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Media > Reasonable Faith Podcast > The Center of the Universe and Spooky Dark Energy

The Center of the Universe and Spooky Dark Energy

August 08, 2016     Time: 14:57
The Center of the Universe and Spooky Dark Energy

Summary

Dr. Craig examines science articles about the center of the universe, whether all is an illusion, and dark energy. Kevin is just confused!

Transcript The Center of the Universe and Spooky Dark Energy

 

KEVIN HARRIS: Three science articles, Dr. Craig. These are some of our favorite topics. This first one here from the New York Times. Dennis Overbye writes[1], “Don’t Let Them Tell You You’re Not at the Center of the Universe. Yes, you are.” You are the center of the universe. He says the misconception is that “The universe started someplace.” People ask, “Where did the Big Bang happen?” He says, “The Big Bang didn’t happen at a place; it happened at a time.” Is he right about that?

DR. CRAIG: Right. The idea here is that space itself is expanding. It is not that the material universe is expanding into a pre-existing empty space, like an explosion inside of a big, big box. It is that the box itself is expanding. So as you go back in time, space shrinks down and down until it simply disappears about 13.8 billion years ago. That is the beginning of space and time. At that time (t=0) you have the beginning of the universe at a certain time in our past. But it isn’t at a certain place because there is no space into which the universe is expanding.

KEVIN HARRIS: Could you then technically say then that everywhere is the center?

DR. CRAIG: Well, that is what Overbye says. I think it is correct to say the Big Bang happened everywhere. But I think it is very misleading to say the center of the universe is everywhere. The fact is the universe probably doesn’t have a center. When he talks about being at the center of the universe, he’s speaking in a very, shall I say, poetic or figurative sense because what he means is that as you look out around you in any direction the information that you receive from your five senses is conveyed to you by finite velocity signals like light waves or sound waves. Because these come at a finite velocity you can’t see what is going on right now in the universe. You see it as it was a fraction of a second ago if it's close. For things farther away like the stars, you are seeing them the way they looked billions of years ago because it is taking that long for the light to get to you at that point. He is saying that you are at the center of the universe in this sort of informational sense that you exist now and that you look out and you don’t see other things that are happening right now. They are happening now but you see them only a brief time or perhaps a long time (if they are far away) after they’ve taken place.

KEVIN HARRIS: That is why he says that Albert Einstein taught us that our eyes are time machines.

DR. CRAIG: Again, you see this very poetic language. What he means is that you obviously don’t see the future – right? - but he is saying you don’t even see the present in a strict sense because all of this information is coming to you by finite velocity signals. When things are close like you and me sitting next to each other, the time lag for light to bounce off your face and go into my retina is so brief that the neural processes in my brain can’t distinguish it. So it is as good as simultaneous when you are close to something. There is what philosophers and psychologists call a specious present which is sort of the minimum time frame that our brains are able to process. It is somewhere between one and a fraction second long to maybe as long as two and a half seconds. Within that frame you can’t distinguish temporal phases. That is exploited in movies. When you watch a movie, you are seeing a sequence of still photographs go by so rapidly that your brain can’t distinguish between them.[2] So it looks like continuous motion when in fact there are actually time gaps in between those frames of the film. So when we say that what we see is only the past, we are talking there in a very technical sense that is not true to human psychology. Within the specious present we can’t distinguish what’s earlier and later, and so it is as though we are perceiving what is present for things that are close to us. This really only gets significant when things get at a distance and it takes longer for the light waves to come to us from them. The idea of the time machine is, as you look out at the universe you are looking out into the past. That is the idea. You are seeing the way the universe used to look billions of years ago when you look up at the stars.

KEVIN HARRIS: He again points out that the cosmic speed limit is the speed of light – 186,282 miles per second. I haven’t asked you much about the speed of light. Do you think it is possible to transcend the speed of light?

DR. CRAIG: It would contradict the laws of physics for something to be accelerated from a subluminal to a superluminal velocity. That would be prohibited by relativity theory. You can’t accelerate something from slower than light speed to faster. But relativity theory is perfectly consistent with particles that travel at superluminal velocity all the time – that they are faster-than-light particles. There is even a name for these. Scientists have dubbed them “tachyons” which comes from the Greek word tachys which means “swift” or “quick.” So these tachyons are hypothetical particles that haven’t been discovered that would always travel at superluminal velocity.

