Jump Shadowing/Masking

[phavoc]

If you get a data file that you think is current, and it's actually 10yrs out of date, everything in it will be located 10yrs from where you are expecting it. Since planets move, that means it's 10yrs further along it's track than you are expecting it to be when you emerge from jump space. That was the point of the statement you seem to miss. No goal posts moved, just none paid attention to.

So you just fast forward the data by 10 years and you know where the planet is now. It's all very predictable. These things simply don't change on that timescale. Maybe if you end up somehow a few thousand years in the future there'd be some cumulative gravitational perturbations that might cause a planet to be a few kilometres away from where the ephemerides say it's supposed to be, but that's about the extent of it.

Again, not what I said. What I said was the data you get is actually 10yrs old, but that it's passed to you as current data. You plot your course with the expectation the planetary bodies positions based upon what you assume to be current data. Except that they are not. Thus their orbits are now 10yrs advanced from that position. IF your plot took you within the 100D jump shadow of a planet or gas giant then your ship would be pulled out of jump space early due to the 100D rule.

AFTER this has happened, and you get current data and match it to your "updated" charts, at THAT point you can determine the data was bad and then update them based upon the new data. BUT, until you arrive in the system, you simply don't know there was a problem or error. Your predictions were based on wrong data - the same sort of error that caused the destruction of the Mars probe - bad data that ultimately was only realized AFTER the probe had destroyed itself.

That's a spurious and specious argument. "Cat videos" and other irrelevant files would simply never be allowed to clog up the storage of computers that are essential for flight and operations, period.

How is it spurious and specious? It's a factually true statement that reflects actual human behavior. Have you SEEN just how many cat (and dog and animal and stupid human) videos are out there? And thousands more being uploaded by the hour.

I work in IT and I can tell you people DO clog their company laptops and stuff up with stupid personal things. And go out to porn sites while at work. All stupid human things that happen every day. The background of the 52nd century tells us they aren't any smarter than us today (they have more knowledge, but still have same wars, same everything else that we do - just on a far larger scale).

So yeah, 52nd century cat videos and other irrelevant crap would still be a thing. And why the hell not? With near infinite space people are gonna fill it up with useless crap just like they do today.

 

[phavoc]

Airplanes don't actually need every little detail. Actually they need relatively few details to plot a course. Now, landing and taking off are different, and if you have ever plotted a course then you'll know that when you get closer to landing is when you'll spend a lot of time plotting flight paths (and in some cases, taking off). But getting between A and B in a modern jetliner? You are flying above any ground-basesd object for the most part. So you just need to avoid restricted airspace and storms.

No, the justification for those iPads with the route information on them is so they have every possible detail they might need in case of an emergency landing; they need every conceivable piece of information they might need to land on some random strip of land they’ve never landed on before; that’s why their data is so intense. There is no comparison to spaceflight operations, which simply don’t have that sort of urgency combined with that sort of complex data.

Actually, that's not true. iPads were introduced as part of the digital flight program for a couple of reasons. The first was that pilots wanted to lug around much lighter flight bags. Secondly the airlines were looking to keep weight down during the days of expensive oil. Other than that the very large and heavy binder they had full of charts and such worked quite well, and still have all the necessary information for airports as needed.

To repeat, the pre-iPad charts had every possible detail needed in case of emergency landings. Digitization just made it lighter. If an airport had changes, it was easy enough to get a new page (for prints) and replace the old one. Again, digitization makes it cheaper and faster.

And again, pilots don't download every airport in the world to their iPad because there is no need to do so. That from the lips of a family friend who flies for American full-time and has for the last 20yrs. Where are you getting your information from?

 

[fusor]

Again, not what I said. What I said was the data you get is actually 10yrs old, but that it's passed to you as current data. You plot your course with the expectation the planetary bodies positions based upon what you assume to be current data. Except that they are not. Thus their orbits are now 10yrs advanced from that position. IF your plot took you within the 100D jump shadow of a planet or gas giant then your ship would be pulled out of jump space early due to the 100D rule.

The only parameter that would change is the Mean Anomaly, which describes exactly where the object is on its orbit. They'd have earlier data from the system that contains that and would be able to calculate where the position of the planets are now.
Ok, and the orbit might precess around the star a little too. Either way, that can be accounted for and calculated on the fly based on previous data.

