Will BICEP2 Lose Some of Its Muscle?

A scientific controversy has been brewing concerning the results of BICEP2, the experiment that measured polarized microwaves coming from a patch of the sky, and whose measurement has been widely interpreted as a discovery of gravitational waves, probably from cosmic inflation. (Here’s my post about the discovery, here’s some background so you can understand it more easily. Here are some of my articles about the early universe.)  On the day of the announcement, some elements of the media hailed it as a great discovery without reminding readers of something very important: it’s provisional!

From the very beginning of the BICEP2 story, I’ve been reminding you (here and here) that it is very common for claims of great scientific discoveries to disappear after further scrutiny, and that a declaration of victory by the scientific community comes much more slowly and deliberately than it often does in the press. Every scientist knows that while science, as a collective process viewed over time, very rarely makes mistakes, individual experiments and experimenters are often wrong.  (To its credit, the New York Times article contained some cautionary statements in its prose, and also quoted scientists making cautionary statements.  Other media outlets forgot.)

Doing forefront science is extremely difficult, because it requires near-perfection. A single unfortunate mistake in a very complex experiment can create an effect that appears similar to what the experimenters were looking for, but is a fake. Scientists are all well-aware of this; we’ve all seen examples, some of which took years to diagnose. And so, as with any claim of a big discovery, you should view the BICEP2 result as provisional, until checked thoroughly by outside experts, and until confirmed by other experiments.

What could go wrong with BICEP2?  On purely logical grounds, the BICEP2 result, interpreted as evidence for cosmic inflation, could be problematic if any one of the following four things is true:

1) The experiment itself has a technical problem, and the polarized microwaves they observe actually don’t exist.

2) The polarized microwaves are real, but they aren’t coming from ancient gravitational waves; they are instead coming from dust (very small grains of material) that is distributed around the galaxy between the stars, and that can radiate polarized microwaves.

3) The polarization really is coming from the cosmic microwave background (the leftover glow from the Big Bang), but it is not coming from gravitational waves; instead it comes from some other unknown source.

4) The polarization is really coming from gravitational waves, but these waves are not due to cosmic inflation but to some other source in the early universe.

The current controversy concerns point 2.

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Did The Universe Really Begin With a Singularity?

Did the universe begin with a singularity?  A point in space and/or a moment in time where everything in the universe was crushed together, infinitely hot and infinitely densely packed?

Doesn’t the Big Bang Theory say so?

Well, let me ask you a question. Did you begin with a singularity?

Let’s see. Some decades ago, you were smaller. And then before that, you were even smaller. At some point you could fit inside your mother’s body, and if we follow time backwards, you were even much smaller than that.

If we follow your growth curve back, it would be very natural — if we didn’t know anything about biology, cells, and human reproduction — to assume that initially you were infinitesimally small… that you were created from a single point!

But that would be wrong. The mistake is obvious — it doesn’t make sense to assume that the period of rapid growth that you went through as a tiny embryo was the simple continuation of a process that extends on and on into the past, back until you were infinitely small.  Instead, there was a point where something changed… the growth began not from a point but from a single object of definite size: a fertilized egg.

The notion that the Universe started with a Big Bang, and that this Big Bang started from a singularity — a point in space and/or a moment in time where the universe was infinitely hot and dense — is not that different, really, from assuming humans begin their lives as infinitely small eggs. It’s about over-extrapolating into the past.

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Wednesday: Sean Carroll & I Interviewed Again by Alan Boyle

Today, Wednesday December 4th, at 8 pm Eastern/5 pm Pacific time, Sean Carroll and I will be interviewed again by Alan Boyle on “Virtually Speaking Science”.   The link where you can listen in (in real time or at your leisure) is http://www.blogtalkradio.com/virtually-speaking-science/2013/12/05/alan-boyle-matt-strassler-sean-carroll What is “Virtually Speaking Science“?  It is an online radio program that presents, … Read more

Courses, Forces, and (w)Einstein

This week and next, I’m very busy preparing and delivering a new class (four lectures, 1.5 hours each), for a non-technical audience, on the importance of and the discovery of the Higgs particle.  I’ll be giving it in Western Massachusetts (my old stomping grounds).  If it goes well I may try to give these lectures elsewhere (and please let me know if you know of an institution that might be interested to host them.)   Teaching a new class for a non-technical audience requires a lot of concentration, so I probably won’t get too much writing in over that period.

