Nyrath

Re: OK this is just too cool: XKCD does a visual representation of Gravity Wells

A slightly more useful whimsical map is the Delta-Vee Tree

http://clowder.net/hop/railroad/deltaveemap.html

Re: OK this is just too cool: XKCD does a visual representation of Gravity Wells

Would be nice to see just how deep the sun is. Very very deep does get the idea across though. Although with that graphic and wikipedia I guess the keen reader could probably work it out.

Well, it is pretty easy if you are a rocket geek like me. The equation is on the diagram.

For the large version of the map, my calculations indicate that the sun's gravity well would be about 62,710 pixels deep, and the sun at the bottom would have a diameter of 4350 pixels.

I can show my work if anybody is interested, otherwise I won't bore you.

Re: Ring around a Moon

Cool! That does have interesting possibilities.

Re: Instantaneous Communications plus Time Dilation Equals ???

The light appearing to do something different' date=' I can accept. The light [i']actually, physically[/i] doing all three and more? No, that's just goofy.

Ummmm, not to put too fine a point on it, there are plenty of things in physics that appear to be just goofy to the layman, but that's just because they are outside of common experience. The technical term for this is Naïve physics. In that link, note that at the end of the examples there is a note about the hard death of absolute simultaneity, which is at the heart of your question.

See that chair? Looks solid, doesn't it? You can sit on it and everything. But on the subatomic level, the chair is 99.999% empty space. Isn't that just goofy?

Here is a sledge hammer. Here on Earth, it weighs sixteen pounds. And it takes sixteen pounds of force to swing it. On the Moon, it weighs only about 3 pounds. But it still takes sixteen pounds of force to swing it. Isn't that just goofy?

Here is a huge bolder and a tiny pebble. The bolder should drop faster than the pebble, since it is heavier. But that clown Galileo proved that both fall at the same rate. Isn't that just goofy?

The sun rises in the morning, moves overhead, then sinks at sunset. Obviously it moves around the flat earth. But no, the earth moves around the sun. Isn't that just goofy?

But I repeat: FIND A PHYSICS PROFESSOR AND HAVE THEM GO OVER IT WITH YOU. They are trained in education, chances are the good folks on this forum are not.

Re: Instantaneous Communications plus Time Dilation Equals ???

So if an electron is neither a wave nor a particle' date=' and that "avoids your question", you're saying that the light neither hits at the same time nor at different times?[/quote']

Yes.

In the same sense, you are neither a male nor a female, you are a Kristopher.

Re: Instantaneous Communications plus Time Dilation Equals ???

It's not a wave' date=' and it's not a particle. It's an electron.[/quote']

 

OK, in that case, the light does not physically hit the end of the train car at the same time, and the light does physically hit the end of the train car at the same time. If you avoid my "pick one", then I have to avoid your "pick one."

 

The basic problem is: under the relativity of simultaneity, there is no such thing as "the same time." It does not exist, not in an absolute sense. So your question is unanswerable.

 

Like I said: find a professor of physics and ask them.

Re: Instantaneous Communications plus Time Dilation Equals ???

An electron is an electron' date=' as a photon is a photon.[/quote']

 

Ah, ah, ah, play fair please. That is not the question I asked.

Re: Instantaneous Communications plus Time Dilation Equals ???

Does the light' date=' itself, physically hit the ends of the train car at the same time, or not? Pick one.[/quote']

Is an electron a particle or a wave? Pick one.

 

Look, you are not going achieve understanding about the relativity of simultaneity on an RPG forum. If you are serious about figuring this out, you should go audit a college course on relatvity, or find a physics professor who is willing to sit down with you and go over things.

Re: Escape From Terra

Although, be warned that the webcomic's author has an agenda.

Re: Instantaneous Communications plus Time Dilation Equals ???

The Doppler effect is an actual change in the frequency of the sound or other wave.

Ummmm, I'm confused. The person on the train hears one frequency, the person on the platform hears a different frequency. So what frequency is it? How can it be two different frequencies simultaneously?

Re: If you Had to Pick, ONE (already) Setting, to Run in, What is it?

correction blease i have space ghost and dino boy the complete series and the line spokenby space ghost is 'so matallus has also discovered the secret of invisibility' also ther series was made before the phrases "teleportaion and "stealth technology were coined

I stand corrected.

But you see the point I'm trying to get across. Style is everything with space opera.

Re: If you Had to Pick, ONE (already) Setting, to Run in, What is it?

I am really liking the Alex Toth setting myself' date=' really tempting to write that up, heh.[/quote']

But it has to be written in the proper voice. Transor did not say to Space Ghost that he had a transporter. He said "I possess the Secret of Matter Transmission!" Similarly Metallus did not say that he had stealth technology. He said "I too possess the Power of Invisibility!"

 

If you are serious about an Alex Toth setting, you might find useful the Space Ghost faq

http://webpages.charter.net/superheroes/space_ghost.htm

Re: Instantaneous Communications plus Time Dilation Equals ???

