Edison: The Man Who Electrocuted Animals to Save His Empire

[sleepy]

I had read of the conflicts between Nikola Tesla and Thomas Alva Edison and how, during the war over which electric system, AC or DC, would become the standard, Edison resorted to a campaign of electrocuting live animals in public in order to demonstrate the supposed "dangers of AC electricity". People were to erroneously conclude that Edison's DC electric system was, by inference instead of by fact, somehow safer than Tesla's AC system. Of course Edison lost the battle owing to the superiority of AC power based on several factors.

Tonight I got lucky and found a youtube of one of Edison's public demonstrations. This film was in fact shot and presented to the general public as entertainment and information by Edison in his own movie houses. He wasn't proud of it, was he?

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These are clips from an audio program about Nikola Tesla. This first clip is the intro.

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This second clip discusses the campaign to discredit AC power as demonstrated in the youtube video above.

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These audio segments came from this following website:

http://www.studio360.org/episodes/2008/01/25

 

[mrschultz]

I had read of the conflicts between Nikola Tesla and Thomas Alva Edison and how, during the war over which electric system, AC or DC, would become the standard, Edison resorted to a campaign of electrocuting live animals in public in order to demonstrate the supposed "dangers of AC electricity". People were to erroneously conclude that Edison's DC electric system was, by inference instead of by fact, somehow safer than Tesla's AC system. Of course Edison lost the battle owing to the superiority of AC power based on several factors.

Tonight I got lucky and found a youtube of one of Edison's public demonstrations. This film was in fact shot and presented to the general public as entertainment and information by Edison in his own movie houses. He wasn't proud of it, was he?

There was no animal rights movement back then, I doubt there was much outcry at the time over the treatment of the animals.

Yea, Edison was a bastard, treated his employees like crap. He refused to accept the fact that a DC system would require huge wires and power plants every few miles, instead he simply went on a smear campaign against AC power.

But that's how things were, there were bitter patent wars over records, radios, etc... Now we have battles over phones and mp3 players, guess things really haven't changed.

 

[sleepy]

No, I think it is the "Tesla vs. Edison" clip that mentions there was an outcry from animal rights groups when the elephant was originally ordered by the courts to be executed.
The owners had built a gallows for the execution which set off the protests.

Something doesn't seem right about it though. The elephant was ordered to be executed for having trampled three handlers in three years, one of which suffered his trampling after feeding the animal a lit cigarette. The background stories also claim that a guy with the nickname "Whitey" responsible for the elephant had taught him to attack Italian Americans, though this part of the story may only be an embellishment.
The problem I'm having with the order to execute is that it was determined due to the violent history of the animal, yet in the film the animal is most cooperative while, for the electrocution, the animal was fitted with the fatal wires and insulating sandals, again behaving cooperatively for the occasion.

I wonder if the execution was a hoax using a trained animal that was unharmed, and the reason I'm thinking it is because the animal wore insulating sandals and because Edison had for several decades sold his DC power systems. Behaving as a madman and apparently 100% devoted to his product might have been a ploy to avoid liability issues over discontinuing support for the DC systems. This is plausible when you consider that Edison adopted the Tesla AC system in the end, but if this is true, then it indicates that the judge who ordered the execution may have been in Edison's pocket.
Edison was based in White Plains, New York at that time.

 

[mrschultz]

The insulating sandals were there to insulate the elephant from the ground (and protect people standing nearby), they had copper wires in them to supply the electricity. That's why you see the feet smoking.

It was no hoax. They also fed Topsy cyanide laced carrots right before the electrocution, in case something went wrong.

http://en.wikipedia.org/wiki/Topsy_(elephant)

As they said in the second audio clip people were dying from Edison's system long before he started his "beware of AC" electrocution demonstrations. I guess they figured more people would see the demonstrations than would read the news about people dying and houses burning down? More likely they were just desperate, they put a lot of money into their system, and they knew it wasn't going to work over long distances.

