My good friend Mark (the king of relentlessly attacking idiocy where he finds it) recently wrote a very long and detailed refutation of the pseudoscience of autodynamics. I would like to add one more piece of evidence to the huge pile he already amassed.
I’ll introduce it in the same way one of my physics teachers did back when I was but a young ‘un: apples and oranges are not the same thing.
This is a simple enough proposition (or common sense) and I doubt that anybody will have any big objections to it. On top of this I need to add one more little definition. When you see an equals sign in an equation it means that in the context of maths and physics:
Two mathematical objects are equal if and only if they are precisely the same in every way. (Wikipedia)
If two things are linked by an equals sign they must be the same thing. If, on the left hand side of an equation you have some oranges there had better be oranges on the right hand side else the whole construction is incoherent. It works the same with physical units, if there is a density on the left hand side of an equation there must also be a density on the right. As a slightly more involved example take the well known relation:
The left hand side is an energy; in the SI system energy has units of kg m2 s-2 the right hand side of the equation has exactly the same units. This simple check lets us know that the equation is plausible (although not necessarily correct!), it is a check that must be carried out on every single equation derived, and is known as performing dimensional analysis. Dimensional analysis is a simple and powerful tool used by every physicist in the world.
I was pretty surprised, therefore, to find the following AD quotes in Mark’s critique:
Carezani is working with some ideas (slowly and sporadically) with energy equal to E = mc3. (See here.)
and
So, does the famous equation “E=mc2” survive in Autodynamics? The answer is, currently, yes. Carezani discovered the Autodynamic equations using the same steps as Einstein, simply with a correction. He assumes this equation to be true for now. It may be that the equation for energy and mass equivalence is something different where E = m K where “K” is some constant other than c^2. But for now, it is assumed to be correct. (Here.)
E=mc3?!?! This is just insane. Even the most cursory examination shows that this makes no sense and that the autodynamicists do not have a rudimentary knowledge of physics between them. Surely at least one of these fine scientists should have noticed that apples and oranges are different things; and that E=mc3 is nothing short of incoherent nonsense.
Nice post. I’ll stick a link on my mega post. I still can’t believe I missed that.
Hi,
Not being a physicsy type, can you tell me what the unit of energy kg m^2 s^-2 actually means? Its easy to see what units of speed mean (how far in how long!) for example, but what is that unit telling me about energy?
Cheers,
Pete
Good question! The interpretation of the units of energy isn’t at all trivial. For starters there are a lot of different forms of energy, including
In each case it is reasonable to expect that ‘energy’ could mean something completely different. However, in essence the definition of energy for each of these wildly different bits of physics can be boiled down to:
Energy is the capacity to perform mechanical work
‘Work’ is again a bit tricky to understand (see e.g. http://en.wikipedia.org/wiki/Mechanical_work), but in a simple case Mechanical work may be defined as (in one dimension) a force multiplied by a distance.
The units of force are kg m / s^2 (mass x acceleration). The units of work (and therefore energy) are Force x distance (mass x length^2/time^2).
So physically “the energy of an object represents the force it can exert multiplied by the distance over which it can apply this force” (Force x Distance), or equivalently “energy is the amount of work an object can perform”