Category Archives: science

Exploring the Boundaries of Science

Here are a few more articles I’ve read recently exploring the boundaries of what science can tell us.

In case you were wondering if scientific realism was a thing that scientists themselves were unsure about, here’s a blog post (via @realscientists) by a physicist about it, which concludes as follows:

So where does this leave us? Pretty much with the concept of realism in science in tatters. The internals of models changes in unpredictable ways when science advances. Even within a given model, the internals can be changed with mathematical tricks and for some definitions of realism, experiment has largely ruled it out.  Thus we are left with our models that describe aspects of reality but should never be mistaken for reality itself. Immanuel Kant (1724 – 1804), the great German philosopher, would not be surprised.

I wouldn’t go so far to say the concept of realism in science is “in tatters,” rather that it’s not a solid assumption as many think.

Next, this article (via @EpicureanDeal) talks about a new approach to quantum mechanics that uses Bayesian methods to interpret the probabilities:

His [Christopher Fuchs’s] view arises from a relatively recent interpretation of quantum mechanics called Quantum Bayesianism, or QBism for short. It’s an approach long championed by quantum physicist Christopher Fuchs, developed with collaborators Rüdiger Schack and Carlton Caves.

Their view is that quantum theory’s conundrums stem from banishing the subject — the scientist or whoever — from the facts about “objective reality.” When a physicist calculates the odds of finding an electron in various locations, or the probability that a radioactive atom will decay today, those probabilities are generally taken as objective facts about nature. So reality is like dice. Einstein didn’t like it. Nevertheless the world respects the probabilities that quantum mechanics provides, and never defies them.

Some of the weirdness in quantum mechanics stems from the fact that it seems that observations “create” reality.

Much of the supposedly inexplicable quantum weirdness dissolves when this view is adopted, the QBists contend. When a measurement is made, for instance, multiple possibilities encompassed by the wave function all disappear, except for the one corresponding to the result of the measurement. This “collapse of the wave function” has elicited all sorts of philosophical hand-wringing about measurements “creating reality” instead of just recording it. But from the QBist perspective, a measurement is just an experience for an “agent” acting as an investigator of nature. What gets created is merely a new experience for the agent.

Any such agent can use the rules of quantum mechanics to calculate the odds for various measurement outcomes on a system described by a given quantum state. But those odds are the agent’s personal judgment. That means that the quantum state in the first place is also a personal judgment of the agent. “The notorious ‘collapse of the wave-function’ is nothing but the updating of an agent’s state assignment on the basis of her experience,” Fuchs, Mermin and Schack write.

This interpretation of quantum mechanics places the agent in the center.

To a QBist, the personal experience of an agent is the most important thing about quantum physics. Quantum states cannot be objective elements of reality because they are subjective, personal information, used by an agent for calculating the odds of future experiences.

Which I’m still trying to wrap my head around.

Lastly, another piece from Michael De Dora about philosophy and science:

Yet an increasing number of people believe philosophy is useless or obsolete, and that all our efforts should be focused on science. This is deeply problematic, mainly because whether we realize it or not, we all must engage in philosophy before we engage in any kind of science. As Daniel Dennett has said, “There is no such thing as philosophy-free science, just science that has been conducted without any consideration of its underlying philosophical assumptions.” To deny this is to oversimplify.

Philosophy deals with the base assumptions about how we interact with the world. Everything else is built on top of that.

More on Scientific Realism

My last post ended on a note that deserves more explanation.

Scientific realism is the view that science describes the world as it actually is (or approximately as it is, for weak forms of scientific realism). There are however, some criticisms of this view.

The first is underdetermination. When multiple, conflicting theories are all consistent with the data, there is no evidence for believing one theory over another. And since they conflict, they cannot both be true.

The next is known as “skepticism about inference to the best explanation”. It builds off of a possible realist response to underdetermination: It’s fine if multiple theories are consistent with the data, since one will explain the data better, meaning that it is true.

One problem with that approach is defining what characteristics make one explanation better than the other. Another, is do those characteristics make one theory more true than another?

A third is the pessimistic induction, which takes a different view. Consider all past scientific theories that have been replaced. The past theories must be considered false in the present. So what’s to say that in the future, we won’t be saying the same thing about current theories?

Each of these arguments sheds some doubt on the view that science describes truth. And yet, scientists mostly go ahead under the assumption that it does. In truth, whether or not science describes the universe as it actually is doesn’t matter to the practice of scientists. Whether or not theories are true, they are enormously successful in allowing us to build things that we couldn’t dream of even 100 years ago.

 

 

Faith and Truth in Science

These two articles are a pretty interesting juxtaposition. The first, from Slate, takes on the argument that faith is compatible with science:

The conflation of faith as “unevidenced belief” with faith as “justified confidence” is simply a word trick used to buttress religion. In fact, you’ll never hear a scientist saying, “I have faith in evolution” or “I have faith in electrons.” Not only is such language alien to us, but we know full well how those words can be misused in the name of religion.

 It mainly argues on semantic grounds, that the way science uses faith is different from the faith of religion. It’s an argument that should be made, since from my perspective, they address different questions, and attempts to make religion answer questions of “what is” is foolhardy.
But, I do think Coyne glosses over some sticky questions when he says this:
The constant scrutiny of our peers ensures that science is largely self-correcting, so that we really can approach the truth about our universe.
It’s an open question whether science is actually truth seeking or not (second link):
But it is important to guard against the notion, so often merely assumed by working scientists but occasionally trumpeted affirmatively by certain mouthpieces thereof, that the instrumental effectiveness of particular sciences provides prima facie proof that their underlying theories correctly describe the underlying reality of the world they purport to.
Whether science is or isn’t approaching the truth about our universe is an open question. For science to describe the nature of the universe truthfully, it would have to answer questions that are taken for granted in the course of normal scientific work.
But science is not immune to the challenges of representation and interpretation which all human attempts to discover and describe the nature of reality are subject to. Science cannot finesse the influences and distortions which its practice by real human beings in real social contexts impose on it. Science cannot evade the problems of justification raised by choices driven more by aesthetics and intellectual convenience—like the preference for theories which are beautiful or which satisfy Occam’s Razor—rather than any a priori necessity. Science possesses no special defenses against the radical skepticism which calls into question our very relation to the world and each other. Science, in other words, does not hold a privileged position outside the core intellectual puzzles of human cognition and relation to reality.
All of this isn’t to say that science isn’t useful, or unsuccessful. So much of what we can do today is because of science.
But there’s a leap of faith that takes place when you say science describes the truth about the universe.