If there are other stars orbiting a black hole, their orbit can be used to determine its mass and location.

* If the Earth is typical, some of these stars likely have planets with intelligent life ;

If the two galaxies do meet they will pass through each other, with gravity distorting both galaxies severely and ejecting some gas, dust and stars into intergalactic space.

If so, these huge stars would have quickly consumed their supply of fuel and became supernovae, releasing heavy elements into the interstellar medium.

If these numbers did change, there should be noticeable effects in the sky ; stars in different directions would have different colors, for instance.

If there were a large ( possibly infinite ) number of universes, each with possibly different physical laws ( or different fundamental physical constants ), some of these universes, even if very few, would have the combination of laws and fundamental parameters that are suitable for the development of matter, astronomical structures, elemental diversity, stars, and planets that can exist long enough for life to emerge and evolve.

If the universe is static and populated by an infinite number of stars, any sight line from Earth must end at the ( very bright ) surface of a star, so the night sky should be completely bright.

If the universe is homogeneous at a large scale, then there would be four times as many stars in a second shell between 2, 000, 000, 000 to 2, 000, 000, 001 light years away.

If the surface of concentric sphere shells were considered, the number of stars on each shell would be proportional to the square of the radius of the shell.

If it does, it will develop into a red giant as described for mid-sized stars below, but never fuse helium as they do ; otherwise, it will simply contract until electron degeneracy pressure halts its collapse, becoming first a blue dwarf and then a white dwarf.

If the core of the star is not too massive ( less than approximately 1. 4 solar mass, taking into account mass loss that has occurred by this time ), it may then form a white dwarf ( possibly surrounded by a planetary nebula ) as described above for less massive stars, with the difference that the white dwarf is composed chiefly of oxygen, neon, and magnesium.

If there are two horizons there is side error ; adjust the horizon glass / mirror until the stars merge into one image or the horizons are merged into one.

If one of a select band of frequently referenced stars is mentioned during these stories, they will be named humorously.

If we were to regard Sirius and Procyon as double stars, the change of their motions would not surprise us ; we should acknowledge them as necessary, and have only to investigate their amount by observation.

If one could see a satellite in geostationary orbit, it would appear to hover at the same point in the sky, i. e., not exhibit diurnal motion, while the Sun, Moon, and stars would traverse the heavens behind it.

When Crawford saw the unflattering photos of both stars that appeared in the papers the next day, she said, " If that's how I look, then they won't see me anymore.

If the motion is part of an orbit, or if the stars have similar radial velocities and the difference in their proper motions is small compared to their common proper motion, the pair is probably physical.

If the relative motion of a pair determines a curved arc of an orbit, or if the relative motion is small compared to the common proper motion of both stars, it may be concluded that the pair is in mutual orbit as a binary star.

If the motion is part of an orbit, or if the stars have similar radial velocities or the difference in their proper motions is small compared to their common proper motion, the pair is probably physical.

If the binary fraction is 50 %, the total cluster population would be at least 300 individual stars.

If they did not appear to move, the stars are either much further away than the Sun and the planets than previously conceived, making their motion undetectable, or in reality they are not moving at all.

If a red dwarf, it would exist in star catalogs, but it would only be confirmed by measuring its parallax ; due to orbiting the Sun it would have a low proper motion and would escape detection by older proper motion surveys that have found stars like the 9th-magnitude Barnard's star.

If the position of the earth ( see above ) is reckoned with respect to the fixed stars, then the dates indicate the zodiacal constellation near which the sun can be found.

If the observer's latitude is − 35 °, then all stars within 35 ° of the south celestial pole will be circumpolar.

If it were not for an old professor who made me read the classics I would have been stymied on what to do, and now I understand why they are classics ; ;

If I even hint at it do you think it will matter that you are his nephew -- and not even a blood nephew ''??

If the circumstances are faced frankly it is not reasonable to expect this to be true.

If his dancers are sometimes made to look as if they might be creatures from Mars, this is consistent with his intention of placing them in the orbit of another world, a world in which they are freed of their pedestrian identities.

If love reflects the nature of man, as Ortega Y Gasset believes, if the person in love betrays decisively what he is by his behavior in love, then the writers of the beat generation are creating a new literary genre.

If to be innocent is to be helpless, then I had been -- as are we all -- helpless at the start.

Defoe then commented, `` If they Could Draw that young Gentleman into Their Measures They would show themselves quickly, for they are not asham'd to Say They want only a head to Make a beginning ''.

If Jews are identified as a religious body in a controversy that comes before a national or international tribunal, it is obviously compatible with the goal of human dignity to protect freedom of worship.

If they are right, they will prevail of and by themselves.

Without preliminaries, Esther asked him, `` If you are a world citizen, will you take Garry Davis' place in his tent while he goes to the hospital ''??

If we are to believe the list of titles printed in Malraux's latest book, La Metamorphose Des Dieux, Vol. 1 ( ( 1957 ), he is still engaged in writing a large novel under his original title.

If the would-be joiner asks these questions he is not likely to be duped by extremists who are seeking to capitalize on the confusions and the patriotic apprehensions of Americans in a troubled time.

If we break the minister to our bit, we are buying back our own sins.

If the record buyer's tastes are somewhat eclectic or even the slightest bit esoteric, he will find them satisfied on educational records.

If Daddy's books are out of bounds his own picture books are not.

If it will simply delay the debates until the qualifications are closed next spring, and then carry all the candidates on a tour of debates, it can provide a service to the state.

If they are to be commended for foresight in their planning, what then is the judgment of a town council that compounds this problem during the planning stage??

If the Communists are sincere in wanting a united, neutral and disarmed Germany, it might well be advantageous for the German people in this nuclear age.

If only this could be done more often -- with such heartening results -- many of the earth's `` big problems '' would shrink to the insignificances they really are.

If any are left, presently, we may expect to see signs specifically prohibiting the feeding of them too.

If the raw population figures are crucially relevant, then it is idle to think of liberation, as idle as to suppose that Poland might liberate Russia.

If it is not enough that all of our internationalist One Worlders are advocating that we join this market, I refer you to an article in the New York Times' magazine section ( Nov. 12, 1961 ), by Mr. Eric Johnston, entitled `` We Must Join The Common Market ''.

If the UN troops are not mercenaries then the Hessians were not mercenaries either.