Tag: LHC

Nej, Jorden går ikke under i dag

Heller ikke i dag.

Lad mig bare citere, hvad jeg i går citerede en fysiker for: “Look, it’s a 10^-19 chance, and you’ve got a 10^-11 chance of suddenly evaporating while shaving.”

En ting man overser i denne diskussion – eller som nogen overser – er, at naturen har udført denne type højenergi-eksperimenter i millioner af år uden at det har medført særligt katastrofale resultater. Hvis der havde været noget om snakken, ville månen have været væk for længe siden …

Update: CERN gør på sin hjemmeside opmærksom på en ny artikel i Journal of Physics G, der konkluderer, at eksperimentet er sikkert:

The safety of collisions at the Large Hadron Collider (LHC) was studied in 2003 by the LHC Safety Study Group, who concluded that they presented no danger. Here we review their 2003 analysis in light of additional experimental results and theoretical understanding, which enable us to confirm, update and extend the conclusions of the LHC Safety Study Group. The LHC reproduces in the laboratory, under controlled conditions, collisions at centre-of-mass energies, less than those reached in the atmosphere by some of the cosmic rays that have been bombarding the Earth for billions of years. We recall the rates for the collisions of cosmic rays with the Earth, Sun, neutron stars, white dwarfs and other astronomical bodies at energies higher than the LHC. The stability of astronomical bodies indicates that such collisions cannot be dangerous. Specifically, we study the possible production at the LHC of hypothetical objects such as vacuum bubbles, magnetic monopoles, microscopic black holes and strangelets, and find no associated risks. Any microscopic black holes produced at the LHC are expected to decay by Hawking radiation before they reach the detector walls. If some microscopic black holes were stable, those produced by cosmic rays would be stopped inside the Earth or other astronomical bodies. The stability of astronomical bodies strongly constrains the possible rate of accretion by any such microscopic black holes, so that they present no conceivable danger. In the case of strangelets, the good agreement of measurements of particle production at RHIC with simple thermodynamic models severely constrains the production of strangelets in heavy-ion collisions at the LHC, which also present no danger.

Du kan læse hele artiklen her.

Enden er nær: Politiken sælger ud til dårlig videnskab

Jorden kan gå under i morgen, udbasunerer Politiken.dk – motivet er selvfølgelig den berømte partikelaccelerator i CERN, som nogle obskurantister og New Age-folk har advaret mod, fordi den nok vil skabe et sort hul, der vil suge hele Jorden og verden som vi kender den til sig.

Nuvel, vi har skrevet om det før, og dengang skrev vi bl.a.:

Verdens undergang er nært forestående. Det mener i hvert fald to amerikanske “forskere”, hvoraf den ene er advokat med en førstedel i biologi, hvorfor de har besluttet at lægge sag an mod CERN for at få stoppet centrets planlagte “Large Hadron Collider” (LHC).

Fysiker og anerkendt skarpretter af dårlig videnskab i medierne Bob Park ripper anderledes op i retssagens “relevans” og karakteren af den fare, verden svæver i:

LHC: A KNIGHT ERRANT TILTS AT HIGH-ENERGY WINDMILL.

Technology has changed in the 400 years since Cervantes first told the story of Don Quixote. Windmills are now particle accelerators and the knight’s lance is a federal court injunction, but the plot is the same.

It begins with a befuddled lawyer in Hawaii named Walter Wagner. Having read far too much science fiction as a youth, Wagner fantasizes that he is a physicist by virtue of an undergraduate biology degree with a minor in physics. Accompanied by Sancho, his loyal TA, Wagner embarks on an adventure to slay the Large Hadron Collider (LHC), a doomsday machine that he believes is posed to destroy the world by creating a black hole. He seems to have forgotten the last time he tried this. In 1999 Wagner warned that RHIC, the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, must be slain lest it create a black hole. The then BNL director, Jack Marburger, named a distinguished panel of physicists to investigate. Their report noted that nature has been conducting the relevant safety test for billions of years by colliding heavy-ion cosmic rays with the moon. It concluded that creation of a black hole is “effectively ruled out by the persistence of the Moon”.

Og hvad kan man så lære af det? At verden er fuld af idioter og nogle af dem elsker at lave larm, og at Jyllands-Postens journalist Morten Vestergaard er for ukritisk i sin vinkling af de to “forskeres” bekymring. Ellers intet nyt under solen.

BoingBoing citerer en mere nøgtern faglig vurdering: “Look, it’s a 10^-19 chance, and you’ve got a 10^-11 chance of suddenly evaporating while shaving.”

Og i dag kan vi så konkludere, at også Politiken har meldt sig i idoternes eller i hvert fald de ukritiske ignoranters rækker.

Update, 10/9: I dag får vi så  i det mindste syn for sagn.