Category Archives: General

The Knowing Problem

Image from salon.com

A few days ago, I posted something about what I called the consensus problem, the idea that many people have that scientists have to completely agree on something in order for the idea to be accepted.  There is, however, an even deeper issue involved and that is what it even means to “know” something is true.  When a scientist of group of scientists reports that, indeed, something is true, what does that mean?

I think that this is an important thing to discuss because I have often encountered the statement, “Well, you can’t be 100% sure, now can you?” in discussion.  I find this statement completely ridiculous; can anyone ever be 100% sure of anything?  But, as metaphysical of a question this that is, it’s important to understand what “knowing” means in science.

The Knowing Problem

Science generally comes in two flavors: experimental and theoretical.  Most often, some physical phenomenon is observed in the world (by experimentalists) and then the scientific community struggles to explain it  and a formal framework is developed (by theorists) that can be used to make further predictions and such.  Take, for example, the Danish scientist Hans Christian Oersted.  During an experiment in the early 1800’s, he happened to have a magnetic compass sitting on a table near a wire.  Completely by accident, he noticed that when the battery that was connected to that wire was switched on and off, the needle of the compass was deflected from True North (I find the concept of True North amusing, especially considering what I’m talking about).  Turns out, he serendipitously discovered that moving electric current creates a magnetic field.  This hitherto unknown connection between electricity and magnetism lead to a revolution in the way that physics was treated and eventually, 100 years later, overturned the behemoth of Newtonian mechanics by establishing that the speed of light was the universal speed limit.

On rarer occasion, someone has a stroke of brilliance and comes up with a theory that can then be established experimentally.  In the early 1900’s, Albert Einstein had the brilliant idea that gravity was a warping of the curvature of space-time as a response to the presence of matter.  This was, needless to say, a revolutionary idea…with no common experience.  It was determined that, since light travels through space and gravity supposedly altered space, we would expect light to be altered by gravity as well.  A massive object such as the Sun, should “bend” the path of light from distance sources as they entered its realm of gravitational control, making them appear elsewhere in the sky like a great cosmic mirage.  In 1919, an experiment was performed where the position stars near the Sun were observed during a solar eclipse and then compared to their positions without the Sun present.  Indeed, as predicted, they were off by just the right amount to show that their light had bent around the Sun due to Einstein’s General Relativity theory.  So here we have theory as a precursor to experiment.

So, in whatever way, a model is presented to explain a particular phenomenon.  Then next step is to then verify that the model is correct, that it fits Nature.  This is where the “100%” argument comes into play.  We now have to measure something and see if the results fit our predictions.  Measurement, however, is messy.  It is imprecise.  In fact, it is absolutely impossible to measure something to infinite accuracy, that is, it is impossible to know a measured value 100%.

Say, for example, I want to measure the width of the laptop computer I’m writing this on.  How do I do it?  I could estimate it; it’s about as wide at the length of my forearm from my elbow to my wrist.  Not very convincing nor precise since your arm probably isn’t the same length.  So, I rummage around and find a ruler (which, surprisingly, took way longer than expected)…14.125 inches.  Well, the edge was somewhere in between 1/8 and 3/16, but closer to 1/8 so…let’s call it 1/8.  But is that any better than saying it’s about the length of my forearm?  I could get a better ruler, one that has divisions down to 1/32 of an inch but I’d still have the same problem.  Hell, I could take the computer to a lab and use an atomic force microscope to literally count how many number of atoms across the laptop is.  Would that be any better?  Maybe if I measure at one point, I count 1 billion atoms (fyi, it would be waaaaaaaaaaaay more than a billion), but I measure somewhere else it’s 1 billion and 5 atoms.  Which is correct?  Maybe I should take the measurement a thousand times and average the values?  What is the width of an atom anyway?

At some point, this exercise becomes ridiculous; the phrase “good enough for government work” comes to mind.  But, it illustrates my point, there is a difference between the concept in our mind and the actuality of it in the world.  Back in the day, Plato referred to this as a Form.  A Form is the idealization of a thing in the mind that can not be realized in the material world.  It is, Plato thought, the highest form of reality.  We can easily think of a triangle but, in reality, anything that we attempt to construct, however precise, is not as perfect as the triangle we imagine.  Maybe we create a triangle by setting individual atoms down on a surface in straight lines.  If one atom is out of place, the side is “kinked” and we no longer have a triangle.  We can think of the number 4, but can we ever truly have 4 things?  If I say I have 4 cookies (delicious, delicious cookies), what am I counting?  What if one cookie is bigger than the rest, is it more than one cookie?  Maybe I have 4.2 cookies.

This all seems pretty silly, right?  But, in science, it’s important.  A theoretical model is a product of the mind, it is one of Plato’s Forms, if you will.  So, if we measure something in the real world, we have to accept that it will not perfectly fit.  And, like the width of the laptop, we will have to choose the level of accuracy which we require for the measurement to be “correct”.  Every piece of equipment scientists use to measure anything have some amount of error: the ruler only has so many divisions, the voltmeter only measures to 3 decimal places, the telescope can only resolve an image to 3 arc-seconds, and so on.  When a measurement is made in science, every data point has what is known as an error bar.  Unlike most graphs, a data point is not really a point, it is a region; the more precisely we can measure a value, the smaller this region is.  It is never be a true point, however, no matter how precisely we measure; a point has, by definition, zero dimension…it is also one of Plato’s Forms.  If we measure 1000 data “points” and the pattern predicted by the theory passes through the region, or fits, say, 100 of the “points”, then the model probably isn’t very good.  If, however, it fits 950 of them, then it’s accurate to say that the model is “correct”.

