Backround
Gamma-ray bursts were discovered serendipitously in the late 1960s A.D. (ancient Solomani Gregorian calendar dating system) by U.S. military satellites which were on the look out for Soviet nuclear testing. These satellites carried gamma ray detectors since a nuclear explosion produces gamma rays. Up until the 1990s A.D., astronomers didn't even know if GRBs originated at the edge of their solar system, in our Milky Way Galaxy or incredibly far away near the edge of the observable Universe. But a slew of satellite observations, follow-up ground-based observations, and theoretical work allowed astronomers to link GRBs to distant galaxies. This initially caused a near panic in the physics community as the energy reaching the Earth from those distances, if it was assumed that the energy radiates in all directions, would mean that the total energy emitted from the fraction observed, using the inverse-square law, generates more energy - and in some cases hundreds of times more energy - than a typical supernova explosion, all in a matter of seconds! That would have meant that the formula, E=mc2, was incorrect. Believing that this was impossible (rightly so) it was hypothesized that the emanations weren't spherical but jet like.
Later, deep space probe observatories were launched to extend the base leg enough to prove this idea. The data gathered thus, showed that the GRB's were indeed spherical.
Eventually this lead to the discovery of what happened to the missing matter from the Big Bang. Immediately after the event, matter and anti-matter separated and caused our curved space to form. Matter (our universe) on one "side" and anti-matter on the other. The interplay between the two is what causes the space curvature. The GRB's were being caused by ruptures in space within the star and anti-matter leaking in and reacting with the stars mass. It was also discovered that the attraction of matter (planets, suns, masses) to the anti-matter is what causes gravity wells on our side and gravity as we experience it.
The deeper you go in a gravity well, the more stressed space becomes. It becomes "thinner" and the weave gets looser. This makes the attraction to the anti-matter stronger.
The 1st anti-grav technology (used by Air-rafts and the like) took advantage of this by using energy to tighten the "weave" on one side of the craft and loosen it on the other side. Thus, causing "gravity" to be lessened one one side and increased on the opposite side. This causes motion to occur. The push pull nature of this tech means that when the Grav drive power is cut, motion stops. Super fine control isn't possible and as you climb the gravity well
space is "thicker" and, this type of drive tech becomes useless as it cannot overcome the fabric of space. This occurs at ~1/1000 of a diameter on Earth. (12.7 kilometers or, 41,000') Planets with higher density will have a corospondingly larger distance where the drive is useful. The opposite is also true.
Gravity Space-Maneuver drives were developed later and use a much, much more energy that planet bound vehicle AG drives. The mechanism is also different. The spaceship based drive only need to work on only one point of space to produce movement. The drive directs energy in the direction of desired travel and weakens the fabric of space enough to allow attraction to the anti-matter on "the other side". This causes the whole ship to "fall" in that direction. For larger vessels the G level is limited to 6 as any higher and it causes tidal stresses at the far end of the ship, opposite the direction of travel. Spaceships can be rotated with this drive but, it isn't the fine control that you get with thrusters placed around a lower tech level reaction drive ship. Small craft using higher G ratings have a quicker rotation time.
Jump drives use enormous energy levels to surgically cut through the fabric of space. A shell of energy is formed and filled with very pure H2. This energy shell acts as a barrier between the ship and the anti-matter on the "other side" of our space. Otherwise, known as Jump space. The H2 is slowly used by the energy shell to react with the anti-matter "outside" creating a power source that propels the ship through this other space. More distance requires more mass to react with the anti-matter to create energy for the propulsion. Only pure H2 is able to be handled in a controlled fashion by the energy shell to react with the anti-matter.
If one imagines space as a rubber fabric, masses on our side create dents that show as protrusions on the other side. A ship using J-Drive does not go that "deep" into the other space. Masses of only ~1.5 kilometers in diameter are massive enough to create a protrusion out to 100 diameters that a ship runs into when on the other side of our space (J-space). This causes the ship to punch through back to normal space.
When a ship is closer to 100 diameters from a mass, space is stressed and the "weave" isn't regular. A Jump drive has a difficult time cutting a surgical hole under these conditions and can instead, cause an irregular tear that also effects the jump bubble. Sometimes in catostrophic ways...
