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Comment Metallic hydrogen (Score 1) 1

Here's an interesting article:

    http://en.wikipedia.org/wiki/Metallic_hydrogen#Metallization_of_hydrogen_in_shock-wave_compression

Especially the discussion of the LLNL shock-wave compression. Metallic indeed :)

3000K is not too far from the temperature of the surface of the Sun, and the pressures are thought to vary from virtually nothing at the surface to Peta-pascals in the core, so somewhere there's a transition by the 140GPa needed for metallization. Whether this is within the convective layers where the temperatures remain low..?

User Journal

Journal Journal: Metallic sun 1

I'm posting this for follow-up commentary from @APODNereid, since the thread is now closed.

http://slashdot.org/comments.pl?sid=2967801&cid=40758811

You ask what would keep the surface metallic. Thinking about this more, I found a couple of facts:

The Sun's surface has an energy flux density ~30x that of a hot metal rod at 3,000 C (around the glow point for tungsten in a lightbulb) in the experiment described here:

Comment Re:Electric Universe crackpots (Score 1) 95

Hm, I think you're missing my point... I wasn't supporting their claims as more correct than a gravitationally-based cosmology, just noting that they seemed to be making reasonable conjectures, albeit non-mainstream, and that they didn't deserve to be called names. I said:

    "That seems reasonable; correct or not is a matter to be determined."

The same can be said about dark energy/matter. Reasonable, but correctness TBD. It is problematic for a simulation to not model all know behaviors of a system, but nonetheless, we do it all the time and often find useful models in them.

Agreed, this is better termed Plasma Cosmology, not Electric Universe as that appears to be commercially co-opted; maybe you're reacting more to that; I was reading more of the folks they cited than the .info website. More:

http://en.wikipedia.org/wiki/Plasma_cosmology#Large_scale_structure

Comment Re:Electric Universe crackpots (Score 1) 95

The one I looked at most closely was in the intro chapter to one of the books they linked:

http://www.thunderbolts.info/EU%20Intro%20and%20Chap1.pdf

That the shapes and spins of galaxies can be shown in simulation by collapsing parallel electric filaments ("pinch" effect), p. 26.. In contrast, from what I understand, you have to introduce a majority of dark matter & energy into such a simulation to get a stable galaxy if the stars interact otherwise with only gravity.

Something I'm looking at that's related to this:

http://en.wikipedia.org/wiki/Millennium_Run

It runs an N-body particle solver using gravitational interactions, to run the cosmic microwave background "forward" to see what kind of modern universe it should develop. This produces the pictures of the filamentary large-scale structure of the universe that I've become accustomed to seeing in recent years, but it turns out you can use the same software to model both radiative and magnetic coupling effects. Here's a variation showing how radiation changes stellar evolution:

    http://www.astro.ex.ac.uk/people/mbate/Cluster/clusterRT.html

Same basic large-scale structure, but different number of "stars", different brightnesses, speeds, etc.

I've got the GADGET code running on my MacBook Air using MacPorts, etc.. should be fun, though very slow :)

Comment Paul Baran, RAND 1964; invented and "discovered" (Score 1) 257

It wasn't just Paul Baran, of course, but the main concepts were invented/discovered in his series of papers from RAND at a time before anyone else was talking about such a thing (late 50s, early 60s):

    Introduction to Distributed Communications Networks
        - http://www.rand.org/content/dam/rand/pubs/research_memoranda/2006/RM3420.pdf

    - distributed mesh network of cheap, heterogenous component parts (the topology is analytically derived as optimal for retaining connectivity after possible partition events), supporting wired and wireless links
    - mail-like asynchronous address/packet-based routing of
    - digitally encoded fixed sized data blocks (inspired by "Morse's code"))
    - adaptive topology based on flood-filling neighbor/connectivity information throughout the network.

This was shelved for 5-10 years for being thought a bad idea by the AT&T engineers that DoD listened to at the time (they were designing progressively more monolithic hierarchical networks with very expensive switching equipment requiring very profitable professional administration), and was picked back up in the later 60s, when it was ironed out and then re-invented by many of the names now famous for it:

Here's an excellent discussion about this between Baran and Stewart Brand:

    http://www.wired.com/wired/archive/9.03/baran_pr.html

Comment Trying to understand the paper's reasoning... (Score 1) 786

Here's my understanding of their reasoning.

