Book recommendation

“Losing the Nobel Prize”  by Brian Keating is a book you should read if you have any interest in l. physics. 2. astronomy 3. cosmology 4. the sociology of the scientific enterprise (physics division) 5. The Nobel prize 6. The BICEPs and BICEP2 experiments.

It contains extremely clear explanations of the following

l. The spiderweb bolometer detector used to measure the curvature of the universe

2. How Galileo’s telescope works and what he saw

3. How refracting and reflecting telescopes work

4. The Hubble expansion of the universe and the problems it caused

5. The history of the big bang, its inherent problems, how Guth solved some of them but created more

6. How bouncing off water (or dust) polarizes light

7. The smoothness problem, the flatness problem and the horizon problem.

8. The difference between B modes and E modes and why one would be evidence of gravitational waves which would be evidence for inflation.

9. Cosmic background radiation

The list could be much longer.  The writing style is clear and very informal.   Example: he calls the dust found all over the universe — cosmic schmutz.   Then there are the stories about explorers trying to reach the south pole, and what it’s like getting there (and existing there).

As you probably know BICEP2 found galactic dust and not the polarization pattern produced by gravitational waves.  The initial results were announced 17 March 2014 to much excitement.  It was the subject of a talk given the following month at Harvard Graduate Alumni Day, an always interesting set of talks.  I didn’t go to the talk but there were plenty of physicists around to ask about the results (which were nowhere nearly as clearly explained as this book).  All of them responded to my questions the same way — “It’s complicated.”

The author Brian Keating has a lot to say about Nobels and their pursuit and how distorting it is, but that’s the subject of another post, as purely through chance I’ve known 9 Nobelists before they received their prize.

It will also lead to another post about the general unhappiness of a group of physicists.

Buy and read the book

A certain Nobel prize

Chemists will be green with envy to find out that a Nobel prize (possibly in Chemistry) is almost certain to be won by someone using using nothing fancier than formaldehyde, acrylamide and an ionic detergent (Sodium Dodecyl Sulfate — the SDS of electrophoresis fans everywhere)_. For details see Nature vol. 497 pp. 332 – 337 ’13 (16 May Issue). It’s by the same man (Karl Deisseroth) who already has a Nobel coming for the invention of optogenetics.

First — a bit of history. The tissue of the brain is so tightly packed that it is impossible to see the cells that make it up with the usual stains used by light microscopists. People saw nuclei all right but they thought the brain was a mass of tissue with nuclei embedded in it (like a slime mold). Muscle is like that — long fibers with hundreds of nuclei here and there. It wasn’t until that late 1800’s that Camillo Golgi developed a stain which would now and then outline a neuron with all its processes. Another anatomist (Ramon Santiago y Cajal) used Golgi’s technique and argued with Golgi that yes the brain was made of cells. Fascinating that Golgi, the man responsible for showing nerve cells, didn’t buy it. This was a very hot issue at the time, and the two received a joint Nobel prize in 1906 (only 5 years after the prizes began).

How tightly packed is the brain? The shortest wavelength of visible light is 4000 Angstroms. Cells in the brain are packed far more tightly. To see the space between the brain cell external membranes you need an electron microscope (EM). Just preparing a sample for EM really fries the tissue. Neurons are packed together with less than 1000 Angstroms between them. So how much of this is artifact of preparation for electron microscopy has never been clear to me. One study injected a series of quantum dots of known diameter into the cerebral spinal fluid (CSF) to see the smallest sized dot that could insinuate itself between neurons [ Proc. Natl. Acad. Sci. vol. 103 pp. 5567 – 5572 ’06 ]. The upper limit was around 350 Angstroms. No wonder the issue was contentious when all they had was the light microscopy.

Your brain (and mine) is mostly fat. Light doesn’t get through fat very well at all. Deisseroth figured out a way to remove the fat leaving the other brain structures intact. The technique even works on brains fixed in formaldehyde for years. First they infused formaldehyde and acrylamide into brain tissue at 4 degrees Centigrade. The formaldehyde hardens the tissue, but it also links the acrylamide to the proteins making up the tissue. Then they raised the temperature to 37 Centigrade causing the acrylamide to polymerize. Then they infused sodium dodecyl sulfate into the tissue using electrophoresis. When the SDS was pulled out of the tissue (again by electrophoresis) pulling the fat (lipids) of the brain with it, this left what they call a hydrogel (which light could go through).

Using the technique it is possible to look through slabs of brain tissue 500 microns thick (5 million Angstroms thick) with a light microscope and see cell bodies and nerve fibers in their natural habitat (e.g. whole populations of neurons along with their projections). Even better you can stain the hydrogel with your antibody of choice and see what protein is where. Then you can wash this out and look at something else.

It is an incredible advance and certain to revolutionize our understanding of the brain. Look at the paper. The pictures are amazing and more are sure to follow from other workers. Definitely Nobel caliber work.

It is extremely amusing to me that this work could have been done 50 years ago. It just took someone smarter than you and I to think of it.