I don’t know much about magnets, but they seem kind of accidental rather than inevitable. Convenient by-products of some random activity (volcanic? Not even sure), and we have discovered them and their magical properties (lodestones, I think they were called), and found ways to make them artificially, better ones, and they help us generate electricity, amongst other things.
So - could we have discovered an alternative way to generate electricity without magnets? Would other technologies fail to happen or need alternative sources to work if we had no magnets?
Electricity can be generated without permanent magnets, but electricity and magnetism are two facets of the same phenomenon (electromagnetic force) - even without discovering magnetism first, I think it’s really unlikely that we could have discovered electricity and scaled it up to practical application, without discovering magnetism shortly along the way - when you run a current through a wire, you make a magnetic field.
I think the concept has been explored in SF - with putative technologies based entirely on static electricity; entertaining fiction, but I don’t think that’s a realistic scenario.
I’m not sure I really understand your question, but the initial discovery of static electrical charges and electrical current had nothing to do with magnets, and in fact, it took the revolutionary insight of Michael Faraday to realize that electricity and magnetism were interrelated phenomena (and that they produced what we now call a field), and the brillian James Clerk Maxwell to put it on a sound theoretical footing with an extensive mathematical model. (The equations that physics and engineering students are taught as “Maxwell’s equations” are actually a very simplified vectorized version of Maxwell’s quarternion based set of 20 equations.) The use of magnets in inducing currents firmly demonstrated the relationship between previously observed phenomena of electricity and magentism, and they are used in certain mechanisms, but induction or coils carrying current that produce magnetic fields are generally used to generate magnetic fields in large motors and generators rather than using permanent magnets as seen in small motors. In short, we don’t really need permanent magnets for anything but affixing pictures to the refrigerator door and measuring the orientation against the Earth’s magnetic field.
Not discovering magnets means either not discovering iron or that there’s no geomagnetic field. I guess both would have changed history and technology a lot.
Light, electricity and magnetism are all the same force in different forms. That’s why you can see objects for example; the light interacts with the electromagnetic forces that holds objects together.
The Weak Force and electromagnetism are extremely closely related. So much so, in fact, that it’s impossible to construct any theory that meaningfully describes the Weak Force, without that theory also describing electromagnetism. And likewise, while it’s possible to describe electromagnetism without the Weak Force (Maxwell did it, after all), the most detailed and accurate theory we have is the one that also describes the Weak Force. Further, any interaction that can be mediated by electromagnetism can also be mediated by the Weak Force.
There are some vague but tantalizing signs of hope that it might further be possible to unify the electroweak interaction with the strong one. But nobody is yet quite sure of the details of how to do so (even describing the Strong Force in isolation is tricky). And there’s also a hope by some physicists that it might even be possible to unify gravity with the others, but there’s no real reason to believe this beyond wishful thinking and the String Model (which amount to about the same thing).
How would magnetism have been discovered if there weren’t metals which were affected by a magnetic field? Not all metals are magnetic, so imagine that all metals aren’t magnetic. I think early scientists noticed that a compass needle moved when it was near electricity, and that helped Faraday reach his conclusions. But what if there were no compass needles or other metals to give clues that there was a magnetic aspect to electricity. How would that have affected the discovery of the magnetic portion of electricity?
What are the different ways to induce a current that don’t require a magnetic field? I can think of a few.
[ul]
[li]Photovoltaics[/li][li]Piezoelectric Effect[/li][li]Thermoelectric Effect[/li][li]Chemical Reactions (batteries, neurons, electric eels, etc.)[/li][li]Friction? (It can create a charge, but can it induce an ongoing current?)[/li][/ul]
Are there others?
I’m sure it would have slowed things down, but we would have eventually gotten there because a changing current in one wire induces a changing current in another wire.
Personally, I love Van de Graff generators, because they work exactly like one would picture the cartoon version of an electrical generator would work. You put a charge on something by rubbing it up against a piece of fur or the like, and then you literally move those charges around on a conveyor belt.
