Posts tagged ‘string theory’

October 15th, 2013

“Belief in Multiverse Requires Exceptional Vision”

by Max Andrews

Original post from Not Even Wrong.

Tom Siegfried at Science News has a new piece about how Belief in multiverse requires exceptional vision that starts off by accusing critics of multiverse mania of basically being ignoramuses who won’t accept the reality of anything they can’t see with their own eyes, like those in the past who didn’t believe in atoms, or superstrings…

The problem with the multiverse of course is not that you can’t directly observe it, but that there’s no significant evidence of any kind for it: it’s functioning not as a testable scientific explanation, but as an excuse for the failure of ideas about unification via superstring theory. Siegfried makes this very clear, with his argument specifically aimed at those who deny the existence of “supertiny loops of energy known as superstrings”, putting such a denial in the same category as denying the existence of atoms. Those who deny the existence of superstrings don’t do so because they can’t see them, but because there’s no scientific evidence for them and no testable predictions that would provide any.

June 9th, 2013

The Philosophy of Science Directory

by Max Andrews

This is a compilation of posts, which focus on the philosophy of science. These posts will cover a broad spectrum within the philosophy of science ranging from multiverse scenarios, scientific theory, epistemology, and metaphysics.

  1. MA Philosophy Thesis: “The Fine-Tuning of Nomic Behavior in Multiverse Scenarios”
  2. Natural Law and Scientific Explanation
  3. Science and Efficient Causation
  4. Which Comes First, Philosophy or Science?
  5. The Postulates of Special Relativity
  6. There’s No Such Thing as Creation Science–There’s Just Science
  7. Time Travel and Bilking Arguments
  8. “It’s Just a Theory”–What’s a Scientific Theory?
  9. Exceptions to a Finite Universe
  10. Teleology in Science
  11. Duhemian Science
  12. The Relationship Between Philosophy and Science
  13. The History of the Multiverse and the Philosophy of Science
  14. Where’s the Line of Demarcation Between Science and Pseudoscience?
  15. Miracles and the Modern Worldview
  16. Mass-Density Link Simpliciter
  17. Scientific Nihilism
  18. Q&A 10: The Problem of Defining Science
  19. Q&A 6: Scientism and Inference to the Best Explanation
  20. The Quantum Universe and the Universal Wave Function
  21. The History and Macro-Ontology of the Many Worlds Interpretation of Quantum Physics
    read more »

October 15th, 2012

What is This Thing Called String Theory?

by Max Andrews

We’ve all probably heard of string theory. I’ve seen specials devoted to it on PBS, it in major science and philosophy books/papers, dialogues with skeptics, and even in [the greatest film of all time… ever] Good Will Hunting. It’s a very complex and confusing field of research. My hope is that my summation here will help give a introductory grasp of the material.

The spontaneous breakdown of symmetries[1] in the early universe can produce linear discontinuities in fields, known as cosmic strings.  Cosmic strings are also common in modern string theories in which the most fundamental reality are astronomically tiny vibrating strings (either closed or open depending on the interpretation of the mathematics).[2]  The combination of the string/scalar landscape with eternal inflation has in turn led to a markedly increased interest in anthropic reasoning.  In this multiverse scenario life will evolve only in very rare regions where the local laws of physics just happen to have the properties needed for life, giving a simple explanation for why the observed universe appears to permit the evolutionary conditions for life. 

July 18th, 2012

Word of the Week Wednesday: String Theory

by Max Andrews

Word of the Week: String Theory

Definition: The leading theory of everything, which describes the earliest moments of the universe in which the four fundamental forces of nature (gravity, electromagnetic, strong nuclear, and weak nuclear) were one force. The most fundamental element of reality are cosmic strings, and their vibration determines what particles or forms it takes.

More about the term:  The spontaneous breakdown of symmetries[1] in the early universe can produce linear discontinuities in fields, known as cosmic strings.  Cosmic strings are also common in modern string theories in which the most fundamental reality are astronomically tiny vibrating strings (either closed or open depending on the interpretation of the mathematics).[2]  The combination of the string/scalar landscape with eternal inflation has in turn led to a markedly increased interest in anthropic reasoning.  In this multiverse scenario life will evolve only in very rare regions where the local laws of physics just happen to have the properties needed for life, giving a simple explanation for why the observed universe appears to permit the evolutionary conditions for life.  It is argued that such anthropic reasoning can give the illusion of intelligent design without the need for any intelligent intervention.[3]  There are at least four ways we can understand the different universes described by string landscape.[4]

October 7th, 2011

Neutrinos Faster Than Light or Extra Dimensions?

by Max Andrews

Source: CERN Press

By now we’ve all heard of the news coming out of CERN and OPERA on 23 September that the Italian accelerator, OPERA, measured neutrinos traveling faster than the speed of light.  I didn’t comment on the finding right away because I wanted to do some research on the claims and on what exactly happened.  So here are my two-cents.

