Locally

we can build orderly patterns locally but that requires energy so the overal entropy of the universe increases

imho since more orderly complexity requires more energy in a way by making more order locally we contribute to the acceleration of disorder (entropy) in the long term, no that we make much of a dent with our current technological level, but maybe a future civilization capable of enginnering star systems moving stars and built wormholes may make a more noticiable dent in the energy budget🙂

Old technology is also often practical. James Webb was delayed because of all the new technology that had to be worked out and same often happens with advanced military hardware like the F35 or the Zumwalt class destroyers.

The intuition: gravity, spinning (rotation), and friction/drag are the dominant factors which shape the largest scale structures.

Absent rotation gravity wants to pull everything into a ball. If you had a planet that was a cube, the sharp edges would be pulled down to make it round.

If you spin that ball, rotation causes that ball to bulge along its equator. Spin it faster and like a pizza that ball flattens into a disk.

Simplified version of solar system formation:

• There is a large cloud of gas and dust. Gravity slowly pulls it into a rough ball. This ball of gas and dust has some tiny, tiny bit of net rotation, in theory it could have 0 net rotations but the odds of that happening in nature are infinitesimally small.
• Gravity wants to pull the ball into a smaller ball. Friction/drag from the gas and dust bumping into each other slows the particles down, radiating their kinetic energy away as heat.
• Conservation of moment comes into play as the ball collapses. Think of an ice skater doing a trick. When they pull their arms in, they start spinning faster, because the amount of angular momentum must stay the same. The same thing happens to the cloud, as it collapses the average distance of particles from the center goes down ⬇️. To honor conservation of moment, the average rotational velocity must go up ⬆️.
• The increasing rotational velocity causes the ball to bulge along the equator. This new shape increases the rate of collisions which increases the rate of drag which makes it collapse more which increases the angular velocity which causes it to bulge more which repeats the cycle. Over a long time this feedback loop flattens the ball of dust into a disk with a large bulge in the center. (Sort of like what a spiral galaxy looks like).
• This is called the proto-planetary disk. The large budge in the middle will become the star. The material in the disk will begin to undergo similar collapse at a smaller scale to form planets with their moons. What is important here however is that all of the material is rotating in the same direction and physically located either in the bulge or in the disk.
• Eventually the bulge will collapse enough for stellar fusion to light within the newly formed star. The solar wind and radiation pressure from this new star will then blow most of the gas and dust which isn’t part of a planet, moon, asteroid, or comet out of the solar system.
• What is left over from this process is a star and a set of planets all rotating in the same direction in a plane

Now is it possible for planets to escape this plane? Yes but it requires an interaction with something outside the solar system because the disk configuration is naturally stable. We see this effect with regards to moons. Most moons in the solar system orbit along the equatorial planes of this planets. But some don’t. Turns out the location of the planets obits within that plane haven’t always been where they are now and they have mucked with each others moons (and even flipped Uranus on its side).

So why have the planets in our solar system not been disturbed by something outside our solar system? (say another star passing too close) Well, the likelihood of life on earth surviving such a close encounter it basically 0. Our orbit would probably get kicked out of the habitability zone, and we’d be bombarded with asteroids and comets. Close encounters of this type happen fairly frequently near the center of the galaxy where stars are close together and infrequently further out where we are. This has lead some scientists to hypothesize that the “galactic habitability zone” only includes a ring around the edge of our galaxy’s disk.

I feel your “early morning brain no worky” pain. Hope you have a great day.

I feel they've painted themselves into a corner calling it BOAT.

Now that explaination makes more sense. I guess that's what happens when you get science news from a business newsletter.

I meant that. Early morning, brain not working.

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And that’s when AI technology started picking up steam. Coincidence?

I just checked (because I have a few weird questions), but I sure don't see the stickied "All Space Questions" thread that is supposed to be at the top of the r/space sub. I even clicked the 'rule' that mentioned it, and it says it is there, but it's not.

Perhaps some fixing or clarification is in order? Thanks.

Educating kids about the realities of shark attacks left an alarmist void that something had to fill. It will be even more fun when quantum sciences become more prevalent and new discoveries lead to headlines like "Quantum Computing Spells Doom For Humanity" when some kid in Italy figures out how to play Doom on a quantum computer.

