Gravitational Lensing - It's Not Just for Black Holes Any More

[Sapyx]

I'm not sure if it's ever formally been noted before...

We've all been up close and personal to a black hole in ED, and seen the gravitational lensing effect. Most of us have probably even been close enough to a black hole to be "inside" the lensing area, so your view of everything else in the skybox is distorted.

But this lensing effect is not restricted to black holes. It's most visible in black holes because with a black hole, there's nothing else really happening - in ED, a black hole is literally nothing but a great big gravity lens, that gets slightly warm if you get too close. But lensing can also be seen in other high-gravity situations.

Next most-visible after black holes are neutron stars. Next time you fly up to a neutron star, preferably somewhere near the core so there's lots of background stars in the skybox, aim your ship to fly past the neutron star. You'll see the background stars close to the neutron star jump and flip, just like they do around a black hole.

All of which makes me wonder if they've programmed in gravitational lensing of the skybox for all massive objects in the game. They first proved Einstein's theory of gravity by observing and measuring the gravitational lensing caused by the Sun during a solar eclipse; I wonder if you can do the same using core stars in ED.

Now, if only they could get around to implementing gravitational lensing for non-skybox objects, such as planets or companion stars... or your wingmate's spaceship.

 

[Galactic Fork]

Neutron Stars have had a lensing effect for a while now.

 

[[VR] optimal_909]

Indeed, NS lensing has been there for a while now. As for stars, those are way too large for visible gravitational lensing.

 

[Edelgard von Rhein]

I think white dwarfs also show gravitational lensing, albeit much weaker than neutron stars, though with the updated graphics for them it might not be possible to notice it any more. I'm fairly sure the lensing has been in since launch, although I didn't visit a black hole until 1.1. I suspect the lensing is not done for anything other than black holes, neutron stars and white dwarfs, however, as it would be extra computation for essentially a negligible effect. It would be great to see in-system bodies affected by the lensing but I suspect it is a low priority. The recent updates to the HUD icon for black holes does suggest that they have something in mind for the future, though.

 

[marx]

All of which makes me wonder if they've programmed in gravitational lensing of the skybox for all massive objects in the game. They first proved Einstein's theory of gravity by observing and measuring the gravitational lensing caused by the Sun during a solar eclipse; I wonder if you can do the same using core stars in ED.

In theory, you could, but you would require two things:
1. Being able to measure positions with much more precision than what an observer can achieve by just eyeballing it
2. Knowing the "regular" position(s) of the star(s) when the star isn't lensing their light
I'm not sure how much any of these two would be feasible in ED. I think it could be done, but it would be very difficult for dubious pay-off: you'd have to put in quite a lot of effort with two people just to confirm whether the game engine does gravitational lensing for all kinds of stellar objects, or if it only does so for "special" stars, where the lensing effect is visible to the naked eye.

The first validation of a testable prediction of Einstein's theory of relativity came from measuring the Hyades cluster at a given time during a solar eclipse by two teams: one was in Africa, the other was in Brazil. The theory of relativity predicted the differences between the two would be more than when the same observations were conducted during nighttime (when the Sun is nowhere near those stars), and even more importantly, the actual measured differences were predicted quite precisely.
You see, it was realised early in the 19th century (by Soldner) that even Newton's laws would predict that light would be bent around a very massive object, and even Einstein calculated this from only the equivalence principle.* However, when he calculated the difference from general relativity, he realised that it gave a different result, half of what Soldner predicted. When the measurement was completed, it turned out that Einstein's new result was the correct one, so the theory of general relativity gave a better prediction of gravitational lensing than classical Newtonian mechanics.

Oh, and I think I can confirm that white dwarfs did do some lensing in ED before, although I don't have a recording. You could see it when you jumped in- or out of the system at fortunate angles to the background, and massive enough dwarfs. I have no idea how well they could be seen with the jets now though.



*: Mind you, for this you have to postulate that light is corpuscular: made up of particles. Newton believed this, but Huygens and others proved later that most often it behaves like a wave instead. It wasn't until Einstein explained the results of another experiment, the photo-electric effect, by postulating that light is made up of photons, and he got his only Nobel prize for his research on this. But it was confusing at the time: so is light a wave or a particle? Neither explanation was sufficient, as you could always find experiments which proved one or the other. It wasn't until de Broglie formulated a hypothesis later (in 1924) that there are no such things as "pure particles" nor "pure waves", and matter waves exist: matter can show wave-like behaviour. (For example, a beam made up of electrons can be diffracted like light waves can; something that you know is made up of discrete particles can exhibit behaviour that continuous waves do.) This was confirmed by experiment a couple of years later, and the principle turned out to be central to quantum mechanics.

 

[CMDR AKIRA MASAKARI]

I think white dwarfs also show gravitational lensing, albeit much weaker than neutron stars, though with the updated graphics for them it might not be possible to notice it any more. I'm fairly sure the lensing has been in since launch, although I didn't visit a black hole until 1.1. I suspect the lensing is not done for anything other than black holes, neutron stars and white dwarfs, however, as it would be extra computation for essentially a negligible effect. It would be great to see in-system bodies affected by the lensing but I suspect it is a low priority. The recent updates to the HUD icon for black holes does suggest that they have something in mind for the future, though.

Yup, the 3 object that created visible lensing at launch where Black Holes, Pulsars and White Dwarves. Now with the emission cones is more difficult to notice the effect in the latter 2.

Probably the ingame lensing is a special effect attached to this star types, but if the gravity rapresentation would be completly accurate and could affect "light" from the skybox, every star and maybe planet could cause a lensing, but not detectable on the nacked eye, especially for a single observer POV.

But that would be a lot of work for an invisible detail indeed.

 

[newman1702]

I think white dwarfs also show gravitational lensing, albeit much weaker than neutron stars...

They do. It's been in the game for a long time now.

 

[Kolato]

Sorry to burst your bubble but i remember seeing neutron star lensing back in gamma (November 2014)

 

[Olivia Vespera]

Regular main sequence stars have slight gravitational lensing. But you have to be in the core where there are loads of stars to notice it.

 

[JesusRocks1988]

I'm pretty sure I've spotted lensing around main sequence stars most prominently while dropping out of hyperspace. It's very very slight.

And yes, gravitational lensing has been a feature around white dwarfs and neutron stars for a very long time.

 

[Sapporo]

And yes, gravitational lensing has been a feature around white dwarfs and neutron stars for a very long time.

This. Been around for a while.

 

[Kabu]

I always woundered how accurately are Black Holes visually represented ingame

 

[JesusRocks1988]

I always woundered how accurately are Black Holes visually represented ingame

Probably fairly accurately, as long as you're talking about black holes that are not accreting, and only in terms of when viewed from a distance by their interaction with the background.

A number of issues remain for black holes:
- They have no visual effect when passing in front of other in-system objects
- Black holes close enough to their stars to be accreting, aren't.
- Black holes close enough to each other surely should have some crazy extra effect? I don't know, but they seem too sterile.
- As you get closer to them, they seem to get smaller in their gravitational effects... Is that correct? I'd suspect not.
- Obvious one: they have an exclusion zone that you bounce off of. Granted this exclusion zone is pretty close to what the black hole's swartzchild radius would be for its mass, but still... Can't enter the event horizon and die... Poor show.
- Jets. Accreting black holes need jets.

Anyone else care to come in with more?