long range laser

Rakhmamort wrote:counter missile targeting is also tougher since we are speaking about relative speeds that can be over light speed...

No they can't. Speeds don't add to more than light speed.

Bill Woods wrote:

Rakhmamort wrote:counter missile targeting is also tougher since we are speaking about relative speeds that can be over light speed...

No they can't. Speeds don't add to more than light speed.

True. However it's worth noting that CMs have grav sensors. So they are tracking the incoming missiles based FTL data.

Bill Woods wrote:

Rakhmamort wrote:counter missile targeting is also tougher since we are speaking about relative speeds that can be over light speed...

No they can't. Speeds don't add to more than light speed.

yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

Rakhmamort wrote:counter missile targeting is also tougher since we are speaking about relative speeds that can be over light speed...

Bill Woods wrote:No they can't. Speeds don't add to more than light speed.

Rakhmamort wrote:yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

The point of relativity is that even if two missiles were heading straight for each other at 0.9c each neither missike would see a closure rate higher than c -- and the crazy part is they'd be correct.

So it's not s mater of hard coding a ~300,000 Km/s max value in their computers. The universe already guarantees that that closure rate won't be exceeded.

Rakhmamort wrote:yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

Yeah, a closing velocity of 0.92c does make things tricky for counter fire. Relativistic velocities don't simply add up, like Bill Woods said you can't get closing velocities above c. This isn't a case of substituting in 300000km/s if your readings would go over that number, its a case of the way the universe works not allowing it to happen in the first place.

The formula for working out closing velocities at relativistic speeds is s=(u+v)/(1+(uv/c^2)), where s is the closing velocity, u is the velocity of the first object, v is the velocity of the second object, and c is the speed of light in the unit system that you are using.

Rakhmamort wrote:

Rakhmamort wrote:counter missile targeting is also tougher since we are speaking about relative speeds that can be over light speed...

Bill Woods wrote:No they can't. Speeds don't add to more than light speed.

yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

I think you really need to read up on how special relativity works. 0.5c + 0.8c doesn't equal 1.3c, it's more like ~0.9286c.

Grashtel wrote:

Rakhmamort wrote:yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

Yeah, a closing velocity of 0.92c does make things tricky for counter fire. Relativistic velocities don't simply add up, like Bill Woods said you can't get closing velocities above c. This isn't a case of substituting in 300000km/s if your readings would go over that number, its a case of the way the universe works not allowing it to happen in the first place.

The formula for working out closing velocities at relativistic speeds is s=(u+v)/(1+(uv/c^2)), where s is the closing velocity, u is the velocity of the first object, v is the velocity of the second object, and c is the speed of light in the unit system that you are using.

You know ... I've been playing with the numbers, and it turns out Mr. Weber also doesn't get this right. For single-drive missiles, Newtonian physics is fine, but for 2DMs and 3DMs, it's noticeably off. As far as the plots go, this isn't a problem, since the missiles should have even greater range than stated, though they shouldn't go so fast.

E.g., in At All Costs

At 46,000 g, their missiles had accelerated to almost 162,400 kilometers per second and traveled 29,230,000 kilometers before they'd shut down. That left the MDMs' third stage available ...[to] add another 81,000 [km/s] over the space of three minutes.

Newton:

Code: Select all

             T            D               v     
          (s)(min)   (e9m)(lt-s)   (e6m/s) (/c)
            0   0      0      0      0    0     
          180   3      7.31  24     81.2  0.271
          360   6     29.2   98    162.4  0.542
          540   9     65.8  219    243.6  0.813
          720  12    117.   390    324.8  1.084


Einstein:

Code: Select all

   t          T             D            v     
(s)(min)   (s)(min)   (e9m)(lt-s)  (e6m/s) (/c)
  0  0      0   0.0     0      0       0  0     
180  3    182   3.0     7.35  25      79  0.264
360  6    378   6.3    30.0  100     148  0.494
540  9    601  10.0    69.5  232     201  0.671
720 12    869  14.5   129.   430     238  0.794 

t, d, v, a are measured by the moving observer (i.e. on board the missile).
T, D, v, A are measured by a 'stationary' observer (i.e. on board the target).
a is a constant, = 46k 'gee' = 46k * 9.807 m/s^2 = 451.12 km/s^2.

Bill Woods wrote:You know ... I've been playing with the numbers, and it turns out Mr. Weber also doesn't get this right. For single-drive missiles, Newtonian physics is fine, but for 2DMs and 3DMs, it's noticeably off. As far as the plots go, this isn't a problem, since the missiles should have even greater range than stated, though they shouldn't go so fast.

