Monday, September 22, 2014

BICEP2 just saw cosmic dust

Here is the current SciAm cover story:
How Big Bang Gravitational Waves Could Revolutionize Physics
If the recent discovery of gravitational waves emanating from the early universe holds up under scrutiny, it will illuminate a connection between gravity and quantum mechanics and perhaps, in the process, verify the existence of other universes
By Lawrence M. Krauss

In March a collaboration of scientists operating a microwave telescope at the South Pole made an announcement that stunned the scientific world. They claimed to have observed a signal emanating from almost the beginning of time. The putative signal came embedded in radiation left over from the action of gravitational waves that originated in the very early universe — just a billionth of a billionth of a billionth of a billionth of a second after the big bang.

The observation, if confirmed, would be one of the most important in decades. It would allow us to test ideas about how the universe came to be that hitherto scientists have only been able to speculate about. It would help us connect our best theories of the subatomic (quantum) world with our best theories of the massive cosmos — those based on Einstein's general theory of relativity. And it might even provide compelling (though indirect) evidence of the existence of other universes.
No, the observation has not been confirmed, and it appears that all BICEP2 saw was some polarization caused by cosmic dust.

Even if it had been confirmed, I don't see how it could have been evidence for either quantum gravity or the existence of other universes. It is widely believed that the big bang was accelerated by something called inflation, but we do not know the source, magnitude, or duration of the inflation force, or even whether it is reasonable to call it a force. So if we see echoes of the big bang, we are probably seeing inflation waves, not quantum gravity waves. And we are certainly not seeing other universes.

A clue to the over-hype is that the title says "revolutionize physics" and the first name in the article is Einstein. No, this would not have been some stupid paradigm shift. Einstein did not even believe in the big bang, gravity waves, or quantum mechanics, and probably would not have believed in the multiverse either.

SciAm also have a couple of letters about free will. A philospher writes:
In “The World without Free Will,” Azim F. Shariff and Kathleen D. Vohs assert that a survey revealed that “the more people doubt free will, the less they favor ‘retributive’ punishment” and indicate that the notion of free will is necessary to social order. What constitutes human freedom is a complex matter, fraught with ambiguities that have been debated for millennia. The authors don't clarify the survey's questions. For instance, what if it had asked respondents to rate the relative influence of several factors, such as physical laws, biological impulses, life experiences, the cultural environment, rational deliberation or a sense of self-determination? Wouldn't that have elicited a more nuanced response?
Yes, more nuanced, as those things cannot be distinguished without a lot of careful definitions. Another writes:
Shariff and Vohs ask the question “What will our society do if it finds itself without the concept of free will?” But they do little to clarify the issue.
How much can you say about what people will do if they find out that they do not have free will? If they do not have free will, then they are just robots who will follow their programming. It always seems funny to me when people who say that they do not believe in free will, and then try to convince people of various beliefs.

Update: Lumo is a believer:
There is a scientific substance. Everyone who is interested in cosmology would love to know whether the imprints of the primordial gravitational waves have been seen. I agree with those who say that this discovery, if true, is the greatest discovery in many years if not decades or a century. I would probably place it above the Higgs boson discovery because unlike the Higgs boson, it wasn't really guaranteed.

However, we must ask: is the discovery real?

Of course that I am not 100.00000% sure. But I still think it's significantly more likely than not that the BICEP2 discovery is genuine and the pattern they see is simply not dust. Why? Because it clearly doesn't look like dust.
And it looks like primordial quantum gravity waves? I don't think so.

1 comment:

  1. If there is no free will, then anything and everything is equally acceptable. You can't tell a man who wishes to murder and rape he is wrong or even suggest he should stop if he is merely following his predetermined programming or nature. Ironically, in such a hypothetical situation, if there was no free will, why would punishment be wrong? If the man who murders and rapes is just following his programming, so is the man who puts a bullet through him to put him down. I don't see why in such a scenario why one behavior should be excused and the other condemned for any reason, after all, it's ALL OK, All of it, not just the parts that certain morally challenged political parties try to ignore (Kermit Gosnell anyone?). Nothing matters since all perception, feeling, and thought, is just the illusion of complexly interacting molecules. Likewise, all racism, misogyny, sexism, hurt feelings, blatant discrimination are equally fine and A-OK, how could they not be? All behavior is just preprogrammed instructions playing out, how could anyone stand up and complain about any kind of behavior whatsoever? They are only bitching because they were programmed that way, and there is no meaning or purpose behind what they say, do, think, or feel.