For the first time , physicist have make a " disastrous hole bomb " in the lab , providing grounds for the " Zel’dovich effect " purport half a C ago .
The idea behind the Zel’dovich burden came from an unusual place . In 1969 , British physicist and mathematician Roger Penrose suggest that energy could be extract from black hole by lowering an object into the ergosphere ( the region just outside of the event sensible horizon ) and allow it to speed the physical object , stealing some of the black gob ’s energy . The idea , known as the Penrose procedure , call for minus energy to be acquired by the object in order for it to be recovered from the black hole – otherwise , all you ’d be doing is feeding the black hollow .
" allow ’s imagine that we launch a particle from very far away into the ergosphere of a Kerr black-market yap , following a retrograde orbit , that is , a trajectory directed against the black hole ’s rotational direction , " Jorge Pinochet , prof in the physics department of the Universidad Metropolitana de Ciencias de la Educación , explains of the process in a recentpreprint paper . " Suppose we calculate the trajectory so that upon entering the ergosphere , the mote fragments into two pieces , one of which is absorbed by the disgraceful yap , and the other escapes outwards , moving an arbitrarily gravid aloofness out . "
" Due to the extreme volume of soberness inside a bleak hole , oecumenical relativity tolerate the absorbed shard to have disconfirming zip . "
Under these circumstances , Penrose showed that the escaping sherd would have more energy than the fragment absorbed by the black hole . That may sound like preservation of energy law of nature are being broken , but according to what we know of universal relativity , that is not the case .
" The trick to obtain this result is that the black hole sop up minus vigour , which leads to a reduction in its mass - Department of Energy , which translate into a decrease in its rotational speed , " Pinochet stay . " In other words , we have extracted rotational energy from the fatal hollow . "
We do n’t have any conveniently close black holes to play with ( probably thankfully ) , but a few year afterwards , Belarusian physicist Yakov Zel’dovich came up with a far more pragmatic direction to test the concept of stealing spare vim from a rotating system . The idea has link to the Doppler effect , which can make light appearred or dark shifteddepending on how the utter object is moving relative to us , as well as the rotational Doppler effect .
" The linear version of the doppler effect is familiar to most the great unwashed as the phenomenon that occurs as the delivery of an ambulance siren appear to uprise as it approaches the auditor but fell as it heads away . It appears to rise because the sound waves are reaching the listener more oft as the ambulance nears , then less frequently as it passes , " study atomic number 82 author Dr Marion Cromb , now Research Fellow at the University of Southampton , explain in astatementconcerning a previous study .
" The rotational doppler effect is similar , but the consequence is confined to a circular space . The twisted sound wave change their pitch when measure from the point of view of the rotating aerofoil . If the surface rotates fast enough then the intelligent frequency can do something very foreign – it can go from a positive frequency to a negative one , and in doing so steal some Energy Department from the rotation of the surface . "
To test the theme , the team previously bounced sound waves off a spinning disk , and heed for a shift in oftenness that indicated vim had been reach from the disc ’s rotation . Then , the squad impart the experimentation using electromagnetic waves .
" The Zel’dovich burden works on the principle that waves with angular impulse , that would usually be absorbed by an object , actually become magnify by that aim or else , if it is rotating at a fast enough angular speed . In this case , the object is an atomic number 13 piston chamber and it must rotate faster than the frequency of the incoming radiation , " Cromb said in astatementabout thatprevious study .
" Colleagues and I successfully tested this hypothesis in sound waves a few long time ago , but until this most recent experiment it had n’t been proven with electromagnetic undulation . Using comparatively simple equipment – a resonant circuit interacting with a spinning metal cylinder – and by creating the specific conditions required , we have now been capable to do this . "
To deal the experimentation , the team needed to rotate the aluminum piston chamber so fast that , from its perspective , it sees a distorted wave pitch in angular rotation with a " negative frequency " .
" The consideration for amplification is from the rotating perspective of the physical object , " Cromb explained . " twist electromagnetic fields hitting it have become rotationally Doppler shifted , so much ( or so depressed ) that they ’ve function through zero and into a ‘ minus ’ angular oftenness . minus frequence then means negative assimilation , and this mean amplification . "
The team manage to create such an analogue black hole bomb , using a contemplative atomic number 13 cylinder rotating slower than a smother electromagnetic field .
" Here , we demonstrate experimentally that a automatically rotating metallic cylinder not only definitively acts as an amplifier of a rotating electromagnetic field modality but also , when mate with a low - expiration resonator , becomes unstable and acts as a generator , seed only by noise . The system present an exponential runaway amplification of spontaneously father electromagnetic modes thus demonstrating the electromagnetic analogue of Press and Teukolsky ’s ‘ black cakehole bomb ’ , " the team writes in their paper , which has not yet been peer reviewed .
While this is n’t exactlystealing energy from a disastrous holelevels of cool , the parallel suggests that disastrous holes could amplify energy in this manner .
" A challenge for the future remains the observation of spontaneous [ electromagnetic ] waving generation and runaway amplification seed from the vacuum , " the team write in their discourse . " However , based on the results presented here , this now remains a purely technological ( even if very hard ) exploit . "
The study is posted to the pre - print serverarXivand is yet to be compeer - refresh .
