# My onions made lightening

**URL:** <https://boards.straightdope.com/t/my-onions-made-lightening/267477>\
**Category:** Factual Questions\
**Created:** [October 4, 2004, 4:46pm UTC](https://boards.straightdope.com/t/my-onions-made-lightening/267477 "2004-10-04T16:46:29Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\
**Post date:** [October 4, 2004, 4:46pm UTC](https://boards.straightdope.com/t/my-onions-made-lightening/267477/1 "2004-10-04T16:46:29Z")

</div>

I wanted to put some onions on the hotdogs that I cooked for lunch today. My insides become displeased when I eat raw onions, so I diced some onion and stuck them on a plate in the microwave. Just a few seconds after turning the microwave on, I heard loud buzzing. I turned around to see a fireworks show in the microwave :eek: . The onions had little burnt bits where they had arced. Does anyone know what’s going on?

I googled a bit and came up with [this](http://www.madsci.org/posts/archives/sep2000/968259641.Ph.r.html). I never really learned anything about this stuff in my undergrad physics classes (easy intro classes that all the pre-med kids took) so this is a bit over my head. Does it make sense? Can anyone dumb it down a bit for me?

---

<div class="post-metadata">

**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\
**Post date:** [October 4, 2004, 6:14pm UTC](https://boards.straightdope.com/t/my-onions-made-lightening/267477/2 "2004-10-04T18:14:34Z")

</div>

I’ve done the ‘grape trick’ described on your link. I think that since the width of the grape/onion is approaching a significant portion of the microwave’s wavelength, different voltages appear on each side of the grape. Different voltages in contact via a conductor don’t get along and _fireworks_.

I was quite suprised at how bright and loud the grape halve in the microwave were the first time I tried it. Still wows my friends who haven’t seen it.

---

<div class="post-metadata">

**Author:** ![bughunter](https://avatars.discourse-cdn.com/v4/letter/b/aeb1de/32.png) [@bughunter](https://boards.straightdope.com/u/bughunter)\
**Post date:** [October 4, 2004, 9:22pm UTC](https://boards.straightdope.com/t/my-onions-made-lightening/267477/3 "2004-10-04T21:22:41Z")

</div>

> [@Ruken](#):
>
> My onions made lightening

Oh yeah?

Well, my beans made thunder! 😃

(Seriously though… you almost answered your own question. A little more googling and you would have run across accounts of [electromagnetic induction](http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=electromagnetic+induction+microwave+grapes) or [ball lightning produced by grapes](http://www.google.com/search?hl=en&lr=&ie=UTF-8&newwindow=1&safe=off&q=ball+lightning+microwave+grapes&btnG=Search).)

---

<div class="post-metadata">

**Author:** ![teela\_brown](https://avatars.discourse-cdn.com/v4/letter/t/d9b06d/32.png) [@teela\_brown](https://boards.straightdope.com/u/teela_brown)\
**Post date:** [October 4, 2004, 9:42pm UTC](https://boards.straightdope.com/t/my-onions-made-lightening/267477/4 "2004-10-04T21:42:21Z")

</div>

Hey! I thought it was just my microwave. I sometimes nuke a couple of chopped cloves of garlic in olive oil in a little pyrex bowl when I want to add them to a recipe. They often spark and arc, but no other veggies do this, IIRC. Of course, the only other veg I nuke is sliced carrots in water.