Kepler's Equation Puns

I'm a little confused here. I believe that generalized coordinates are theta and r, right? But how do I found the lagrangian? V must be the gravitational potential energy. Should I use the angular momentum to find the kinetic energy? Thanks :')

Hello, I have no idea how to start with these two questions.

For number 1 do I set Fg=Fr and then just cancel out the terms that I can and leave it at that.

For 2 am I am just confused.

https://preview.redd.it/8gbyvn7se9t51.png?width=792&format=png&auto=webp&s=a211de50b2776ccc5ffb6c7dd87a6b960fbd0a86

https://preview.redd.it/w5s3qwrf7my11.jpg?width=220&format=pjpg&auto=webp&s=54f36934a7b81cd8376075c62e7428f20f5e845b

Using the data on new planets suspected, released on January 7th, 2013, I am wondering what the best estimates are for extraterrestrial life using the Drake Equation.

I'm trying to calculate the positions of the planets. The JPL has a paper describing how to do this at [1]. However, the coordinates I get are nothing like orbit diagrams that you can see on other places, for example here [2]. This means the ecliptic X,Y coordinates I get are wrong. According to [2], Jupiter currently has positive X,Y coordinates, however what I get are negative X and positive Y. So I would really appreciate it if someone can take a look at what I'm doing wrong here.

In reference to the paper, I'll use these variable names:

• Lp for longitude of perihelion (omega with a bar on top)
• Lan for longitude of ascending node (capital Omega)
• p for argument of perihelion (omega)

Also, I'll say "dsin" when I mean sine for degrees, and "sin" when I mean sine for radians, same with dcos/cos, because it's good to be clear on that.

So, step 1, calculate the time and the initial values for the elements. Today's Julian Date is 2455880.89156.

T = (2455880.89156 - 2451545.0) / 36625
  = 0.118710401486

a = 5.20288700 + T * -0.00011607 
  = 5.202873221302303

e = 0.04838624 + T * -0.00013253 
  = 0.04837050733173315

I = 1.30439695 + T * -0.00183714 
  = 1.3041788626674733

L = 34.39644051 + T * 3034.74612775
  = 394.6518853300851

Lp = 14.72847983 + T * 0.21252668 
   = 14.753708923445224

Lan = 100.47390909 + T * 0.20469106 
    = 100.49820801510504

Step 2, calculate argument of perihelion p and mean anomaly M:

p = Lp - Lan
  = 14.753708923445224 - 100.49820801510504 
  = -85.7444990916598

M = L - Lp
   = 394.6518853300851 - 14.753708923445224
   = 379.8981764066399

Step 3, iterate the solution to Kepler's equation to get the eccentric anomaly E. I'll use the variable ee to mean eccentricity in degrees. (Which is a bit strange to do!) And dM for delta M, dE for delta E.

ee = e * 57.29577951308232
   = 0.0483705073105 * 57.29577951308232 
   = 2.7714259217983446

M = (M + 180) % 360 - 180 
  = (379.8981764066399 + 180) % 360 - 180
  = 19.89817640663989

E0 = M + ee * dsin(M) 
   = 19.89817640663989 + 2.7714259217983446 * dsin(19.89817640663989)
   = 20.841430173809666

dM = M - (E0 - ee * dsin(E0))
   = 19.89817640663989 - (20.841430173809666 - 2.7714259217983446 * dsin(20.841430173809666))
   = 0.042772005284021475

dE = dM / (1 - e * dcos(E0)) 
   = 0.042772005284021475 / (1 - 0.0483705073105 * d

Some background:

Kepler's equation is given by: [;\phi(e,M) = e\sin\phi + M ;].

Writing [; e\sin\phi;] as a Fourier Series gives:

[;e\sin\phi = \sum_{k=1}^{\infty}b_k\sin(kM) ;], where [;b_k = \frac{2}{\pi}\int_0^{\pi}e\sin\phi\sin(kM)dM ;]

Upon using integration by parts on this I get the boundary term:

[; \frac{2}{k\pi}[-e\sin(\phi(e,\pi))cos(k\pi) + e\sin(\phi(e,0))] ;],

which is said to equal zero in some of the sources I've looked at. I don't see how this is true however, unless sin(phi(e,pi)) = 0 and sin(phi(e,0)) = 0?

Any ideas?

Hi, I'm a programmer, artist, and game dev by hobby, and I like space. What I'm trying to do is A) Calculate the shape of a spacecraft's orbit as an ellipse between apo and periapsis, then B) find all points this path intersects on an imaginary grid centered on the planet that spacecraft orbits.

