media/cache/resolve/entry_thumb/32/37/3237811ea71dcafca5f0892c8fe1d48b8df63488e38a7166d84b6e418dec39ea.jpg)
This is an abrasive disk, rotating at 1500 rpm. When I shine my flashlight at it, it carries the glow with it, approximately halfway around the disk. What am I seeing happen here?