Big Questions: What is Reality?

A Live Chat with Professor Steven Gimbel,Ph.D.

On April 6, 2016, Professor Steven Gimbel sat down for a live Q&A session with his fans from across the globe. The chat is over, but the transcript is posted below for you to enjoy.

GIMBEL: Hey everybody! Steve here (then again, are any of us REALLY here? — this is virtual, after all). Ready for whatever questions you have — auto mechanics to quantum mechanics.. What’s on your mind?

Photo of Professor Steven Gimbel
Professor Steven Gimbel

LEE HAYDEN: I have heard that, as the universe increases in complexity in the big bang theory, physics does a great job of providing a “description” of each individual change but not the “why” causing the change. To what extent does the big bang theory provide some sort of completeness? Doesn’t the 2nd law of thermodynamics for open systems require boundary conditions for changes to occur? Does physics admit the possibility of a creator of the universe (as opposed to a personal god)?

GIMBEL: The question depends on what sort of answer to a why question we are looking for. If we ask why does a rock fall to the ground when I drop it, science can give us an equation of gravitation which is considered to hold for all of the universe and under which the dropped rock’s behavior could have been predicted and can be explained. But why does the rock (and everything else we have observed) obey that law? An old friend of mine said, “When you ask why once, you are doing science. When you ask why twice, you are doing philosophy. When you ask why more than twice, you are a three year old annoying your mother.” Science gives us sets of equations which “cover” lots and lots of observable phenomena. Why those laws? Why do the laws work? Those are not questions science examines — that is the realm of philosophy and theology, some systems of which fit with those views of the universe, some of which don’t. Could you be a theist and a physicist? Are there some interpretations of various religious scriptures that are inconsistent with the findings of science? Yup. So, like so much in philosophy, the answer is “it depends.”

SANDY EVANS: Well, now that I look more closely, the subject of this chat will ‘really’ be about reality. I just bought your course ‘Introduction to Formal Logic’ and have not received it yet. My interest in the subject of logic comes from my profession, in which I use software based on logic relationships to model construction projects – Critical Path Method scheduling. So, in general I am just interested in studying how effectively logic can be used to model real world actions and probable outcomes, and I thought your courses would be interesting.

GIMBEL: We can talk logic as well which is, indeed, the subject of my latest course from the Teaching Company. In it, we look at formal and informal reasoning, deductive and inductive reasoning, and topics in contemporary logic (fuzzy logic, three-valued logics,…). Model construction is discussed when we look at first order predicate logic. It should bear a strong resemblance to the work you mention — sounds like you’ve got some fun stuff to be playing with!

GEORGELUHRMANN MD: A marvelous course. How have you managed to accumulate a certain expertise in so many areas?

GIMBEL: Thank you for the kind words, George. Actually, I just made it all up. To be honest, as a philosopher of science I am able to work with scientific colleagues of all sorts. Every scienetific field has questions at the foundation and I’ve been lucky to have a lot of interested and interesting intellectual chums to play with.



CPP: 1. Do you believe that if a mathematical concept is logical, then it applies to the real world, and we just have to discover it? Basically, does math precede physics as a fundamental truth that, if logically consistent, is an actual physical reality?
2. Godel’s theorems showed mathematically that a logical statement cannot be both self-consistent, complete, and provable. Logic, being the underpinning of math, and math the underpinning of physics, does that mean the universe is fundamentally and essentially “unknowable” through traditional Western means of logical deduction? Is the mystical approach of “no thought” the only means of grasping the complete essence of reality, and logical deduction only good for understanding parts of the universe, but not a complete picture?

GIMBEL: 1. No. Mathematics is a wonderful field because mathematicians are not bound by mere reality. They can postulate any realm, no matter how strange, and see what must follow from the assumptions they decided to make. Axiom of choice? Want it, fine. Don’t want it, also fine. It is one of the reasons physicists consider themselves superior to mathematicians because physicists see themselves pursuing real truths about the universe, whereas mathematicians are playing a complicated version of Dungeons and Dragons. Until, that is, the physicists realize that the mathematical tools they have been trained to use are insufficient for the complexities of this universe when trying to solve an open problem. At that time, they have to go to the mathematicians and find the tools they developed for their custom universe which just happens to resemble ours in an interesting structural way. So, the concepts of the mathematicians do not have to apply to this universe, but interestingly they often seem to.