 

[sleepy]

A couple of thoughts. As to the invention of AC power vs. the limited distance of DC power, by that time, Tesla may have realized that the long distance transmission of telegraphy or telephony indicated the potential for using either a variable DC current or an alternating current system. Or, as the clip points out, Tesla saw things, and may have seen the potential of AC from the working communications systems.

Something else I did not know, and this is that Tesla studied the uses of AC current while attending his home university, or so says Wikipedia, though these studies may not have indicated the usability of AC as a long range system which is part of what Tesla is credited for.

http://en.wikipedia.org/wiki/Nikola_Tesla#Early_years

 

[mrschultz]

A couple of thoughts. As to the invention of AC power vs. the limited distance of DC power, by that time, Tesla may have realized that the long distance transmission of telegraphy or telephony indicated the potential for using either a variable DC current or an alternating current system. Or, as the clip points out, Tesla saw things, and may have seen the potential of AC from the working communications systems.

Something else I did not know, and this is that Tesla studied the uses of AC current while attending his home university, or so says Wikipedia, though these studies may not have indicated the usability of AC as a long range system which is part of what Tesla is credited for.

http://en.wikipedia.org/wiki/Nikola_Tesla#Early_years

Tesla picked up and understood a lot of theory way better and faster than Edison (Tesla was more of a scientist), he probably understood right away that AC power would work better for long distance transmission. Add to that his obsession with trying to transmit power through the air, the types of coils and generators needed to attempt that are not that different from what's still used to send power through the big cross country lines.

There have been a few really good documentaries on Tesla in the last few years, can't remember if it was PBS or the cable channels.

 

[sleepy]

I wonder if Tesla realized the long-distance transmission of AC power was possible due to overcoming the capacitances of the wires which was also the reason why a constant-level DC power level was difficult to maintain over those same distances.

Capacitors do not pass DC current as a function of voltage and the same is said to occur with lengths of wire, though I suspect it is not capacitance by voltage but load capacitance as a function of current, the same as coil load resistance as a function of current, the same as a length of wire wound to produce an electromagnetic coil. In both the case of a straight length of wire and the forming of a coil by winding the very same straight length of wire, the resistance is the same. Only the gauge and length and the material used to make the wire affect the resultant resistance

 

[mrschultz]

I wonder if Tesla realized the long-distance transmission of AC power was possible due to overcoming the capacitances of the wires which was also the reason why a constant-level DC power level was difficult to maintain over those same distances.

Capacitors do not pass DC current as a function of voltage and the same is said to occur with lengths of wire, though I suspect it is not capacitance by voltage but load capacitance as a function of current, the same as coil load resistance as a function of current, the same as a length of wire wound to produce an electromagnetic coil. In both the case of a straight length of wire and the forming of a coil by winding the very same straight length of wire, the resistance is the same. Only the gauge and length and the material used to make the wire affect the resultant resistance

A big factor that limits DC is that every single electron sent out onto the wire has to make the return journey in order to do any work. In an AC system it's a push/pull thing. And of course the biggest factor is being able to use transformers, you can't change a DC voltage without loosing a lot of power, a good transformer can step down or step up AC voltage with very little loss of power. So they can send out power at voltages that would be very unsafe to have in your home, step it down on the pole to a safe level.

The great thing about stepping down is you can draw a little current on the high side to supply a lot more current on the low side. So you can send 200,000V over 3 wires into a town, step that down to 10,000V and feed all the top lines on the poles all over town, and every few blocks step that down to 220/110V and feed every house. Can't do that efficiently with DC.

All of Tesla's work with transformers and coils would have given him the insight as to how it would work on a citywide scale. He also studied and understood magnetism, there's a reason the larger unit for a magnetic field is called a tesla (1 tesla = 10,000 gauss or about 3000x a typical refrigerator magnet). Having an understanding of how magnetic fields work let him design all the crazy transformers we still use today.

 

[Isaac Sauvage]

i wish it had been only recently that i'd read the "deathworld" novels by harry harrison- i would have a lot of questions fresh in my mind to ask, if so.

in one of the novels, the hero is marooned on a primitive planet and is forced to come up with his own electrical plant in order escape. so he fills some urns with a weak acid or alkali metals (or something like that) to produce electrical cells. DC, i guess? and would you need a fairly-sophisticated setup in order to produce AC?

