Right: a 19th-century mandarin's court observes an eclipse. The scientific view it enthusiastically through a telescope while the superstitious fearfully hide their faces.  Like eclipses, timeslips may one day be understood

But the mechanism of timeslips eludes us still; we can only sift the evidence and search for some common denominators among the experiences - and possibly some relationship with known laws of physics. So far these common factors have been discovered:

1. A trigger factor that appears to set the occurrence in motion.

2. Abrupt onset of the experience.

3. A sensation of living in two time zones at once, either past and present or future and present.

4. A feeling of being an integral part of the experience or a participant in the action.

5. A noticeable absence of sound from beginning to end of the timeslip.

6. A marked difference is frequently mentioned between normal light conditions and those experienced during the timeslip. A 'silvery light' is often described.

An electric experience

From the above it seems that certain physical effects take place; the subject sees and hears abnormally and experiences a feeling of disorientation or detachment. Occasionally, people have reported a tingling sensation or nausea immediately before they experienced a timeslip just as particularly sensitive people may react to an impending earthquake or thunderstorm. (It is interesting that several of the sensations described can also herald hauntings or other paranormal happenings.) One subject wrote describing 'a tingling in arms and legs: a feeling of being "plugged in".' She may have been very near the truth for there are indications that some form of electrical activity plays a part in many paranormal experiences.

Captain Flowerdew (inset) who, as a child, picked up a pink pebble from a beach and instantly 'remembered' a desert city built of pinkish stone where 'he' had died in a battle centuries ago. Detailed as the memory was, it was not until he saw a television programme about the ancient site of Petra (above) that he remembered the city's name

A 'plugging in' or trigger was a major factor in the case of Mrs Anne  May, the Norwich teacher who, in May 1973, at Clava Cairns in Scotland experienced a slip into what appeared to be the remote past of the area (see page 648). Significantly, it was not until she leaned back against one of the standing stones that the extraordinary transition into the past took place, as though a switch had been thrown. Several correspondents have used that very phrase in describing their individual timeslips. And the immediacy of the slip is always pronounced. It is as though the trigger object (in Anne May' s case, the stone) itself contained the power to evoke the time dislocation.

This may not be so far-fetched as it sounds, for if the operation of timeslips is due to the transmitting of information from past or future into the present, then that information must already be in existence somewhere. Perhaps every single component of the world in which we live is continually broadcasting information about itself (its form, colour, texture, situation, and so on by means of 'waves' as yet unknown to science. Some of this information may be received and absorbed by surrounding material and, when conditions are appropriate, rebroadcast by the receiver. Any human being then in the area whose own brain is at the time operating on the same frequency as the transmitter may register an audio or visual impression of the original 'wave' pattern sent forth by the first broadcaster. Thus we ourselves in moments of high emotion or stress may be sending out signals into the air that will be received years hence by some sensitive individual. Most (though perhaps not all) hauntings can probably be attributed to this type of mechanism.

What are these mysterious waves that have the power to carry pictures and sounds through time? We do not know. But it is a physical fact that all objects radiate electromagnetic waves. Light waves, which enable us to perceive the world around us, are just one example; radio waves, infra-red and ultra-violet waves, x-rays and gamma rays are all electromagnetic. Most of these invisible radiations were discovered within the last century; who can say what further kinds of radiation await discovery?

The girl from Scotland One afternoon in 1950 Brigadier K. Treseder and colleagues from the British and American embassies in Oslo, Norway, went skiing. On preparing to return, the Brigadier, his wife and a friend were separated from the others. They were suddenly confronted by a tall old lady dressed in Edwardian clothes who demanded to know why they were trespassing on her land. She spoke English with a Scottish accent and was obviously very angry. The three apologised but she continued to complain, adding some bitter comments about modern manners. A shouted enquiry from the others made the three look round; when they turned back the old lady had vanished. And, it transpired, none of the others had seen her at all. Local enquiries revealed that, although no eccentric Scottish lady lived there then, the local landowner's great grandfather had married 'the girl from Scotland' at the turn of the century. Was the figure a curiously talkative ghost? A collective hallucination? Or did the skiers hold a real conversation with a woman from the past - 'the girl from Scotland'?

The fascinating branch of physics called quantum mechanics posits the concept of electrons in atoms (and our Universe is constructed on the atom) moving backwards and forwards in time equally easily. Perhaps, therefore, it is possible for information from the future to be returned to the present by some, as yet, totally unknown mechanism.