Gamma-ray bursts were discovered serendipitously in the late 1960s A.D. (ancient Solomani Gregorian calendar dating system) by U.S. military satellites which were on the look out for Soviet nuclear testing. These satellites carried gamma ray detectors since a nuclear explosion produces gamma rays. Up until the 1990s A.D., astronomers didn't even know if GRBs originated at the edge of their solar system, in our Milky Way Galaxy or incredibly far away near the edge of the observable Universe. But a slew of satellite observations, follow-up ground-based observations, and theoretical work allowed astronomers to link GRBs to distant galaxies. This initially caused a near panic in the physics community as the energy reaching the Earth from those distances, if it was assumed that the energy radiates in all directions, would mean that the total energy emitted from the fraction observed, using the inverse-square law, generates more energy - and in some cases hundreds of times more energy - than a typical supernova explosion, all in a matter of seconds! That would have meant that the formula, E=mc2, was incorrect. Believing that this was impossible (rightly so) it was hypothesized that the emanations weren't spherical but jet like.

Later, deep space probe observatories were launched to extend the base leg enough to prove this idea. The data gathered thus, showed that the GRB's were indeed spherical.
Eventually this lead to the discovery of what happened to the missing matter from the Big Bang. Immediately after the event, matter and anti-matter separated and caused our curved space to form. Matter (our universe) on one "side" and anti-matter on the other. The interplay between the two is what causes the space curvature. The GRB's were being caused by ruptures in space within the star and anti-matter leaking in and reacting with the stars mass. It was also discovered that the attraction of matter (planets, suns, masses) to the anti-matter is what causes gravity wells on our side and gravity as we experience it.

The deeper you go in a gravity well, the more stressed space becomes. It becomes "thinner" and the weave gets looser. This makes the attraction to the anti-matter stronger.
The 1st anti-grav technology (used by Air-rafts and the like) took advantage of this by using energy to tighten the "weave" on one side of the craft and loosen it on the other side. Thus, causing "gravity" to be lessened one one side and increased on the opposite side. This causes motion to occur. The push pull nature of this tech means that when the Grav drive power is cut, motion stops. Super fine control isn't possible and as you climb the gravity well
space is "thicker" and, this type of drive tech becomes useless as it cannot overcome the fabric of space. This occurs at ~1/1000 of a diameter on Earth. (12.7 kilometers or, 41,000') Planets with higher density will have a corospondingly larger distance where the drive is useful. The opposite is also true.
Gravity Space-Maneuver drives were developed later and use a much, much more energy that planet bound vehicle AG drives. The mechanism is also different. The spaceship based drive only need to work on only one point of space to produce movement. The drive directs energy in the direction of desired travel and weakens the fabric of space enough to allow attraction to the anti-matter on "the other side". This causes the whole ship to "fall" in that direction. For larger vessels the G level is limited to 6 as any higher and it causes tidal stresses at the far end of the ship, opposite the direction of travel. Spaceships can be rotated with this drive but, it isn't the fine control that you get with thrusters placed around a lower tech level reaction drive ship. Small craft using higher G ratings have a quicker rotation time.
Jump drives use enormous energy levels to surgically cut through the fabric of space. A shell of energy is formed and filled with very pure H2. This energy shell acts as a barrier between the ship and the anti-matter on the "other side" of our space. Otherwise, known as Jump space. The H2 is slowly used by the energy shell to react with the anti-matter "outside" creating a power source that propels the ship through this other space. More distance requires more mass to react with the anti-matter to create energy for the propulsion. Only pure H2 is able to be handled in a controlled fashion by the energy shell to react with the anti-matter.
If one imagines space as a rubber fabric, masses on our side create dents that show as protrusions on the other side. A ship using J-Drive does not go that "deep" into the other space. Masses of only ~1.5 kilometers in diameter are massive enough to create a protrusion out to 100 diameters that a ship runs into when on the other side of our space (J-space). This causes the ship to punch through back to normal space.
When a ship is closer to 100 diameters from a mass, space is stressed and the "weave" isn't regular. A Jump drive has a difficult time cutting a surgical hole under these conditions and can instead, cause an irregular tear that also effects the jump bubble. Sometimes in catostrophic ways...