Good scientists will spend a lot of time minimizing error and accounting for anomalies so that the results can be said to be “true” or “false” to high levels of reliability.  There are many measurements in science that are ridiculously difficult to make and, thus, have a large window of accuracy.  The mass of the electron (rest mass, before an internet tough guy gives me any shit) is known to be 9.10938215(45)×10−31 kg.  The (45) at the end are the decimal points that are not precisely known.  In other words, we know to stupid accuracy the mass of the electron.  The age of the known universe is 13.798±0.037×109 years, still pretty good.  But, we know the mass of the electron to half a billionth of a percent (!), while we only know the age of the universe to 0.4%…that’s a factor of 100 million times more imprecise.  In systems such as the Earth’s climate, precision may only be known to 1% or 10% due to the complexity of the system and variables that are hidden from view.  The more we know, the smaller we can make the error.

What’s the point?  Telling me that I don’t know something 100% is ridiculous because a) neither do you, b) neither does anyone else, and c) no one ever can.  We have to choose the level of precision when we say we know something to be correct.  The higher the level of precision, the more accurate and more trusted the value is.  In addition, that measurement is repeated by others; the more measurements that yield the same result, the better it is.  If a value is then reported to what scientists call “5-sigma accuracy”, a typical level, it is accurate to 1 millionth of a percent.  And that is, indeed, good enough for government work.

“…with all of its rights, honors, and responsibilities.”

So…now I have a blog.

The obvious question is…why? Why contribute to the millions (literally millions; WordPress alone hosts 60+ million blogs) of blogs that are already out there? What exactly do I expect to add to the “blogosphere”? My reasons for doing this are, I suppose, two-fold: catharsis and responsibility.

Catharsis

Over the last few years, I’ve had a lot of stressful things happen in my life. From employment to graduate school to death, it’s been an interesting ride. Do I want to expound on every detail of these experiences and chronicle it for all time? Not at all. As a matter of fact, I’d like to forget a lot of it. However, I have noticed a shift, shall we say, in my personal philosophy and outlook in general. For those of you that have experienced the death of both of your parents, you’ll probably relate. You suddenly realize that you are now alone in the world. Now, this isn’t really a bad thing and, of course, you have loved ones, other family, friends. But, the two people who were always there, every single day you have existed, the two people who gave you your core support for your entire life, just…aren’t anymore. It’s truly the point in life when you become an adult, the point when you are forced to face the world without support and make your own way, no longer having to worry about the “paradigm” of your life that your parents had. All you have is the memory of the lessons taught over the years and the free will (though that is debatable) to use knowledge in whatever way you see fit. There is a forlorn freedom in it all.

What did my parents teach me? To boil it down to its essence, they taught me not to be an asshole.

So, catharsis comes for me in writing about my experiences and thoughts simply because the process of self-reflection makes you less of an asshole…and that’s what Mom and Dad would have wanted.

Responsibility

When I graduated with my last degree, a Bachelors in Physics, I was forced to sit through an entire day of convocation ceremony. Forced is a bit strong…I wanted to be there, I suppose. But, those ceremonies can drag on like nothing else I’ve experienced. At least I was participating; the only thing worse than graduating for hours is watching someone else graduate for hours. Apologies to my family…

During these ceremonies, a ridiculous number of people get up and talk about nothing, give cliché speeches, and toot each others horns in a process that can only be expressed as “academic masturbation”. However, during one of the ceremonies, the Dean of the College of Science, Dr. Pierre Sokolsky, made a statement which I found profound. He pointed out that we all now held a science degree “with all its Rights, Honors and Responsibilities” entailed thereof. We were now responsible for this body of knowledge known as science and we were obligated to defend it in public and to pursue the quest of curtailing mis-information. We had been tasked with spreading truth, epistemological truth with a capital T.

So, the other reason for this blog is to facilitate that responsibility. I have learned a lot over the last 35 years and I want to share it. I want to share because I love knowledge and teaching and I know that being informed and battling ignorance is important (a subset of the don’t-be-an-asshole lesson from my parents). From time to time, I’d like to talk about certain topics on science, design, and whatever else, simply to attempt to make clear difficult things that I find interesting and think other people would as well, if only they were more accessible. Particularly with science, the amount of “language” one has to learn to even be able to approach the subject is daunting. But, there are so many wonderful things to be explored, so many vitally important topics to be discussed, so many world-changing events that people should know about. Knowledge swings both ways; I can’t spend my entire life learning and not attempt to spread that knowledge to others.

Plus, I can play a mean game of Trivial Pursuit.

So, there you go. Why blog? To spread knowledge, counter mis-information, and make myself feel better in the process. You’re more than welcome to come along for the ride, if you’d like…