> We know astronauts to Mars will be in space for nearly 2 years. We should have had him stay 2 years.

However they will likely be in microgravity for 4-5 months per leg of the trip. During the time at Mars they will experience gravity (albeit less). Plus the radiation flux on the Martian surface is only slightly higher than on the ISS. The thin Martian atmosphere alone blocks radiation surprisingly well.

New classes of rockets like Starship from SpaceX pack enough delta_v to lower the old numbers (6-9 months) significantly.

Theoretically Starship could reach Mars in about 80 days with 100 tons of payload and fully refilled in LEO. But then the arrival velocity at the Martian atmosphere would be too high for the heat shield. So the trip duration has a lower limit of roughly 4 months in a good synod.

https://youtu.be/Am5pWWlFmyc

Systems as a whole have an average angular momentum that’s not obvious right away. Over time the collisions make that angular momentum more prominent

If you spin a ball of pizza dough it flattens into a plane.

Hello u/JimmyNotDrake, your submission "How come planets are tilted?" has been removed from r/space because:

• Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

Hello u/Durrynda, your submission "Do planets of solar system have parallel orbits?" has been removed from r/space because:

• Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

Yes, but sad as it is, right now there's no alternative to the SLS, maybe Starship and who knows when that will be operational.

Meanwhile Starliner is just another one of many space capsules.

Having alternatives is good, but damn, how long has this thing been in development now?

yeah maybe i just got confused with the rotational axis. I think he was more talking about the orbital plane planets are orbiting on

Even Earth has a tilt. Further from the sun gets more tilt. Something unseen seems to be pulling at the outer planets.

To add to this, due to OP's comparison with electrons orbiting a nucleus in 3D space: where planets and other materials in space all PULL on each other due to gravity (don't ask what gravity is, IDK, okay? Nobody knows!), electrons PUSH on each other, they repel one another. So they get pulled in by the nucleus, but when they come to close to each other, they start repelling one another, and thus they can end up in seemingly 3D orbits, because this allows them to be the furthest from each other.

gravity is one of the major force in the universe, id guess it has something to do with the way celestial objects are spinning and how their mass affect things around them. I would hazard a guess that planets in the solar system turn on the same plane the sun is.

>Why is it happening so? Sounds way to simple to be true in something so complicated as space. Even electrons have 3-dimensional orbits but planets somehow don’t?

Astronomer here:

I would like to clarify that, while each planetary system is on a plane, and the galaxy is on a plane, they are not all the same plane. The planes of the planetary systems are essentially random, and not aligned with the galaxy. Our own solar system is not aligned with the galaxy either.

The reason why spiral galaxies and planetary systems come out in planes has to do with the fact that they are all born from a gas cloud. Any initial gas cloud has some initial angular momentum. As it collapses by its own self-gravity, it has to spin faster to conserve angular momentum. This by itself is not enough to make the gas form a disk. The last ingredient is that gas in space actually behaves like gas ---- it feels pressure, it emits energy. So the initial gas cloud is a "blob" with a lot of random motions, pressure (think gas drag) dissipates most of the random motions, leaving only the "average" motion, which would be a rotation in some direction corresponding to the net initial angular momentum of the blob.

Stars in the galaxy are on a plane because stars from form the gas, and the gas was on a plane. Planets are on a plane, because planets form from the gas (well, Earth forms from the 1% of dust inside the gas) and the gas is on a plane.

most stars within their own galaxies are lined up in a plane though

It's always good to find problems in the safest way possible, but wow these guys need a win right now. Hope they move forward quickly and safely.

I must admit I'm terrible at physics so I don't fully grasp it, but seems like it's because the solar system formed out of a spinning ball of gas and over time the spin caused it to flatten out (like a pizza dough, I guess?).

https://science.psu.edu/science-journal/winter-2021/FlatSolarSystems

As for why atoms aren't similarly flat, it seems to be because at that small scale the gravity is a negligible factor compared to the other forces, such as electromagnetism. The electrons repulse each other.

https://www.quora.com/Our-solar-system-spins-on-a-flat-plane-so-do-atoms-also-do-this