So, what exactly is a neutrino?  A neutrino is a fundamental particle and crucial for the standard model of particle physics.  The neutrino comes tin three types: [associated with] the electron, muon, and tauon, which are fermions and part of leptons.  The have no electric charge and interact only via the weak nuclear force (see the Oxford Companion to Cosmology for more on this).  These particle are incredibly difficult to detect and pass through our bodies all the time (this is a nice little Italian cartoon that has an excellent depiction of neutrinos).

So, what happened?  CERN sent the neutrinos 730lm to the Italian accelerator OPERA.  The journey only took 2.43 milliseconds and the scientists timed it to within 10 nanoseconds. (A millisecond is a thousandth of a second, 1/1,000s and a nanosecond is a billionth of a second, 1/1,000,000,000s).  The neutrinos arrived 60 nanoseconds earlier than they would have if they were traveling at the speed of light (c = 299,792,458 m/s). There are three options of what could have happened.

  1. Option One.  The experiment was in error and the calculations are simply incorrect.
  2. Option Two.  The speed of light is not the cosmic speed limit and there must be slight adjustments for relativity theory.
  3. Option Three.  The neutrinos took a shortcut through extra dimensions.

Option One: Experimental Error.  The OPERA team spent three years trying to calculate and find every error they could possibly find.  The neutrinos are produced by colliding protons into a graphite target to produce pions and travel a 1km tunnel and decay to produce neutrinos.  Electronic delays in the timing system that records when protons arrive at the graphite target introduce uncertainty.  However, this margin of error is 5 nanoseconds. Where the pions decay is also unknown, which produces an error of 0.2 ns.  Measuring the distance is also difficult because the OPERA lab in Gran Sasso is inside of a mountain, which is undetectable to GPS.  However, the distance can still be calculated to within 20 cm.  The error is 0.67 ns.  With the other errors taken into consideration, the total error bar is 7.4 ns.  Remember, if experimental error is going to be the prevalent option the errors have to account for 60 nanoseconds.

Option Two: Adjusting Relativity.  If it really is the case that the neutrinos did travel faster than the speed of light then Einstein isn’t completely thrown to the curb.  There must be a theory that will account for this that will be closer to the truth.  This has historical precedence.  Newtonian physics were thought to explain the universe until Einstein came around with the concept of relativity.  Newton wasn’t necessarily wrong, Einstein just provided a more accurate theory.  If neutrinos can travel faster than c then we need another Einsteinian discovery.  Not that big of deal.

Option Three: Extra Dimensions.  It may be the case that the neutrinos, when travel with an incredible amount of energy, travel through the smaller curled up dimensions.  Consider the neutrinos traveling into the fourth dimension, this would actually make the distance much shorter.  Hopefully this illustration will help.  Take a piece of paper and draw a straight line across the paper.  Label one end of the line A and the other B.  This line is one-dimensional.  Take the paper and fold it so it creates an upward arch.  Now, if you were to travel from A to B by going through the paper instead of curving around the outside of the paper then the distance would be shorter.  This may, perhaps, be what happened to the neutrinos. (For more information on the discovery see New Scientist No. 2832, October 1-7 2011).

I tend to lean more towards option three, that the neutrinos passed through the smaller extra dimensions.  This would be an incredible development that would contribute to and, possibly, confirm a prediction of string theory.  Part of this may be wishful thinking on my part but this may potentially be an incredible empirical find that would confirm the mathematics.  Now, what about further philosophical or theological implications?  I don’t think this has too much of an impact on philosophy or theology that hasn’t already been addressed concerning the philosophy of science or of scientific theology.  For more on these implications see “The Relationship Between Science and Philosophy,” “Einstein, the Big Bang, and Natural Theology,” “Einstein on Free Will,” and “Einstein’s Impact on the Epistemic Method.”