But again, the chance of anything getting in the ship's way is miniscule anyway. I think the chance that any given system would be exactly aligned with the ecliptic plane of the departure system would be something like 0.0000171% (the axis of the system at 90 degrees to the ecliptic would be pointing in a specific direction in space (an imaginary line through the pole of the star), there are 360 degrees around the x axis, y axis, and z axis, there would be two possible lines (one rightway up, the other upside down), so I think that's (1/180 * 1/180 * 1/180)? If that's right then it's about a 1 in 5.8 million chance that the ecliptics line up - and there'd probably only be of the order of 10 systems in range of the departure system anyway.

So even if the data was wrong somehow, it wouldn't make any difference in practice. The ship appears, the system looks a bit different, the captain shrugs and carries on.

How is it spurious and specious? It's a factually true statement that reflects actual human behavior. Have you SEEN just how many cat (and dog and animal and stupid human) videos are out there? And thousands more being uploaded by the hour.

The flight systems of a spacecraft simply would not be full of that crap. Bloody hell, they don't put cat videos in the avionics and guidance systems of the space shuttle! And nobody would look at porn on the life support systems of the International Space Station. Sure, maybe the pilots' datapads would have lots of that, but that's not what we're talking about here. You're talking about a totally different and irrelevant thing.

And as far as divergence from the plot of the thead here, going on about cat videos when we're supposed to be talking about jump shadowing is taking the biscuit!

 

[Tenacious-Techhunter]

Again, not what I said. What I said was the data you get is actually 10yrs old, but that it's passed to you as current data. You plot your course with the expectation the planetary bodies positions based upon what you assume to be current data. Except that they are not. Thus their orbits are now 10yrs advanced from that position. IF your plot took you within the 100D jump shadow of a planet or gas giant then your ship would be pulled out of jump space early due to the 100D rule.

That is not what you said at all; but let’s look at that on face value...

In order for you to get mis-marked system data, that data would have had to have been deliberately hacked, since the astrometric sensor recordings would have logged it with the correct time and date, because otherwise that data would be completely useless. Is bad data going to put your ship in the wrong place? Yes. But that’s your fault for using Streetwise to acquire system data at cut-rate prices. But even that wouldn’t happen, because the fake 10-year-old update would have diverged so far from the previous version of the data that the computer would recognize the data as false. Even if you failed to notice that the data was 10 years old by human error, the Navigation software wouldn’t, and would project the Jump Precipitation location based on the previous, known-good version.

 

[Tenacious-Techhunter]

Actually, that's not true. iPads were introduced as part of the digital flight program for a couple of reasons. The first was that pilots wanted to lug around much lighter flight bags. Secondly the airlines were looking to keep weight down during the days of expensive oil. Other than that the very large and heavy binder they had full of charts and such worked quite well, and still have all the necessary information for airports as needed.

To repeat, the pre-iPad charts had every possible detail needed in case of emergency landings. Digitization just made it lighter. If an airport had changes, it was easy enough to get a new page (for prints) and replace the old one. Again, digitization makes it cheaper and faster.

And again, pilots don't download every airport in the world to their iPad because there is no need to do so. That from the lips of a family friend who flies for American full-time and has for the last 20yrs. Where are you getting your information from?

No one was arguing that the iPads had different data from the preexisting charts. You’re just trying to sound smart by pointing out a factoid everyone already knew. We were talking about the quantity of data, which hasn’t changed... except that the iPads can store more than a sea of binders.

 

[Jeff Hopper]

Guys? You do not have to concern yourself with gravitons as long as you view gravity as a measure of the curvature of space-time around a mass. You do not have to transmit anything as long as you take that into account.

I have to give credit where credit is due... you had me doubting myself for a minute there... Could I have simply have fallen behind in my understanding of Science, the same way Traveller itself has??? But... that thing you said...

All that graviton crap belongs in the same trash heap as tachyons and Shawn Driscoll's trolling.

Tell that to Neil Degrasse Tyson!

Gravitons are the predominant theory for transmission of gravitation from one body to another.

Stop infecting myself and others with your ignorance! Read a damn book!

You know, Neil Degrasse Tyson is not some kind of religious icon who is the source of all science, regardless of the weight you place upon his pronouncements.

You also should not be an antagonistic whelp on forums. Having a lot of people place you on ignore does not help your own credibility when you post. If you really care about getting your message across, instead of just being a nitpicking troll.

 

[Tenacious-Techhunter]

You know, Neil Degrasse Tyson is not some kind of religious icon who is the source of all science, regardless of the weight you place upon his pronouncements.