2. Godel’s theorem shows that any attempt to ground mathematical truth on nothing but logical truth as Bertrand Russell wanted to do would necessarily fail. There are several other philosophical positions one could take to justify mathematical truth, so Godel’s 1931 result does not completely undermine our confidence in mathematics. Further, while we certainly use mathematics in physics, we also rely on observation. We have experimental physicists who tell us if the musings of the theorists matches what we would expect to see in the universe. This means that science has not only a deductive element to its methodology, but an inductive one as well. As a result, Godel’s result gives us no real concerns about the foundations of our scientific reasoning.

DAVID: What would it be like if reality had 2 time dimensions like some strange versions of string theory are working with? and would it be possible for some particles to feel the effect of one but not the other? I love your humour and ability to provoke thoughts!

GIMBEL: I had a discussion about this with one of my physics professors in graduate school who had sent the question to Richard Feynman, the Nobel Prize winning physicists who said that he and his son spent a weekend trying to figure out what such a world would look like and couldn’t.

What makes the question even more interesting for physicists is that to create this world, all we have to do is change a single minus sign to plus in one equation. But what makes it so strange is that we take one’s path through the 4-dimensional space-time manifold that is our universe and the length of it is the amount of time experienced by that individual.

When we have two times, this privileged meaning for time disappears. At the same time, the calculations for such a world can be done. Time is a dimension like those of space, and we would locate events in this peculiar universe by a set of numbers like we do now.

Particles would always feel the effects of both, though. The results would be odd in that we could, say, be early in one direction, but late in the other. It’s hard to envision, but possible to calculate.

ANNETTE: Do you agree with the following statement I think therefore I am. Why or why not

GIMBEL: This quotation comes from Rene Descartes who was concerned with what we could believe with absolute certainty. He seemed to rule out everything. But then, he realized that there was one thing he could not be wrong about — he exists. How does he know this? There can’t be a question without someone to ask it. So, he must exist in order to think about his existence. So, given that I am thinking — a proposition my wife might disagree with on occasion — I must exist.

ALEXIS DIX: Sounds like it could come right out of “The Matrix”

DEAN H. JUDSON: Dr. Gimbel, let me first compliment you on the scope of your lectures (many diverse topics you had to manage), and on your jolly use of humor, which worked well.  My question involves your scheme: Individual->interaction->field. This scheme works *very* well for physics/calculus, and it generated some interesting thoughts on the psych/social psych/sociology axis. But, for the biology part, the metaphor felt a bit “forced”, a little procrustean (don’t get to use that word much). Could you elaborate a bit on how it works in the biosciences, in your view?

GIMBEL: Thanks for the compliment, Dean. As for biology, I believe the scheme works in terms of the scope of interest in biology. Evolutionary theory looks at the biological “field” (No, that is not why they call them “field biologists).

Evolutionary explanations require species-level considerations. Species evolve, not individuals.

So, we have individual based investigations — genetic level — interactive level investigations — individual and environment — and field-levle — species level interactions

ALEXIS DIX: How are we to know? If there is a God it would be so beyond us it would be like an ant it tick contemplating us.

VRAIG HEMPHILL: Then the problem is the nature of the question. Is there a God in whose likeness man was created? More would answer, “No!” resoundingly. If God is matter, then almost all would agree that there is, and then the question is still unaswered as to the origin of matter, for as yet there are merely random hypotheses with varying degress of articulation.

BEAN H. JUDSON: My partner Carole, also watching, adds another question: What, in your view, does “philosophy of science” add to science proper?

GIMBEL: Philosophy does not add directly to science per se. We don’t tell them what to think or how to thing, but what we do is once they have created a theory, we (1) look at the presuppositions it contains to see whether they are well supported, what sorts of propositions they are (empirical, conventional, or philosophical) and (2) try to figure what that theory would mean if it were true, that is, which parts of the theory are meant to reflect the nature of reality itself. Scientists provide the theories and we argue about their meaning.

