How to Make the Electric Pickle Experiment


A long-desired experiment in many Intro-to-Lighting lectures, the famed Electric Pickle Experiment is something that many older lighting teachers have shown to their classes over the years.  Ever seen this done?

Also, this:

And one more, for posterity — what’s hilarious at the end of this video is the comment “I wonder what other fruits will glow?” followed by the hot dog…

The Electric Pickle is an interesting experiment that literally burns out the idea of a non-ohmic resistor.  Think light emitting diode — dependent on voltage in order to work.  What happens in the Electric Pickle Experiment is that once a voltage (120V) is placed across the pickle, there are Sodium anodes (Na+, electron expelling) and Chloride cathodes (Cl-, electron grabbing) that are excited to outside orbital levels of the atom.  Just like a sodium vapor lamp, once the electric field charges the pickle, sodium atoms let go of an electron, causing a photon to be released once the haul tail back to lower energy levels in the atom.  The result?  Pickle light!



  • The most salty pickles are the ones that work the beat for this experiment.
  • MAKE SURE that you’re working with some kind of circuit-breaking device in line, like a 15A power strip or a custom-built breaker system in line for this experiment.
  • KEEP THE STUDENTS and OTHER OBSERVERS AWAY FROM THE EQUIPMENT!!!!!!!!!  If possible, get some kind of a blast shield or Plexiglas panel between the pickle and the observers.
  • Get some air to the place you’ll be doing the Electric Pickle Experiment, this thing stinks like none other, seriously.
  • REFRAIN from EATING THE COOKED PICKLE!  It tastes like roasted refried shit!


  • two (2) large nails
  • some kind of circuit breaking device in line with your “pickle circuit”
  • a length (let’s say 3 feet for posterity) of 12 gauge, INSULATED 2-conductor lamp cable or a white insulated and black insulated 12 gauge lead
  • obviously, a male Edison plug (which is a redundant statement, five extra credit points for WHY)
  • a glass container that is JUST larger than the pickles you’re using
  • two 20A alligator clamps WITH RUBBER SAFETY SHIELDS on them


  1. install your lamp cable or single lead runs into the Edison plug
  2. install the alligator clamps to the other ends of the lamp cable or single leads — ONE CLAMP PER LEAD!
  3. insert a nail into either side of the pickle
  4. place the pickle onto the glass jar, allowing the nails to rest on the glass jar, suspending the pickle
  5. plug your circuit breaking device into the power source with the DEVICE IN THE OFF POSITION
  6. attach the alligator clamps to the nails, one per nail, to complete the circuit once the pickle is plugged in
  9. Have someone standing by at the light switch in the room
  10. Plug in the pickle in to the power, then switch the breaker ON
  11. shut off the room lights, observe the pickle light!

Lots of care and caution need to go into this experiment.  Why?  Because I said so, and because this is putting 120V, 15-20A through a PICKLE.  It’s DANGEROUS!

Items of Note:

  • You can use a dimmer or rheostat to achieve this experiment successfully, too — just make sure you kill the power when the pickle quits doing its light bulb trick.
  • Make SURE you have some air to your room, this is a stinky experiment!
  • Once you have done the experiment, make sure that you either remove the “pickle probe” from student pervue for safety.  You never know, even in University settings.  Hide that thing.
  • If the pickle weren’t already green, you’d be seeing light in the 588-590nm wavelength range.  Crazy, huh?



BONUS NERDERY:  Here’s Vladimir Bulovic to tell the world about how OLEDs and the glowing pickle have SO many things in common!

Thanks to PopSci and S3 for the pickle-images!

Moonlight Mini-Lesson

The above photo by Andrew Tallon was taken at 10:30 pm! What I love about this image is it perfectly exemplifies that our moon is just a reflector for sunlight.

So why don’t we see our night landscape this way, if a camera can capture it?

A number of fascinating factors!

