As we mentioned in Chapter 1, the main reasons for a predisposition towards a critical density universe are theoretical. We will address these issues carefully, but please be aware at the outset of our view that, ultimately, the question of Ω0 is an observational question and our theoretical prejudices must bow to empirical evidence.

Simplicity

In the period from the 1930s to the 1970s, there was a tendency to prefer the Einstein–de Sitter (critical density) model simply because – consequent on its vanishing spatial curvature – it is the simplest expanding universe model, with the simplest theoretical relationships applying in it. It is thus the easiest to use in studying the nature of cosmological evolution. It is known that, on the cosmological scale, spatial curvature is hard to detect (indeed we do not even know its sign), so the real value must be relatively close to zero. Moreover, many important properties of the universe are, to a good approximation, independent of the value of Ω. The pragmatic astrophysicist thus uses the simplest (critical density) model as the basis of his or her calculations – the results are good enough for many purposes (e.g. Rees 1995).

There are, in addition to this argument from simplicity, a number of deeper theoretical issues concerning the Friedman models which have led many cosmologists to adopt a stronger theoretical prejudice towards the Einstein–de Sitter cosmology than is motivated by pragmatism alone.

We now turn our attention to the evidence from observations of galaxy clustering and peculiar motions on very large scales. In recent years this field has generated a large number of estimates of Ω0 many of which are consistent with unity. Since these studies probe larger scales than the dynamical measurements discussed in Chapter 5, one might be tempted to take the large-scale structure as providing truer indications of the cosmological density of matter. On the other hand, it is at large scales that accurate data are hardest to obtain. Moreover, very large scale structures are not fully evolved dynamically, so one cannot safely employ equilibrium arguments in this case. The result is that one is generally forced to employ simplified dynamical arguments (based on perturbation theory), introduce various modelling assumptions into the analysis, and in many cases adopt a statistical approach. The global value of Ω0 is just one of several parameters upon which the development of galaxy clustering depends, so results are likely to be less direct than obtained by other approaches. Moreover, it may turn out that the gravitational instability paradigm, which forms the basis of the discussion in this chapter, is not the right way to talk about structure formation. Perhaps some additional factor, such as a primordial magnetic field (Coles 1992) plays the dominant role. Nevertheless, there is a persuasive simplicity about the standard picture and it seems to accommodate many diverse aspects of clustering evolution, so we shall accept it for the sake of this argument.

Excerpts of the letter referred to in this note appear in Appendix C.

Dear Colleagues,

Though the attached letter to prospective participants of your Colloquium provides most of the essential information, let me emphasize that the success of the Colloquium will depend on the skills of the moderators.

The attached letter will be mailed to all prospective panelists together with the invitation. We hope that its message is clear, and that it will make your chore easier.

As soon as the final composition of your panel of discussants is clear, we will ask you to contact them and to obtain a rough outline of the issues they wish to present. Thereafter, it will be up to you to coordinate the sequence of presentations, and to familiarize all panelists with the issues to be considered.

Hopefully, you will be able to prevent talks that exceed 10 minutes. If the discussants adhere to the time schedule, there will be 40–50 minutes for a general discussion with questions from the audience.

Most scientific meetings involve more than one type of event. One can look at these events as building blocks, and it is their combination and placement that will be instrumental for the success of the meeting (see Chapter 5). The following listing is arbitrary and merely highlights options that can be modified to suit a particular situation.

Scientific events

Lectures

All good lectures have one thing in common: they are not too long. It seems that all over the world the attention span has shrunk during recent decades. Blame it on our hectic lifestyle or the impact of the mass media: most people get restless when lectures exceed one hour.

To prevent monotony, lectures (with the possible exception of Main Lectures) should be followed by a discussion period and a break. The length of the break must vary with the circumstances, as detailed in the following sections. However, even ‘Short Communications’ should be scheduled at least three minutes apart. During sessions with several consecutive lectures, one or two extended breaks are definitely indicated (see below).

Within a series of lectures, it is imperative to leave the time slot unused if a speaker does not show up, unless the change can be announced well in advance. Otherwise, participants may miss the event. Any change of schedule during a meeting is likely to cause confusion.

Punctuality of lectures is a must when parallel sessions are held. A cautionary example: At an international conference convened in a country known for its ‘relaxed’ lifestyle, the projectionists appeared routinely late after lunch and resumed their jobs at different times.