JACOB: Professor, do you think that any particular scientific theory will remain in place, not to be overturned by future advances? It seems as though when we study the history of science, theories are constantly changing. Does this mean any given theory, at any given time, is not necessarily providing an objective picture of an underlying reality, but rather, it is providing us with the best description possible at that particular time? If the latter is the case, how should we view current scientific theories?

GIMBEL: Science is like professional boxing — there is a champion (sometimes disputed, sometimes undisputed) and the champ has to take on all comers. But eventually, someone will knock off the champ and become the new champ. The philosopher of science Imre Lakatos wrote that all scientific theories are born refuted, that is, the ones that earn the belt will eventually lose it. But while this means we do not accept the theory as true, we do see it as providing insight into the nature of the universe it is describing. We get better and better theories. So, while we cannot have complete confidence in any given theory, the length of time is has been the champ and the breadth of explanation it gives us reason to think that it likely (not definitely) gives us a sense of the real working of the world. But we could be wrong and we might need to reconfigure our picture of reality — that is what makes science, science.

JEFF SHEPPARD: Evolution is a scientific ‘theory’ – hasn’t it only been explored, expanded and refined rather than refuted?

GIMBEL: Evolution is indeed a theory (we do need to distinguish theory from hypothesis) and as a scientific theory is falsifiable, that is, might be false. However, the breadth and amount of evidence in its favor is wide and deep and so the scientific consensus is that it is the proper explanatory model for the emergence of species. After 300 years, Newton’s physics, which everyone thought would stand forever, was overthrown, so there is always a chance it will need to be replaced, too. But, no one expects a Spanish Inquisition.

JEFF SHEPPARD: Thank you. I’m curious what you think the possibilities created by the invention of CRISPR will be. Professor Doudna has asked for a moratorium on it use – a chance to consider its global implications. It seems like it could change the world the way the internet changed communication.

MARK OBUKOWICZ: How do knowledge and reality differ compared with a century ago, prior to special and general relativity? I’m thinking, for example, of Bertrand Russell’s description in his book, The Problems With Philosophy.

GIMBEL: Now THAT is another entire course! Relativity did alter several things — in terms of the content of science, it forced us to adopt new concepts of mass, energy, space and time. In terms of methodology, it changed the order in which physics is done. Before Einstein, observe and then come up with a theory to explain the observations. After Einstein, theorize and leave it to the experimentalists to figure out how to test the darned thing.

ALEXIS DIX: It greatly changed how we perceive the universe around us.

GIMBEL: Philosophically, it meant we had to move away from simple empiricism — the universe isn’t just what we see and how we see it. It meant that philosophers who wanted to talk about reality itself had to learn some physics, and math, and biology, and sociology and and and …and that is what makes philosophy today so interesting.

ODYSSOMA: It is still wrong to say Newton was overthrown. The Principia is still valid in the realms which were perceived when Newton worked. Newtonian physics is a simplified form of general relativity, and is perfectly commensurate for velocities much less than c, and gravitational fields in the realm of earthly experience. In fact, most of NASA’s orbital work has been done with Newtonian physics, and the earliest intrusion of relativity I am aware of was with frame-dragging corrections for GPS satellites.



ALEXIS DIX: Nothing in life happens in a vacuum. Everything is connected.

BP: none of the above? I don’t think I can work through this … ever.

ODYSSOMA: Professor, you seem to be of the view that science is what philosophy becomes when we finally get it right.

MICHELE ZAPPANO: Hello prof. Gimbel. I am currently halfway through your new logic course, why is this subject not mandatory? It seems as though it should be, given our political system rests on it.

GIMBEL: I entirely agree and if nominated at either convention it will be the first plank in my platform. Logic is important. We are not rational by nature despite the fact that we often believe whatever we think. It is a topic that requires training and can be helpful in daily life.

ALEXIS DIX: I completely agree. I am currently taking a course called “Logical and Critical Thinking” on FutureLearn.

BP: math logic versus language-based logic is very different. The latter is like play-doh, and it is played with freely. And the term “logic” can give it an air of authority that it may not deserve. Isn’t the complexity more tquite often that what human cognitive capabilities can handle?

BP: “science” is often hijacked. “medical science”, e.g. rests on commerce and stats, providing the motive and the means to direct “thinking”. How do we figure out when science is not science?