Our moon’s albedo (the measurement of amount of light reflected by astronomical objects) is 0.12, which means about 12% of light which hits the moon is reflected. This amount is subject to fluctuation by numerous factors, including the phase of the moon. The amount which hits the earth’s surface can be–and frequently is–significantly less.

To capture the above image, the shutter was open for 30 seconds. Our eyes have our own tricks for seeing in low-light scenarios, which involve our fantastic friends the rods and cones. The outer segment of rods contain the photosensitive chemical rhodopsin (you might know this as visual purple). Cones contain color pigments in their outer segment. Our rods predominantly help us in low light level environments, which means that we have significantly decreased color perception in moonlight.

Cones are located in the center of the eye and are high-density. Rods meanwhile are located around the cones, so in extreme darkness, a 1° blind spot is developed in the central region of the eye where there are only cones. Rods reach their maximum concentration around 17° each direction from the center line, so sneaking some sideways glances actually improves your nighttime perception.

Our rods are not equally sensitive to all wavelengths of light. They are far more sensitive to blue light, and at around 640 nm, are pretty much useless! Click this graph from the University of New Mexico to check it out:

This means that the color of light the moon is actually reflecting appears significantly different to us because of its low intensity.

A neat example I found on the American Optometric Association’s Website which caught my interest was:

For example, in a darkened room, if one looks at two dim lights of equal illumination (one red and one green) that are positioned closely together, the red light will look brighter than the green light when the eyes are fixating centrally. If one looks to the side of the dim lights about 15-20 degrees, the green light will appear brighter than the red.

If you’re planning on shooting your own moonlight landscapes, be a light geek! It is hard to find focus at night, so place a luminous object near your focus, whether it’s a lantern, or a friend with their cell phone! If you want to be super geeky, tape a laser pointer to the top of your camera, then manually focus on the dot.


So, with all of this science in mind, how would you replicate moonlight now, vs how you did previously?

What the #$%& is Amber Drift? [Infographic]

A few months ago, I received an email from a reader about explaining the phenomenon of Amber Drift.  I was feeling froggy, so I figured I’d make an infographic to attempt to give a simple explanation to this phenomenon.  Happy FRIDAY!

If you click on the image, it’ll open up in its original large size – so check it out!

Cree LED Launches TEMPO – An LED Luminaire Testing Service

You all know me, I’m not really a “press release” kind of guy when it comes to content.  When I find a press release worthy of a nod, I try to get some of the commentary in there that made me want to talk about the release in the first place.  This press release from Cree, Inc made me want to know more about this service they’re starting up called TEMPO.  From the press release at Cree:

Cree, Inc. (Nasdaq: CREE), a market leader in LED lighting, announces the commercial availability of TEMPOâ„¢ Services, a comprehensive set of quantitative and qualitative tests and analyses for LED-based lighting fixtures and lamps. TEMPO (Thermal, Electrical, Mechanical, Photometric and Optical) Services represent the accumulated advantage of Cree’s extensive experience with customer LED systems combined with the use of calibrated test equipment to give LED lighting manufacturers and end users confidence in LED product designs.

Third-party labs currently provide testing services, such as IES LM-79, which is widely regarded as the most comprehensive LED luminaire test in the industry. However, through years of experience with component LEDs and Cree LED-based lighting systems, Cree has identified many other aspects of end-product quality that are not and cannot be examined by third parties. These aspects of quality include chemical compatibility between materials used in the luminaire and the LEDs, the effectiveness of mixing slightly different color LEDs for enhanced color consistency and TM-21 LED lifetime projections.

Ok, interesting.  What this service provides is an evaluation of a fixture (LED lamp source) by a bunch of standards used by the Department of Energy and Illuminating Engineering Society.  Cree also adds to the service that they have about eleventy billion man hours working with LEDs and creating designs that worked and did not work, and learning from their mistakes.  You know, like Edison said – and I’m paraphrasing here – “I didn’t fail at inventing the light bulb.  I came up with 2,000 ways NOT to make a light bulb.”  I can totally get behind that.  In my head, it’s kind of like taking advice about being an alcoholic from someone who’s never had a drink.  I’d want to know about it from someone who’s succeeded AND failed.

