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Our universe is perfectly tailored for life. That may be the work of God or the result of our universe being one of many. by Tim Folger Published online November 10, 2008.
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Our universe is perfectly tailored for life. That may be the work of God or the result of our universe being one of many. by Tim Folger Published online November 10, 2008 A Fine Tuned Cosmos: Illusion, God, or Multiple Universes?David HeddleChristopher Newport UniversityThomas Jefferson National Accelerator Laboratory “If there is only one universe, you might have to have a fine-tuner. If you don’t want God, you’d better have a multiverse.” (Bernard Carr)
Outline • Introduction Fine-Tuning • Cosmology Big bang, Cosmological Constant • Fine Tuning Examples • Other Possibilities • Tie Breaker? • Conclusion
What is Fine Tuning? Fine Tuning: Observation that complex life of any kind† would be impossible anywhere in the universe if the values of physical constants differed by small amounts. Example: If the universe expanded faster, stars could not have formed. If slower, the universe would have recollapsed. No stars means no life of any kind. † Based on the modest assumption that life of any kind requires stars to produce heavy elements, and that complex life requires water.
A preview (from the Discover article) • Had matter in the universe been more evenly distributed, it would not have clumped together to form galaxies. Clumpier, and it would have condensed into black holes. • If the nuclear force (which holds nuclei together) was slightly stronger, protons would have paired off and there would be no hydrogen, which fuels long-lived stars. Water would not exist, nor would any known form of life.
Just to Ponder: Amazing Water Anomalous properties Effects • High latent heats • High specific heat of water • Ice’s low thermal conductivity • Great ability to dissolve • Expansion on freezing • High melting/boiling points • High surface tension • Thermal stabilization of cells, organisms, Earth • Chemical weathering (rocks broken down into nutrients) • Chemical reactions (especially with carbon chemistry)
A remarkable fact: Ice Floats • One of only a few substances that floats in its own melt • If water didn’t float • Rivers, lakes, etc. would freeze from bottom up • All marine life would die • Climate on earth altered so radically that complex life would be unlikely
Who Believes in Fine-Tuning? • Everyone. Virtually all physicists of agree that the universe is fine-tuned†. • There is no testable explanation for fine-tuning. Theism is one (untestable, supernatural) explanation. Multiple universes (multiverse) is another (untestable, naturalistic) explanation. † Although most would argue that the fine-tuning is “apparent.” That is, the universe was not actively fine tuned by an intelligence.
The Possibilities God One universe or many universes? “everyone” accepts this We are lucky There is only one universe Our Universe is fine-tuned It’s an illusion Many universes (multiverse) each with different constants Our universe “appears” fine tuned because if it weren’t, we wouldn’t be here
Fine Tuning is related to sensitivity, not improbability • If some constant has to be close to its actual value for life to exist we have “fine tuning” regardless of the improbability of the value. • In fact: • The is no way to calculate the a priori probability • Multiverse theories in fact predict our constants are “low probability” • Opposite what most ID proponents suggest, fine-tuning (sensitivity) plus high probability (fundamental theory) is the strongest case for a designer
Quotes on Fine Tuning • You’ll see quotes from world-class physicists throughout this talk. • All view it as an interesting problem that demands an explanation • Some view it as evidence for multiple universes • A few view it as prima facie evidence for an designer
My Perspective as Christian and Scientist • The bible† and science cannot, ultimately, disagree. • When theologians and scientists disagree, scientists are often right • Galileo is still a good example. • But for the question of a beginning of our universe, theists were there first. • Homosexuality: nature or nurture? † That is, the original autographs. We affirm biblical inerrancy along the lines of the Chicago Statement.
For anti-Science Christians: Consider Special and General Revelation Scripture Special Revelation Fallible Exegesis Fallible Translations Theology We should not make snap judg-ments about which side is wrong As a result of human error on either/both sides, these can be in conflict Cannot be in conflict Science Fallible Interpre- tations Fallible Observations General Revelation Creation
My “niche” ministry, such as it is • To proclaim the necessary compatibility between science and the bible/Christian Faith • Opposition • Militant atheists—seek no reconciliation • My fundamentalist brothers—view science as evil and in opposition to the Truth • Support • Mainstream scientists • Mainstream Christians
Fine Tuning: Poker Analogy • Suppose I take a deck of cards • I tell you that unless I shuffle them and deal you a royal flush of hearts (one try) you’ll die • And then I do just that… Three competing explanations… • Blind Luck. • (Naturalistic) There are an infinite number of universes, in most of them you died. • (Design) I cheated.