GIMBEL: We do think of science as distinct from the rest of the human world as somehow purely objective and distinct from the flaws and foibles of mere mortals. However, scientists are people (well, some of them at least — try watching them eat…) And since scinetists are people, they are affected by the times like anyone else. Science aims to produce laws of nature — rules that apply no matter where, no matter when, but it is a necessarily political field.

ALEXIS DIX: That issue came up in my logic course on FutureLearn. The section is called Science and Pseudoscience.

GIMBEL: Science needs to be funded. Scientific fields have squabbles within them and often power within the community plays a part in who gets published, who speaks at conferences,…The hope is that the give and take, the brutal attempts to falsify will help us adjust for the human factors that might lead us astray. But, at any given time, with live science, there is always the chance that what is the most accepted view might be ultimately overturned. That’s the fun of science. It’s a process.

BP: There is a Greek prof who makes a living as a meta-studies expert, and makes the bold statement that “most of the published research is false” and is grounded in fatal but often even relatively simple stats error.

BRADLEY STEEG: Lawrence Krauss wrote a book titled, “A Universe from Nothing”? in which Krauss says current cosmology and particle physics prompts us to think our universe “could result literally from nothing by natural processes.” I’m confused by his usage of nothing because it sounds like he’s saying something — natural processes — is nothing. Luckily, you’re both a physicist and a philosopher. Do physicists and philosophers use different definitions of “nothing”?

GIMBEL: This is the weirdness of quantum mechanics. The Heisenberg uncertainty principle tells us that there are pairs of observable quantities that are related — evil twins, so to speak. The more exactly we determine the value of one, the less the other has a value, the more spread out it is. We usually think of this in terms of position and momentum.

ALEXIS DIX: If we can’t define reality, how can we define nothing?

JACOB: Krauss commits the fallacy of ambiguity in that book. He calls “nothing” one thing, and the next paragraph he redefines the same concept. He is inconsistent in his reasoning and terminology and so your confusion is to be expected, if you are reading critically. Apologies for my comment, I will refrain from anything more.

GIMBEL: But it also holds for time and energy. If you squeeze the time small enough, the uncertainty in the energy skyrockets. It goes high enough to give rise to mass (remember from Einstien E=Mc^2). So, in a small enough duration there is a tiny, but finite probability of an energy state arising which would — pop — give us a particle. The original competitor to the Big Bang theory, the Steady State theory used a mechanism like this.

Alexis –– bingo. And another traditional concept is forced to be redefined by modern science. Hey, someone should make a course about that!

BP: Feynman made the statement (I think) that no one understands quantum mechanics. But we have come a few years since then. So maybe there are some who do? Otherwise it’s just more play-doh!

GIMBEL: Jacob, please don’t refrain. You are pointing at one of the great worries about doing metaphysics at all. We have questions that seem well formed because we intutively have a sense of what we are asking, but when you really push on the concepts, sometimes they aren’t as rigorous as we thought. There is an entire school of philosophers — the logical empiricists — who argued that metaphysics cannot be done at all for exactly that reason.

ALEXIS DIX: Do you want to volunteer for that job, professor??

STEVE WINKLEBAUM: Please critique this line of thinking
“You can’t disprove solipsism, but maybe there’s a way to attack a big motivation for why people would believe it. The idea that your mind is the only thing in existence, and that you’re imagining everything else in the world, has a satisfying unification to it. There is only one thing in the universe: your mind. People like believing everything can be boiled down to one thing.

But, like, if part of your mind is consciously aware of your thoughts, and another part of your mind is sending imaginary information to the other side and creating a hallucination of reality, what you effectively have is two minds, you and the thing making up information. I mean, you can call it a part of your mind, but honestly if it’s disconnected from your thoughts to such an extent and has to run calculations apart from your mind in order to form a false reality, it’s basically a separate entity. So now we have two things in the universe: you and the Cartesian demon. That’s not nearly as satisfying as only your mind existing.

So in summary, solipsism requires part of your mind to act so separately from your consciousness that basically it’s not only your mind existing.”

