The Hierarchical Universe

A talk by Ernst J. Öpik

Öpik in the Library at Armagh
EJ Öpik in the Library at Armagh

The following is a transcript of the last talk given by Ernst J. Öpik. It was delivered in the library at Armagh Observatory in 1981 (?) at a meeting of the Astronomical Science Group of Ireland (ASGI). It is also available in audio format as a streaming MP3 and as a downloadable 5MB MP3 file.

The speakers are;
Dr Mart de Groot - Director of Armagh Observatory, 1976 - 1994
Dr Ernst J. Öpik - Astronomer at Armagh, 1948 - 1981
Dr Brendan Byrne - Astronomer at Armagh, 1978 - 1997
A.N. Other
Prof. Patrick Wayman - Director of Dunsink Observatory, 1963 - 19??


Mart de Groot:
".... he has been working in, maybe update certain things or whatever and finally ended in quietly telling him some time ago that he would be our guest of honour and that we would expect of him to deliver the last talk of the day. To be in astronomy for three quarters of a century is quite something, that's about the time I think, three quarters of a century? Well, you can ask him and he can correct me later. You may have noticed that especially Edwin van Dessel has referred to work done by Öpik because I told him that this might be happening, and if you would try very hard you might even find connections between every speaker and what Öpik has at some time in his career done. It would require a bit of investigation. But he will not speak about all his, shall I say, purely scientific activities but he will remind not only the speakers of today but all of you that whatever you are doing that, whether you are concerned with magnetic fields or with double stars or with extra-terrestrial observations, that you must at some time or other or in some form or other be asking the big question about the universe and we all have different formulas for that question and I have the feeling that in this final talk we will move into this somewhat more philosophical area of science. So I have the pleasure to announce, Ernst J. Öpik, The Multi-stage or Hierarchical Universe, whatever that may mean."

The Hierarchical Universe

Ernst J. Öpik:
"I intend to say a few words about communication and isolation in our hierarchical universe. Hierarchic means that the universe is built in stages; various solid bodies, the planets, the quite solid suns. Then the solar systems are joined into stellar systems, stellar systems make up galaxies and so forth, and this happens by interposition of so-called "empty space" - actually a background space which may, or may not, be filled uniformly with something else. Because interposition of this space. To the layman the strange thing is that higher order systems are always of lower density. It is self evident that it must be this because we put nothing in between. And this goes on from stage to stage and the big question, not solved yet, is "where does it end?"

"Thus, to the ancients and to primitive people the Earth represented the main part of the universe ???? No doubt. Its surface being crammed more or less uniformly with dense matter - solid stone or often water. It was the centre of the universe to them which was considered as one single system ruled from the centre, the Earth. At present this simple model has been replaced, as you all know, by an unlimited number of systems, those of higher order consisting of aggregates of smaller subordinate systems with the interposition of so-called empty space - empty means filled with a uniform background, material or vacuum or radiation, whatever it is. Characteristically, the distances between system members increases with higher system order - clearly there are more of them when the systems are greater - in such a manner that the average density of the systems decreases drastically with each step despite the increasing total mass. A contradiction, again, to the layman but very clear and simple, absolutely logical. The bigger the system the more dilute it is and the more massive.

"With the Sun as a typical star of density 1.4 times that of water the density of its system, including the Sun itself, and approximating the space being bounded by the orbit of Pluto, that way we know where it ends, this density is 10 to the minus 11 grammes per cubic centimetre. Already a nothing from our Earthly standpoint and the important all overwhelming nothing. One hundred thousand million times - I had written first one hundred thousand times but it is one hundred thousand million times, you see I get mixed up with big or small numbers - one hundred thousand million times less than that of water and just as many times greater than the mean density of our star filled galaxy - ten to the minus 22 grammes per cubic centimetre. And so forth.

