Tag Archives: Science

Harvard University astrophysicist discusses fine-tuning in the Washington Post

Christianity and the progress of science
Christianity and the progress of science

I’m pretty sure my readers already know about the fine-tuning argument, but it’s not every day you see it discussed (however briefly) in a far-left mainstream newspaper like the Washington Post. (H/T Carmen)

The author is Howard A. Smith:

Howard A. Smith is a senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and a member of the Harvard Department of Astronomy. His research emphasizes the origins of stars, stellar systems and galaxies, and he is an author on more than 250 scientific articles. Previously he was Chair of Astronomy at the Smithsonian’s National Air and Space Museum; he also served for three years as a visiting scientist at NASA Headquarters.

Here is some of what he wrote in the far-left Washington Post:

There was a time, back when astronomy put Earth at the center of the universe, that we thought we were special. But after Copernicus kicked Earth off its pedestal, we decided we were cosmically inconsequential, partly because the universe is vast and about the same everywhere. Astronomer Carl Sagan put it this way: “We find that we live on an insignificant planet of a humdrum star.” Stephen Hawking was even blunter: “The human race is just a chemical scum on a moderate-sized planet.”

An objective look, however, at just two of the most dramatic discoveries of astronomy — big bang cosmology and planets around other stars (exoplanets) — suggests the opposite. We seem to be cosmically special, perhaps even unique — at least as far as we are likely to know for eons.

The first result — the anthropic principle — has been accepted by physicists for 43 years. The universe, far from being a collection of random accidents, appears to be stupendously perfect and fine-tuned for life. The strengths of the four forces that operate in the universe — gravity, electromagnetism, and the strong and weak nuclear interactions (the latter two dominate only at the level of atoms) — for example, have values critically suited for life, and were they even a few percent different, we would not be here. The most extreme example is the big bang creation: Even an infinitesimal change to its explosive expansion value would preclude life. The frequent response from physicists offers a speculative solution: an infinite number of universes — we are just living in the one with the right value. But modern philosophers such as Thomas Nagel and pioneering quantum physicists such as John Wheeler have argued instead that intelligent beings must somehow be the directed goal of such a curiously fine-tuned cosmos.

It seems likely that exoplanets could host extraterrestrial intelligence. But intelligence is not so easy to produce. Paleontologist Peter Ward and astronomer Donald Brownlee summarize the many constraints in their book “Rare Earth: Why Complex Life is Uncommon in the Universe ” and show why it takes vastly more than liquid water and a pleasant environment to give birth even to simple (much less complex) life. At a minimum, it takes an environment stable for billions of years of evolution, plus all the right ingredients. Biologists from Jacques Monod to Stephen Jay Gould have emphasized the extraordinary circumstances that led to intelligence on Earth, while geneticists have found that DNA probably resulted from many accidents. So although the same processes operate everywhere, some sequences could be unlikely, even astronomically unlikely. The evolution of intelligence could certainly be such a sequence.

There is, moreover, a well-known constraint: the finite speed of light, which ensures that even over thousands of years we will only be able to communicate with the comparatively few stars (tens of millions) in our cosmic neighborhood. If the combined astronomical, biological and evolutionary chances for life to form and evolve to intelligence are only 1 in 10 million, then we probably have no one to talk to.

What is really strange is when I try to talk to atheists about this evidence, and they tell me about Star Trek and Star Wars and how the universe isn’t specially designed and there are aliens everywhere.  Atheists like the science fiction, they don’t like the science facts.

If you would like to hear a good lecture on the fine-tuning argument, this one with Robin Collins is very good. You can hear him debate the fine-tuning argument with Peter Millican here. And in this lecture Collins talks about his new research. Another discussion between Luke Barnes and an atheist is useful to understand how objections to the argument can be answered.

Are endogenous virus genes evidence for common descent?

Investigation in progress
Investigation in progress

This is a guest post by JoeCoder.

It’s often argued that when two or more organisms share viral genes in the same place, it is evidence those organisms evolved from a common ancestor.  Wikipedia’s Evidence for Common Descent page frames it as follows:

Endogenous retroviruses (or ERVs) are remnant sequences in the genome left from ancient viral infections in an organism. The retroviruses (or virogenes) are always passed on to the next generation of that organism that received the infection. This leaves the virogene left in the genome. Because this event is rare and random, finding identical chromosomal positions of a virogene in two different species suggests common ancestry.