You also should not be an antagonistic whelp on forums. Having a lot of people place you on ignore does not help your own credibility when you post. If you really care about getting your message across, instead of just being a nitpicking troll.

Nor is he someone who you can easily dismiss as incorrect, as he is an expert in his field of astrophysics, which is the field of physics within which gravitons and other theories of gravitation are most easily studied.

Trying to dismiss gravitons as no longer scientific is the pinnacle of ignorance, because it is completely baseless. If you don’t have a basis for saying something negative about science, don’t.

All that graviton crap belongs in the same trash heap as tachyons and Shawn Driscoll's trolling.

How is that not antagonistic? You’re the one who started with the antagonism; I merely defended my point in kind.

 

[Sigtrygg]

What actual scientific evidence is there for gravitons, dark matter, dark energy, string theory?

None.

They are theories that attempt to use our limited current understanding to describe observations.

Science is in danger of becoming a religion based on faith in theories that can not be proven or have any physical evidence.

Ether, phlogiston, humours - do these ring any warning bells?

 

[Tenacious-Techhunter]

What actual scientific evidence is there for gravitons, dark matter, dark energy, string theory?

None.

They are theories that attempt to use our limited current understanding to describe observations.

Science is in danger of becoming a religion based on faith in theories that can not be proven or have any physical evidence.

Ether, phlogiston, humours - do these ring any warning bells?

Regardless, when trying to apply theories of gravity to Jump Physics, you have to start with existing theories. I’m not about to apologize for not coming up with a better theory of how gravity works than astrophysicists. Being able to successfully apply gravity based phenomenon that isn’t inextricably tied to the inverse-square law, and is instead tied to pure geometry, is enough of an accomplishment... for this forum, anyway.

 

[fusor]

What actual scientific evidence is there for gravitons, dark matter, dark energy, string theory?

None.

Actually, there's a hell of a lot of evidence for dark matter and dark energy - the former from the excess invisible mass that apparently surrounds galaxies that is detectable through its gravitational effects, and the later from the accelerating expansion of the universe.

I'll grant you that gravitons and string theory are on somewhat shakier ground though.

 

[Tenacious-Techhunter]

To an extent, if it’s the best ground we’ve got, it doesn’t matter how shaky it is. Eggs will be broken, but then we’ll have omelettes. In the meantime, there’s no harm in speculating about what happens if the first egg is broken perfectly.

 

[Jeff Hopper]

It is like the reincarnation of an inept Constantine Thomas.....

 

[Sigtrygg]

Actually, there's a hell of a lot of evidence for dark matter and dark energy - the former from the excess invisible mass that apparently surrounds galaxies that is detectable through its gravitational effects, and the later from the accelerating expansion of the universe.

I'll grant you that gravitons and string theory are on somewhat shakier ground though.

Now you are showing your ignorance of the scientific method.

There is no evidence, just a theory - "the excess invisible mass that apparently surrounds galaxies that is detectable through its gravitational effects" - is just a theory, there are others that can explain it but the elders in their towers have decreed that St Einstein must not be questioned and as a result dark energy and dark matter must be right, despite there being no proof, just a theory.

 

[fusor]

Actually, there's a hell of a lot of evidence for dark matter and dark energy - the former from the excess invisible mass that apparently surrounds galaxies that is detectable through its gravitational effects, and the later from the accelerating expansion of the universe.

There is no evidence, just a theory - "the excess invisible mass that apparently surrounds galaxies that is detectable through its gravitational effects" - is just a theory, there are others that can explain it but the elders in their towers have decreed that St Einstein must not be questioned and as a result dark energy and dark matter must be right, despite there being no proof, just a theory.

I guess everything here is just imaginary, right? https://en.wikipedia.org/wiki/Dark_matter#Observational_evidence

Sure, other possible explanations exist, but they don't explain things as well as Dark Matter and Dark Energy do (or just fail to explain some of the observations). But don't let actual evidence stop you from trying to frame science as a religion. Honestly, I can't think of any other profession that has such a lack of respect or appreciation from people online. There's always some smartass who thinks they know better that people who have spent their entire careers up to their eyeballs in the subject and in the data.

(Never mind that Dark Energy is actually something that Einstein deliberately *removed* from his original equations because he couldn't believe it existed, but was added back in once the evidence of the accelerating expansion of the universe was found - so much for your frivolous conspiracy theory that people don't want to question Einstein).