Elizabeth Weise

The sun's light is actually a mixture of all colors. It's not white, but that's how our eyes perceive it. So if you want to make an LED light that is white,

The sun's light is actually a mixture of all colors. It's not white, but that's how our eyes perceive it. So if you want to make an LED light that is white,

the way that it's usually done in these streetlights is you have a royal blue led and you top it with this silicon phosphor layer that is yellow and then some of the light from the led gets through and is blue but some of it is filtered through the phosphor silicon layer and is yellow. And together, those two things we perceive as white light.

the way that it's usually done in these streetlights is you have a royal blue led and you top it with this silicon phosphor layer that is yellow and then some of the light from the led gets through and is blue but some of it is filtered through the phosphor silicon layer and is yellow. And together, those two things we perceive as white light.

Some of the batches that were made, and they've clearly been widely distributed because these have shown up not just in more than 30 states, but also in Canada and in Ireland, that silicon phosphor layer started to crack and eventually fall off. And so instead of You know, it's kind of like you put a filter in front of the light and it's suddenly a different color.

Some of the batches that were made, and they've clearly been widely distributed because these have shown up not just in more than 30 states, but also in Canada and in Ireland, that silicon phosphor layer started to crack and eventually fall off. And so instead of You know, it's kind of like you put a filter in front of the light and it's suddenly a different color.

That filter went away and suddenly they're just emitting purple light.

That filter went away and suddenly they're just emitting purple light.

Nobody has attributed any massive pileups or anything to them, if that's what you're wondering. The lighting experts have said that, you know, one thing is drivers really rely on color.

Nobody has attributed any massive pileups or anything to them, if that's what you're wondering. The lighting experts have said that, you know, one thing is drivers really rely on color.

as a way to identify objects that are either next to the roadway or in the roadway so if the purple light makes things take on a different color it might be harder especially if you're driving quickly to identify them fast and to react to them also there's concerns that these lights they're just you know they're kind of surprising and they can be a little glary and so it might distract drivers and create some issues so that's why they're being replaced though in some places people are saying no we really like these and

as a way to identify objects that are either next to the roadway or in the roadway so if the purple light makes things take on a different color it might be harder especially if you're driving quickly to identify them fast and to react to them also there's concerns that these lights they're just you know they're kind of surprising and they can be a little glary and so it might distract drivers and create some issues so that's why they're being replaced though in some places people are saying no we really like these and

The cities are like, yeah, no, we really kind of need to go back to white.

The cities are like, yeah, no, we really kind of need to go back to white.

As always, a pleasure.

As always, a pleasure.