# physics4me

physicsgg

## How Much Would it Cost to build the Death Star?

Star Wars fans hoping to build a real Death Star had better get saving – economists have worked out it would cost more than £541,261 trillion just for the raw materials.

Economics students at Lehigh University in Pennsylvania have calculated that it would require one quadrillion tons of steel to build a Death Star Photo: ALAMY

By Richard Gray – telegraph.co.uk
Is seems that while you should never underestimate the power of the Dark Side, you should also pay attention to the depth of their pockets.
Economics students at Lehigh University in Pennsylvania have calculated that it would require one quadrillion tons of steel to build a Death Star like those that featured in the movies.
It would cost 13,000 times the world’s gross domestic product (GDP), or £541,261 trillion, to supply the steel for such a structure while labour and other construction costs would send the price even higher.
They also worked out it would take more than 833,315 years at current production levels to supply enough steel for the 87 mile diameter space craft.
In a tongue-in-cheek report on the Centives blog run by the Lehigh University economics students, they said: “We decided to model the Death Star as having a similar density in steel as a modern warship.

“After all, they’re both essentially floating weapons platforms so that seems reasonable.
“Building a massive space weapon is all very well, but you have to find the materials to build it with.”
The students also calculated that with all the iron in the earth, it would be possible to build just over 2 billion death stars.
They warned, however, that most of the iron is in the core of the planet.
They said: “Before you go off to start building your apocalyptic weapon, do bear in mind two things.
“Firstly, the two billion death stars is mostly from the Earth’s core, which we would all really rather you didn’t remove.
“Secondly, at today’s rate of steel production (1.3 billion tonnes annually), it would take 833,315 years to produce enough steel to begin work.
“So once someone notices what you’re up to, you have to fend them off for 800 millennia before you have a chance to fight back.”

Written by physicsgg

February 26, 2012 at 12:05 pm

Posted in Science fiction

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## Micro black holes in the laboratory

with one comment

Marcus Bleicher, Piero Nicolini, Martin Sprenger, Elizabeth Winstanley
The possibility of creating microscopic black holes is one of the most exciting predictions for the LHC, with potentially major consequences for our current understanding of physics.

We briefly review the theoretical motivation for micro black hole production, and our understanding of their subsequent evolution. Recent work on modelling the radiation from quantum-gravity-corrected black holes is also discussed……..

………………………………………………….

4. Conclusions

The quest for signatures of the formation of microscopic black holes in particle detectors or cosmic rays is a fascinating and ambitious program.

In this short paper  we showed how their observation is connected to deeper problems concerning the very nature of quantum gravity.

We have presented both an overview of the state of the art in this ﬁeld and the latest ﬁndings based on quantum gravity improved black hole metrics.

We stress that the work in this ﬁeld is ongoing and many questions are yet to be settled. Apart from the issue of drawing a robust and widely accepted scenario for the evaporation end point, there exists a list of open problems concerning the initial phases.

For brevity we only recall that the mechanism of the collapse, the computation of the production cross section, the duration of the balding and the spin-down phases, the role of color ﬁelds, and the eﬀects of the brane tension are currently subjects of investigations.

We stress that these issues are very topical: both the LHC and the Pierre Auger Observatory are now collecting data and soon consistent explanations of experimental results will be necessary.

Read also: Black Holes at the LHC, Savas Dimopoulos and Greg Landsberg

Written by physicsgg

November 9, 2011 at 2:16 pm

## Lost in Space

By C. CLAIBORNE RAY
Q. Science-fiction films often depict people being killed by going out an airlock into space. What would that be like?
A. In the near-vacuum of space, death would most likely occur within a couple of minutes, but consciousness would be lost in about 15 seconds as oxygen failed to reach the brain, NASA scientists determined after animal research in the 1950s and ’60s.

Death by vacuum is not spectacular or instantaneous, unless the subject tries to hold his breath. In that case, the delicate lungs are likely to rupture as the gases within them expand. The skin is sufficiently strong to prevent the body from exploding, however.

A study published in 1968 in The Journal of Applied Physiology found that if primates breathing pure oxygen were suddenly exposed to a near vacuum for up to 210 seconds but then given oxygen at a fairly high pressure for 4 to 24 hours, they could recover and survive for years.

An accidental experiment on a human occurred in 1965 at what is now Johnson Space Center when a spacesuit leaked in a vacuum chamber. Repressurization began within 15 seconds, and the subject survived.

According to a NASA account of the incident, “the subject later reported that he could feel and hear the air leaking out, and his last conscious memory was of the water on his tongue beginning to boil.”

http://www.nytimes.com

Written by physicsgg

November 1, 2011 at 6:44 pm

Posted in Science fiction, SPACE

## The Evolution of ‘Star Trek’

Source: SPACE.com

Written by physicsgg

September 8, 2011 at 8:00 am

Posted in Science fiction

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## Aliens may destroy humanity to protect other civilisations…..

….say scientists
Rising greenhouse emissions may tip off aliens that we are a rapidly expanding threat, warns a report for Nasa

When they see what a mess we've made of our planet, aliens may be forced to take drastic action.

It may not rank as the most compelling reason to curb greenhouse gases, but reducing our emissions might just save humanity from a pre-emptive alien attack, scientists claim.

