Sunday, April 7, 2013
Things Are Happening Here
(Picture from here.)
There are a lot of things we can be upset about these days. The sequester. Intransigence in Washington. Unemployment. However, one thing we should be happy about: the state of science.
A lot of things came across my desk that showed this.
NASA is looking into 3D printing-- on the moon. (See here.) How to produce a structure on the moon where humans can live? Print it. On another NASA front, they're looking into capturing an asteroid and bringing it back to the moon where we can get at it. (See here.)
Mars has water-- there's been evidence for it from previous Mars studies. There might be a fair bit of it underground. (See here.) We still don't know how much subsurface water there is right now but there might have been a whole lot of it as recently as 500 million years ago. (See here.) Use of ground penetrating radar has uncovered flood channels. Big flood channels. As big or bigger than any that we know the earth has ever seen. Such a huge water outburst that the area that had housed it collapsed. 500 myears is a long time but it is considerably later than previously thought.
On the good science/bad news front, a new study (see here.) demonstrates the planet was in an accelerating cooling trend-- until around 1900. Bad news: we're heating up the planet and making the world a worse place. But hey. We avoided an ice age.
Oh, an a whole lot of the heat is getting picked up by the deep ocean. (See here.) Who knows what that's going to do.
The Neanderthal genome has gotten more interesting. Apparently there are a lot of sites that have preserved Neanderthal DNA. The Denisovans are more and more being shown to be separate from the rest of the Neanderthals and we now have a clearer idea of the separation between modern humans and Neanderthals. (See here.) Although a recent fossil find in Italy (see here.) has been suggested to be a hybrid between humans and Neanderthals. Though it was hard to take Discovery News' title ("Love Child between Humans and Neanderthals") very seriously.
Staying with human evolution for a moment, there's been some re-dating occurring. For a while now the fossil evidence and genetic evidence have confirmed one another. Humans came out of Africa around 50k years ago, etc. Well, some recent studies have suggested the mutation rate upon which the molecular clock was based have to be rethought. (See here.) This puts humans coming out of Africa considerably early-- 90 to 130k years ago.
There was also a gentleman discovered whose Y-chromosome genetically predates modern humans-- 334k years ago. (See here.) To be quite clear on this, this man's Y-chromosome had genetic material that looked as if it were descended from individuals much older. One theory is that there was a sub-group of modern humans that interbred with an older population and that Y-chromosome was preserved. This is interesting for a lot of reasons. Humans have one mother and one father. For a long time it's been thought that all living human beings descended from a single woman. This was derived from mitochondrial DNA research. The mitochondria of cells come only from the mother, hence the term "mitochondrial Eve." However, all males get their Y-chromosome from their fathers, only. Hence, there was thought to be a Y-chromosome Adam. This new evidence throws that out and, to me, brings the mitochondrial Eve into question. We might have a more varied ancestry than we thought and that it will come out the more people whose DNA are sequenced.
Voyager 1 fell over the "heliocliff" (see here.) but we're still trying to figure out if it actually made it into interstellar space. Certainly, particles emitted by the sun have dropped precipitously and there's been a corresponding increase in particles indicating interstellar space. However, the suns magnetic field is still there. So our identification of the boundary between us and out there is still in flux.
But before we get two full of ourselves, I must relate the story of Val St. John and Scott Fish, two DJs down in Florida. (See here.) They put out a supposed news report that the water supply was filled with Dihydrogen Oxide, a dangerous substance that could fill your lungs if inhaled and kill you. A number of people called the water supply officials to ask if the water supply was contaminated. Turns out it's against the law to impugn the quality of water and the two DJs were suspended.
Makes me worry when people fall for something as silly as that.
Goes to show you can take some people right up to the Dihydrogen Oxide but you can't make them think.