KEVIN HARRIS: The second article is from a science writer and author George Musser, “Why Space and Time Might Be an Illusion.”[3] Bill, I am seeing this headline everywhere. I this something kind of new?

DR. CRAIG: This is, I think, a very unfortunate byproduct of scientific popularization. I thought what this article was going to be about was that perhaps we inhabit a virtual reality such as in the movie The Matrix where it is not real but space and time are an illusion that we experience. But that is not at all what this article is really about. What it is about is whether or not space and time as described in the General Theory of Relativity are what are called emergent phenomena rather than fundamental phenomena. To give an illustration analogously, take the property of water of being wet. The wetness of water is an emergent property of water. When you go down to the subatomic level, the hydrogen and oxygen molecules that make up water aren’t wet. But wetness is an emergent property of water on the macroscopic level on which we live. So some theorists have suggested that maybe space and time as described in the General Theory of Relativity are emergent phenomena that exist on the level of our lives but that when you dig down on the subatomic level (the quantum level) then maybe at that level space and time as described in General Relativity don’t exist at that level. This is purely conjectural, and it has nothing to do with saying space and time are an illusion. To say that something is emergent doesn’t mean it is illusory. The wetness of water is not an illusion. It is just a property that emerges only on the macroscopic level.

KEVIN HARRIS: The only other time I recall seeing the term “emergent” a lot is in the mind-body problem – that mind is an emergent property from the brain.

DR. CRAIG: Yeah, you're right. It comes into discussions of mind-body relations and whether or not the mind is a sort of emergent property of these brain states. When you go down to the specific brain states, like neurons and synapses, you are not going to find any mind there.[4] But on the sort of higher level you have a consciousness or a mind which exists that could be based upon this base of a physical brain. Sometimes these properties are called supervenient properties, and then the things that underlie them would be subvenient properties. So the question is: is space and time as described in General Relativity a supervenient property rather than a fundamental property? Again, what I want to emphasize is, this difference between emergent and fundamental is not a distinction between real and unreal. It is just a matter of levels of description. So it is very misleading to say these are illusions. That is not at all what is being said. There is no reason to privilege the quantum level as being the way things really are and reality on the macro level as not being real.

KEVIN HARRIS: He is not arguing in this that we are living in the Matrix.

DR. CRAIG: No, not as far as I can tell. It is just the attention-grabbing headline of the article that suggests that. What is very, very interesting is when these theorists talk about space and time as emergent properties, this does not mean – it cannot mean – emerging chronologically over time. You can distinguish two kinds of emergence. One would be diachronic emergence. That would be emergence over time. For example, in the theory of evolution, biological complexity emerges over time. It is diachronic. The other type of emergence would be synchronic where they are simultaneous but you are just talking about different levels of description. Clearly time cannot emerge in a diachronic sense because that is to presuppose a time in which time emerges, which is self-contradictory. So these theories about the origin of the universe that postulate emergence cannot, if they are to be coherent, be talking about a temporally prior primordial state of the universe out of which emerges our space-time chronologically. That is incoherent. What they have to be talking about would be just different levels of description so that our universe when described by the present laws of General Relativity, present physics, would exhibit a beginning about 13.8 billion years ago. But when the universe is described on the more fundamental level, perhaps you wouldn't see any sort of beginning because there wouldn't be that sort of time in your description on that more fundamental level. But that doesn't mean that that universe is therefore eternal or beginningless. It is the same universe – the universe that has a beginning. But it is just at a different level of description in which that doesn't appear.

KEVIN HARRIS: Talk a little bit about, on the last page, because I think you've addressed everything in this article, the phenomena of quantum non-locality. Einstein called it “spooky action at a distance.”

DR. CRAIG: Yes, what scientists have discovered is that if you shoot two light particles – two photons – in opposite directions and you perform a measurement on one of them the other one automatically has the corresponding value as well even though you didn't measure it. There is no way that your measurement of the one particle could send a signal to the other one to influence it because they are light particles and nothing goes faster than the speed of light to travel from the measured particle to the other one to influence it. So how is it that both of these particles exhibit this correlation?

