1 MILLION YEARS: IS THE UNIVERSE LOPSIDED?

Glenn Starkman, physicist at Case Western Reserve University

The heat of the big bang left behind radiation that has permeated the universe ever since. Space probes have mapped this cosmic microwave background, or CMB, over the entire sky and found it to be extraordinarily uniform save for small, random fluctuations, just as big bang theory had predicted. Such smoothness implies that the early universe was itself uniform. Yet some analyses, including those by my collaborators and me, saw an excess of symmetry between opposite sides of the sky and other anomalies, including a lack of the largest fluctuations, those that should span more than 60 degrees in the firmament.

To find out if these are real features or statistical flukes, we just need to keep observing. The CMB picture we see today is an accident of our place in space and time. The CMB has traveled to us from all directions for 13.7 billion years. Surveying it thus means mapping a spherical surface that surrounds us and has a radius of 13.7 billion light-years—the distance light has traveled in this time. If we wait long enough, the sphere will get bigger and bigger and thus cross new regions of the early universe. The anomalies are so large that it may take a billion years for the CMB sphere to get past them—when the sphere's radius would reach 14.7 billion light-years. If we could wait “just” one million years, most of the anomalies should be still there but slightly changed. By then, we would be able to see if they were on their way to disappearing—suggesting that they are flukes—or if their persistence reveals the presence of larger cosmic structures.

Will our heads get bigger?

“The narrowness of the human birth canal is a major bottleneck on the size of our heads. Will our use of C-sections, continued for hundreds of thousands of years, lead us to evolve larger brains?”

Katerina Harvati, paleoanthropologist at the University of Tübingen in Germany

How will giving birth at later ages change our biology?

“People are having children at an older age, when mutation rates in sperm are higher and the style of parenting is different. After tens of thousands of years, could these cultural changes affect our biology?”

Marcus Feldman, mathematical biologist at Stanford University

1 MILLION YEARS: ARE PROTONS FOREVER?

Sean M. Carroll, theoretical physicist at the California Institute of Technology

The universe's ordinary matter consists, for the most part, of protons—particles that have been around since the big bang. Whereas other subatomic particles, including neutrons, can spontaneously decay, protons appear to be exceptionally stable. Yet some grand unified theories, or GUTs—attempts to reinterpret all of particle physics as different facets of a single force—predict that protons should break down, too, with average life spans of up to 1043 years, depending on the theory. If we wait long enough, though, could we finally see it happen?

To see the proton decay, all you have to do is fill a large underground tank with water and monitor it for little flashes of light that would go off as the protons in the water's atoms finally died. The more protons you monitor, the higher the chance that you will see one decay. Studies done with existing detectors show that protons last at least 1034 years, values that have already ruled out numerous GUTs. To have the final word, these detectors might need to run for 100 million years. But if we built detectors 100 times larger—making them about the size of a professional football stadium, voluminous enough to hold five million tons of water—just one million years should do. Unifying particle physics might be worth the wait.

This article was originally published with the title Questions for the Next Million Years.

MORE TO EXPLORE

Life's Rocky Start. Robert M. Hazen in Scientific American, Vol. 284, No. 4, pages 76–85; April 2001.

Ripples in Spacetime. W. Wayt Gibbs in Scientific American, Vol. 286, No. 4, pages 62–71; April 2002.

Inconstant Constants. John D. Barrow and John K. Webb in Scientific American, Vol. 292, No. 6, pages 56–63; June 2005.

Is the Universe Out of Tune? Glenn D. Starkman and Dominik J. Schwarz in Scientific American, Vol. 293, No. 2, pages 48–55; August 2005.

What Is a Species? Carl Zimmer in Scientific American, Vol. 298, No. 6, pages 72–79; June 2008.

6 Comments

1. 1. junior144 07:43 AM 9/5/12

   oh bull

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2. 2. gesimsek 10:21 AM 9/5/12

   If someone could live forever, there would be no question worth to ask

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3. 3. dicklipke 10:39 AM 9/5/12

   They could fail time after time after time.Blowing up or poisoning everyone around themselves and keep coming back to try,try again. Never the need of finally admitting to failure.What a exciting life after life after life to lead forever.And It would never be necessary to find a answer.

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4. 4. dudleybrooks 03:04 PM 9/5/12

   I would like to suggest that SciAm use notation such as 10^43 to indicate powers of ten. In the Mac/Safari browser, at least, the currently used notation shows up as "1043". It's very amusing to read that the lifetime of a proton might be 1043 years.

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5. 5. basudeba 09:20 PM 9/14/12

   We wish you could have measured the electric charges of protons and neutrons. According to our theory, the present value of the charge of quarks contain an error element of 3%. In stead of 2/3 and 1/3, they are 7/11 and 4/11. This makes the charge of protons +10/11 and that of neutrons -1/11. The net charge is not perceptible as it is a negative charge directed towards the nucleus. This theory also predicts the value of fine structure constant alpha as 7/960 and zero energy level and 7/900 at the weak interaction level, which fairly matches with the measured value. This shows that our understanding of atomic shells itself is too primitive. It may take a 1000 years to get a complete picture.
   
   

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6. 6. ToryTheTall 12:28 AM 11/25/12

   It's amazing to think that anything would take us this long to understand. Looking at the technological innovations of the last 150 years, and the decreasing time between major breakthroughs, to think that *anything* is out of reach within a relatively short timeframe is mindboggling.

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