Bloggfrslur mnaarins, janar 2013

Hugsanleg skring blingu jvega...?

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Hva var a sem vann sem gikkur og hleypti ferlinu af sta nnast samtmis hundru klmetra kafla, nokkrum mnuum eftir a klningin var lg? Blingin fr skyndilega af sta og htti jafn skyndilega. Nnast samtmis alls staar.

Getur veri a skringin essu s eftirfarandi fyrirbri sem vi gtum kalla "frostdlingu"?

Hugsum okkur a hitastig s a sveiflast umhverfis brslumark vatnsins, sem er 0C ef a er hreint, en lgra ef a er blanda hreinindum ea salti. annig hefur veurfar lklega veri undanfari, en vi vitum ekki hve hreint vatni hefur veri og ekkjum v ekki vel vi hvaa hitastig a frs/inar. Munum eftir v a vatn enst skyndilega t um 8% um lei og a frs og breytist klaka.

- Sprunga hefur myndast yfirbori.

- Hugsum okkur til einfldunar a frost s a nttu en a a degi til.

- Vatn seitlar niur um sprunguna og safnast fyrir undir klningunni mean frostlaust er.

- Hitastig fer niur fyrir frostmark vatnsins a nttu. Vatni enst t og rstist frosi upp um sprunguna samt olu/biki sem undir klningunni er.

- Nsta dag fer hitinn upp fyrir frostmark vatnsins. sinn brnar og sprungan samt holrminu undir klningunni fyllist aftur af vatni.

- Nstu ntt er frost, vatni/sinn enst t um 8% og rstir meira af olu/biki upp um sprunguna samt krapi.

- Daginn eftir inar og sprungan fyllist aftur af vatni.

- O.s.frv., aftur og aftur. Gumsi mjakast upp um sprunguna me hjlp essarar "frostdlu" sem er sfellt a vinna egar hitastigi sveiflast umhverfis frostmark vatnsins... Meira og meira gums rstist upp...

a er svo anna ml hvers vegna svona mikil ola ea bik er undir klningunni. Skringin v liggur kannski v hvernig stai er a verki egar klningin er lg.

(Myndin er r frtt Morgunblasins).




mbl.is Svakalegt a lenda svona
Tilkynna um vieigandi tengingu vi frtt

Antikyera reiknivlin, 2100 ra htknitlva...

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Htknibnaurinn sem fannst ri 1901 skipi sem skk vi eyjuna Antikyera skammt norvestur af Krt um 80 fyrir Krist hltur a teljast meal merkustu fornminja allra tma. etta er furuflkinn tlvubnaur ea reiknivl sem nota mtti fyrir flkna stjarnfrilegra treikninga.

Tki er fr v um 100 fyrir Krists bur, og v meir en 2000 ra gamalt. Hugsanlega m rekja tilvist ess til smiju Arkmedesar svo hann hafi di um hundra rum ur en essi vl var smu. Vel m mynda sr a Arkmedes hafi gert frummyndina.

etta er reyndar ekki stafrn tlva (digital computer) eins og vi ekkjum dag, heldur hlirn tlva (analog computer) sem notar fjldan allan af tannhjlum, grum og rum vlbnai sta rafeindarsa.

etta er trleg smi og miki hugvit og ekkingu strfri samt smakunnttu hefur urft til a hanna og sma gripinn. a kemur vart a essi flkni gripur er ekki miki strri en feratlva dag. Hr hefur snillingur komi a verki.

Hugviti og ekkingin sem liggur a baki essarar smi er a mikil a maur fellur nnast stafi vi tilhugsunina. Hva var um essa ekkingu og hvers vegna gleymdist hn? Hvernig vri jflag okkar dag hefi etta hugvit og tkniekking n a rast fram sta ess a falla gleymsku?

Mikill frleikur er til netinu og frigreinum um Antikyera tlvuna og verur hann ekki endurtekinn essum stutta pistli, en ess sta vsa myndbnd, myndir og vefsur sem fjalla um ennan merkisgrip. Myndbndin er rtt a skoa fullri skjstr og hmarksupplausn ef ess er kostur. Nleg mjg hugaver kvikmynd fr BBC um ennan merkisgrip er hr fyrir nean.