But I think I'm just going to drop it. That there can be two different realities of the same event is just too impossible to take seriously.

Well, not to put too fine a point on it, but engineers who design high tech equipment have to take it seriously.

If you do not take into account Einstein's relativity, things like GPS devices will not work. They have to make corrections for relativistic effects.

From a practical standpoint, it does not matter if it seems to be impossible, it is just the way the universe works.

If you want a dark, gritty storyline for your Star Hero campaign, try reading this

http://www.viruscomix.com/page505.html

It is a long read, but it is quite worth it. That one blasted cartoon could be turned into an entire SF novel.

Re: If you Had to Pick, ONE (already) Setting, to Run in, What is it?

Space Angel would also be a great Toth suggestion. Certainly a lot of Classic room there. To bad the Evil Utube disabled the Embedding.

That particular one had embedding disabled by the uploader. But you can click through to Youtube to see it.

Re: What's in YOUR future history?

The trouble is when religion in one's campaign leads to irrational, counterproductive, violent behavior on the part of the players!

Re: Instantaneous Communications plus Time Dilation Equals ???

It's in a different frame of reference. Correct me if I'm wrong' date=' Nyrath, but it's essentially an extreme case of how relativity redefines simultaneity.

Yes, that's it.

Re: An interesting article on the Physics of Space Combat

There is a list of interesting Rocketpunk Manifesto entries on space combat here:

http://www.projectrho.com/rocket/rocket3t.html#introduction

Re: If you Had to Pick, ONE (already) Setting, to Run in, What is it?

Alex Toth for the win!

I grew up with Space Ghost, and Alex Toth is one of my heroes.

But I cut my teeth on an even earlier Alex Toth cartoon: Space Angel!

http://www.youtube.com/watch?v=mnkVbp9Ic4I

Re: An interesting article on the Physics of Space Combat

The main thing my experts were complaining about was the natural desire to think that high maneuverability matters, talk about 'dogfighting' and 'fighters', thinking that attacks naturally come from all directions, etc.

Re: Instantaneous Communications plus Time Dilation Equals ???

Right. So why does that matter? It's not as if it's 99 years earlier outside "Unit B" -- after the ship gets back' date=' A and B are right there at Earth, at +100 years.[/quote']

 

No, it does not work like that.

Consider that the crew on the starship carrying unit B are only one year older from their age when the ship departed Earth, while their twin brothers who stayed on Earth are 100 years older.

 

When the crew set foot on Earth at the end of their journey, they do NOT suddenly catch up the missing time and age 99 years in an instant.

 

Neither does the wormhole mouth.

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

More here

http://www.centauri-dreams.org/?p=10624

http://www.technologyreview.com/blog/arxiv/24499/

I'll believe it when I see it

http://sciencenews.org/view/generic/id/50418/title/Chink_found_in_armor_of_perfect_cloak

Tiny charged particles could reveal the location of a perfect invisibility cloak. Such a cloak — which exists only in theory at the moment — would render an object invisible by gently deflecting photons around it. But charged particles wouldn’t be fooled: they would interact with the cloak in a telltale way, giving up the cloak’s location, researchers report in a paper to appear in an upcoming Physical Review Letters.

Invisibility by using metamaterials has not been invented yet, but already they are working on counter-measures.

Re: Instantaneous Communications plus Time Dilation Equals ???

It's understood that communications using quantum entanglement defies current theory. But this is one of those cases in which I made a conscious decision to insert a bit of 'handwavium' into the campaign' date=' because it has so much potential as a plot device.[/quote']

 

That's OK. I'm just trying to set the record straight before more impressionable people jump to the incorrect conclusion that is how things operate in the real world.

 

Quantum entangled communicators are extremely rare in this campaign -- some star systems can't afford any' date=' most systems have one, and a very few have multiple units. They aren't gadgets for the PC's to buy at the Rigel Kent branch of Sharper Image; they're [i']strategic assets[/i], only used for government, military, intelligence, and sometimes high-level academic data transfers.

 

The result is a distinctly two-tiered interstellar communications network. The 'Powers That Be' have access to instantaneous communications, while everyone else has to use courier vessels which take up to a month to reach the next system. These so-called fast courier ships are often derisively referred to as the "phony express."

 

There is a similar situation in Glen Cook's STARFISHERS trilogy. The starfishers have plentiful FTL communicators, while the Confederacy only has a precious few. The starfishers has a smaller space navy, but the FTL coms multiply their effectiveness.

 

The local color is colorful. There are creatures called star whales whose bodies are composed of magnetic fields, ionized hydrogen, and nuclear fusion. They are also quite intelligent. Unfortunately they are vulnerable to star sharks.

 

The starfishers use their combat starships to defend star whales from star sharks. In exchange, the star whales give the starfishers "ambergris nodes", which are the sine qua non of FTL coms. So the starfishers have a virtual monopoly on FTL com.