They were first derived by Alexander Friedmann in 1922 from Einstein's field equations of gravitation for the Friedmann-Lemaître-Robertson-Walker metric and a fluid with a given mass density and pressure.

Together with H. P. Robertson, the well known Robertson-Walker metric for the Friedmann-Lemaître-Robertson-Walker cosmological models, which are exact solutions of the Einstein field equation.

The Friedmann-Lemaître-Robertson-Walker metric is a curved metric which forms the current foundation for the description of the expansion of space and shape of the universe.

His equations describe the Friedmann-Lemaître-Robertson-Walker universe, which may expand or contract, and whose geometry may be open, flat, or closed.

In 1927, the Belgian Roman Catholic priest Georges Lemaître independently derived the Friedmann-Lemaître-Robertson-Walker equations and proposed, on the basis of the recession of spiral nebulae, that the universe began with the " explosion " of a " primeval atom "— which was later called the Big Bang.

The best antidote for the bitterness and disappointment that poisoned him was hard work.

( The best evidence is that he received a monthly wage of about $125, very good money in an era when top hands worked for $30 and found.

Singing into the mirror and his interested eyes, he was pleased to note, when he stripped for his own bath, that he still had the best part of his Italian sun tan.

Washington never had a chance to work for an extended stretch at the occupation he loved best, plantation management.

The networks for military communications are one of the best examples of networks which not only must be changed with the changes in objectives but also must be changed with the addition of new machines of war.

Ironically no president we have had would have regretted more than President Eisenhower the possibility to which his own words, in the press conference held at the beginning of August, testified: that unable as he was himself to say his running was best for the country, unconsciously he had placed his party before his nation.

The best gifts of the novelist will be wasted on the reader who is insulated against any surprises the novelist may have in store for him.

The Rooseveltian America was a haven of liberalism and progress and seemed to him to constitute the last best hope for civilization.

Here Wright gave a slight sigh of weariness, and continued, `` It means more long years lived across the social grain of the life of our people, making shift to live in the face of popular disrespect and misunderstanding as I best can for myself and those dependent upon me ''.

A truism is that the time to prepare for the worst is when times are best.

In `` My Song's Young Virgin Date '', for example, Thompson wrote: `` Yea, she that had my song's young virgin date Not now, alas, that noble singular she, I nobler hold, though marred from her once state, Than others in their best integrity.

Obviously the commander-in-chief had confidence that Morgan would furnish him good intelligence too, for on the 23rd of May, he told Morgan that the British were prepared to move, perhaps in the night, and asked Morgan to have two of his best horses ready to dispatch to General Smallwood with the intelligence obtained.

Affirmatively Baker worked on the premise that `` young men spontaneously prefer to be decent, and that opportunities for wholesome recreation are the best possible cure for irregularities in conduct which arise from idleness and the baser temptations ''.

Sturley wrote to Quiney that Sir Edward `` gave his allowance and liking thereof, and affied unto us his best endeavour, so that his rights be preserved '', and that `` Sir Edward saith we shall not be at any fault for money for prosecuting the cause, for himself will procure it and lay it down for us for the time ''.

they merely do their best to make it real for others ''.

It was, the brief writers decided, `` man's best hope for a peaceful and law abiding world ''.

And there, on the way, had been the box turtle, that slow, self-contained, world-ignoring relic of pre-history, bent, for reasons best known to itself, on crossing the road.

Civil Defense has far to go and many problems to solve, but is it not in the best spirit of our pioneer tradition to be not only willing, but prepared to care for our own families and help our neighbors in any disaster -- storm, flood, accident or even war??

Yet although the Kennedy Administration, and the Eisenhower Administration before it, have both declared themselves solidly for repeal of the Connally amendment, as contrary to our best interests, no action has yet been taken.

His parents talked seriously and lengthily to their own doctor and to a specialist at the University Hospital -- Mr. McKinley was entitled to a discount for members of his family -- and it was decided it would be best for him to take the remainder of the term off, spend a lot of time in bed and, for the rest, do pretty much as he chose -- provided, of course, he chose to do nothing too exciting or too debilitating.

He knew who was riding after him -- the men he had known all his life, the men who had worked for him, sworn their loyalty to him.

Two of the new hands, a Mexican named Jose Amado and a kid known only as Laredo, were picked for the first trick of riding night herd.

I have just asked these questions in the Pentagon, in the White House, in offices of key scientists across the country and aboard the submarines that prowl for months underwater, with neat rows of green launch tubes which contain Polaris missiles and which are affectionately known as `` Sherwood Forest ''.

I had known him for some years, when I was a delegate and before, and this manner had never been his ''.

On one visit he stopped at the office of the American, where he was known surreptitiously as `` the Great White Chief '', and for the first time met his managing editor, fat Moses Koenigsberg.

It need hardly be remarked that Thompson was not generally known for his scrupulosity about keeping his social engagements, which makes his irritation in this letter all the more significant.

Taking into account Thompson's capacity for self-dramatization and the possibility of a wish to identify his own life with the misfortunes of other poets who had known unhappy loves, there can be no doubt about his genuine emotion for Katie King.

What is not so well known, however, and what is quite important for understanding the issues of this early quarrel, is the kind of attack on literature that Sidney was answering.

The CTCA program of activities was profuse: William Farnum and Mary Pickford on the screen, Elsie Janis and Harry Lauder on the stage, books provided by the American Library Association, full equipment for games and sports -- except that no `` bones '' were furnished for the all-time favorite pastime played on any floor and known as `` African golf ''.

Sturley's allusion probably explains why Greville took out the patent in the names of Best and Wells, for Sir Anthony Ashley described Best as `` a scrivener within Temple Bar, that deals in many matters for my L. Essex '' through Sir Gelly Merrick, especially in `` causes that he would not be known of ''.

In light of the scholarly reappraisals engendered by the higher criticism this is a most remarkable statement, particularly coming from one who was well known for his antifundamentalist views.

The Dominican people have known no democratic institutions and precious little freedom for a generation, and all alternative leadership has been suppressed.

Since little is known about autism, and almost nothing has been written for the layman, we'd like to share one experienced mother's comments.

But as the more concrete plans for the work of the Council gradually became known, there was a rather sharp and abrupt disappointment on all sides.

And thus torn between his desire to be known as the composer of a successful opera and the necessity of remaining true to his proclaimed desire for anonymity, Rousseau suffered through several painful weeks.

Both of them had known the feeling of the small life in her waiting, ready, for the two of them to run up her sails.

It is known that at least five towns ( Barrington, Bristol, Narragansett, Newport and Westerly ) place some value on some boats for tax purposes.

Control would be limited to those rodents for which economical means of control are known.

The Chenoweth brothers were experienced bridge builders, and against the competition of other, and better known, bridge designers and builders they had constructed nine of the covered, wooden bridges on the Parkersburg and Staunton Turnpike a dozen years before, as well as many other bridges for several counties.

The group known as the American Association for Health,, Physical Education, and Recreation ( a division of the National Education Association ) initiated a conference which brought together representatives of the National Rifle Association, SAAMI and the American Fishing Tackle Manufacturers.

After it has reached terminal velocity, the time for the tape to travel a known distance is recorded.