The best times for scientific meetings are probably the pre- and post-seasons. The advantages are obvious: reasonably good weather, no mass tourism, reduced room rates, and frequently lower airfares. In most of Europe, weather conditions make late spring and early autumn equally attractive; in the southeastern United States and the Caribbean region, on the other hand, the hurricane season (from about August to December) is a risk factor for larger meetings. Similar considerations apply to many places in southern and eastern Asia with seasonal typhoons. Also, it will not create fond memories when your participants grow mildew on their heads while waiting for the repair of a bridge during the monsoon. Of course, it also does not make sense to select locations where snow or ice could prevent participants from either arriving or leaving. Will you pay for their rooms when they are trapped for days in an expensive airport hotel? Furthermore, don't choose a time when many families traditionally get together, i.e., in particular between Christmas and New Year. Last but not least, remember that air fares may be extremely high at the weekend. This could be a deterrent for prospective participants when a meeting closes on a Friday or Saturday.

There is one more factor to consider: special local events. No matter what type of meeting you envision, make sure that your meeting does not clash with an event that causes local overcrowding of roads, parking lots, restaurants, hotels, etc. Typical examples would be major conventions or sports events.

There is one overriding principle for the selection of your office staff: a few thinking people. Do not fall to the temptations of status display and hire people you don't need; and don't try to save money by hiring cheap labor. You will be better off paying good people overtime than employing helpers who need all the help they can get.

The ideal person for the office of a smaller meeting would be a secretary who has organizational talents, writes flawless English, is familiar with scientific terminology, is a good proof-reader, is experienced in the use of computers; and, above all, is reliable. Unfortunately, they don't always make them that way.

For a larger meeting, you may split the work between an assistant and a person mainly involved in typing. The job of the assistant includes the mailing of announcements and various types of forms, book- and budget-keeping, monitoring the timely submission of payments and scientific material (e.g., abstracts, questionnaires), and answering routine letters and e-mail. Ultimately, the assistant will also be in charge of the registration desk, even if it is staffed by employees of a professional service, or of a society (see below). The typist will handle most of the typing, from letters to forms, abstracts, manuscripts, etc. Familiarity with word processing is essential, particularly since the typist will have to update and correct continuously a list of addresses that can be transferred to mailing labels. The respective roles of the assistant and typist must be clearly understood from the beginning, and one of them must be replaced instantly if they cannot cooperate.

Some food for thought

I have been touched by the decency of colleagues who were not well off financially and yet asked to give their share of travel support to younger researchers. On the other hand, I have been appalled by the avarice and egotism of some very illustrious and well-to-do scientists.

The first time I had to allocate funds for a meeting, I called up the invited speakers as soon as I had received the award. Joyfully, I asked the first fellow if several hundred dollars would be helpful for his travel arrangements. The answer was prompt: ‘No, not really.’ Dazzled, I asked if that meant he would not come. In a diplomatic reflex, he then assured me that he was very happy to accept the money.

Some scientists seem to believe that the rules of a bazaar also apply to requests for travel support. They ask for outrageous amounts hoping that this will garner them the lower amount they are actually shooting for. Some of my friends have become so allergic to this attitude that they look with apprehension at any scientist from certain nations.

Similarly unpleasant is the expectation of some retired scientists to receive lavish travel support for meetings they have attended for decades. Of course, you want them to come, but how can you justify paying for suites for them if you don't have enough funds to pay for beds for outstanding younger colleagues? What granting agency would approve an application requesting preferential funding for retired honorees?

General audience

Sometimes, an organizer must decide if a meeting should be open to all those interested, or restricted to a certain audience. Since restrictions often create animosity, it is better to avoid them if possible.

Meetings with restricted audiences, such as the Gordon Conferences, may be desirable for confidentiality and/or in-depth discussions. To keep bad feelings to a minimum, however, one should be honest about the purpose of ‘closed’ meetings, and the rules that apply. Blackball schemes have a tendency to backfire, sometimes to the point of ostracism of the organizer. As they say, every dog will have his day.

Of course, the difference between ‘open’ and ‘closed’ meetings can be blurred. For instance, when a society raises the convention fee for non-members to prohibitively high levels; or, when someone convenes a conference in a place with limited overnight accommodation, and fills the available rooms with friends.

The weirdest proposal I ever came across requested funds for a special conference. The audience was limited to the number of seats in a small room. And how were the participants to be selected? By inviting everybody interested to submit an application that was to be reviewed by the organizer – who himself had no research funds whatsoever!

Question: Why should anyone pretend a de facto closed meeting is ‘open?’

Answer: In general, public money is easier to get for ‘open’ meetings.

In some fields of research, growing numbers of participants have changed the family atmosphere of the conferences.

1. Bulletin/message board and mail board.

2. Sign indicating location of the registration desk.

3. Desk and chairs.

4. Completed and coded (‘problem’ or ‘message’) portfolio sets for registered participants. These sets may include: list of registered participants; note pad and pen; name tag and holder; tickets; refunds and/or financial support (with receipts to be signed); updated meeting information; local information and/ or advertisements (with coupons for discounts).