Your first question (“…if there weren’t any metals which were affected by a magnetic field?”) is basically saying, “What if the physics of the universe were totally different?” There is really no answer to this question because it posits a fundamental difference in reality. You are correct that Faraday noted the swinging of a ferromagnetic needle in response to an electric current but he was not the first to do so; others saw the influence between electric current and magnetism previously, but assumed that they were two seperate phenomena that were somehow linked together by various proposed mechanisms. Faraday’s particular insight was that elecric current was the movement of the charges observed in static electricity, and that this movement created a graduated field orthogonal to the direction of current which acted upon diamagnetic materials, and that furthermore the two phenomena were intrinsically linked. His insight was all the more remarkable for his lack of formal training, but his rudimentary mathematical abilities meant he could only describe it in qualitative terms.
As Chronos notes, just as electricity and magnetism are two intrinsic aspects of the same interaction (involving the movement of electric charge and exchange of real or virtual photons, which are the bosonic force carriers mediating electrodynamic interactions), the weak interaction is another layer in which electromagnetism is one aspect, and thus we have electroweak theory, which got Weinberg, Glashow, and Salam a nice dinner in Stockholm. This was really the first example of predicting a piece of fundamental physics prior to empirical observation. (Although we can obviously observe decay of radioactive isotopes, we cannot ever directly observe the exchange of W and Z bosons as we can with photons, so from an observational standpoint atomic decay is purely stochastic, while electroweak theory can make exact predictions of decay rates and interactions.)
Because of the symmetries we see in this, we then developed the Standard Model of Particle Physics which suggests that the intranuclear interactions (strong and residual) which hold nucleons together and which bind quarks into the prosaic hadrons that make up nucleons are all part and parcel of one unified force to be described as a Grand Unified Theory (GUT). However, the energy levels and densities required to observe unification are not found anywhere except just after the singularity event which begat the universe, or perhaps someday in partical accelerators powerful enough to make the Large Hadron Collider look like a Bic lighter in comparison. Whether gravity is a part of this as well is an open debate; since we have not been able to effectively quantitize gravity the way we have in other interactions, we can’t even make qualified guesses about what a holistic theory of all forces would look like, but while it is an entirely speculative position I think most physicists would intuit that gravity should be another aspect of this global field at energy levels that even make GUT interations look sick.
Here is the interesting thing historically about electromagnetism; even after Faraday concocted the hypothesis that electromagnetism was a unified force which formed a field permeating all of space, and other physicists came along and quantified his ideas, there was little practical application, and the field was largely considered only interesting as a parlour trick. The only way to produce enough current to see useful effects was to mix hundreds of gallons of electrolytes and create giant batteries which was laborious and costly (not to mention often dangerous) so there seemed to be little ways to use electricity in any constant operation or moveable application. It took the development of both the dynamo (and from there, both the alternating generator and the electric motor) and useful steam engines in order to harness enough energy to make applications using electromagnetism practical.
Today, of course, devices dependant on electricity and magnetic effects are so common it is nearly impossible to imagine living without them, to the point that we would regard such a lifestyle as savagery, whereas people from two centuries ago would have regarded our electric lights, cell phones, and flying drones as so much sorcery. We cannot currently harness the kind of energy necessary to affect the electroweak force in any practical device, nor apply it with sufficient precision to control the resulting interactions beyond smashing particles together, but once we do (and the optimist in me hopes and believes) that we will again experience a revolutionary jump in applied technology that we can only vaguely imagine; the ability to store and release vast amounts of energy in tiny cells; creating targeted radiation that can treat illnesses or proces material efficiently; propulsion technology that lets us fly into orbit and between planets nearly as readily as we fly from continent to continent today; et cetera.
Was Faraday the first person to see continual rotational motion from electricity? On a show (about Einstein?) they showed his experiment where he had a dangling wire in an electrically conductive fluid. When electricity was applied to the experiment, the wire moved in a circle in the fluid. In the show it mentioned that people had seen compass needles move, but the movement of the needle was at most 1/2 a turn to align with the magnetic field. In Faraday’s experiment, the wire spun in circles as long as current was applied.
I would think seeing rotational motion from electricity would be a critical “Ah Ha!” moment in realizing that electricity could do work and that rotating something could produce electricity.