14 Billion Years Ago: The Big Bang… • Was not an explosion that hurled matter into pre-existing space • Was an expansion of space occurring everywhere at once time Furthermore… • The observable universe was tiny at the big bang, but perhaps not the entire universe • Because of expansion, the farthest visible object is not 14 but 46 billion light years away • God cannot put us in the center, because there is no center
Fine Tuning—Carbon Production • No other element equals its ability to form large molecules needed to store information (for complex life.) • Water “fits” carbon chemistry: H20 is liquid over the range of temperatures at which carbon chemistry is most active. • Non Carbon-based life is probably science fiction—only Silicon and Boron based life is possible, and their chemistry is not as rich as Carbon nor as synergetic with water.
Water and Carbon “Despite our best efforts to [avoid] chauvinism and to seek out other [chemistries] for life, we are forced to conclude that water is the best of all possible solvents, and carbon compounds are apparently the best of all possible carriers of complex information.” John Lewis, Planetary Scientist (Univ. of Arizona) “If you want physicists (or any other life forms) you need carbon.” Robert Dicke, Astrophysicist, (Princeton University)
So it would seem… • We (minimally) need Hydrogen, Carbon, and Oxygen. Where do they come from? • The Big Bang produced a universe which at first had only Hydrogen and Helium (and a little Lithium) • Where did the heavier elements such as Carbon and Oxygen get made?
We are made of Star Dust • Big-Bang → Hydrogen and Helium • Inside stars, heavier elements (e.g., Carbon) are manufactured through nuclear fusion • Stars explode (super novae) seeding space with these life-essential elements • Other stars, planets, and humans are made from this star dust
Anthropic Principle (Barrow & Tipler) • (Weak) The observed values of the physical constants take on values restricted by the requirement that there exist sites where carbon-based life can evolve. • (Strong) The Universe must have those properties which allow life to develop within it at some stage in its history. • To paraphrase: we can use the fact that we are here to guide predictions. Science need not ignore the obvious fact of the existence of humans.
“Anthropic” Prediction (Hoyle) He He He He Unknown Excited State C* + Be Better, but step 2 is too slow, unless… Hoyle made an anthropic argument. We’re here, so somehow C12 gets produced. What would help is a unknown “excited” state of Carbon. Hoyle predicted the state on the basis that we are here. It was later discovered. C Carbon is made inside stars. One way: He4 + He4+He4 → C12 Unlikely (3 He have to meet.) Maybe: Step 1: He4 + He4 → Be8Step 2: He4 + Be8 → C12 C
But Wait, there’s More… He He He + O C + Ne O • Short lifetime of Be8 (10-17 s) prevents runaway fusion. Be8instability leads to stellar stability. • So two fine-tunings: short life of Be8 and the lucky level of C12 that together allow Carbon production at a fortuitous rate. • But wait: Two more coincidences: (1) The lack of a similar state in O16 prevents all the C12 from converting to O16 and (2) A conservation law prevents O16 from being easily converted to Ne20. C* + Be C Net Result: Carbon and Oxygen produced abundantly, and in comparable amounts
From Hoyle, an anti-theist “A superintellect has monkeyed with the physics, as well as the chemistry and biology.” Fred Hoyle, Astrophysicist, The Universe: Past and Present Reflections", Ann.Rev. Ast. and Astrophys. 20, 1982, p. 16. Hoyle also reported that his atheism was “greatly shaken” by the discovery that carbon just manages to form and then avoids complete conversion into oxygen.
Recent Discoveries • The Universe is Flat (Normal, High-School Geometry works!) • After a period of slowing down, the expansion of the universe is now accelerating. It will not bounce back and start over. The Little Prince’s “universe” is not flat
Best Evidence†: Cosmic Background Radiation 3000 K hot c o l d ~3 K • When the universe was ~0.3 My old atoms formed, decoupling light from matter (universe no longer opaque) • Temperature is related to the wavelength – longer wavelengths → lower temperature • As the universe expands, the wavelength increases, so the temperature drops (has expanded by factor of 1000) • Today, the temperature (nearby) is about 2.7 K † OK, that’s debatable. The other two “best evidences” for the standard Big Bang model are Hubble’s Law and the abundance of light elements.
Background is not perfectly uniform. Cosmic Background Explorer (COBE) 1992 Background fluctuationsaccount for galaxies (with fine-tuning of 10-6)† This is a picture of the universe when light separated at 0.3 Million Years † Problem: Such uniformity requires superluminal communication. Solved by introducing “cosmic inflation”—1050 size increase in 10-32 s
Implication: The Universe, began “The best data we have (concerning the Big Bang) are exactly what I would have predicted, had I nothing to go on but the five books of Moses, the Psalms, and the Bible as a whole.” Arno A. Penzias, Nobel Laureate (Physics), and co-discoverer of the Cosmic Background Radiation
The Big Bang was Resisted by Some “Philosophically the notion of a beginning of the present order is repugnant to me. I should like to find a genuine loophole. I simply do not believe the present order of things started off with a bang …the expanding Universe is preposterous… it leaves me cold… We [must] allow evolution an infinite time to get started.” Sir Arthur Eddington, astronomer
The Cosmological Constant ‘L’ • L measures the energy and pressure of empty space. It causes an anti-gravity stretching. • Observation: The universe’s expansion is accelerating. A nonzero L can explain this observation. In 1998, the Cosmological Constant was awarded the “breakthrough of the year” by the journal Science.
