With Newtons law of gravity, there is a big, but seemingly solved problem that’s been known for a long time: things must not touch. Potential energy is calculated by dividing a term by the distance of two objects. You can’t devide by zero, so if the distance goes to zero, energy goes to infinity, which doesn’t make sense. The solution is to prevent the centers of mass of things from touching. This isn’t a problem, because in real life, masses aren’t points, but solid objects and the centers of mass are in the middle, so they can’t touch, because the outer parts collide first. And in simulations you can just make a rule that says no touching.
This kind of gap in a formula, where it stops being defined, is called a singularity in math. And to deal with them, you just have to know, when to expect them. For hundreds of years, people thought, collisions were the only singularities in Newtonian gravity. Easy to avoid, so not a problem. Now in this paper, they prove, that there are other, non-collission singularities and give an explicit example.
The arrangement in the picture has the middle mass going back and forth between the two binaries faster and faster and it reaches infinite speed in finite time. It basically leaves the universe, like a glitch in a video game. Also the reverse is allowed too: you just need the four masses from the two binary systems and there is nothing in Newtonian gravity that says a fifth mass can’t randomly appear from out of nowhere with infinite speed, slow down and settle between the too binaries.
Since only five masses were necessary to create this problematic constellation, it’s likely that there are many more possible.
Luckily, we have Einsteins theory of gravity now, so don’t have to worry about Newton too much. However, this does have its own, completely different kind of singularity, where the curvature of spacetime goes to infinity. People initially thought, that would be a problematic, unphysical behavior, like Newtons singularities, but it turns out that’s just a real thing that happens: black holes. Here the annoying singularities are mercifully shrouded in an event horizon, so at least we don’t have to look at them. Unless… But there is a solution for that too.
Given there are known polar planetary discs, and this orbit seems stable, wouldn't that suggest that polar systems are formed because of some past interaction between the two stars that disrupted them from the original plane of formation?
Possibly. I didn't dive in deeper to see if they even know the shape of the orbit. From my understanding a capture is very unlikely to have a near circular orbit. But planetary discs definitely aren't captures, so something changed the stars in those.
I think that !space is the most general community, and communities like “!astronomy” and “!spaceflight” are subsets.
Interesting data from a telescope? Astronomy and space, but not spaceflight.
A new GPS satellite is launched? Spaceflight and space, but not astronomy.
The Perseverance rover drills into a neat rock on Mars? Space, but not really astronomy or spaceflight.
A new space telescope is launched? Definitely all three.
These are just my thoughts though, and I’d love to hear what others think.
@Bee, @otter, @Bitswap Thoughts on changing the display name of !space from “Space & Astronomy” to just “Space”? Not that astronomy posts wouldn’t be welcome, but it could help reduce confusion with this community.
What I like about this image is that this is probably the biggest object that I can compare to something I know, that I can “comprehend”. With 6 km wide, it is about the same size as Grenoble, a city I have seen from above while hiking. I can understand how far the picture looks from it, how small a human would be on it
Neat to see a 6-7 solar mass black hole spotted. First one without a companion star to give it away! As we get better at finding black holes of this size, will be interesting to see if they end up explaining part of the “dark matter” problem.
In the best case, the detection is at the 2.4 sigma confidence level (less than the usual 3 for reasonable confidence and will below the 5 required for strong confidence), and if previously suspected issues with the instrument are true, the detection could disappear completely.
I do not have a strong confidence in this result. (But at least they didn’t publish it in Nature, in which case you would absolutely know it’s wrong…)
NASAs “habitat words observatory” was ment to be the next major telescope after the Roman space telescope, and was meant to have its primary function be the search for extraterrestrial life which would help tremendously with these kinds of situations.
Was being the key word as apparently the shitbag GOP administration decided they want to axe ALL future telescope programs including the Hubble replacement Nany Roman… Scumbags.
Their only interest in space is glory and imperialism. They don’t give a shit about the science they just want to claim Mars as US territory. And as someone that has been a huge space nerd ever since I was a kid I am absolutely livid at the defunding of NASA.
“For Services provided on Mars, or in transit to Mars via Starship or other colonization spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities. Accordingly, Disputes will be settled through self-governing principles, established in good faith, at the time of Martian settlement.”
From the SpaceX TOS. Oligarchs want to rule as kings on Mars, not as Americans.
Even the commercialisation of space flight bothers me. I mean, I know its inevitable but when the point of crewed space flight currently is still overwhelmingly for science, there’s just something gross about for-profit companies making a mint off human endeavour. But I also grew up in the 80s when science and the future seemed bright and exciting and not a capitalist dystopia.
This is just super fucking cool. It’s so rad they can pick out chemical signatures from the light passing through a planet’s atmosphere from a star 120 light years away. Absolutely gonzo bananas, the JWT is too cool. I will go on a personal mission to punch Donald Trump in the taint if they actually do cut the Roman telescope.
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