---

vefsu hins ekkta tmarits Nature er frttagrein um Antikyera tlvuna hr.

Myndband Nature, hluti 1 og hluti 2:

rjr rntgen sneimyndir af gripnum:

Lkan sma me Lego snir vel hve flkinn bnaurinn er:

Lkan sma str armbandsrs:

Michael Wright: Lkan sma:

Og a virkar!:

Ntma tlvulkan snir hvernig hin forna tlva vinnur:

hugavert: Klukkutma lng mynd fr BBC: Antikythera Mechanism, The Two Thousand Year Old Computer. (Horfa fullri skjstr og 720HD upplausn):

Ekki sur hugavert:
The 2000 Year-Old Computer - Decoding the Antikythera Mechanism (2012)

"Ekkert verur til af engu. Einnig menningin, hversu frumleg hn virist vera fyrstu, sr djpar rtur, sem oft og einatt liggja va a. etta sr jafnt sta um grsku menninguna sem menningu allra annarra ja. Enda tt Forngrikkir vru kaflega gfu j og allt lki svo a segja hndum eirra, var menning eirra sjlfra svo sem engin, er eir settust fyrst a landinu. hinn bginn uru eir svo skjtir til menningar og menning eirra var svo mikil og fgur, a a er nr skiljanlegt, hversu brroska eir uru, nema eir hafi stt v meiri hrifum utan fr.

Og ef vi ltum landabrfi, dylst okkur ekki, a svo hefur hloti a vera. arna l Egyptaland, einhver helsta bkist fornmenningarinnar, sunnan a Mijararhafi, og in Nl, lf lands essa, kvslaist ar t hafi, lkt og hn vildi spja hjartabli menningar sinnar t til beggja hlia..."

Saga Mannsandans, Hellas, gst H. Bjarnason1950.

The Antikythera Mechanism Research Project Grikklandi hr.

Grein sem birtist ri 2008 Nature Calendars with Olympiad display and eclipseprediction on the Antikythera Mechanism m skoa vefnum hj EBSCOhost.com hr.

Sem handrit m lesa greinina vef www.antikythera-mechanism.gr hr.

Mjg hugavert tarefni vi greinina m skja vef hist.science.online.fr hr.

Grein Nature 2010 Mechanical Inspiration m lesa hr vef Nature.

World Mysteries: Antikythera Mechanism

Universe Today: The Antikythera Time Machine.

Allar greinar sem tengdar eru essari frslu eru agengilegar netinu. Sj hr a ofan.


Skrr tengdar essari bloggfrslu:

Ntt fr NASA / NRC: hrif slar loftslag jarar geta veri meiri og flknari en ur var tali...

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gr 8. jan. 2013 birtist vefnum NASA Science News athyglisver frtt. Innihaldi kemur eim sem essar lnur ritar ekki miki vart, en eim mun ngjulegra er a lesa frttina og ekki sur skrsluna sem hn vsar til.

stuttu mli er vsa til skrslu fr National Research Council (NRC) sem nefnist "The Effects of Solar Variability on Earth's Climate". NCR geri sr grein fyrir a nausynlegt vri a smala saman fimm tugum srfringa fr hinum msu srfrisvium svo sem plasmaelisfri, slvirkni, loftslagsefnafri, straumfri, elisfri horkuagna, loftslagssgu jarar... etta vri a flki ml a enginn einn srfrihpur eins og t.d. loftslagsfringar hefu ngilega yfirgripsmikla ekkingu mlinu.

Oft er vitna til ess a heildartgeislun slar breytist aeins um 0,1% yfir 11-ra slsveifluna, en a tti ekki a hafa mikil bein hrif hitafari. a gleymist oft umrunni a arir ttir geta veri miklu hrifameiri, en tfjlubli ttur slarljssins breytist miklu miklu meira, en hann breytist um 1000% ea meir yfir slsveifluna. a benti bloggarinn reyndar fyrir 15 rum hr

Svo m ekki gleyma rum ttum svo sem agnastreymi fr slinni, horku rafeindum og geimgeislum sem fjalla er um skrslunni.

