Carl Zimmer,who is of course, THE MAN! of parasite parables and paraphenalia, has posted a more in-depth
analysis
of this story at his weblog, The Loom
, going into the genetic/molecular mechanism. Additionally, Zimmer responds
to the creationist take
on the story (the usual move-the-goalpost panic of those advocating irreduceable complexity). Of larger concern, why does this incredibly fascinating discussion about scientific sleuthing and the potential and beauty of proteomics, get automatically sidelined into a discussion on "what does creationism say about this?" I don't blame Zimmer for responding; indeed, that's the duty of science writers as gifted as he. But it diminishes the power of the story itself to have to ask, imnsho.
They're a long way away. The light from them has to have taken a long time to get here (speed of light being constant) so the picture we see of them is the one made up of light that left a long time ago. You can also tell they're old because of their composition, which brings us to your next question...
Actually, the clusters observed are within our own milky way galaxy and are therefore not distant. Although it seems counterintuitive, if you want to see extremely old objects in the universe, it is best to look close by, because, as you mention, looking far out into space you see light that left a long time ago and therefore you are looking at the universe as it was when it was younger.
The ages of the clusters are determined from the Hertzsprung-Russell Diagram which plots the brightness versus temperature of the cluster. A description of this method may be found in the full article in Science for those at a university with a subscription (Main-Sequence Turnoff Ages) article
or though a number of other web pages, such as this one
They might have been, but it's a simple thing to check. The early universe was composed almost entirely of hydrogen, which they converted to helium. When they died, their helium was scattered and helped form younger stars, which started converting the helium into heavier stuff.
A substantial amount (30% I think) of the early universe was helium because of Big-Bang Nucleosynthesis. The first generation stars formed other elements throughout the periodic table and then went supernova, distributing the material for second generation stars. Uranium and other radioactive elements have been seen in very few of the very earliest second generation stars, leading to an independent age determination based on radioactive decay rates (a method often used to measure ages of earth rocks). The detections and method are described in the Science article.
The moon landing is a great example of separate intersecting lines of evidence converging on the conclusion that we did indeed land on the moon. For the conspiracy theorists, no amount of evidence is going to convince them so we might as well be speaking another language. Still, I think interesting things can come out of the discussion. My favorite piece of evidence of the landing is the storage bag from the Apollo 15 mission. NASA astronauts threw it out, it ended up at auction, someone bought it and realized that it was saturated with moon dust (you can tell the dust is from the moon by comparing the ratios of certain isotopes). The isotopic ratios of certain elements in moon rocks is different than that of any rocks found on earth. The collector has since been selling sections at an enormous profit.
see this link
Now, I suppose they could have gone to the moon with an unmanned mission which landed, blasted off, returned with a bunch of rocks and dust which was subsequently distributed. At that point, why not just go there. Occam's Razor would say manned missions is a much more likely solution given the other evidence.
One simple DIY demo is to use a CD and show the interference pattern by reflection. This is the many-slit extrapolation of the double slit problem but it is conceptually similar and it is easy to set up.
The classic explanation of the double slit and its applications to quantum mechanics can be found in Richard Feynman's Lectures on Physics Vol. III or in Six Easy Pieces or Six Not so Easy Pieces which are outtakes from these lectures. The explanation therein is so beautiful that when pertaining to quantum mechanics the double slit problem is often referred to as the "Feynman Double Slit". Putting this into google will return a number of very useful resources.
As a physics lecturer it is hard to avoid Feynman envy.
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Carl Zimmer,who is of course, THE MAN! of parasite parables and paraphenalia, has posted a more in-depth analysis of this story at his weblog, The Loom , going into the genetic/molecular mechanism. Additionally, Zimmer responds to the creationist take on the story (the usual move-the-goalpost panic of those advocating irreduceable complexity). Of larger concern, why does this incredibly fascinating discussion about scientific sleuthing and the potential and beauty of proteomics, get automatically sidelined into a discussion on "what does creationism say about this?" I don't blame Zimmer for responding; indeed, that's the duty of science writers as gifted as he. But it diminishes the power of the story itself to have to ask, imnsho.
They're a long way away. The light from them has to have taken a long time to get here (speed of light being constant) so the picture we see of them is the one made up of light that left a long time ago. You can also tell they're old because of their composition, which brings us to your next question...
Actually, the clusters observed are within our own milky way galaxy and are therefore not distant. Although it seems counterintuitive, if you want to see extremely old objects in the universe, it is best to look close by, because, as you mention, looking far out into space you see light that left a long time ago and therefore you are looking at the universe as it was when it was younger.
The ages of the clusters are determined from the Hertzsprung-Russell Diagram which plots the brightness versus temperature of the cluster. A description of this method may be found in the full article in Science for those at a university with a subscription (Main-Sequence Turnoff Ages)
article
or though a number of other web pages, such as this one
They might have been, but it's a simple thing to check. The early universe was composed almost entirely of hydrogen, which they converted to helium. When they died, their helium was scattered and helped form younger stars, which started converting the helium into heavier stuff.
A substantial amount (30% I think) of the early universe was helium because of Big-Bang Nucleosynthesis. The first generation stars formed other elements throughout the periodic table and then went supernova, distributing the material for second generation stars. Uranium and other radioactive elements have been seen in very few of the very earliest second generation stars, leading to an independent age determination based on radioactive decay rates (a method often used to measure ages of earth rocks). The detections and method are described in the Science article.
The moon landing is a great example of separate intersecting lines of evidence converging on the conclusion that we did indeed land on the moon. For the conspiracy theorists, no amount of evidence is going to convince them so we might as well be speaking another language. Still, I think interesting things can come out of the discussion. My favorite piece of evidence of the landing is the storage bag from the Apollo 15 mission. NASA astronauts threw it out, it ended up at auction, someone bought it and realized that it was saturated with moon dust (you can tell the dust is from the moon by comparing the ratios of certain isotopes). The isotopic ratios of certain elements in moon rocks is different than that of any rocks found on earth. The collector has since been selling sections at an enormous profit. see this link Now, I suppose they could have gone to the moon with an unmanned mission which landed, blasted off, returned with a bunch of rocks and dust which was subsequently distributed. At that point, why not just go there. Occam's Razor would say manned missions is a much more likely solution given the other evidence.
One simple DIY demo is to use a CD and show the interference pattern by reflection. This is the many-slit extrapolation of the double slit problem but it is conceptually similar and it is easy to set up.
The classic explanation of the double slit and its applications to quantum mechanics can be found in Richard Feynman's Lectures on Physics Vol. III or in Six Easy Pieces or Six Not so Easy Pieces which are outtakes from these lectures. The explanation therein is so beautiful that when pertaining to quantum mechanics the double slit problem is often referred to as the "Feynman Double Slit". Putting this into google will return a number of very useful resources.
As a physics lecturer it is hard to avoid Feynman envy.