"From the standpoint of space communications - you see I am practical - it is just dead matter but it refers to us living, intelligent and thinking beings having a soul, a consciousness and the only reality which we know exists, whether you exist that is a just a mere matter of fantasy, at least such philosophies exist, such philosophers exist and, if they doubt, they have to doubt about their own existence - a sophism. Now we are not arguing about such things. As I often say "thinking requires? thinking". Well, from the standpoint, now from the practical standpoint, practical I never hit? in billions of years for living beings, whether we will be up there or somebody else, whether we here on Earth or somebody else there in space, there are people doubting that there is anything similar to humanity except we ourselves. That we cannot prove or disprove but it appears to be very unreasonable to think we are the only ones in this world. We have not made the universe ??? to be alone. From the standpoint of the matter of space communications or possible contacts with other civilisations which can be reasonably expected - reasonably, whether you trust your reason or not, to exist in other solar systems among the stars, the most significant conclusion is that visits from or to our stellar neighbours must be, must face hundred of thousands years of travel assuming that they are not quanta of light which travel with the velocity of light and even then going at the velocity of light it is still the same conclusion. Travel ??? in all appearance, not physical, the limit of time we are temporarily existing.

"The only guide here is that we believe that the laws of organic nature are everywhere the same and in that case the limit of longevity is probably, if there exists other living beings, must be of the same order of magnitude. Maybe not, but still there is a limit. Even information sent out at the velocity of light, even when a suitable universal code could be devised so that we will be understood, told what we are actually saying and not just flashes???? of light, could be devised would also take many years between letter and answer to it and if the answer comes after one hundred years already we are not there to hear it. Also, we are not alone in the universe, at least I firmly believe it. In one proof of the coming Journal (IAJ?) Dermot Mullan put the question, "who are we?" which means that he doesn't believe it. Well, I think most people believe it.

"Also, we are not alone in the universe. We are completely separated, physical contact being ruled out and this seems to be quite wisely planned - to our advantage. On Earth, visits to newly discovered continents, such as America was discovered or in the southern regions of Asia or Australia or Africa(?), had led to bloody encounters, to wars and genocide. Willful genocide and also some destruction caused by imported diseases, germs to which the primitive people were not accustomed. One of the diseases is called alcohol. Visits have ended again in genocide or and that of the others somewhere in the universe. Practical isolation in the stellar universe guarantees the uninterrupted evolution of species, biological evolution, and civilisations which maintain a continuing cosmic variety of life on our planet, a variety over long intervals of time, a variety which could be destroyed by the appearance of a foreign, temporarily and technically but maybe not morally, superior outsider and ??? This is guaranteed.

"Thus space travel is and will be limited to the boundaries of our solar system believing that the laws of biological evolution are more or less identical giving similar longevity to the organisms. So, for example, consider my article, I just refer of course to myself, "Interstellar Travel by Hibernation" (?) just a fantasy ?? asleep, asleep for, if not for ever, for a long time, we don't know. But still it's limited and this is for our good. Over the entire span of our future earthly existence humanity will, and its descendants will, form part of the following hierarchy of systems, the amendments(?) or distances between them being even increasing gradually in light time one second at the velocity of 300,000 kilometres per second, so and so many hundreds of thousands of miles per second. In other words, seconds, a second three hundred thousand kilometres and so forth. Millions years. First the Earth, one tenth of a second ??? light goes seven times around the Earth's equator and that's just an order of magnitude. Then comes the Earth-Moon system. In just one second times light comes from the Moon to us. Third, the Solar system, from eight minutes if we are very important and consider our own position or to five hours if it goes out to Pluto. The Galactic stars, hundreds of thousands years to most of them. Fifth, the galaxies, one million to thousands of millions of years distance, light time.

"Only the solar system will remain within our reach and, happily or not, there apparently are no other intelligent beings to be looked for in its ramparts - no man-eater hopefully??? But we are standing here maybe something may change. Maybe some discoveries will find that inside Jupiter there is developing life. maybe its only maybe, but they will not change our viewpoint because the bandwidth has not come out to the surface it is not in ???? direct contact with us. Thus, happily we are free of dangerous competitors. Hoping for friends we may get the worst enemies, as actually we ourselves, our race, has been for, example, for the aborigines of North America. Well that's a good point to finish."


de Groot:
"... more than Dr Öpik will try but "

"Mr Brendan Byrne is a bit restless. Probably he has something to say."