Motivation:
        - Insolation changes and CO2 ecosystem feedbacks have been identified as the main causes of climate variability for the past million years (by citation).
        - However, global climate models are either too short to or don't attempt to integrate longer-term or low-frequency insolation changes, which might mean they're mis-estimating temperatures and temperature changes.
        - and while tree ring records should be affected and are important and widespread, a suitable long-term record that accounts for insolation changes hasn't been developed.
        - so, let's make one...

Methods:
        - measures tree ring width in Scandinavia for the past 2k years among ~580 trees, both living and dead.
        - fits a regression model between the tree ring width and "instrumental" measurements back to 1812, so that an observed tree ring width for a given year can be used to compute a temperature for that year, with some statistically measured error.
        - extrapolates temperatures before 1812 using the observed tree ring widths as inputs to the temperature regression model
        - derives a trend on these temperatures that shows a small, slow cooling for the past 2k years *in Scandinavia*.

Analysis:
        - notes that this slow downward trend/signature is missing from global published models
        - deduces that global temperature estimates for previous eras may then be *underestimated*, which implies that they could have been warmer and so today may not be as relatively warm as short-term models indicate.

However, they don't offer a reason how/why Scandinavian temperature trends should track global trends, or alternatively establish how/why orbital forcing should be accounted into global models? These both seem like reasonable expectations, and it seems the reasonable next step is to reproduce this project for other forrest areas to see if it holds.

Comment trying to understand methods & analysis (Score 1) 3

Here's my understanding of their reasoning.

Motivation:
    - Insolation changes and CO2 ecosystem feedbacks have been identified as the main causes of climate variability for the past million years.
    - However, global climate models are either too short or don't integrate low-frequency insolation changes, which might mean they're mis-estimating temperatures and temperature changes.
    - and while tree ring records are important and widespread, a suitable long-term record that accounts for insolation changes hasn't been developed.
    - so, let's make one!

Methods:
    - measures tree ring width in Scandinavia for 2k years among ~500 trees, both living and dead.
    - fits a regression model between the tree ring width and "instrumental" measurements back to 1812, so that an observed tree ring width for a given year can be used to compute a temperature for that year, with some statistically measured error.
    - extrapolates temperatures before 1812 using the observed tree ring widths as inputs to the temperature regression model
    - derives a trend on these temperatures that shows a small, slow cooling for the past 2k years *in Scandinavia*.

Analysis:
    - notes that this signature is missing from global published models
    - notes that global temperature estimates for previous eras may then be *underestimated*, which implies that they could have been warmer and so today may not be as relatively warm as short-term models indicate.

However, they don't offer a reason how/why Scandinavian temperature trends should track global trends, or alternatively establish how/why orbital forcing should be accounted into global models? These both seem like reasonable expectations, and it seems the reasonable next step is to reproduce this project for other forrest areas to see if it holds.

Comment Re:Electric Universe crackpots (Score 1) 95

They don't read like crackpots to me. Name-calling alternative perspectives is something more indicative of religion than science ;p Also, this is the interwebz; there are actual crackpots in abundance.

From their site:

"... theories tend to harden into ‘facts,’ even in the face of mounting
contradictions. Astronomer Carl Sagan’s Cosmos was published a
quarter-century ago. At that time, some questions were still permitted.
On the issue of redshift, Sagan wrote: “There is nevertheless a
nagging suspicion among some astronomers, that all may not be right
with the deduction, from the redshift of galaxies via the Doppler effect,
that the universe is expanding. The astronomer Halton Arp has found
enigmatic and disturbing cases where a galaxy and a quasar, or a pair
of galaxies, that are in apparent physical association have very
different redshifts....” - p 20. http://www.thunderbolts.info/EU%20Intro%20and%20Chap1.pdf

They're overall arguing that electrodynamics can better explain many astronomical observations than gravitation + dark matter, dark energy and modifications to cosmological constants.

That seems reasonable; correct or not is a matter to be determined.

