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Message: <blockquote data-quote="bolen" data-source="post: 483058" data-attributes="member: 1442">This is what I work on so I will try to explain some things1) Gravitational waves do travel at c.  If you believe in Einstein's theory nothing can travel faster then that.  Note: you might be saying, "well they said that about flying faster then sound, now planes fly at Mach 2 and 3. So these physicists are just underestimating technology."  Well no, it turns out that as you move faster and faster time is moving slower for you and you don't measure distances the same.Think about this you are on a train moving at 30 m/hr you thow a ball at 30 m/hr in the direction that you are moving.  Now I am on the ground I would say that the ball is moving at 30 + 30 = 60 m/hrNow instead of a ball you have a flashlight and lets change the train into a rocket which is traveling at half the speed of light.  How fast would that light be moving to me on the ground.  you might be tempted to say that it is moving at 1.5 c. WRONG!! It is still moving at c.  How can this be?  It is because our definitions of time and space are linked to what reference frame we are measuring in.  Both you and I say that the light is moving at c, what we do not agree on is the definition of length and time.This is called special relativity.2)  So what is a gravity wave.  well lets talk about electromagnetic waves first.  If I accelerate a charge (shake it up and down as in what happens in a radio tower), it emits a electromagnetic wave.  The same thing goes on with masses and gravity.  But remember gravity is about 10^40 times weaker then the electromagnetic force.  So in order to get a gravity wave to measure we need a very massive object (such as a black hole or a neutron star)3)  What will LIGO see?  well the esimates that I have heard (I am not on on that experiment, just in the field)  is that the advanced LIGO should be able to detect a GW of amplitude 10^-22 (that is a unitless number because it is just a ratio of stress/strain) That should enable us to see a BH-BH merger at the virgo cluster.  We should have a few events per year (again I am going by memory of a talk I heard a few months ago.  BH-BH mergers are not the only source however.  we are also looking for Neutron Star -BH and NS-NS. In addition we thing there should be a background of primordial GW left over from the Big Bang.  (good luck in seeing that however)  This would be analogous to the background 3K radiation that we see in the EM spectrum.4)  GW have been seen indirectly.  In the 1970's two physicists were observing a Binary pulsar system.  Thay saw that the system was loosing energy.  This loss of energy exactly agrees with what one would calculate from General Relativity for loss due to Gravitational radiation (gravity waves).  They won the Nobel prize in 1996 (I think that is the date) for this.5)  As far as gaming for a realistic sf game.  I cant imagine a place in our universe where GW would play a role, unless you are role-playing physicsists doing work on LIGO and I doubt anyone does that.6)  GW are hoped to provide a new window into astronomy and are useful just as radio telescopes are. (that is after we detect them, which I am fairly confident we are)  The money we are talking about here is on the order of a hundred million (not a lot for a huge science project, compare this to the SSC or LHC)Hope this helps clear stuff up</blockquote>

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