Watching from afar, extraterrestrial beings might view changes in Earth’s atmosphere as symptomatic of a civilisation growing out of control – and take drastic action to keep us from becoming a more serious threat, the researchers explain.

This highly speculative scenario is one of several described by scientists at Nasa and Pennsylvania State University that, while considered unlikely, they say could play out were humans and alien life to make contact at some point in the future.

Shawn Domagal-Goldman of Nasa’s Planetary Science Division and his colleagues compiled a list of plausible outcomes that could unfold in the aftermath of a close encounter, to help humanity “prepare for actual contact”….. Read the rest of this entry »

Written by physicsgg

August 19, 2011 at 1:36 am

Posted in Science fiction, UFO

## UFO sighting files released in UK

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UFO sighting files released in UK
The latest batch of UFO files released today contain sightings of mysterious lights over the Glastonbury Festival, a “flying saucer” outside Retford town hall and the bizarre story of “Mork and Mindy’s” visit to East Dulwich.
Defence experts were called in to examine a 2004 photo of a “flying saucer” taken outside Retford town hall in Nottinghamshire.

The series of images were captured by Alex Birch and having ruled out lens flares and aircraft, he contacted the Ministry of Defence, who sent them to the Defence Geographic and Imagery Intelligence Agency (DGIA) in July 2004.

The photograph was digitally enhanced and the DGIA report stated: “No definitive conclusions can be gathered from evidence submitted, however it may be coincidental that the illuminated plane of the object passes through the centre of the frame, indicating a possible lens anomaly, eg a droplet of moisture.”

The files also contain first-hand testimony of retired RAF fighter controller Freddie Wimbledon and retired MoD official Ralph Noyes, on the famous 1956 UFO incident at RAF Lakenheath in Suffolk.

Mr Wimbledon remembers the RAF scrambling fighter planes to intercept a UFO seen on radar and by observers on the ground. The UFO reportedly latched onto to a fighter plane, “following its every move” before speeding off at “terrific speed”.

Staff involved were sworn to secrecy, while Mr Noyes recalls being shown gun camera footage of the UFOs taken from aboard the aircraft at a special MoD screening in 1970.

One of the more bizarre tales from the files is the 2003 sighting of “worm-shaped” UFOs “wriggling around in the sky” over East Dulwich in London.

A mother and daughter reported it to the police but according to testimony she later gave to the MoD’s UFO desk, the two police constables who attended the scene were joined by two men dressed in “space suits and dark glasses who called themselves Mork and Mindy”.

The woman complained of being made “to look foolish”. In a letter dated January 21 2003, the woman says “your men have fed us with a lot of rubbish, presumably to make us look foolish and our story unbelievable, which they have succeeded in doing”.

Police told the MoD they sent two ordinary PCs to the address but “they could not see anything in the sky and concluded it was possibly a reflection of a star and a street light in her window”.

Another report describes mysterious lights seen moving 300ft above the Pyramid stage at the Glastonbury Festival on June 28 2003. There are also details of a UFO sighting over a music festival at Llanfyllin, Wales, in July 2006.

A file also contains a number of sightings reported to the MoD during the summer of 2006, that describe formations of orange lights in the sky. These appear to be observations of Chinese lanterns, released at parties and public events, the experts concluded.

Other incidents include UFOs spotted by the pilot and passengers of an aircraft over the Channel Islands in 2007 and F-16s scrambled to intercept UFOs over Belgium in 1990.
http://www.independent.co.uk

Written by physicsgg

August 12, 2011 at 2:41 pm

Posted in Science fiction, UFO

## Search for ET: The high-profile supporters

### The resumption of operations at California’s Search for Extraterrestrial Intelligence Institute (SETI) was made possible by donations from celebrity supporters including Jodie Foster.

Jodie Foster - Contact

Following an appeal on the website of the Allen Telescope Array project, named after its first financial backer, Microsoft co-founder Paul Allen, donations from more than 2,200 supporters – known as SETIStars – meant the institute easily reached its \$200,000 initial fund-raising goal.
Miss Foster has made several films about alien life, including Contact in 1997, about an SETI astronomer who makes radio contact with extraterrestrials. She is due to star as the head of an alien planet in District 9 director Neill Blomkamp’s latest blockbuster Elysium, which is planned for release in 2013.
She has also indicated that she plans to direct a science fiction film once her current commitments have ended.
In a post on the SETIStar website, Miss Foster said she was supporting it because “we need to return it to the task of searching newly discovered planetary worlds for signs of extraterrestrial intelligence”.
“In Carl Sagan’s book/movie Contact, a radio signal from a distant star system ends humanity’s cosmic isolation and changes our world,” she said.
“The Allen Telescope Array could turn science fiction into science fact, but only if it is actively searching the skies. I support the effort to bring the array out of hibernation.”
Another SETIStar is Larry Niven, the science fiction writer who penned books including the multi award-winning Ringworld, The Magic Goes Away and The Draco Tavern.
“Finding intelligent tool users would reset all parameters. All of human history would look like a preface,” he said on the SETIStars website.
Astronomers and astronauts are also supporting the project, including former Apollo 8 crewman Bill Anders, who said on the website that it would be “absolutely irresponsible” not to search for evidence of extraterrestrial life.
http://www.telegraph.co.uk

Written by physicsgg

August 11, 2011 at 4:52 pm

Posted in Science fiction, UFO

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