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NATURE|Vol 438|10 November 2005 NEWS

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The US patent office has granted a patent on adesign for an antigravity device — breaking itsown resolution to reject inventions that clearlydefy the laws of physics.

This is not the first such patent to begranted, but it shows that patent examiners arebeing duped by false science, says physicistRobert Park, watchdog of junk science at theAmerican Physical Society in Washington DC.Park tracks US patents on impossible inven-tions. “The patent office is in deep trouble,” he says.

“If something doesn’t work, it is rejected,”insists Alan Cohan, an adviser at the patentoffice’s Inventors Assistance Center in Alexan-dria, Virginia. And when something does slipthrough, he says, the consequences are not sig-nificant: “It doesn’t cause any problems becausethe patent is useless.”

But Park argues that patenting devices thatso blatantly go against scientific understand-ing could give them undeserved respectability,and undermine the patent office’s reputation.“When a patent is awarded for an idea thatdoesn’t work, the door is opened for sham.”

Patent 6,960,975 was granted on 1 Novem-ber to Boris Volfson of Huntington, Indiana. Itdescribes a space vehicle propelled by a super-conducting shield, which alters the curvatureof space-time outside the craft in a way thatcounteracts gravity. The device builds on a claim by the Russian physicist Eugene

Podkletnov that superconductors can shieldthe effects of gravity. NASA was at one stageinvestigating the idea, but it has becomealmost as notorious as cold fusion as an exam-ple of fringe science.

One of the main theoretical argumentsagainst antigravity is that it implies the avail-ability of unlimited energy. “If you design anantigravity machine, you’ve got a perpetual-motion machine,” says Park. Shield half of awheel from gravity and it will keep turning for ever.

The US patent office has long fought to pre-vent applications for patents on perpetual-motion machines. In 1911, after a constantstream of applications, one commissionerruled that they would not be considered untila working model had been running for a year.More recently, inventor Joe Newman sued theoffice after it rejected his application for such adevice. The court finally ruled against New-man in 1990, a decision that the patent officecites in its rules about which inventions arepatentable.

Unfortunately, it is not always easy to tellwhat the implications of a patent are. One previous patent for a device using putative“hydrinos” — shrunken hydrogen atoms — toproduce huge amounts of energy was granted.It is currently being reviewed after several scientists complained that hydrinos are impos-sible according to the laws of physics.

Park says he sympathizes with the difficul-ties that patent examiners face. “Their burdenhas gone up enormously,” he says. “It’s not surprising they get in a jam.” ■

Philip Ball

Antigravity craft slips past patent officers

Bush buries US bunker-buster project

Balls up: US patent office falls for antigravity devicethat would allow perpetual-motion machines.

WASHINGTON DCBowing to congressional pressure,the administration of PresidentGeorge W. Bush has killed aprogramme to design a nuclearwarhead capable of striking targetsburied deep in the ground. It hasinstead chosen to developreplacement warheads for the existing nuclear stockpile.

The cancelled weapon, called the Robust Nuclear EarthPenetrator (RNEP), was proposedthree years ago (see Nature 415,945; 2002). It was to have been atoughened version of an existingwarhead that could strike bunkersand other underground targets.

However, some physicists weresceptical that the warhead, known

as the ‘bunker-buster’, couldpenetrate deeply enough to containits massive nuclear blast. ANational Research Council studyreleased in May showed that theweapon would be highly effective atdestroying deeply buried targets.But casualties could still number inthe thousands, says John Ahearneof the scientific research societySigma Xi, who chaired the study.

Within Congress, Republicansand Democrats alike opposed RNEP development on both political and technical grounds. Lastyear, a bipartisan coalition killedfunding for the programme. In theface of such opposition, theadministration has essentially

pulled the plug on the project by withdrawing the $4 millionrequested to study RNEP, accordingto Senator Pete Domenici(Republican, New Mexico).

“The focus will now be with the defense department and itsresearch into earth-penetratingtechnology using conventionalweaponry,” Domenici said in astatement.

“This decision simply confirmswhat the critics have been saying allalong,” says Christopher Paine, a senior analyst at the NaturalResources Defense Council. “Theprogramme had become a thorn inthe side of the administration.”

But as RNEP disappears, anotherproject is on the rise.

A congressional budget billexpected out this week wouldallocate $25 million to speed up the Reliable ReplacementWarhead project. The programme,established to design the nextgeneration of weapons for theageing nuclear stockpile, has itself been generating controversyamong researchers, some of whombelieve it to be unnecessary (seeNature 434, 684; 2005).

“RNEP may be politically dead,”says Daryl Kimball, executivedirector of the Arms ControlAssociation in Washington DC.“But I would be very surprised if the debate over new weapons endsany time soon.” ■

Geoff Brumfiel

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