(keep in mind i'm often thinking about the crash of civilisation and what skills and technologies man will be able to recover once the population thins out)

side-question: has anybody audited the free online courses MIT put up a couple years ago? there's courses on electricity and magnetism on offer, for example:
http://ocw.mit.edu/OcwWeb/Physics/8-02TSpring-2005/CourseHome/index.htm

 

[mrschultz]

i wish it had been only recently that i'd read the "deathworld" novels by harry harrison- i would have a lot of questions fresh in my mind to ask, if so.

in one of the novels, the hero is marooned on a primitive planet and is forced to come up with his own electrical plant in order escape. so he fills some urns with a weak acid or alkali metals (or something like that) to produce electrical cells. DC, i guess? and would you need a fairly-sophisticated setup in order to produce AC?

(keep in mind i'm often thinking about the crash of civilisation and what skills and technologies man will be able to recover once the population thins out)

Yes, he was making a battery, ever see one of those "potato clocks", stick a copper rod and a zinc rod (people use galvanized nails) into a potato and you make a weak battery, 2 of them in series and you can power an LCD wrist watch. Batteries are direct current, electrons flow from one end to the other in a steady stream.

To make AC you need to spin magnets around a coil, or spin the coil inside some magnets, or magnets inside a coil, basically, you need a mechanical device that spins. So the voltage makes a sine wave, positive and negative, electrons being pushed and pulled back and forth. Of course this is happening at 60Hz (60 times per second) (in North America), with the electrons moving hundreds to thousands of miles each cycle depending on the voltage.

You can get inverters, ever see those things you can plug into your car and power AC devices? They use electronics to take DC and invert it, problem with most of them (the cheaper ones) is they make a square wave that some devices can't deal with. More expensive inverters try to smooth out the square wave into something close to a stepped sine wave. They also waste a lot of power doing the inverting so they are not great if you want a battery to last.

As for end of the world stuff...

If there's no more gas to run generators, take a generator apart and replace the gas motor with a windmill or waterwheel or stationary bicycle...

side-question: has anybody audited the free online courses MIT put up a couple years ago? there's courses on electricity and magnetism on offer, for example:
http://ocw.mit.edu/OcwWeb/Physics/8-02TSpring-2005/CourseHome/index.htm

Didn't know they did that, that's a nice picture on that page of the magnetic fields being repelled by a superconductor. We have a few of those demos at work, a little ceramic magnet and a high temperature superconducting disk, put the disk in liquid nitrogen and the magnet will float on top of it...

 

[sleepy]

Hey, that's a great find Nic. MIT has a course on Introduction to Computer Science and Programming with video lectures and d/l quizes on each chapter. The course uses Python
as the study language

http://ocw.mit.edu/OcwWeb/Electrica...er-Science/6-00Fall-2008/CourseHome/index.htm


As for electricity, if you have a motor that contains permanent magnets, then you also have a generator, but if the motor is a DC motor then it will only produce DC power and then you'll need to turn it at it's rated RPM in order to produce the same power level that it uses as a motor. Question: With two fixed magnets in the motor, would inverting the polarity N/S of one magnet while leaving the second magnet polarized S/N with respect to the armature coils produce AC if turned at a sufficient rate?

In general, a generator that produces DC is known as a generator, but a generator that produces AC is known as an Alternator which is commonly used in modern vehicles.

You could produce magnets by drawing a lightning strike with a makeshift lightning rod conducting through a magnetic metal to earth ground.

Like the motor used as a generator, a voice coil PM (permanent Magnet) loudspeaker can also be used as a microphone, though sound quality and output may be poor and the impedance of the amp input should be matched to avoid hum. The speaker is microphonic by the sound pressure or vibrations striking the diaphragm and producing a tiny electric current which varies with the sound pressure or vibrations at the speaker terminals, and if you connect a pair of matched PM speakers with only speaker wires and nothing else in between, this will make an electric version of the paper cup and string telephone, except this method uses the generation of electricity by electromagnetic action in the voice coil to work.

