If disk galaxies merge with another galaxy of comparable mass ( at least 15 percent of its mass ) the merger will likely destroy, or at a minimum greatly disrupt the disk, yet the resulting galaxy is not expected to be a disk galaxy.

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 there is insufficient kinetic energy, however, the group may evolve into a smaller number of galaxies through mergers.

If one divides a change in proper distance by the interval of cosmological time where the change was measured ( or takes the derivative of proper distance with respect to cosmological time ) and calls this a " velocity ", then the resulting " velocities " of galaxies or quasars can be above the speed of light, c. This apparent superluminal expansion is not in conflict with special or general relativity, and is a consequence of the particular definitions used in cosmology.

If disc galaxies had mass distributions which were similar to the observed distribution of stars and gas, the rotation curves velocities should decline at large distances ( dotted line A in illustration ), in the same way as other systems with most of their mass in the centre, such as the Solar System of planets or the moons of Jupiter, following the prediction of Kepler's Laws.

If masses of galaxies are derived solely from the luminosities and the mass-to-light ratios in the disk and core portions of spiral galaxies are assumed to be close to that of stars, the masses derived from the kinematics of the observed rotation and the law of gravity do not match.

If this is the case, there must be a population of objects not beamed towards us, and, since we know the lobes are not affected by beaming, they would appear as radio galaxies, provided that the quasar nucleus is obscured when the source is seen side-on.

If lenticular galaxies are an evolved stage of spiral galaxies then they should have a similar Tully-Fisher relation with spirals, but with an offset in the luminosity / absolute magnitude axis.

If our universe is approaching a de Sitter universe then eventually we will not be able to observe any galaxies other than our own Milky Way ( and any others in the gravitationally bound Local Group, assuming they were to somehow survive to that time without merging ).

If this hypothesis is correct, dwarf galaxies may be the building blocks of today's giant galaxies.

If this happens that would increase the density at the center of a galaxy, and thus make a bulge that has properties similar to disk galaxies.

If secular evolution, or the slow, steady evolution of a galaxy, is responsible for the formation of a significant number of bulges, then that many galaxies have not experienced a merger since the formation of their disk.

If tired light was a correct explanation, these galaxies would appear blurred in comparison to closer galaxies.

If he looks into the oncoming wavefronts at distant galaxies which have already encountered the wave, he will see their images undistorted.

If a nearby cluster of galaxies is used to calibrate the Tully-Fisher relation, and then that relation is applied to a distant cluster, the distance to the farther cluster will be systematically underestimated.

If this is the case, it would provide an excellent illustration of the distortion caused by interacting galaxies, discussed in the article Galaxy formation and evolution under the Spiral galaxy heading.

If resolved into stars they might be the first galaxies to be identified as such.

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.

If the mechanics are similar, we can also infer that the thermodynamics will also be similar.

If this be true, the possibility exists that an occlusive lesion of the bronchial arteries might cause widespread degeneration of supportive tissue similar to that seen in generalized emphysema.

If an antibody is developed to stabilize a molecule that's similar to an unstable intermediate of another ( potentially unrelated ) reaction, the developed antibody will enzymatically bind to and stabilize the intermediate state, thus catalyzing the reaction.

If they decide to keep it, what about the growing list of other recently discovered similar bodies ( Sedna, Quaoar.

If he told others about it, her reputation would be ruined, as was his after a similar " indiscretion ," even though he was never prosecuted.

If chosen, the SysOp could then initiate a text-to-text chat with the caller ; similar to what commercial websites have used to sell and support products.

If a similar dispute has been resolved in the past, the court is bound to follow the reasoning used in the prior decision ( this principle is known as stare decisis ).

If all the brands are similar, they must all be similarly good.

If a similar ball is charged by the same glass rod, it is found to repel the first: the charge acts to force the two balls apart.

If one concept is defined by another, and the other is defined by the first, this is known as circular definition, somewhat similar to a circular reasoning: neither offers us any enlightenment about what we wanted to know.

In 1951, he summed up his vision as follows: " If the camera is to make a contribution at all to dance, this must be the focal point of its contribution ; the fluid background, giving each spectator an undistorted and altogether similar view of dancer and background.

If the physical material that will be used in production is derived from bones, dilute acid solutions are used to remove calcium and similar salts.

* If possessing the ball, players must dribble ( similar to a basketball dribble ), or can take up to three steps for up to three seconds at a time without dribbling.

If one builds a table T of all record numbers, using such a hash function, then similar records will end up in the same bucket, or in nearby buckets.

* Klal ufrat ukhlal, a generality, a particularity and a generality: If there is a particularity inserted between two generalities, we only add cases similar to the particularity.

* If creatures similar to plesiosaurs lived in the waters of the Loch Ness, they would be seen very frequently as they would have to surface several times a day to breathe.

If so, the equivocation would be similar to the Vedic sandhi representation of intervocalic retroflex-ḍ-as-ḷ -.

If the Mesolithic is more similar to the Paleolithic it is called the Epipaleolithic.

If a past storyline wherein a direct depictions of a then-current president or similar is referenced in a later era, it tends to become updated accordingly, sometimes with an " in-joke " acknowledgement.

" If filmed at the higher speed, Grieve concluded that the creature " walked with a gait pattern very similar in most respects to a man walking at high speed.

He asks why postmodernist intellectuals do not respond like people in other fields when asked, " what are the principles of their theories, on what evidence are they based, what do they explain that wasn't already obvious, etc ?... If requests can't be met, then I'd suggest recourse to Hume's advice in similar circumstances: to the flames.

If I have seen that from an ethical point of view I am just one person among the many in my society, and my interests are no more important, from the point of view of the whole, than the similar interests of others within my society, I am ready to see that, from a still larger point of view, my society is just one among other societies, and the interests of members of my society are no more important, from that larger perspective, than the similar interests of members of other societies ...