GIMBEL: Solipcism is the view that you are the only thing that exists. You can have no certainty about anything outside of your own mind, so the only thing you can say is real is you. (I had a college roommate like that.) It may be the case that we cannot give a dedujctive proof of the existence of an external world or other minds, but it doesn’t mean we don’t have good inductive reason for suspecting it is likely true. This question, for example, is one I didn’t think was going to be asked, so while I cannot prove it, I have some reason — good reason, I believe — to think it came from a different mind.

CARMELJON: Forgive me, but I haven’t yet taken your course. My question is, do you consider the word “Reality” to have any real meaning apart from the prior existence of minds like ourselves, that is, consciousness able in principle to discriminate “real” from “unreal”? In other words, do you have a theory about what “reality” mean in a universe entirely devoid of consciousness of any kind whatsoever? If so, what would such a “reality” mean and how would it be distinguished from “unreal”?

STEVE GIMBEL: You are forgiven. As for the meaningfulness of the word “reality,” you are asking the central question in metaphysics. I have access to my mind, I know what I am feeling, observing, and thinking (Freud, of course, would deny this).
But how do I know that what is in my mind connects to anything outside of my mind. How do I know whether the thing which gives rise to the thoughts resembles the thoughts. I may see a chair, that is, have the internal experience of “chairness,” but how do I know that the thing causing it is a chair shaped object?
The answer is that with absolute certainty, I don’t. I sometimes dream of chairs or hallucinate chairs (it was college, I was young, someone handed me the cup). But I also have mental images of other people who are acting like I do.

ODYSSOMA: Freud might deny that you have anything like full access to your own mind, but he would allow that you may accurately report your thoughts and feelings. How do we know …? This gets back to solipsism. The only principle I can think of to counter solipsism is Occam’s razor. The ontology needed to support Berkeley’s solipsism requires a moment-to-moment recreation of the entire universe, whereas current thinking about the perceptual universe rests on a kind of self-sustaining epistemology.

JACOB: A universe devoid of consciousness is inconceivable, I think. We could say what it might be like, from our point of view, if we weren’t here, kind of like painting a picture of a distant future without humans, but still from our perspective. But a universe devoid of consciousness is inconceivable, there would be no perspective to determine what it might be like.

GIMBEL: I think they are likely other people and those people seem to see the chair also. Could it all be a dream? Could be. But the complexity and the fact that it is not something I can change (as in a daydream) gives me some confidence that they are real beyond my own mind.

BP: At some level do we not really (can not) see the chair? Even our sight is based on saccades that give us a statistical sampling that we make a deduction from. Is that a fair characterization?

GIMBEL: The fact that we can develop scientific theories that make predictions that I never would have imagined to be true of the world and have experiments that confirm them seems to say that there is something out there that is not of my mental making. Also, if it wans’t real, how come I’m paying so much on my mortgage? I guess that’s why they call it “real” estate.

BRADLEY STEEG: A recent artificial intelligence algo “hallucinates” colors when fed black and white photos. It looks at a B&W and figures out how to color what it sees. I’m thinking AI could help indicate if our minds are actually connected to reality.

GIMBEL: BP — absoluitely correct. Hold your hand up by your face and it will seem bigger than the moon, but we know it is not. Observation is not direct access to the world, but the mind has a role in developing what we see. Some of this is empirical — we learn it — some of it is innate — we have certain psychological faculties that occur naturally. Observation is much more intricate a process than we give it credit for.

BP: do we not see things at different levels of granularity and different slices based on the context of what matters to us? So the same thing can end up being many “things”?

CPO: Does scientific empiricism really make any sense at all when we consider that not only different people, but different animals have different perceptions of the universe? Does consciousness really “create” reality?

GIMBEL: Different people do have different perceptions, but what is interesting is that there are certain things that we see the same. It is from these regularities that science emerges. If this observation is not merely subjective, but inter-subjective — shared by multiple minds — is there a pattern to it? If there is a pattern, can we describe it. Propose a description and — bam — we have a scientific theory. Could the pattern break at some point? Yup, and then the theory is rejected. Use the pattern to make predictions and see if we see what it says we’ll see. That’s a test of the theory. At the same time, the theory will require certain concepts, notions that do not come from seeing, But are needed to make the theory work. Are these real?

JACOB: Because the laws of nature seem to hold, and we can make predictions within science, I think scientific empiricism makes some sense. It might not give us some ultimate picture of an independent underlying reality, though.