It’s important to look at the standards Cree mentions in their press release regarding the TEMPO service.  IES LM-79, which is the IES’ approved method for “Electrical and Photometric Measurements of Solid-State Lighting Products.”  LEDs, for all-intensive purposes, are solid-state lighting products, in case you hadn’t quite yet put that together:

IES LM-79 tells how to test and get reproducible measurements with solid state lighting – things like using integrating spheres and goniophotometers, measuring Luminous Flux, Efficacy, Intensity Distribution, and so on.  It’s a standard for having a standard way to test LEDs. It also talks about power supplies and regulating voltage, thermal conditions for the products being tested, product seasoning and stabilization, and orientation to name a little bit.  The other IES standard being mentioned by Cree is the IES TM-21 standard, which deals with Lumen Depreciation and long-term lamp life estimating.  TM-21 is a long-term version of IES LM-80-08 in a way, as LM-80-08 (the standard for testing Lumen Maintenance in LEDs and arrays) doesn’t deal with long-term predictions.

It’s so exciting whenever I get to break out my IES Compendium!  NO WONDER I’m single!

I pulled a sample report from the Cree TEMPO Service website to see what kinds of things that would be included in their heaviest service, the TEMPO 21 service.  I have to say that from learning what I learned in Sweden about luminaire inefficiency, this would be a pretty awesome service to have if you were a luminaire designer or LED engineer.  Cree’s TEMPO21 provides the following testing:

Thermal & Mechanical

  • Solder Point Analysis (Tj/Tsp)
  • Thermal Imaging With IR Camera*
  • Qualititive Mechanical Construction Analysis*
  • Chemical Compatibility Analysis*
  • X-ray Of Printed Circuit Board (Solder Joint Analysis)*
  • LED Lifetme Estimate (TM-21)*
  • Review Against ENERGY STAR Criteria*


  • Driver Efficiency*
  • Transient Analysis (surge, inrush, hot-plug)*
  • Power Analysis (Power Factor, THD)
  • Vf/Current Balancing Of Series-Parallel Arrays*
  • Hi-Pot (Dielectric Breakdown) Test*
  • Dimmer Compatibility Check*

Photometric and Optical

  • Luminous Flux
  • Radiant Flux
  • Chromaticity (includes CRI, CCT, x-y, u’v’)
  • Spectral Distribution (350 nm to 850 nm)
  • Illuminance (ft-cd, lux)
  • Fixture Optical Efficiency (% loss)
  • Fixture Efficacy (lumens/watt)
  • Binning And Color Point Evaluation*

* denotes a test not offered by other third-party luminaire testing facilities

You need to check out a copy of their sample report, which gives the full range of what the TEMPO service provides for your luminaire.  I took a few screen grabs of the report, but it’s free, you should just go and download it:

Cool.  I’m excited to see how this plays out, this kind of analysis really appeals to me and my nerdiness.

The State of Electronics – Karl von Moller’s Documentary on the Electronics Industry

Have you all heard about this cool documentary that’s being made by Karl von Moller?  Karl’s making a “State of Electronics” documentary on the history and progress of the Electronics Industry in Australia.  Electronics is a wide industry – but I think what a lot of people forget is that semiconductors is a large part of that industry, and semiconductors is a very large portion of the modern industries of light.  Solar cells, light emitting diodes (which I think I like calling “leds” a lot lately) and other optoelectronic components and systems.

That kind of blows my mind for a minute there – after going to Photonics West in SanFran this last January, I realized how little I actually knew about life.

