So about 10 million stars in a volume of radius 75 light years means a sphere about 2 million cubic light years and that would seem to be about 5 stars per cubic light year so on average stars would be about 1/5th light year apart. Does that sound reasonable? Can you imagine what the night sky would look like if there happened to be a planet like Earth somewhere inside? That would put about 20 stars in a sphere the size of the distance between the sun and Alpha Centauri. Anyone care to fact check my calculation? Volume of a sphere, 4/3 pi R^3.
@sonhouse saidComing soon to a VR headset near you.
Can you imagine what the night sky would look like if there happened to be a planet like Earth somewhere inside?
I don't expect planetary orbits would be very stable around any star in such a cluster. Even 0.2 ly is a huge distance, but over millions of years much closer encounters I imagine would be not infrequent, and would likely perturb orbits significantly. This would pose special challenges to any life trying to make a go of it.
It is thought that passing stars have in the past perturbed objects in the Oort cloud around old Sol, sending killer comets hurtling into the inner solar system.
@Soothfast
Yep, that must be a chaotic place for planets. I calculated roughly 1/5 th of a LY apart on average, some ten times closer than Alpha Centauri but not just 2 stars 1/5th of a LY, but dozens, not sure exactly how many though.
Do you think you could figure the average night time luminosity level of thousands of such stars so close together?
BTW I think you said where in Pa you live, I live in the Pocono's north of Allentown but I forget where you are.
@sonhouse
I'm in Montgomery County, PA. I've been to the Poconos a few times, but not for many years now.
So I see the stars in the Omega Centauri cluster are 10 to 12 billions years old, so probably pretty metal poor, and I guess mostly K-type or M-type. So not very bright, either. It would be a stunning night sky, were one in the middle of such a cluster, but the combined light of 1000 such stars all between 1/5 to, say, 5 light years away probably wouldn't add up to the brightness of a full moon on Earth.
Heh -- maybe! It couldn't be too bright, anyway. Two full moons? Gotta figure out the average absolute magnitude of the stars in the cluster, and then figure out the apparent magnitude of hundreds of such stars at varying distances. Could be done, but I got other fish to fry.
@Soothfast
I would be a great painting if it could be done! What are the other fish on the barbie?
So Montgomery county, like Norristown or so?
My wife and I play folk music, have a good amount of new tunes on SoundCloud now, up t0 410 tracks there now. If you are interested I could PM the URL.
I did a paper on gravitational lensing I showed to my son in law, a physicist born in India now living with my daughter in Brazil, she is working on her Phd in music, Gandhi has one in statistical physics. I made some interesting findings about gravitational lensing as it applies to stars and the focusing involved.
That was a long journey for sure, and I have an idea for a book about what I found.
@sonhouse
I'm not much into folk music. What I listen to is kind of all over the place. Sometimes classical, other times techno, sometimes opera, other times EDM or dubstep, then it'll be goa trance, and the next day it'll be some group that is a fusion of J-pop and hip-hop. I used to be purely into metal (anything from power metal to death metal) and industrial, but far less so now.
However, my wife is hugely into folk music, all the way from the 1960s to today. She might dig your stuff. It is her "main thing."
As for what I'm busy doing, that is a bit complicated at the moment. Technically today is my last day at a college teaching job that I've had for 22 years. It was a great job at the start, but during the last few years it has gotten more and more miserable and soul-sucking.
But during all that teaching I accumulated vast quantities of notes, and worked on various manuscripts, to the point that I may as well finish and try to publish a textbook on differential equations, and others on discrete mathematics, linear algebra, and perhaps even complex analysis ("complex" here referring to the complex number system). I'm considering getting a degree in philosophy, with an emphasis on analytic philosophy which, together with my PhD in mathematics, would open up possibilities for doing interesting cross-disciplinary research.
But I'm not in a hurry at the moment. I've been running ragged for a long time, so right now I'm going to go with the flow and see where fortune takes me.