Constituents of the Universe Dark Matter passed a recent experimental test (2006) Dark Matter ~26% Normal Matter ~4% Dark Energy (L) ~70% Dark Energy (L) explains the universe’s flatness. It must be comparable to the matter contribution (it can’t be too small) If Lis too big, space would be too curved and stars and galaxies would not exist (expansion too fast)† †Not to mention we would all be vampires.
The Greatest Fine Tuning Problem Best Calculations: L≈ 1 Some unknown fine-tuning gets us from here to here Observed L 0.0000000 ………01 to here 120 zeroes ~Unacceptable L 0.0000000 ………10 without stopping here (notionally) UnacceptableL Exactly Zero or proceeding to there
On The Fine-Tuning Problem of L “Our current understanding of gravity and quantum mechanics says that empty space should have about 120 orders of magnitude more energy than the amount we measure it to have. That is 1 with 120 zeroes after it! How to reduce the amount it has by such a huge magnitude, without making it precisely zero, is a complete mystery. Among physicists, this is considered the worst fine-tuning problem in physics.” Lawrence Krauss, Cosmologist, Sci. Am., Aug. 2004, pp. 83-84.
Fine Tuning: Number Of Dimensions • String Theory: Universe is 10 or 11 dimensional • At 10-43 seconds six of the dimensions stopped expanding1, leaving us with three (expanding) space dimensions (length, width, depth) and one time dimension. • Exactly three expanding space dimensions is critical for life • Resulting force law (r-2) is necessary for stable planetary and atomic orbits. • Only 3D universes allow for transmission of high fidelity signals2. 1 The details of these six dimensions determine the physical constants 2 J.D. Barrow, “Dimensionality”, Phil. Trans. Royal Soc of London A310 (1983) p, 341
Coincidences “The possibility of life as we know it depends on the values of a few basic physical constants and is, in some respects remarkably sensitive to their numerical values. Nature does exhibit remarkable coincidences.” Martin Rees, Cosmologist, Cambridge University
Strong Nuclear Force n p p n p n p n • Binds neutrons and protons in the nucleus • If weaker, then fewer stable nuclei. (50% weaker reduces number of elements to ~20; no iron, iodine, molybdenum) Carbon, Nitrogen, Oxygen probably radioactive. • Other calculations suggest that if the strong force were stronger or weaker by as little as 0.5%-2%, life would be impossible—e.g., the effect on Red Giant stars1,2 and on the diproton catastrophe. 1 Barrow and Tipler, The Anthropic Cosmological Principle. Oxford Univ. Press, (1986) 322. 2 H. Oberhummer, A. Cst, and H. Schlattl, Stellar Production Rates of Carbon and Its Abundance in the Universe, Science 289 (2000): 88-90.
More on Fine Tuning… “The present arrangement of matter indicates a very special choice of initial conditions… The really amazing thing is not that life on Earth is balanced on a knife-edge, but that the entire universe is balanced on a knife-edge, and would be total chaos if any of the natural 'constants' were off even slightly.” Paul Davies, Professor of theoretical physics, Adelaide University
Gravity • If stronger, stars would be hotter, burn up too quickly and unevenly • If weaker, stellar nuclear furnace would not ignite, so no heavy elements • If gravity/EM was changed by 1 part in 1040, then no life-sustaining stars like our sun1 • A star of the right mass, color, and life cycle that, allows a planet to get close enough for liquid water; not so close that the planet phase locks; has a very stable luminosity period; etc. 1 Related to convection/radiative heat transfer. Balance related to (a/G)20. B. Carter, Large Number Coincidences and the Anthropic Principle in Cosmology, M. S. Longair, ed., (1974) pp, 291-298.