This argument presupposes that the viruses inserted themselves into genomes randomly and stick around as junk DNA baggage, rather than genomes originally being designed with viral-like genes that perform useful functions.  However this argument has unraveled as we’ve discovered useful functions for many viral-like genes, including functions that specifically require a viral-like sequence.  Some examples among many:

  1. ERV sequences protect against viral infection through interference–a matching-but-opposite strand of RNA is created to bind to and disable RNA from a virus.
  2. Likewise, ERV’s seem to function “during embryo implantation to help prevent immune recognition by the mother’s immune system”
  3. In worms, an ERV has been observed to create actual viruses that transfer DNA from somatic cells (skin/brain/heart/etc.) to germline (sperm/egg) cells whenever the worm is exposed to too much heat, allowing them to rewrite their own DNA for future generations.
  4. Viral envelopes from ERV transcripts attach to cell membranes in the placenta and causes them to fuse as a normal part of development: “The HERV-W [a human ERV] envelope glycoprotein named syncytin 1 is expressed in all trophoblastic [part of the placenta] cells and directly involved in human trophoblast fusion and differentiation [cells taking on specialized roles]”

These aren’t isolated cases of function.   Phys.org interviewed one researcher:  “When we investigated public data from embryonic cells, we found that many RNAs originated from regions in the human genome that are ERVs.  We did not only observe isolated events, but systematic activation of these ERVs. Every cell type showed transcription of specific classes, something that is very unlikely to occur by chance”.

Those cases all involve RNA viruses and that’s old news.  But two weeks ago, a single-celled eukaryote called Cafeteria roenbergensis was found to harbor maviruses within its own DNA that remain dormant until it is attacked by a large virus known as CroV.  When this happens the maviruses activate to form an attack fleet, as NewScientist reports:

A voracious marine predator plagued by a giant virus has a defence system we’ve never seen before – it fights back by making its very own virus… Rather than waiting for maviruses to arrive by chance when CroVs attack, it actually carries the genes that code for mavirus inside its own genome.  These genes are usually dormant, but they get turned on when Cafeteria is invaded by CroV. “It acts as an inducible antiviral defence system,” write Fischer and his colleague Thomas Hackl in a new preprint paper.

This process kills the Cafeteria roenbergensis cell, but is useful in defending other members of its own species.  In this experiment maviruses were deliberately inserted into the Cafeteria roenbergensis genome (see the original paper), but more interestingly, sequences similar to the Cafeteria roenbergensis viral genes have been found in a wide range of animals:

A wide range of animals, from sea anemones to crocodiles, harbour genetic elements called Maverick transposons that closely resemble the mavirus genes. It’s possible that some of these organisms can also unleash viruses that attack giant viruses.

In spite of this, New Scientist still argues “our genomes are littered with the mutant remains of viruses and genetic parasites.”  But these discoveries reveal this as a rapidly-shrinking argument of the gaps. 

Save this for the next time someone insists that viral genes are useless junk DNA and therefore evidence of common descent.

Michael Strauss lectures on scientific evidence for a Creator at UT Dallas

Christianity and the progress of science
Christianity and the progress of science

The lecture: (from 2013)

Note: there is a period of 19 minutes of Q&A at the end of the lecture.

About the speaker:

His full biography is here.

Summary:

  • It used to be true that most of the great scientists were believers in God
  • But now science has advanced and we have better instruments – is it still true?
  • Today, many people believe that science has shows that the universe and Earth are not special
  • We used to believe that the Earth was the center of the universe, and Darwin showed we are not designed
  • The problem with this view is that it is based on old science, not modern science
  • Three topics: origin of the universe, fine-tuning of the universe, the Rare Earth hypothesis

Experimental evidence for the origin of the universe:

  • #1: Hubble discovered that the universe expands because of redshifting of light from distant galaxies
  • #2: Measurements of the cosmic microwave background radiation show the universe had a beginnning
  • #3: Measurements of the light element (hydrogen and helium) abundances confirm an origin of the universe
  • The best explanation for an absolute origin of space, time, matter and energy is a supernatural cause

Experimental evidence for the design of the universe:

  • #1: The amount of matter: a bit less = no stars and galaxies, a bit more = universe recollapses
  • #2: The strong force: a bit more = only hydrogen, a bit more = little or no hydrogen
  • #3: Carbon resonance level: a bit higher = no carbon, a bit lower = no carbon

Experimental evidence for galactic, stellar and planetary habitability:

  • #1: Galaxy: produces high number of heavy elements and low radiation
  • #2: Star: long stable lifetime, burns bright, bachelor star, third generation star (10 billion years must elapsed),
  • #3: Planet: mass of planet, stable orbit, liquid water, tectonic activity, tilt, moon

Naturalistic explanations:

  • Humans evolve to the point where they reach back in time and create finely-tuned universe
  • Eternally existing multiverse

Hawking and Mlodinow response to Rare Earth:

  • There are lots of planets so one must support life
  • Odds of a planet that supports life are low even with 10^22 planets

Hawking and Mlodinow proposal of M-theory multiverse:

  • There is no experimental evidence for M-theory being true
  • M-theory is not testable now and is not likely to be testable in the future
  • But science is about making testable predictions, not about blind speculation

Hawking and Mlodinow no-boundary proposal:

  • This theory requires the laws of physics to exist prior to the universe
  • But where do you get laws of physics before there is any physical world?
  • There is no experimental evidence for no-boundary proposal
  • All the evidence we have now (redshift, CMBR, H-He abundances) is for Big Bang

What science has revealed provide abundant evidence for a transcendent Creator and Designer.

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