 

[mrschultz]

Question: With two fixed magnets in the motor, would inverting the polarity N/S of one magnet while leaving the second magnet polarized S/N with respect to the armature coils produce AC if turned at a sufficient rate?

Interesting question, it depends on how the coil(s) and magnets interact. Probably very few motors would give you an AC signal that way, I would think the normal way the coils are connected would mean the current from the reversed magnet would probably cancel out the current from the normal magnet, giving you no power at all... I guess it would depend if the motor is designed so the coils repel against both magnets at the same time or if they go slightly out of phase, if they are out of phase then there's a chance a reversed magnet would give you some kind of AC, but I'm sure it would be an ugly looking signal and not a nice sine wave.

I know the little DC motors that I use on my rc helicopters can be modified to run brushless. They have 3 coils and 2 magnets, normally the brushes keep the DC power going to the coils lined up with the magnets. But if you clamp down the shaft with the coils and allow the can with the magnets to spin, you can bypass the brushes and send AC signals to the 3 coils and cause the can to spin. In that setup spinning the magnets would produce a 3 phase AC voltage (just like the the 3 wires on the tops of the power poles, 3 phase is commonly used in industrial motors). That would be the way to modify a DC motor or generator to produce AC, but in a collapsed civilization scenario there would be plenty of AC generators around, like you said, every car and truck has one, just take the rectifier out of a big truck alternator and you've got a nice AC generator.

 

[Isaac Sauvage]

thanks marty, arne for the answers... and keep these threads coming.

i am so ignorant about so much of the basics of science.
undergrad college courses wear off mighty fast when they're not reinforced by experience. :/

side-question: would you say edison's resistance to AC was entirely due to professional reasons, ie wanting to manipulate public opinion towards the area he specialised in and had financial interest in, or was there also some personal animosity going on as well?

ie, AC seems more complex (and even elusive) in nature to me and maybe edison didn't really understand it and maybe that fueled his resentment towards the concept and towards tesla, someone who clearly understood that area in a way which edison did not.

 

[sleepy]

I think the second audio clip identifying the source of the name "Brooklyn Dodgers" pretty much says it. The cable cars in Brooklyn were running on Edison DC. Edison had already sold his system to enough early adopters. His system was already in use and expensive to maintain and he was forced to promote it or *I think* face contractual liability issues for not supporting his product. The way he played it, no one could accuse him of non-support.

It may have been very similar to the failure of the HD DVD disk format a couple of years ago. Remember how the manufacturers and studios promised continued support of the format to the end and then dropped it several months later citing a lack of buyer support?

 

[mrschultz]

side-question: would you say edison's resistance to AC was entirely due to professional reasons, ie wanting to manipulate public opinion towards the area he specialised in and had financial interest in, or was there also some personal animosity going on as well?

ie, AC seems more complex (and even elusive) in nature to me and maybe edison didn't really understand it and maybe that fueled his resentment towards the concept and towards tesla, someone who clearly understood that area in a way which edison did not.

If I remember correctly there was a lot of animosity between Edison and Tesla, and it really ramped up when Tesla made a deal with Westinghouse. Edison and Westinghouse had been battling each other for a long time prior to the Tesla deal.

I doubt it had anything to do with Edison not understanding AC, the advantages were pretty obvious. I suppose he could have blinded himself to the obvious, but I'd guess it was more an ego and business thing.

 

[mrschultz]

I think the second audio clip identifying the source of the name "Brooklyn Dodgers" pretty much says it. The cable cars in Brooklyn were running on Edison DC. Edison had already sold his system to enough early adopters. His system was already in use and expensive to maintain and he was forced to promote it or *I think* face contractual liability issues for not supporting his product. The way he played it, no one could accuse him of non-support.

I doubt any contract would require him to "promote" his system, but it probably had provisions for maintenance. Edison would still be making money off the parts to maintain his system, but would lose that if the people that bought the system replaced it with the more efficient AC system...