Check out the first teaser for the State of Electronics series first:

State of Electronics – Trailer from karl von moller on Vimeo.

then watch this newer one – “Roll Call – State of Electronics,” which has Dave Jones of the EEEV Blog! (I love this dude, I could only DREAM of being that huge of a brain!)

Roll Call – State of Electronics from karl von moller on Vimeo.

Fill up your brain! Be full of knowledge and less full of bulls**t! 🙂

Dark Matter and Dark Energy, Easily Explained

Well, easy may be a kind word for it, but watch this video of Dr. Neil deGrasse Tyson explaining what these two things are and how important they are.  If you’ve ever seen Dr. Tyson on NOVA scienceNOW, you know that his brain is awesome!  Also, follow Dr. Neil deGrasse Tyson on Twitter – he is a smart, mophos.

Tear it up, Doc:

Thanks, Geeks are Sexy!

LER: Luminaire Efficacy Rating

Have you ever heard of a factor called the Luminaire Efficacy Rating, or LER?

Luminaire Efficacy Rating is exactly what it sounds like – it is a measure of how efficient a luminaire is, which basically means “how much light does it put out based on how much energy it consumes?”  Imagine it as “miles per gallon” for lighting fixtures; that example is pretty oversimplified, but it’s a good comparison of how the LER relates to the overall efficiency of a luminaire.  LER is expressed in “lumens per watt,” which makes sense if you think about it very briefly – how many lumens does a fixture produce per each watt of power that it uses, or how much light does this thing produce when it eat this much power?

The Luminaire Efficacy Rating generally deals with three important criteria:

  • the efficacy of the luminaire, or how much light it delivers per watt
  • the ability for the luminaire to direct light outside of itself
  • the ability of the luminaire’s ballasts to deliver power to the lamps efficiently

The LER is a factor that the National Electrical Manufacturers Association (NEMA) has put into play – fluorescent luminaires are one of the categories being compared in the case of LER, and the figure compares many factors.  There are three major categories of luminaire types that are broken down with the Luminaire Efficacy Rating – fluorescent luminaires, high-intensity discharge industrial luminaires (arc lamps), and commercial, non-residential downlight luminaires.

I put together an image with the breakdown of the terms and basic definitions – I hope it is helpful!


NEMA breaks down the standards for Luminaire Efficacy Rating in the following documents:

  • Fluorescent Luminaires:
    NEMA LE5
  • High-Intensity Discharge Luminaires:
  • Commercial (non-residential) Downlights:

The LER factor mostly deals with luminaires using a ballast.  You can certainly calculate the LER for a luminaire using an incandescent lamp – the difference is that you wouldn’t multiply the Ballast Factor into the equation.  Your new equation would be:

LER = (EFF x TLL)/input watts
Luminaire Efficacy Rating for an incandescent luminaire = the product of the luminaire’s efficiency multiplied by the total lamp lumens of the luminaire, divided by the input watts of the luminaire.  Makes sense, right?  No ballast in an incandescent luminaire!

Let’s look a bit at the definitions in this LER equation.  Not everyone might have heard of all of these figures, and some people might be saying “SAY WHAAAT?”

EFF, or Luminaire Efficiency:
This term refers to the output of the luminaire proportionally to the lamp or lamps’ output.  Technically, it is a measure of the amount of luminous flux of the luminaire divided by the amount of luminous flux of just the lamp itself.

(HEY JIM!  What the heck is luminous flux?)

Luminous flux is the measure of the perceived brightness or “light power” – it’s different than radiant flux, which measures all of the light emitted.  Luminous flux is geared towards what the eye can see and the brain can interpret.

TLL, or Total Lamp Lumens:
This term refers to the total measured (rated) quantity of lumens coming from the lamps.  This amount is also multiplied by how many lamps are in the luminaire.  Pretty understandable, right?  So, for example, if I have a luminaire with 3 lamps with a 2000 lumen output each, the total lamp lumens is 6000 lumens – 2000 lumen lamps multiplied by 3 lamps = 6000 lumens.  Cake.

