Thursday, September 18, 2014

Weakening scientific criteria is dangerous

Physicist George F. R. Ellis writes in SciAm:
Why the Multiverse May Be the Most Dangerous Idea in Physics
Proof of parallel universes radically different from our own may still lie beyond the domain of science

In the past decade an extraordinary claim has captivated cosmologists: that the expanding universe we see around us is not the only one; that billions of other universes are out there, too. There is not one universe—there is a multiverse. In Scientific American articles and books such as Brian Greene's The Hidden Reality, leading scientists have spoken of a super-Copernican revolution. In this view, not only is our planet one among many, but even our entire universe is insignificant on the cosmic scale of things. It is just one of countless universes, each doing its own thing. The word “multiverse” has different meanings. Astronomers are able to see out to a distance of about 42 billion light-years, our cosmic visual horizon. We have no reason to suspect the universe stops there. Beyond it could be many—even infinitely many—domains much like the one we see. Each has a different initial distribution of matter, but the same laws of physics operate in all. Nearly all cosmologists today (including me) accept this type of multiverse, which Max Tegmark calls “level 1.” Yet some go further. They suggest completely different kinds of universes, with different physics, different histories, maybe different numbers of spatial dimensions. Most will be sterile, although some will be teeming with life. A chief proponent of this “level 2” multiverse is Alexander Vilenkin, who paints a dramatic picture of an infinite set of universes with an infinite number of galaxies, an infinite number of planets and an infinite number of people with your name who are reading this article.

Similar claims have been made since antiquity by many cultures. What is new is the assertion that the multiverse is a scientific theory, with all that implies about being mathematically rigorous and experimentally testable. I am skeptical about this claim. I do not believe the existence of those other universes has been proved—or ever could be. Proponents of the multiverse, as well as greatly enlarging our conception of physical reality, are implicitly redefining what is meant by “science.”
Ellis now repudiates the title:
This just shows the dangers of having subeditors assign titles to what you write, without consulting when they do so. I do not agree with that title, and disassociate myself from it.

What is dangerous is weakening the criteria for what science is. Multiverses are only dangerous to science if they are used to motivate that move. String theory is of course another theory that has also been used to motivate that move. It is that move that is dangerous to science, not the theories that are defended in this way.
It is very sloppy of SciAm to publish this title without checking with the author. Preparation of an article like this might involve 20 different communications between the author and editors, but editors often stubbornly refuse to use one more to check the title.

The multiverse idea is to speculate about unobservable universes. As Greene and Tegmark explain, there are several completely different proposals for such universes. What they have in common is that assertions about them are complete untestable, and more like religion than science.

Ellis is quibbling about the title. Usually an idea is dangerous because it might be right, and I guess that is what he is objecting to. Ellis is not saying that the multiverse might be right. It is dangerous because it is an anti-science ideology that is invading physics.


  1. I'm all to familiar with the multiverse conjectures...unfortunately. There actually is no difference between the multiverse and Star Trek, literally, since everything actually exists and works somewhere else according to different rules. The problem really is not that anti-science is invading physics, it is that the invasion is actually long over, and only now are a few people beginning to realize it. The moment physics allowed incredibly sloppy reasoning and poorly defined terms and concepts like 'superposition' in through the front door, the barn door and almost any other mechanical restraint almost literally became irrelevant to the imaginary, er, virtual teleporting horses. Good grief, there is no actual physics anymore, not really. We live in a glorious magical mystery era that will put the myths of quaint old religions to shame!

    Quantum physicists are now crowing about how they 'teleport' information without actual energy or matter being moved or used to convey the information at all, all you need are handy dandy virtual particles that exists only in your math and you can work miracles! No mention of course is made how virtual particles can be detected by actual machines, but WTF, anything goes if you call it science and dress it up with buzz words. The scientific community drinks cool aid like this and then frets about dangerous ideas that threaten their mathematical rigor? Rigor? Really? Pin heads who can't really tell the difference between physical actuality and made up virtual numerical abstraction and simulation are concerned about anti-science? Oh the irony, it burns, it burns!!!

    But, oh, hey, they have the scientific method and peer review to protect them from the deniers, so no worries, the terms will all be adjusted just like historical temperature records until it means whatever they want.

    /end rant

  2. Follow up on Neil the not so much science Guy,
    It appears that Neil's dismissive attitude of his critics is also shared by his followers. This article pretty much nails Neil to the wall, he is no scientist, not in any meaningful way in any case. His groupies are actually defending the whole 'factually false but truthiful anyway' meme.

    Please see for yourself.