It may have been very similar to the failure of the HD DVD disk format a couple of years ago. Remember how the manufacturers and studios promised continued support of the format to the end and then dropped it several months later citing a lack of buyer support?

The only similarity would be something I've never heard of: What did the appliance industry do? Did they make gadgets for both systems? Or did they start picking sides and make stuff for AC only?

The Blu-Ray HDDVD war is probably a very good analogy, with Toshiba being like Edison. Only difference is the 2 disc systems were just about equal technically, with Blu-Ray having a little more storage capacity but HDDVD being cheaper to make. In the end it came down to software, more studios choosing BD so Toshiba quit. I waited it out, the week it ended I got a Blu-Ray player, the war was killing both sides and had to end.

 

[sleepy]

Let me clarify, and this is only a conjecture. In continuing to promote the DC system after the advent of the AC system, Edison appears to be providing 100% support, and this becomes crucial if and as he may have been planning to drop product support dependent on the success of the AC system.
In this case, if his contracts pledged product support with an exemption for failure in the marketplace, then by continuing to promote it he looks good and avoids lawsuits. He then doesn't have to pay back the money.

He may have also had a warehouse full of soon-to-be-obsolete DC components and, like the claims of HD DVD in the final months, continued to promote his system to dump the stockpile on trusting customers.

 

[mrschultz]

Let me clarify, and this is only a conjecture. In continuing to promote the DC system after the advent of the AC system, Edison appears to be providing 100% support, and this becomes crucial if and as he may have been planning to drop product support dependent on the success of the AC system.
In this case, if his contracts pledged product support with an exemption for failure in the marketplace, then by continuing to promote it he looks good and avoids lawsuits. He then doesn't have to pay back the money.

He may have also had a warehouse full of soon-to-be-obsolete DC components and, like the claims of HD DVD in the final months, continued to promote his system to dump the stockpile on trusting customers.

Reading this Wikipedia entry, there were some DC hold outs up until the 1960s:

http://en.wikipedia.org/wiki/War_of_Currents



I really doubt Edison was worried about being sued for dropping his system, there's no evidence for that. Most of the laws concerning warranties and parts availability are fairly recent. "support" even if in a contract would not have been free, so he still would have made money off spare parts, so his campaign for his system was really him trying to get more contracts than Westinghouse... Read up on his battles with Westinghouse over the light bulb, those guys were bitter rivals.

I wish I had picked up a bunch of HD-DVD movies when they got down to less than $5, I now have a combo drive on my computer that can read both Blu-Ray and HD-DVD. I was amazed how fast they disappeared, but I think the stores were tired of people getting confused between the 2 formats and wanted one completely gone as quickly as possible. Even months later I was buying a Blu-Ray and the sales person asked me if I was aware the disc I was buying would only play on a blu-ray player....

 

[sleepy]

I wish I had picked up a bunch of HD-DVD movies when they got down to less than $5....

Fantastic coincidence, but the banner for this site popped up over at http://www.worldofkj.com/forum/ and they are selling HD DVDs starting at $1.99
so maybe...

http://www.inetvideo.com/HD DVDs/?gclid=CNj71qzCnZ0CFRgbawodTG7-_A

 

[mrschultz]

Fantastic coincidence, but the banner for this site popped up over at http://www.worldofkj.com/forum/ and they are selling HD DVDs starting at $1.99
so maybe...

http://www.inetvideo.com/HD DVDs/?gclid=CNj71qzCnZ0CFRgbawodTG7-_A

Was interested until seeing their shipping charges, almost $3 each up to 5 and then $1 each after that, $4.95 each for sets (anything more than 2 discs)...

I know it's still pretty cheap overall to get several hd movies but on principal I don't buy from companies that pull you in with cheap prices and get their money from the shipping charges. Actual shipping cost in the USA for 5 single pack discs would be less than $5, add a few bucks for packing but not $10...

 

[sleepy]

I agree about the shipping charges. I wonder if they're paying outside people to ship?