Dark matter, dark energy, etc. are the first examples I give to friends who are skeptical of big bang cosmology or even science in general, showing it as an example of how science is full of bad "working" theories, but we know it and keep chipping away. I hope I'm not wrong.

Comment Re:Variance, Risk, Interest, Hours (Score 1) 472

You might find this lecture interesting:

    http://www.psy.fsu.edu/~baumeistertice/goodaboutmen.htm

This passage in particular presents a different way at looking at the correlations in the Kane and Mertz study:

"Creativity may be another example of gender difference in motivation rather than ability. The evidence presents a seeming paradox, because the tests of creativity generally show men and women scoring about the same, yet through history some men have been much more creative than women. An explanation that fits this pattern is that men and women have the same creative ability but different motivations.
                        I am a musician, and I’ve long wondered about this difference. We know from the classical music scene that women can play instruments beautifully, superbly, proficiently — essentially just as well as men. They can and many do. Yet in jazz, where the performer has to be creative while playing, there is a stunning imbalance: hardly any women improvise. Why? The ability is there but perhaps the motivation is less. They don’t feel driven to do it.
                        I suppose the stock explanation for any such difference is that women were not encouraged, or were not appreciated, or were discouraged from being creative. But I don’t think this stock explanation fits the facts very well. In the 19th century in America, middle-class girls and women played piano far more than men. Yet all that piano playing failed to result in any creative output. There were no great women composers, no new directions in style of music or how to play, or anything like that. All those female pianists entertained their families and their dinner guests but did not seem motivated to create anything new.
Meanwhile, at about the same time, black men in America created blues and then jazz, both of which changed the way the world experiences music. By any measure, those black men, mostly just emerging from slavery, were far more disadvantaged than the middle-class white women. Even getting their hands on a musical instrument must have been considerably harder. And remember, I’m saying that the creative abilities are probably about equal. But somehow the men were driven to create something new, more than the women."

Comment The conditions that led to UNIX... (Score 4, Interesting) 293

There's a talk from 1986 by Richard Hamming at Bellcore, about how to do great research, but it also ends up in a short discussion about the conditions there that led to UNIX:

http://www.paulgraham.com/hamming.html

The whole talk is really excellent, and there's this theme in it that the really great things come from some unexpected places, by the compounding of seemingly unrelated character traits, work habits and organization dynamics.

At the end in the Q&A, Hamming gets into a short discussion with the host Alan Chynoweth about the origins of UNIX, evincing from Alan a favorite quote:

"UNIX was never a deliverable!"

expanded:

"Hamming: First let me respond to Alan Chynoweth about computing. I [was in charge of] computing in research and for 10 years I kept telling my management, ``Get that !&@#% machine out of research. We are being forced to run problems all the time. We can't do research because we're too busy operating and running the computing machines.'' Finally the message got through. They were going to move computing out of research to someplace else. I was persona non grata to say the least and I was surprised that people didn't kick my shins because everybody was having their toy taken away from them. I went in to Ed David's office and said, ``Look Ed, you've got to give your researchers a machine. If you give them a great big machine, we'll be back in the same trouble we were before, so busy keeping it going we can't think. Give them the smallest machine you can because they are very able people. They will learn how to do things on a small machine instead of mass computing.'' As far as I'm concerned, that's how UNIX arose. We gave them a moderately small machine and they decided to make it do great things. They had to come up with a system to do it on. It is called UNIX!

A. G. Chynoweth: I just have to pick up on that one. In our present environment, Dick, while we wrestle with some of the red tape attributed to, or required by, the regulators, there is one quote that one exasperated AVP came up with and I've used it over and over again. He growled that, ``UNIX was never a deliverable!''"

Cloud

Submission + - Amazon, watch out, OpenStack is coming (networkworld.com)

Julie188 writes: "The open source cloud platform, OpenStack, promises to end cloud-vendor lock-in by making it easier to move workloads between cloud providers. Only problem was, there were no OpenStack cloud providers. Until now. Internap has launched the first OpenStack public cloud, and it chose the open source Xen as the base hypervisor. Rackspace, the official corporate champion of OpenStack, is in beta with its cloud as is HP. A stew of other OpenStack projects are ready to bubble over soon, too."

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