What does one part in 1040 look like? • Suppose you win the lotto on Monday • Then you win it again on Tuesday • And again on Wednesday • Now suppose that to collect your money you had to close your eyes and, with one try, select the only red grain of sand in the world. • Your chance of doing all this is about one in 1040
More on Fine Tuning… “The remarkable fact is that the values of these numbers seem to have been very finely adjusted to make possible the development of life.” Steven Hawking, A Brief History of Time, 10th ed., p. 129. “The universe, in some sense, must have known we were coming” Freeman Dyson, Theoretical Physicist, Princeton Institute for Advanced Studies
Electron to Proton Mass Ratio ∞ ? (electrons become nucleus) 10 Unstable relativistic atoms No Ordered Structures me/mp 1 0.1 We are here No Stars 0 0 0.1 1 10 ∞ Electron charge
Matter/Anti-Matter + For every 10 billion antiparticles created by the big bang, there were 10 billion plus 1 particles—this minute excess of particles accounts for the matter in the universe. If the excess was: • smaller: not enough matter in the universe • larger: too much radiation trapped—no stars (and diamonds aren’t forever) matter and antimatter annihilate, producing energy
Neutron Mass • The neutron is ~0.14% more massive that the proton. • After the Big Bang, there were about seven times as many protons • If the neutron were about ~0.1% heavier, there would not be enough of them to make the nuclei of heavy elements • If the neutron were ~0.1% lighter, protons would transform into neutrons so readily that stars would collapse into neutron stars or black holes
Lunar Fine Tuning • Generally, the greater a planet’s gravity and distance from the sun, the thicker its atmosphere. Earth violates this rule, with an atmosphere 40 times lighter that Venus. • Usually moons are much smaller than the planet and are formed of the same material. Earth has a huge moon which is not made of the same material as the earth. What happened? An object the size of Mars collided with the young (250 My) earth, and mostly absorbed into the core. The collision blasted most of the original overly-thick atmosphere into space. The cloud of debris coalesced into the moon. Belbruno and Gott, The Ast. J., 129, 1724-1745, 2005
The Collision: • Destroyed a thick, poisonous atmosphere. • Increased in the earth’s mass just enough; its gravity can retain water vapor (18), but not ammonia (17) or methane (16). • Boosted iron content of the earth (magnetic field) and made the oceans nutrient rich. • Slowed the earth’s rotation rate, which stabilized weather patterns. • Because the moon is big, its tidal effect cleans coastal waters and replenishes ocean nutrients. • However the moon is not too big –no excessive erosion, no excessive alteration of earth’s orbit.1 • The moon also stabilized the tilt of the earth’s axis, preventing climactic extremes. 1 A new calculation shows that if the moon were slightly bigger, the earth-moon system would go unstable. See Dave Waltham, Astrobiology4, No. 4: 460-468 (2004)
What else could explain fine tuning? • Luck? If we only had to be a little lucky, then this would be viable. But ~25 or more “fine tunings” makes this untenable. • Fundamental Theory? No— fine tuning is not an artifact of not knowing how to calculate the constants, but of life’s sensitivity to their values. • Multiverse? Yes, this explanation of fine tuning competes with design. If there are an infinity of universes, then we would show up in one of the lucky ones.
One Multiverse: Cosmic Landscape There are ~101000 String Theory solutions each → a different universe with different constants • Like most multiverse theories, our universe is (apparently) fine-tuned because it is one of the few habitable universes • Not testable (its leading proponent suggests that we may have to give up science’s scared testability requirement) • No hope for a fundamental theory explaining the constants—this, along with the previous point, means that physics is dead
It really is ID or Multiple Universes Q: If we do not accept the landscape idea are we stuck with intelligent design?A: If, for some unforeseen reason, the [Multiverse] turns out to be inconsistent - I am pretty sure that physicists will go on searching for natural explanations of the world. But I have to say that if that happens, as things stand now we will be in a very awkward position. Without any explanation of nature's fine-tunings we will be hard pressed to answer the ID critics. One might argue that the hope that a mathematically unique solution will emerge is as faith-based as ID. Leonard Susskind, Physics Professor, Stanford University, author of The Cosmic Landscape.
Another Possibility: Cosmic Evolution • Black Holes create new universes with similar constants • By Darwinism, universes with many black holes would be selected • The same kind of universe (with stars) that produces black holes are also life friendly • Advantage: habitable universes common • Disadvantages: No testable reason why black holes produce “similar” universes. (No proof that black holes produce universes at all.) No way to detect other universes. Where did the first universe come from? What if it had no black holes? If it was from a multiverse, then the whole theory is superfluous.
Tie Breaker? • If neither a designer or another universe is detectable, is there any additional evidence that favors one view? • Maybe—what if our location is not just fine-tuned for life, but also for scientific observation? • Ironically, the IDers who propose this view (Gonzalez and Richards in the Privileged Planet) also neuter it (they argue that habitable planets are necessarily good observation platforms—observability is not an “extra” miracle.
Observability Coincidence #1 Is the universe also fine-tuned for doing science? Because of accelerated expansion, we’re in an era of maximal observability. Distant galaxies will begin to “blink off”; their light will no longer be able to reach our telescopes. This is the first time in cosmic history that light from the most distant galaxies has reached the Milky Way—G. Veneziamo, Sci. Am., May 2004