KEVIN HARRIS: Yeah, how is it? [laughter]

DR. CRAIG: Well, I think that this suggests that in fact relations of absolute simultaneity do exist in the universe.[5] That it is not true that simultaneity is relative, as Einstein postulated in the Special Theory of Relativity. Quantum phenomena suggest that these particles can have a kind of entanglement with each other such that you have absolute simultaneity of the variables that are characteristic of these particles. There is a whole lot more that could be said about this, but from my point of view, that is the really significant thing that falls out of this – it gives some scientific reason to believe in the reality of absolute simultaneity. One of the pioneers of this study – John Bell, who developed a theorem about non-locality (Bell's Theorem) – explicitly advocated going back before Einstein to the way relativity was conceived by H. A. Lorentz, the Dutch physicist, in which there are relations of absolute simultaneity but we just can't measure it due to the limitations of our measuring instruments. There really is absolute simultaneity in the world but our clocks and other instruments are affected by their motion and so this makes it impossible for us to measure relations of absolute simultaneity.

KEVIN HARRIS: In reading so much of this, I find it fascinating. Over time I noticed one thing, I'm just not getting this because I'm kind of slow perhaps, so many things in this topic that we are talking about in this podcast and other podcasts come to the glory of God. But there are so many paradoxes. Einstein and physicists spend a lot of time trying to figure out these paradoxes, these seemingly contradictory things. Am I right about that?

DR. CRAIG: Yes, I think that is fair to say. Right now people may not realize that the pillars of physics – the two pillars on which modern physics rests, General Relativity and quantum theory – are incompatible with each other.

KEVIN HARRIS: They are not compatible with each other?

DR. CRAIG: They cannot both be right. They are incompatible with each other. So the whole edifice of modern physics is built on two theories that are incompatible with each other, and everyone knows it. This is what has propelled the quest for a combination of General Relativity with quantum theory that would give us a quantum theory of gravity. That is the sort of Holy Grail that scientists are searching for today.

KEVIN HARRIS: One more article quickly. There are so many things in this article remind me of your book Time and Eternity (by the way, pick that up at ReasonableFaith.org) - “New Research Suggests Dark Energy Might be the Reason Time Runs Forward.” This is by Todd Jaquith for Hard Science.[6] He starts out,

A new study may have found a link between dark energy and the Second Law of Thermodynamics—suggesting that the very expansion of the universe may impart a direction to time.

You spend a whole book talking about this.

DR. CRAIG: Yes, I have nothing to contribute to the scientific question of this correlation between dark energy and the second law. This is something that they are suggesting in this recent article that needs to be explored. But what I would comment on, I think, is the kind of reductive approach in this article to this question of the direction of time. It seems to me that that is quite mistaken. At best the expansion of the universe, the increase in entropy according to the second law of thermodynamics, the dark energy perhaps, are evidence of the direction of time, but they do not constitute or are the basis of the direction of time. On the contrary, in fact, it is only by first saying that one direction is the future and the other is the past that one can say entropy always increases in the future direction! It would be viciously circular to say that entropy determines that direction. We have to beware of science articles which are reductionistic in their analyses of things like time and the direction of time and so forth. I think these are really metaphysical realities, and at best what science gives us would be tangible evidence of these realities like the direction of time.[7]

KEVIN HARRIS: I am trying to figure out how dark energy, which is – what? – physical, is going to affect a metaphysical concept.

DR. CRAIG: Exactly. It is crazy when you think about it. How is vacuum energy in the universe going to affect time? It would only be by giving a reductionistic definition of time that . . .

KEVIN HARRIS: By reductionistic you mean?

DR. CRAIG: Trying to explicate it in purely physical terms like “time is the universe being larger and larger. That is what time is.” That is not what time is. The universe is growing larger and larger in time as time passes or as you go into the future. But it isn't constituted of time.

KEVIN HARRIS: Well, Bill, we've looked at these three articles and we are here at the end of this podcast. Do I take it your answer is we are not an illusion? That we are really here?

DR. CRAIG: Right! That's right, we are really here. I think the lesson here is one that the philosopher of science, George Gale, stated a few years ago. He said the scientist now finds himself in a condition where he has outrun his philosophical base camp and he is ready and waiting for some relief from his philosophical comrades in arms.[8]

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