N er a spurning hvort hratt minnkandi slvirkni um essar mundir eigi sinn tt a hitastig jarar hefur stai sta undanfarin 16 r samkvmt HadCrut4 ggnum bresku veurstofunnar MetOffice, en n um jlin kom fram nrri sp fr eirri smu stofnun a essi stnun veri a.m.k. til 2017, .e. fulla tvo ratugi. Hva tekur vi mun tminn leia ljs.

Auvita svarai essi srfringanefnd ekki llum spurningum sem brenna vrum manna, en vonandi er etta bara byrjunin v a menn lti til himins eftir skringum, a er nefnilega svo rstutt t geiminn fr yfirbori jarar...

Sj frtt NASA Science News Solar Variability and Terrestrial Climate hr.

Sj drg a skrslunni fr NCR The Effects of Solar Variability on Earths Climate hr.

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Mynd r skrslunni

Klippt r frtt NASA:

In the galactic scheme of things, the Sun is a remarkably constant star. While some stars exhibit dramatic pulsations, wildly yo-yoing in size and brightness, and sometimes even exploding, the luminosity of our own sun varies a measly 0.1% over the course of the 11-year solar cycle.

There is, however, a dawning realization among researchers that even these apparently tiny variations can have a significant effect on terrestrial climate...

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Of particular importance is the sun's extreme ultraviolet (EUV) radiation, which peaks during the years around solar maximum. Within the relatively narrow band of EUV wavelengths, the suns output varies not by a minuscule 0.1%, but by whopping factors of 10 or more. This can strongly affect the chemistry and thermal structure of the upper atmosphere.

Several researchers discussed how changes in the upper atmosphere can trickle down to Earth's surface. There are many "top-down" pathways for the sun's influence. For instance, Charles Jackman of the Goddard Space Flight Center described how nitrogen oxides (NOx) created by solar energetic particles and cosmic rays in the stratosphere could reduce ozone levels by a few percent. Because ozone absorbs UV radiation, less ozone means that more UV rays from the sun would reach Earth's surface.

Isaac Held of NOAA took this one step further. He described how loss of ozone in the stratosphere could alter the dynamics of the atmosphere below it. "The cooling of the polar stratosphere associated with loss of ozone increases the horizontal temperature gradient near the tropopause, he explains. This alters the flux of angular momentum by mid-latitude eddies. [Angular momentum is important because] the angular momentum budget of the troposphere controls the surface westerlies." In other words, solar activity felt in the upper atmosphere can, through a complicated series of influences, push surface storm tracks off course.

-

Many of the mechanisms proposed at the workshop had a Rube Goldberg-like quality. They relied on multi-step interactions between multiples layers of atmosphere and ocean, some relying on chemistry to get their work done, others leaning on thermodynamics or fluid physics. But just because something is complicated doesn't mean it's not real...

-

The solar cycle signals are so strong in the Pacific, that Meehl and colleagues have begun to wonder if something in the Pacific climate system is acting to amplify them. "One of the mysteries regarding Earth's climate system ... is how the relatively small fluctuations of the 11-year solar cycle can produce the magnitude of the observed climate signals in the tropical Pacific." Using supercomputer models of climate, they show that not only "top-down" but also "bottom-up" mechanisms involving atmosphere-ocean interactions are required to amplify solar forcing at the surface of the Pacific...

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Indeed, the sun could be on the threshold of a mini-Maunder event right now. Ongoing Solar Cycle 24 is the weakest in more than 50 years. Moreover, there is (controversial) evidence of a long-term weakening trend in the magnetic field strength of sunspots. Matt Penn and William Livingston of the National Solar Observatory predict that by the time Solar Cycle 25 arrives, magnetic fields on the sun will be so weak that few if any sunspots will be formed. Independent lines of research involving helioseismology and surface polar fields tend to support their conclusion...