E.g., in At All Costs

At 46,000 g, their missiles had accelerated to almost 162,400 kilometers per second and traveled 29,230,000 kilometers before they'd shut down. That left the MDMs' third stage available ...[to] add another 81,000 [km/s] over the space of three minutes.

Newton:

Code: Select all

             T            D               v     
          (s)(min)   (e9m)(lt-s)   (e6m/s) (/c)
            0   0      0      0      0    0     
          180   3      7.31  24     81.2  0.271
          360   6     29.2   98    162.4  0.542
          540   9     65.8  219    243.6  0.813
          720  12    117.   390    324.8  1.084


Einstein:

Code: Select all

   t          T             D            v     
(s)(min)   (s)(min)   (e9m)(lt-s)  (e6m/s) (/c)
  0  0      0   0.0     0      0       0  0     
180  3    182   3.0     7.35  25      79  0.264
360  6    378   6.3    30.0  100     148  0.494
540  9    601  10.0    69.5  232     201  0.671
720 12    869  14.5   129.   430     238  0.794 

t, d, v, a are measured by the moving observer (i.e. on board the missile).
T, D, v, A are measured by a 'stationary' observer (i.e. on board the target).
a is a constant, = 46k 'gee' = 46k * 9.807 m/s^2 = 451.12 km/s^2.

The text above (my emphasis) is another example of Writers Cannot Do Math. See The Great Resizing as the biggest example of in the Honorverse.

I suspect he didn't even know there was an issue. Relativistic objects don't work like you would expect, and unless you know there is an issue you can't solve it.

The Honorverse isn't a physics or an economics textbook.

Rakhmamort wrote:yeah yeah yeah... put that into your targeting computers and your counter fire will suck when your fleet is travelling towards the enemy missiles at .5c and the incoming salvo is coming towards you at .8c .

we can go theoretical all your ships are gonna get f'd up if you tell your computers they should substitute 300000km/s everytime their readings go over that number... lol!

Grashtel wrote:Yeah, a closing velocity of 0.92c does make things tricky for counter fire. Relativistic velocities don't simply add up, like Bill Woods said you can't get closing velocities above c. This isn't a case of substituting in 300000km/s if your readings would go over that number, its a case of the way the universe works not allowing it to happen in the first place.

The formula for working out closing velocities at relativistic speeds is s=(u+v)/(1+(uv/c^2)), where s is the closing velocity, u is the velocity of the first object, v is the velocity of the second object, and c is the speed of light in the unit system that you are using.

Bill Woods wrote:You know ... I've been playing with the numbers, and it turns out Mr. Weber also doesn't get this right. For single-drive missiles, Newtonian physics is fine, but for 2DMs and 3DMs, it's noticeably off. As far as the plots go, this isn't a problem, since the missiles should have even greater range than stated, though they shouldn't go so fast.

E.g., in At All Costs

At 46,000 g, their missiles had accelerated to almost 162,400 kilometers per second and traveled 29,230,000 kilometers before they'd shut down. That left the MDMs' third stage available ...[to] add another 81,000 [km/s] over the space of three minutes.

Newton:

Code: Select all

             T            D               v     
          (s)(min)   (e9m)(lt-s)   (e6m/s) (/c)
            0   0      0      0      0    0     
          180   3      7.31  24     81.2  0.271
          360   6     29.2   98    162.4  0.542
          540   9     65.8  219    243.6  0.813
          720  12    117.   390    324.8  1.084


Einstein:

Code: Select all

   t          T             D            v     
(s)(min)   (s)(min)   (e9m)(lt-s)  (e6m/s) (/c)
  0  0      0   0.0     0      0       0  0     
180  3    182   3.0     7.35  25      79  0.264
360  6    378   6.3    30.0  100     148  0.494
540  9    601  10.0    69.5  232     201  0.671
720 12    869  14.5   129.   430     238  0.794 

t, d, v, a are measured by the moving observer (i.e. on board the missile).
T, D, v, A are measured by a 'stationary' observer (i.e. on board the target).
a is a constant, = 46k 'gee' = 46k * 9.807 m/s^2 = 451.12 km/s^2.

You aren't the first to note this irregularity. Acceleration under impeller drive appears to ignore relativistic effects on the acceleration math, whilst the time dilation effects still happen(at least, they do while under sails, per HotQ).

It is possible that the impeller drive, bending space as it does, is in effect, something like an alcubeirre drive or the Path of the Fury-verse Fasset drives at velocities approaching c, but there's not really any support for that other than ignoring relativistic effects on acceleration, and even if that bit of speculation is viable, there would be no way to test it - particle and radiation shielding wouldn't support those velocities, and you'd blow up your testing platform in short order.