Thursday, December 31, 2009

Complicated chemicals have been found that replicate and evolve!

The abstract Theory of Evolution simply requires a population of entities that:
  1. reproduce
  2. at least some new entities in some generations differ from their parent(s) in at least one characteristic that affects their ability to reproduce
  3. these characteristic(s) are inherited

So any system that satisfies the above conditions can evolve. Note that these entities are not required to be considered alive by any definition. Which is why evolution applies from humans to algorithms used in sophisticated database software like PostgreSQL.

Obviously populations that have frequent generations and where there is a huge variation in the new entities, evolve the fastest - this has been observed, for example compare the rate of evolution of primates (such as humans) to that of bacteria.

Now evidence has been found that complicated chemicals called prions (as implicated in Mad Cow Disease) can also evolve:
"This means that this pattern of Darwinian evolution appears to be universally active.

"In viruses, mutation is linked to changes in nucleic acid sequence that leads to resistance.

"Now, this adaptability has moved one level down- to prions and protein folding - and it's clear that you do not need nucleic acid (DNA or RNA) for the process of evolution."

Thursday, December 24, 2009

New Brain Connections Form Rapidly During Motor Learning

The following article is well worth reading in full, it covers experiments that help explain why learning certain types of skills, like riding a bike, are remembered over many years even when not using those skills.

New Brain Connections Form Rapidly During Motor Learning
When previously trained mice were reintroduced to the reaching task four months later, their skill at the task remained high, and images of their brains did not show increased spine formation. When previously trained mice were taught a new skill, however, they showed enhanced spine formation and elimination similar to that seen during the initial training. Furthermore, spines that had formed during the initial training persisted after the remodeling process that accompanied the learning of a new task.

These findings suggest that different motor behaviors are stored using different sets of synapses in the brain, Zuo said. One of the questions she would like to explore in future studies is how these findings apply to different types of learning.

Friday, December 18, 2009

Open Source Geology

The general public can now access maps and other useful information about the geology of the British Isles. I wrote it up as an open source article.

Scientists are Careful and Responsible

Tom Whyntie, a physicist at the LHC, commented on the possible detection of Dark Matter by a rival experiment. Note that he is respectful of them, and also points out the importance that independent experiments have in verifying discoveries.

Dark matter appears to be responsible for over 80% of the mass of the Universe, but we have not yet discovered any, despite much evidence suggesting it exists. So there would be huge prestige for any scientist who discovered it.

Most people never realize how careful and responsible scientists are, as despite intense rivalries they fully appreciate the need for cooperation.

The quoted article gives a good insight into what makes good science practice.
In a very real, technical sense, the answer is no (and, of course, I'm not just saying that because I work on the LHC!). The observation of "only" two events does not a discovery make, and CDMS very carefully and responsibly state this in their announcements -- not because of modesty, but because they are good scientists. Statistics, to put it mildly, are tricky at the best of times and pretty much a nightmare when it comes to discoveries. They are very rightly exercising caution. It's how science works.

Monday, December 14, 2009

Can we see the surface of a star - other than our Sun???

This an article about a star dying, and shows several images of it varying in size that show the actual surface of a star!
"We have essentially created an animation of a pulsating star using real images," stated Lacour. "Our observations show that the pulsation is not only radial, but comes with inhomogeneities, like the giant hotspot that appeared at minimum radius."

Saturday, December 12, 2009

Force Fields For Spaceship Re-entry Protecion

I have seen recently several articles about using magnetic fields to deflect plasma around a spaceship. The first was about deflecting "cosmic rays", such as protons being part of the stellar wind from the Sun. They all involve the use of super conducting magnets, similar in concept to those used in the Large Hadron Collider - essntially you get a hugely powerful magnetic field, without having to constantly generate fresh electric current.

Here is an article about a proposal do avoid the need for a physical heat shields.

In a very real sense it is a Force Field, though not in the way of Star Trek.

The Next Generation of Heat Shield: Magnetic
The next generation of heat shields to protect astronauts and payloads on their re-entry into the Earth's atmosphere may use superconducting magnets to deflect the plasma that forms in front of spacecraft as they travel at high speeds in the air. The first test of such a heat shield could happen as early as ten years from now, and the basic technology is already in development.

Tuesday, December 8, 2009

A Physical Marriage

Well, think of a better title for 2 Theoretical Nuclear Physicists who married each other, and who collaborate in the same line of work!

This is the blog of the wife, Nicole. Who says:
I always knew I wanted to be a scientist. I just had a hard time deciding what kind of science to do, because it all seemed so interesting. After a love affair with chemistry and a flirtation with computer science in high school, I finally settled for physics, as the most fundamental of the natural sciences.
I am married to another theoretical physicist. We both work at IPMU and write our papers together.

Saturday, December 5, 2009

How Science Works

Scientists don't just think of an idea and do a simple experiment that beautifully verifies it - except in extremely rare instances. Normally data is mucky, has noise, that is say that not all the evidence will support the idea, even when it is mostly correct. Some of the data may not be too relevant to the domain in which the idea applies - try proving Newtons 3 laws of motion in everyday life - you can't, this does not mean that the 3 laws are wrong, just that you need to find the appropriate conditions.

When dealing with something as complicated as weather, one needs a good understanding of Statistics, in addition to knowledge about Physics, Chemistry, and Geography. It also helps enormously if you understand the jargon, and the difference between informal discussions and peer reviewed conclusions. Plus it helps to realize scientists are human, and therefore not expected to be diplomatic about climate denialists in private correspondence.

So sometimes scientists have to either omit data, and/or modify it to be useful.

For example if two boys where trying to decide which of their girl friends preferred chocolate the most, by analysing what the girls bought - they would omit any data relating to buying unrelated items like clothes. Similarly if they wanted to to decide the best level of loudness the girl friends liked music, they would adjust the data depending size of room (and several other factors) to 'normalize' the measurements - so that comparing loudness associated with a party of many people in a large room to the volume for 2 people in a small room. Or planet hunters, who deliberately omit the light from a star to pick the light of a planet - they are modifying the data.

So if an email talks about selecting data sets, and the reader does not bear the above in mind, and is naturally disposed to be untrusting - then quite the wrong conclusion could be drawn.

For a good coverage of this, see the articles about the significance of the leaked climate emails and his follow-up by Phil of Bad Astronomy (he started the site to debunk the Apollo Moon Hoax and others of a similar ilk).

Friday, December 4, 2009

New Zealand's own Space Rocket

On Monday, November 30th, a New Zealand company Rocket Lab, launched a small rocket into space. It has a bigger rocket being developed. The company innovated a rather novel fuel and technology for the actual rocket engine, that is far more cost effective than that used by NASA!

The launch was in an article on the BBC news site.

I feel that this New Zealand company has a great future, and all New Zealanders should be proud of it.

Thursday, December 3, 2009

There are planets around other Stars, besides the Sun

There have been over 400 hundred planets discovered orbiting stars, in addition to the ones around our Sun. Several different methods are used. Most of these planets, are much bigger than Jupiter, because it is difficult to detect planets about the size of the Earth or smaller. Also a few of the planets are very close to their stars and have day time temperatures io the thousands of degrees Celsius.

This BBC article talks about one of the methods, which in this case actually images the planets directly - albeit a trifle on the tiny image side...