Physicists at the M P Birla Planetarium here have dubbed the work of Dey, a Bengali post doctoral fellow at John Hopkins University in Baltimore, USA, as a ``real landmark'' in the field of astrophysics.

Dey's theory, a breakthrough in the field, is based on the study of the shifts (called red shifts in astrophysics) of spectral lines between galaxies. For the first time, a scientist has found evidence of the red shift between two galaxies to be more than five points on the spectral scale.

``This pushes our belief on the origin of galaxies, earth and other planets to about three billion years further back in time,'' director of the planetarium, R Subramaniam, told newsmen.

Though researchers, Subramaniam said, had been working to demystify the secrets of the universe for quite some time now,nobody had quite struck the right chord.

``There had been no theory after `Big Bang' which had pushed up the furthermost limit of universe calculated so far. Dey's work, which puts this limit at more than 100 million light years further back, has come as a real landmark.''

The Big Bang theory postulates that the expansion of primordial matter began after a huge cosmic explosion about 18 billion years ago. However, based on their spectral observations, Dey and his team have pushed the time further back by 15 to 20 per cent which comes to about two to three billion years more back in time. Shifting of cosmic bodies is calculated on the basis of spectral lines between them.

As the bodies keep moving away from each other, the spectral lines between them, measured in points, also keep increasing. ``The greater the recession of the galaxy or cosmic body is, the greater is its red shift,'' Subramaniam said. A five point shift is the greatest reported as yet.

State-owned television channel Doordarshan, whichaired a telephonic conversation with Dey soon after he made his work public, quoted him as saying that it has been an `exciting discovery' since very little is known about this stage of the universe and the cosmos.

``It is great to go back in the past,'' a jubilant Dey was heard saying.Dey, who along with his team of astrophysicists of the Space Research Centre at Hopkins University, discovered the five point red shift in mid-March this year, will publish his findings in the next issue of Astrophysical Journal brought out by Chicago University.

The phenomenon of red shift was being observed by four scientists Dey, Spinard, Stern and Graham of the John Hopkins University for quite some time now.

The team began with analysing the constellation of triangulum (a cosmic area in between the constellations of Aries and Pisces) from the Keck observatory in Hawaii.

During initial observations, they found bright sparks in the area and after increasing the intensity of the telescope, struck upon a newconstellation which they called RD-1.

The team then analysed the red shift possibilities of RD-1 with its nearest galaxy and surprisingly found it to have a shift figure of 5.34, the greatest ever reported in between two cosmic bodies.

The director of the planetarium said the discovery has come as a personal triumph to him since decades back he was part of the astrophysicists' group at the John Hopkins University working on these lines.

Asked how it would enhance further research in astrophysics, Subramaniam said, ``We are going nearer and nearer to the origin of galaxies and cosmic bodies. This is only a step further.''

Sources at the Positional Astronomy Centre here said it was heartening to hear that an Indian has performed one of the ``greatest feats in the history of cosmic research''.

The Director of the Positional Astronomy Centre, Dr K K Chakraborty said, he had read about the discovery in a foreign journal and was eagerly waiting for the detailed publication of Dey's work.