5. Portfolio sets for late registrants, containing the same as in (4), but also program and abstracts. Tickets may have to be added.

6. Calculators with printout paper (important for instant check of calculations!).

7. Computer with diskettes, printer, printer paper. If there are security problems, use a laptop (notebook) type computer that can be taken easily to a safe place.

8. Typewriter with large typefaces for name tags.

9. Pencils, pens and markers.

10. Note pads and other paper, folders and envelopes.

11. Sticky tape, scissors and thumb tacks (for boards).

12. Stapler with extra staples, paper clips, hole punch.

13. Receipts and other forms.

14. Tickets for various events.

15. Cash box for money and change.

16. Copies of the list of participants.

17. Copies of program and abstract volume.

18. Maps and local information, including telephone numbers of taxis, ambulance and police.

19. Copies of hotel reservations for participants.

20. Telephone.

21. Spare frames for slides.

22. Spare foils and markers for overhead projections.

23. Address list of all members of the Society.

24. Mobile phone (cell phone).

Initial consultations

When preparing the budget of a meeting, it helps to consult with those who have organized a similar event before. Ask them for a general, rough breakdown of their budget, and suggestions they may have for you. But don't insist on seeing their files; that may be the end of their cooperation. The organizers of a scientific meeting, like anyone carrying major responsibilities, may have to make pragmatic decisions. Just think how you, as a department chairman, would react if a visitor asked you to show him the files with individual salaries and budget allocations, or how you would feel if he were to ask you to mail him copies. The issue here is not irregularities or unfairness; the issue is that tough decisions, based on complex circumstances, can easily by misinterpreted or misrepresented.

Instant savings

One of the first steps in your budget preparation should be an estimate of the savings. As good old Benjamin Franklin noted: ‘A penny saved is a penny earned.’ The sad fact is, however, that many organizers inflate the meeting costs by neglecting opportunities to save money, and then are unhappy when people do not come because they can't afford it. How does one save money right from the start? First of all, one does not spend money on unnecessary frills such as memorabilia, expensive posters or announcements on multi-colored paper. Just think how many hours of typist's time you could pay for with the funds allocated for this self-glorification! If a photographer requests permission to take pictures, allow it with the proviso that he bears the financial risk. Do not commit any funds, unless you are ordering official group photographs.

Are you sure?

Experience and commitment

The preceding examples suggest that the prospective organizer of a scientific meeting had better look before leaping. To run a major meeting without prior experience would be foolish, no matter how much your friends encourage you. If you hope to muddle through, you are inviting disaster. Remember: the reputation from an unsuccessful meeting may stick with you for a long time.

For the novice, there are several ways to gain experience. One is to assist in the preparation of a major convention. Just carrying a minor responsibility, watching the progress of the preparations, and learning how unexpected problems are handled provides invaluable insights.

Another way to start out is to organize a special session, or a small symposium for a major meeting. Dealing with six speakers from the first letter of invitation to the receipt of the last manuscript is a good introduction to handling different, and more likely difficult, personalities.

You can also try it the harder way. The first scientific meeting I organized was a regional conference with more than a hundred participants. I had no experience, and major problems arose during the first morning: (1) The registration desk had been set up too late; some participants never returned to pay their fees. (2) Students and some of the faculty of the host institution appeared unexpectedly, refused to pay fees for an event in ‘their’ lecture room, and caused overcrowding. (3) The service in charge of coffee and cookies appeared when the morning break was over, almost at lunch time.

A frequent mistake made in the design of posters is an overabundance of text. On the other hand, in the information on poster boards, the most serious omission is the lack of precise dimensions of the usable area. The usable area of a poster board will be smaller than the total size if the board extends almost to the floor. Furthermore, the dimensions of poster boards vary greatly and thus may demand a differing design of the title and list of authors' names.

The following example applies to the more user-friendly type of poster board. However, the dimensions of boards may be different (e.g., 1.2 meters (4 feet) wide and 1.5 meters (5 feet) high), which obviously saves space in the exhibition area.

Specific instructions

1. The poster board (usable area starting 2 feet = about 0.6 meters above ground) is 6 feet (about 1.8 meters) wide and 4 feet (about 1.2 meters) high.

2. Keep text to a minimum. Use less than a total of 1000 words for the poster (including legends of figures, and tables), and avoid redundancies.

3. The title should be concise and readable from a distance of at least 7 feet (about 2.1 meters). Use a bold and black typeface, about 1/4 inches (about 30 millimeters) high.

4. The names of the authors should be somewhat smaller, about 15–20 millimeters high.

5. The text type should be no less than 5 millimeters for capitals and taller letters such as 1 or b.

6. Bear in mind that your illustrations may be inspected from a distance of 1 meter (about 3 feet) or more. Keep them simple and use (but don't overuse) color whenever helpful.