BF, or Ballast Factor:
Ballast Factor isn’t a difficult thing to understand, but there are a few components to understanding it.  Ballast Factor deals with both parts of the creation of light – the ballast and the lamp.  Ballast factor is the ability of a ballast to produce light from the lamp or lamps that it energizes.  A ballast not only fires up the lamp, but after it’s started, it maintains the processes of the lamp.  The Ballast Factor is measured by taking the lumen output of  lamp and ballast combination and dividing it by a reference lamp/ballast combination.

Reference Ballasts are ballasts that are designed to be nearly “perfect” in order to perform under a particular set of conditions.  NEMA has guidelines set forth for Reference Ballasts, which is how we are able to use them to compare other ballast/lamp combinations.

Luminaire Watts Input:
Another very easy thing to understand – Luminaire Watts Input (also called Watts Input, Input Watts, or a number of terms generally related to the idea) is how many watts of power that the luminaire consumes.

I hope this makes a bit more sense if you didn’t know about it before.  Please send me an email through the contact form if you have any questions!

The Nernst Lamp – An Early Ceramic Glower


In my research on light sources for a project here at KTH, I wandered across an interesting historical light source called the “Nernst Lamp.”  This source is very interesting; it was marketed by The Westinghouse Company for a while back in the early 1900’s and saw a total sale of over 130,000 units.  This lamp was invented by a pretty intelligent guy, Walther Nernst – a Nobel winner and the guy who discovered the Third Law of Thermodynamics (you know, the Law of Thermodynamics that says a crystal at absolute zero has an entropy of zero – theoretically of course).

A smart dude, that Walther Nernst.

This Nernst Lamp was a pretty interesting source – instead of using a tungsten burner, it used a ceramic rod that was open to the air and not enclosed in a vacuum environment full of Noble gas.  Since the ceramic rod didn’t oxidize, there was no need to enclose it.  Granted, it did get a bit dirty from time to time, but a cleaner kit was sold to maintain and upgrade the Nernst Lamp when it needed a little “loving.”  From the image above, the slits above the screw base and below the glower was a ballast of sorts.

A diagram of the “glower” in the Nernst Lamp:


What I found interesting about the Nernst Lamp is that it seemed to be marketed on the same principle that the whole CFL vs incandescent argument is based upon – better light with lower energy consumption, even though we know that both of those things are a crock in one form or another.  The company that filed the public holding on the Nernst lamp back in 1899, Nernst Electric Light, LTD, had many great ideas about how this source-interchangeable-glower lamp could be used in the market.  The company’s engineering consultant and board member, James Swinburne, was quoted as saying “Nernst’s Lamp is, in my opinion, the greatest invention in Electric Lighting, since the infancy of the industry.” He also happened to be the Vice President of the Institution of Electrical Engineers, too.  I mean, granted he was probably selling that thing Billy Mays style and all, but it was an interesting and popular source for a while.

I found a public holdings announcement from 1899 when the Nernst Electric Light company went public; in the holdings announcement, there was a list of things that make the Nernst Lamp “better” than the regular incandescent.  Does any of this stuff remind you of the CFL vs incandescent fight?

1. The consumption of power is, at most, 1.5 to 1.6 watts per candle power, being about 60 % less than the ordinary 4 watt incandescent lamp, thus saving three-fifths of the Electric Lighting bill.

2. The Nernst Lamp is pleasant and becoming. Its light does not fall off materially during the life of the rod, and, as there is no bulb, there is no loss of light through either internal blackening or external dust and dirt.

3. Unlike the present type of incandescent lamp, which can only be used commercially in circuits not exceeding 250 volts, the Nernst Electric Lamp can be commercially employed either with direct or alternating currents, up to any pressure compatible with safety.

4. The manufacture on a small scale of the rods or light-emitting bodies, has already resulted in rods which have lasted the equivalent of a year’s ordinary daily usage. Further experience in wholesale manufacture may be expected to give even better results.