GIMBEL: The have certainly been constructed and in this way scineice constructs a reality which may or may not be the case. Which of these constructs ought we posit to the universe itself and which ones are just part of the grammar of the theory? Welcome to philosophy of science, that’s what we argue about.

ODYSSOMA: As for reality based on your “real estate,” do you mean to imply that any ontology which contains something you could not foresee is necessarily “real?” Your capacity of foresight is necessarily limited to your conscious mind. Were you never surprised in a dream? I don’t think you can escape solipsism with this argument. Wait, back up. How do we know when we have a “real” theory?

GIMBEL: I don’t escape solipsism, but did very much want to escape my real estate agent. If I am the only thing in reality, why did i have to spend so much time in his car?

ODYSSOMA: Now you sound like Groucho. Which is why I am tending to believe you.

JACOB: Solipsism is self-defeating, in a way. It is much more plausible to infer the existence of other minds. After all, you are here picking the brain of Professor Gimbel. 🙂

ODYSSOMA: This is great. I must go now. Thanks Professor, and thanks all.

GIMBEL: “you are here picking the brain of Professor Gimbel” — should he have one…

KHALIL KHAN: KANT believed that while our view of reality is grounded in sense experiences he disagreed with the notion that our thoughts could not be justified (by reason). Did Kant ultimately set the course for how modern western civilization views/ defines Reality? and what extensions or revisions can we add that add depth to his understanding of the Real World.

GIMBEL: Kant sets the stage for everything. Kant contends that through our senses, we receive the “raw manifold of perception,” that is, an undifferentiated spray of color splotches and from that we form our observations by applying concepts from the mind. Some of those concepts we gain through experience, others are innate. (a priori is the technical term, if you want to impress a philosophy major at a dinner party). The concepts that Kant held were necessarily part of the human mind include Newtonian physics and Euclidean geometry which we now know are not the only way we can think of the world. So, Kant’s picture is not accepted wholesale, but the idea that we need to add something from the mind to get the world we “see” remains. The question is what is added and how do we know if it is true?

Some contend that it is our scientific theories that give it to us. In this way, Kant’s hopefulness that all can be ultimately justified by reason remains. Others contend that our theories are simply another class of artificial constructs and the hope is dashed. Who is right? Welcome to philosophy. There are smart answers on both sides and the discussion continues.

BP: if we get a thousand things wrong and a couple of things right, and can’t tell between the two, we may not have much?

STEVE WINKLEBAUM: what are your thoughts on moral intellectualism?

GIMBEL: Immoral intellectual is a lot more fun, but since I’ve been married… The question is whether propositons about the moral rightness or wrongness of an action are rationally determinable. I would argue that they are. We do use several different rational measuring sticks, however, and sometimes they conflict with one another. That is where our moral conundrums come from.

Most of the time they point in the same direction, but occasionally they don’t and those are the hard questions. But when we debate them, we give reasons. and sometimes we change our minds on moral questions, for good reason. The fact that there are such reasons is reason to think that reason is part of the thinking.

GIMBEL: Wow! What incredible questions. I hope the responses were thought-provoking. (I hesitate to use the word “answers” here because in philosophy it rarely clear that there is a final answer — and if there was, once we found it philosophers would have to go out and get real jobs). If you have a question that I was not able to get to or that pops into mind after the fact (doesn’t that always happen?), please feel free to contact me at [email protected] and I’ll try to send you my thoughts on the matter.

Thank you for your time today and the time you have spent with Redefining Reality or Introduction to Formal Logic. If you watched the lectures in a group and have questions or discussions that emerged which you wish to continue, feel free to contact me and we can see if we can arrange a visit to discuss them in person. I have had wonderful experiences spending time with church groups, retirement communities, and other organizations, so if there is interest, let me know and we’ll see what we can arrange.

Please take care and keep on thinking.



Professor Steven Gimbel holds the Edwin T. Johnson and Cynthia Shearer Johnson Distinguished Teaching Chair in the Humanities at Gettysburg College in Pennsylvania, where he also serves as Chair of the Philosophy Department.
His lecture series 
Redefining Reality: The Intellectual Implications of Modern Science is now available to stream Wondrium.