Thanks for the graphs!  I've always wondered what shadows would look like in multiple star systems- especially with different colored stars!

I've always wondered what shadows would look like in multiple star systems- especially with different colored stars!

Space Engine is a good way to experience it.

Thanks Wat!  I would love to see that but I have a hard time seeing shadows with Space Engine.  Maybe it's a setting I need to fix?  Can you show an example of where I could see what shadows look like on a planet that orbits a multiple star system with different colored stars?  I really appreciate it!

Thanks Abner, I just saw the example you posted!  Is that what you meant, Wat?  I was looking to see something on the surface of a planet, for example, multiple shadows cast by a mountain on a plain it overlooks?  Something like that!

I'm not Watsisname (by a long shot!), but I'll try and answer anyway...

Unfortunately, SE does not do terrain or ship shadows yet. But planets, moons, and asteroids do cast shadows (although even potato-shaped asteroids and dwarf moons cast round shadows, no matter the shape of the object). So the best you can do right now is eclipse shadows of a moon on a planet. (I'm sure I have some sample screenshots of such an event somewhere, I'll poke around and see if I can find one or two for you.)

In my pic above, that is a dwarf moon casting a shadow on a rather large ship. Two shadows, actually, as there were two suns here. Also of note is not only are they different colours, but one shadow is rather sharp and the other somewhat fuzzy. I believe the one casting the sharp shadow was a white dwarf.

Edit: Oh! And rings! Rings also cast shadows.

I recall seeing some amazing screenshots posted over the years of lighting in multiple-star systems with multiple colors.  I don't have any offhand, but they shouldn't be hard to find, or to discover yourself in SE.  Just like Mr. Abner said, good ways to see it are with eclipse shadows and ring shadows.

Thanks, this is something I've always wanted to see!  I shall go shadowhunting

It happened again. Binary neutron star merger detected at LIGO. INTEGRAL detected a gamma ray burst and now it looks like they've identified the optical counterpart, some supernova somewhere. Somehow these are related. They note that it has an unusual spectrum.

GCN CIRCULAR

Gravitational wave detection

Excellent!  With more events like these, we might independently measure the value of the Hubble constant with better precision, and possibly resolve this old discrepancy.

measure the value of the Hubble constant with better precision

I read in the tabloid press today that scientists were "shocked" to discover that the universe is expanding faster than thought making the universe significantly younger than previously believed, younger than 13 billion years.  But I couldn't find the paper this supposedly is based on.  Does anyone know where this comes from?

But I couldn't find the paper this supposedly is based on.  Does anyone know where this comes from?

Should we be at all surprised that tabloids misinterpret, exaggerate and prematurely publish scientific theories?

But I couldn't find the paper this supposedly is based on.  Does anyone know where this comes from?

Probably this:  Cosmological constraints from the Hubble diagram of quasars at high redshifts.

PBS Space Time has a good summary of it, and in the cosmology thread I also give some further insight for what it could mean (such as how a higher expansion rate can be fit by changing the universe's age and/or its mass-energy contents), and why it isn't as big of a shock as the tabloids like to present it as since these sorts of discrepancies between methods and data sets have a long history.

[youtube]tAtVgHvt05M[/youtube]

Should we be at all surprised that tabloids misinterpret

No, but even if they do, it can still be interesting to track down the source and read what it says.  One step closer to the source is this AP story.  And further digging led me to this article.

And further digging led me to this article.

This paper is relevant too.  What the authors (including Adam Riess, who is a big name in this field!) are checking is whether some effects of local structure in the universe could be causing our estimates of the uncertainties in the measurements in the Hubble constant to be too small, in which case we may have values that seem to contradict each other, but are actually consistent within error.  

They found that these effects don't seem to provide enough room for the error bars to be large enough to overlap, so we are still stuck with this discrepancy.  We don't know why.

But I couldn't find the paper this supposedly is based on.  Does anyone know where this comes from?

I found this article: https://www.space.com/universe-expandin ... ysics.html
There is a link to an article on 'arXiv.org': https://arxiv.org/pdf/1903.07603.pdf
But I do not know if that's what you're looking for.
[hr]
(Another article is here: https://www.nationalgeographic.com/scie ... ectations/)

But I couldn't find the paper this supposedly is based on.  Does anyone know where this comes from?

Should we be at all surprised that tabloids misinterpret, exaggerate and prematurely publish scientific theories?

They love the "hits" they get and meanwhile they let the real stories slide.  Right now we have a superbug infestation going on in our local hospitals (Candida Albans) that's resistant to all antibiotics and the state is worried people will find out what hospitals have it so they refuse to reveal the info and the media isn't even covering it outside of one station (WABC).

Right now we have a superbug infestation going on in our local hospitals (Candida Albans) that's resistant to all antibiotics and the state is worried people will find out what hospitals have it so they refuse to reveal the info and the media isn't even covering it outside of one station (WABC).

Yes, it is a bit worrisome that there is nary but a mention of this global problem in the news, besides a few online blogs writing about it. I see this as a failure of the journalistic industry. They focus on new outbreaks of, admittedly still dangerous, Ebola half a world away in the Congo, and yet the lethal threat of superbugs invading our hospitals and food is being blithely ignored.

I guess honesty is an overrated trope in the media.