Still, as many of you requested, I do hope soon to follow up last week’s article (on how particle physicists talk about the strength of the different forces) with an article explaining how both particles and forces arise from fields — a topic I already addressed to some extent in this article, which you may find useful.

Now — a few words on the flap over the suggestion that math Ph.D. and finance expert Eric Weinstein, in his mid-40s, may be the new Albert Einstein.  I’ve kept my mouth shut about this because, simply, how can I comment usefully on something I know absolutely nothing about?  (Admittedly, the modern media, blogosphere and Twitter seem to encourage people to make such comments. Not On This Blog.) There’s no scientific paper for me to read.  There’s no technical scientific talk for me to listen to.  I know nothing about this person’s research.  All I know so far is hearsay.  That’s all almost anyone knows, except for a few of my colleagues at Oxford — trustworthy and experienced physicists, who sound quite skeptical, and certainly asked questions that Weinstein couldn’t answer... which doesn’t mean Weinstein is necessarily wrong, only that his theory clearly isn’t finished yet.  (However, I must admit my expert eye is worried that he didn’t have ready answers to such basic questions.)

What I do know is that the probability that Weinstein is the new Einstein is very low.  Why?  Because I do know a lot about how very smart people with very good ideas fail to be Einstein.  It’s not because they’re dumb or foolish.

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Why the Higgs Matters, In A Few Sentences

One of the big challenges facing journalists writing about science is to summarize a scientific subject accurately, clearly and succinctly. Sometimes one of the three requirements is sacrificed, and sadly, it is often the first one.

So here is my latest (but surely not last) attempt at an accurate, succinct, and maybe even clear summary of why the Higgs business matters so much.

`True’ Statements about the Higgs

True means “as true as anything compressed into four sentences can possibly be” — i.e., very close to true.  For those who want to know where I’m cutting important corners, a list of caveats will follow at the end of the article.

  • Our very existence depends upon the Higgs field, which pervades the universe and gives elementary particles, including electrons, their masses.  Without mass, electrons could not form atoms, the building blocks of our bodies and of all ordinary matter.
  • Last July’s discovery of the Higgs particle is exciting because it confirms that the Higgs field really exists.  Scientists hope to learn much more about this still-mysterious field through further study of the Higgs particle.

Is that so bad? These lines are almost 100% accurate… I’m sure an experienced journalist can cut and adjust and amend them to make them sound better and more exciting, but are they really too long and unclear to be useable?

Some False Statements about the Higgs

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Why, Professor Kaku? Why?

Professor Michio Kaku, of City College (part of the City University of New York), is well-known for his work on string theory in the 1960s and 1970s, and best known today for his outreach efforts through his books and his appearances on radio and television.  His most recent appearance was a couple of days ago, … Read more

European Weather Model Does It Again?

We’re gearing up for another big-time storm predicted for the northeastern United States — we’ve had more than we need over recent months — so before we perhaps lose power (or you do)… …I want to remind you that Sean Carroll and I were interviewed last night by science writer Alan Boyle.  My impression is … Read more

Wednesday: Sean Carroll & I Interviewed by Alan Boyle

On Wednesday February 6th, at 9 pm Eastern/6 pm Pacific time, Sean Carroll and I will be interviewed by Alan Boyle on “Virtually Speaking Science”.   The link where you can listen in (in real time or at your leisure) is http://www.blogtalkradio.com/virtually-speaking-science/2013/02/07/sean-carroll-matt-strassler-alan-boyle What is “Virtually Speaking Science“?  It is an online radio program that presents, according … Read more

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