5. The rod of the Nernst Electric Lamp with its wire mounts is detachable, and when worn out can be easily replaced by any one, the body of the lamp serving for an indefinite period, whereas the ordinary incandescent electric lamp is of no use when its filament is broken or the glass darkened. This is an economic advantage in favour of the Nernst Electric Lamp of the utmost importance.

6. The cost of production of the Rod will be exceedingly small.

7. The process of manufacture is very simple, and plant of an inexpensive kind only is necessary. There is no “flashing,” no electrical mounting, no expensive vacuum, and, comparatively, no waste, as a used-up rod merely means mounting another in the same wire; it does not mean scrapping a complete lamp. The holders of the automatic lamps are merely ordinary fitting work, demanding no new type of manufacture.

8. Compared with the Arc Lamp, the Nernst has many advantages in respect to–
(a) First Cost, which is about one-eighth to one-tenth of the Arc.
(b) Maintenance, the whole of the expense of carbons and trimming and the cleaning of the elaborate mechanism of the Arc regulator being saved.
(c) Pressure. Unlike the Arc, the Nernst Electric Lamp can be made to take very high pressures, for instance, a single rod for 400 volts is only about 2 1/2 in. long, and by arranging two in series in each lamp, there is no difficulty in running parallel on 1,000 volt circuits without transformers.
(d) Absolute steadiness and freedom from flickering and hissing.

I think Walther Nernst and James Swinburne had something with this removable-replaceable-filament idea.  I’ve been thinking about this for a while, mostly in the fact that we don’t recycle CFL ballasts – we just throw everything away when they die.  When I met Willem van der Sluis and he mentioned that he had the same idea of replacing a CFL’s fluorescent tube when it burns out and not the whole ballast and electronics, I was enthralled.  A few days ago I went on a trip to OSRAM here in Stockholm, and learned that when incandescents were first being manufactured here in Sweden, lamps with broken filaments were recycled – washed out, cleaned up, and re-filamented.  What a concept.  It makes me wonder whatever happened to the Nernst Lamp.  Why did we abandon the idea of making light sources that didn’t make so much waste?  The easy answer is that the Nernst Lamp became obsolete when carbon filaments were replaced by metal filaments.  Too bad we didn’t maintain the idea in some form.

Nernst Lamp images:





Thanks Spark Museum, Nernst, and Wikipedia!

Happy Birthday, Michael Faraday!

If you work with anything that requires electricity, you might want to know who Michael Faraday was – as today is his birthday!


Who’s that?  Is that Michael Faraday?  Hey, HAPPY BIRTHDAY, Michael Faraday! (September 29, 1791 to August 25, 1867)

Michael Faraday was one of the fathers of our thinking on electricity and electrical theory – ever heard of Faraday’s Law of Induction?  Yeah, same Michael Faraday.  Faraday had his hands in a lot of electro-magnetic theory of his time, and we have lots of his contributions in use today, either directly or indirectly by people like James Clerk Maxwell:

  • obviously, Faraday’s Law (of Induction)
  • the Faraday Cage
  • the unit of capacitance, the Farad
  • the Faraday (magnitude of electric charge per mole of electrons – I told you I was a nerd)
  • Faraday’s first version of the electric motor

A model of Faraday’s early motor:


Just in case you were wondering – Faraday’s Law states:

The induced electromotive force or EMF in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit.

What does this mean?  In basic terms, it relates to how a magnetic field can generate an electric field.  When you have a magnet and you wrap some coils of wire around it and then spin the magnet in order to change the magnetic fields, you create an electromotive force, or EMF.  This force is referred to as voltage.  That is a really general,  basic definition – but nonetheless the gist.

It’s good to learn something every day!  Happy birthday, Michael Faraday!

My favorite Michael Faraday quote:  But still try, for who knows what is possible…