The future is now

But, if such information can be returned from the future, then that future must already exist 'somewhere', in some form. And it may be that we ourselves - and indeed all atomic material- carry within us the seeds of our own future.

The behaviour of individual atomic particles is unpredictable, but it is possible to predict how they will behave en masse. In other words, by cause and effect all events seem to be predetermined. Perhaps the idea of destiny arose from an instinctive knowledge of this very fact: that we are what we are and do what we do because we are constructed genetically in a certain way.

If this were always and wholly true, we and the whole of human history would indeed be predestined and our futures would be laid down for us inescapably. However, it appears that we do have the power to alter and modify our 'destiny' - at least occasionally - by the exercise of our will.

Therefore when we encounter precognitive experiences, whether dreaming or waking, it may be that we are receiving from matter already existing people animals, buildings and so on information about its own future development. In the short term such information is likely to prove true, in the long term less so, for over a longer period of time there is greater likelihood of human will being used to intervene in the cause and effect - the causality - process. With more time available there are more opportunities for action- and therefore more opportunities for change.

However, there are exceptions. Occasionally precognitive experiences will come to completion accurately several years after they have been encountered. There are two known cases where there was a full 20-year lapse between the experience and its accurate fulfilment.

This is, however, unusual. Past slips cannot always be explained as 'recordings' of past events, though doubtless this mechanism accounts for a great number. Several persons have reported finding themselve sactively involved in some historical occasion. One woman, Mrs D. Dove, while walking near Bootham Bar, York, suddenly found herself in the past when a shaft of sunlight struck a coat of arms on the medieval city gate. At once her awareness of the present dissolved and she discovered herself standing in the midst of a medieval scene; milling barrows, carts and a great crowd of people. She saw mounted horsemen clearing the way for some great personage who followed them. Then the Sun went in and the whole glowing picture disappeared. There seems little doubt that Mrs Dove 'saw' an actual. historical scene and was herself briefly a part of it; much as Mrs Turrell-Clarke of Pyrford found herself in the role of a nun in 13th-century Surrey (see page 647).

Above: Bootham Bar, one of York's medieval city gates, where Mrs Dove experienced a slip back into the city's past when a sudden shaft of sunlight struck a coat of arms on the Bar. Was the sunlight a trigger that somehow 'replayed' a real historical scene?

Here again the trigger factor is present; in this case the sudden shaft of light on the coat of arms on the city gate. Is it possible that the Bar itself had 'recorded' this scene from its own past, and that the particular conditions of light provided by the sudden flash of sunshine 'switched on' the 'playback'? If that were so, why did the Bar 'choose' to replay this scene out of all its millions of recorded moments? And why was the scene not witnessed and reported by everyone else present in the modern precincts of Bootham Bar in 20th-century York? Perhaps that particular scene had some special significance for Mrs Dove, such as' a spontaneous memory of a past life? Or perhaps her brain alone was in the necessary state to receive the information and transform it into pictures and sound.

Tuning in to time

The human brain operates electrically and uses several frequencies. There is some variation from brain to brain, and not all operate on exactly the same frequencies. It is possible that persons sensitive to psychic phenomena are merely tuning in to existing wave patterns (either past or future) by accident, their own brain activity being on the correct frequency for reception at the time. Tom Lethbridge, the master dowser (see page 566), reached much the same conclusion.

Further reading J. W. Dunne, An experiment with time, A & C Black 1934 Joan Forman, The mask of time, Macdonald and Jane's 1978 J. B. Priestley, Man and time, W.H. Allen 1964 J. G. Whitrow, The natural philosophy of time, Nelson 1961

It is also true that many bizarre time experiences can be explained as hallucinations. The brain's memory processes are incompletely understood, and the subconscious mind has proved to be very complex; dreams and hypnosis reveal a level of creativity inaccessible to the conscious mind. And the full scope of genetic inheritance is not yet known. Time dislocations may sometimes be the result of these or of imaginative responses, hysteria (see page 670), drug usage or illness. However, when all these factors have been considered and eliminated, there remains a great number of experiences that cannot be accounted for - or can only be accounted for by analogies that relate to the electromagnetic force field every human possesses, and through which he doubtless gives and receives information. If electrical data fed into the brain from outside sources is capable of being translated by that brain into terms of pictures and sound, then many so-called psychic phenomena, including time-slips, may be explained.

Timeless What is Time? The Flow of Time Entropy and the Arrow of Time