Greetings fellow nerds.
I was recently informed of a very interesting property about peanut butter.
Apparently it glows in the dark. Yeah I totally didn’t believe it either at first.
All you need is some fresh peanut butter, pretty much any brand should work.
Then you’re going to need a blue or violet laser pointer.
The glow in the dark effect is very weak and barely noticeable with regular light so a laser pointer is needed.
Now when we shine it on the peanut butter
it fluoresces a bluish white light that’s very different from my violet laser pointer.
So it’s definitely reacting to light.
To see the glow in the dark effect, turn off the lights and let your eyes acclimate to the darkness.
Now shine the laser pointer at the peanut butter.
After letting it charge up a few seconds we turn it off.
And that is amazing. It’s actually glowing!
Peanut butter glows in the dark.
The effect is very weak though and it only lasts for a couple of seconds, but it’s happening.
Now you might have trouble seeing it yourself because the laser spot is bright enough that it photobleaches your eyes
making it harder to see faint objects.
The same effect occurs when you go from a bright room to a dark one and have to wait for your eyes to adjust.
If this is happening, close your eyes while the laser beam is on and then open them just as you turn off the laser.
You should be able to see the afterglow a lot better.
For extra help, you can also look at the effect through a camera like the one on a cell phone.
Cameras tend to recover a bit quicker than eyes.
Now some people might say that this afterglow is actually the camera being affected by the laser and not from the peanut butter itself.
An easy way to disprove this is just to shine laser on my logo sign here.
As you can see there is no afterglow on the sign but there is an afterglow on this peanut butter.
So it's not the camera it's the peanut butter.
Now why does peanut butter do this?
There are a number of phenolic compounds and proteins that fluoresce
and also exhibit delayed luminescence or afterglow.
This also occurs with a lot of other nuts like almonds and cashews but works particularly well with peanut butter.
As for the exact name and state of the compound that’s doing this, I honestly don’t know.
Biological substances can have millions of unique natural chemical compounds in them.
Perhaps a biochemist can respond in the comments.
Now some people might argue it’s not the peanut butter, it’s the jar that’s glowing.
Well that can be disproven by just getting some of the peanut butter out in the open.
It’s still working. So it’s not the jar, it’s definitely the peanut butter.
Now is there a way to improve the persistence of this effect? Actually yes.
Here is some peanut butter i’ve put in a plastic bag and i’ve frozen it in the freezer.
Freezing tends to improve fluorescence and phosphorescence for some compounds.
Let’s see if peanut butter is one of them.
I think the glow did last a bit longer.
So if you want to improve the glow of your peanut butter, freeze it first.
For a thorough explanation of why this works, check out my video on fluorescence.
I’ve also included the links in the video description.
Okay, let’s go all the way now.
If freezing ice cold improves the persistence, let’s try something even colder, liquid nitrogen.
So here is our dewar of liquid nitrogen, and here is our spatula of peanut butter that i’m going to drop in.
Okay, here is our laser.
That lasted a good second or so longer than the ice cold peanut butter we had earlier.
Overall this really amazes me.
I honestly never thought that something like peanut butter would glow in the dark.
Man I love science.
Thanks for watching.
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