Verkefni nefndarinnar strum drttum samkvmt skrslunni:

The Sun and Solar Variability: Past and Present
- Overview of solar and heliospheric variability
- Observations of the Suns variable outputs
- Techniques for revealing past solar changes

Sun-Climate Connections on Different Timescales
- Evidence of solar influences in the troposphere and stratosphere
- How the climate system works and how it might respond to solar influences
- Indications of influence based on paleoclimate records

Mechanisms for Sun-Climate Connections
- Mechanisms connecting variations in total solar irradiance directly to the troposphere
- Mechanisms that influence upper parts of the atmosphere, such as variations in solar
ultraviolet radiation and possibly solar energetic particles
- Mechanisms that link variations in galactic cosmic rays to climate change.

Nefndina skipuu:

Caspar Ammann, National Center for Atmospheric Research
Susanne Benze, University of Colorado, Boulder
Blair Bowers, Caset Associates, Ltd.
Matthias Brakesusch, University of Colorado, Boulder
Gabriel Chiodo, Universidad Complutense de Madrid

Odele Coddinggon, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Guiliana de Toma, High Altitude Observatory, National Center for Atmospheric Research
Ells Dutton, Global Monitoring Division, National Oceanic and Atmospheric Administration
Juan Fontenla, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Joe Giacalone, University of Arizona

Sarah Gibson, High Altitude Observatory, National Center for Atmospheric Research
Douglas Gough, JILA, University of Colorado, Boulder
Madhulika Guhathakurta, Living With a Star, National Aeronautics and Space Administration
Jerald Harder, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
V. Lynn Harvey, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder

Lon Hood, University of Arizona
Charles Jackman, NASA Goddard Space Flight Center
Philip Judge, High Altitude Observatory, National Center for Atmospheric Research
Farzad Kamalabadi, University of Illinois at Urbana-Champaign
Peter Kiedron, Earth System Research Laboratory, National Oceanic and Atmospheric Administration

Hyosub Kil, Applied Physics Laboratory, Johns Hopkins University
Greg Kopp, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Andrew Kren, University of Colorado, Boulder
Hanli Liu, High Altitude Observatory, National Center for Atmospheric Research
Jesse Lord, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder

Dan Lubin, Scripps Institution of Oceanography, University of California, San Diego
Janet Machol, National Geophysical Data Center, National Oceanic and Atmospheric Administration
Youhei Masada, Kyoto University, Japan
Joe McInerney, High Altitude Observatory, National Center for Atmospheric Research
Scott McIntosh, High Altitude Observatory, National Center for Atmospheric Research

Aimee Merkel, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Mark Miesch, High Altitude Observatory, National Center for Atmospheric Research
Raimund Muscheler, Lund University, Sweden
Seung Jun Oh, SELab, Inc.
Ethan Peck, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder

Jeffrey Pierce, Dalhousie University, Halifax, Nova Scotia
Douglas Rabin, NASA Goddard Space Flight Center
Cora Randall, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Mark Rast, University of Colorado, Boulder
Alan Robock, Rutgers University

Fabrizio Sassi, Naval Research Laboratory
Harlan Spence, University of New Hampshire
Mark Stevens, University of Colorado, Denver
Michael Thompson, High Altitude Observatory, National Center for Atmospheric Research
Juri Toomre, JILA, University of Colorado, Boulder

Thomas Woods, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
Lawrence Zanetti, Applied Physics Laboratory, Johns Hopkins University

Abigail Sheffer, NRC Space Studies Board
Michael Moloney, NRC Space Studies Board and Aeronautics and Space Engineering Board
Amanda Thibault, NRC Aeronautics and Space Engineering Board
Terri Baker, Space Studies Board


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Mynd r skrslunni
sem nlgast mr hr

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Ágúst H Bjarnason
Ágúst H Bjarnason

Verkfr. hjá Verkís.
agbjarn-hjá-gmail.com

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