Brendan Byrne:
"I was just wondering if you denied categorically the possibility of faster than light information transport such as the proposals for so-called tachyons etc"

"There was a lady called Bright,
who travelled faster than light
and returned on the previous night"

"What I'm really trying to say is ... I think one must accept that our present knowledge is limited and therefore estimates of the future are limited by our knowledge of the present. So, in making these very confident predictions one has to bear in mind one's own state of ignorance."

"In regard to many things but in this material things moving faster than light, that is against our experiments. It means not only infinite mass but imaginary mass ????? In that case it is not only Einstein, it is part of relativity that mass is energy and energy increases to a limit of infinity when the velocity of light is approached. It has been confirmed by experiment. One must get other experiments. Yes, there are, of course, naive contradictions, for example, take my flashlight and it throws an illuminated area there, then I turn it round, and the velocity this area will move on the Moon, for example, so it reach say after one second may be faster than light but it is not ???"

"Could I just follow that up. There is the concept of time dilation. Would you rule out inter-stellar travel? If you can get close to the speed of light time dilation might become useful."

"Rule out inter-stellar travel? As long as the concept of our time is valid it takes too much time."

"With time dilation, for the traveller it may not."

"Yes, that is right. Well if we could accelerate to near the velocity of light then there will be again according to the same relativity a contraction of time and while the Earth will get older and older we may return just almost as young as we are after millions of years. That is, of course, only on paper and in mathematics and probably those are correct except that in getting to near the velocity of light our material mass must be increased also to enormous proportions. For example, just one ton of matter, even to gain five times for that time ?? I don't remember exactly the figures, a ton will weigh more than one thousand million tons. We must put in masses and masses of energy, mc2. It means that that is an actual inhibition."

de Groot:
"I don't know who will do that but I would know what for. I know why I would do it if I had the money. I think I would try to find out and to prove to you that the limits of longevity are not valid throughout the universe."

"Are not the same? Yes, I believe it, yes I believe it."

de Groot:
"You believe that they are the same everywhere?"

"But there are some limits."

de Groot
"No, I don't think so."

"Alright, its a question of believing, but some limits and if there are limits, the limits can be always surpassed. Only unlimited things cannot be. In any case, we are dealing with physical laws and physical events. We are bound by our knowledge and by our own experiments. There may be, of course, exceptions and so forth. Who was that American, I forgot his name, just a more or less popular writer but a religious man, who said that, those who say that there is no other life, I will believe them only if somebody comes from the other world and tells me that. There is nothing else. There are ??? there are regions of knowledge which we have not yet covered at this time. We have no guarantee that everything is known but we have to keep to our experiments if we are dealing with knowledge and not with fantasy or with beliefs which cannot be disproved or cannot be proved because we deal with things which can be proved. And this we must ??"

de Groot:
"It is good to end our day with wise words because certainly we haven't found, we haven't discovered all the realms of knowledge, we have just been reporting, some of us have just been reporting about a little corner of the realm that they have recently trodden. To quote another few words out of context; Back to our experiments. This is about the time that we are going to break up again and some of you probably will be back to your experiments, that is IUE or CLICL1906 or whatever it will mean. Most of you will have to travel. For those who travel by train there is the train to Dublin that leaves at 6 O'clock so leave here just after half past five. For the others we all wish you a happy journey back and we thank you very much for being with us this day. Some of you may find it interesting to note that ??? will give a colloquium tomorrow at half past two in this same room about the optical counterparts of X-ray binaries and maybe I should also remind you of the AGM of the Irish Astronomical Society that is going to be held at Birr and Birr Castle this Saturday afternoon. I think most of you know about that but Dr. Byrne here, I think, has all the details on his sleeve and can inform you further if you wish. Thank you very much for now and we hope we meet again in about half a year."

Patrick Wayman:
" Ladies and gentlemen I would like to express the thanks of all of you to Dr. de Groot for the hospitality here today and a very smooth and very interesting meeting but also I would like to thank Dr. de Groot for his two years of chairmanship of the group in which all the meetings have been of this high standard and we are very glad to offer our thanks ???"

Last Revised: 2010 February 23rd