In my current project, I need to move objects in realistic orbits around the planet, but I also want to keep the spacecraft at the center of the simulation and move everything else around it. So what I'll do is calculate the orbits of these objects as ellipses around the planet. Then the game would check what coordinates each object is moving to, subtract the coordinates my spaceship should be entering, and move it to that point. Spaceship coordinates cancel out into zero, and everything moves relative to it in proper orbits.

Thanks in advance. Its 11:30 1 am on Christmas eve so I think I'll stop working now.

I'm currently replaying Mass Effect and clicking on planets in systems when something that caught my interest in the planetary details.

I'm in a 6 planet system and the orbital periods for the planets are as such

Planet 1: 0.1 Earth years

Planet 2: 7.8 Earth years

Planet 3: 20.4 Earth years

Planet 4: 1.1 Earth years

Planet 5: 37.5 Earth years

Planet 6: 90.5 Earth years

Everything is typical regarding orbits getting longer the further away a planet is from its home star except for planet 4. I'm wondering if this is just an error or if it could be scientifically possible. It defies everything I know about orbital mechanics and escape velocities.

Theoretically the planet should have an orbital period of 28ish Earth years. I would assume that if it had the horizontal velocity needed to achieve such a fast orbit that it would just break away from the stars gravity

Because I'm full of dumb ideas. Spoilers because direct reference is made to locations (and to the astrometrically astute, their characteristics).

I strongly suspect OW's astrophysics is a simplified Keplerian model, and accordingly it should be possible to derive good approximations of the orbital elements for everything in the solar system simply by observation. The Outer Wilds are in fact a relatively idealized system for the following reasons:

• There is practically no orbital inclination above Timber Hearth's ecliptic (with the exception of the Deep Space Satellite, which is perfectly polar);
• Other than the Interloper all the orbits are almost perfectly circular;
• All satellite orbits are perfectly circular as well.

So I put together a spreadsheet with the Keplerian parameters and several formulae that should allow most of the parameters, and some other interesting points like planetary mass, to be derived. Bold rows require some input; others are derived.

Specific methodologies for each (in the order they could optimally be captured):

1. Fly to the object in question.
2. Apoapsis/periapsis: Respectively the maximum/minimum distance to the body this object orbits. Measure both (they may be identical, or close to, given most orbits in the Outer Wilds are circular). Called aphelion/perihelion when the body orbited is the Sun, and apogee/perigee when the body orbited is Timber Hearth.
3. Observed Surface gravity: Read off the G reading on the suit.
4. Polar diameter at surface: Fly to either pole and put down a Scout. Fly to other pole and take distance directly. Avoid terrain distortions where possible.
5. Obliquity of rotation: Look straight up and walk around until you find the point where the body the object you are on orbits crosses DIRECTLY overhead. This will in most cases be on or slightly above/below the equator. The obliquity is the angle between the equator and where you are currently standing.
6. Rotational period: From the position you were in when you found the obliquity, start a timer the moment the body the object you are on orbits crosses your field of view. Stop timing when it crosses a second time. (Technically, for bodies orbiting the sun, this is literally finding local solar noon).
7. Gravity test:
   1. Have a stopwatch ready. Timing accuracy needs to be better than one second.
   2. Place a scout at your feet.
   3. Climb straight up to a convenient, survivable altitude above the scout

Hello everyone, here is a quick rundown of some of the tips I used to achieve a perfect study score of 50 in Physics in 2021! This guide includes information on how to approach each AOS of the subject, whilst some general advice is given in another post. Do not get overwhelmed by the sheer size of this guide, I know it’s a lot to take in haha. I encourage you guys to bookmark this page for future in-depth reading once you get up to a particular topic in class.

Anyways, let’s get started  :)

Introduction

VCE Physics is no doubt some of the most challenging VCE subjects, and, if not for the cheat sheet, would probably match Methods in terms of raw difficulty. However, despite how overwhelming the subject may seem, I firmly believe that a systematic approach in dealing with the subject can really ease the tension when learning new topics. Having not even done unit 1/2, I used the below tips to learn new concepts swiftly and effectively. So, if these worked for me, chancing are you may get something out of this article yourself

Unit 3

Unit 3 covers to main areas, fields and motion, with the two being interconnected in some parts of the course.

I'll start off with motion, as your school will likely cover this before fields. Motion, unlike fields, is VERY related to YR11 Physics, with around 80% of the concepts being the same. However, if you struggled with this last year (or didn't do YR11 Physics like me), then DON'T WORRY, your teachers will still the class enough time to learn the topic as it is a full AOS instead of something that they breeze over. For this topic, I really believe that's its all about the practice since, unlike other topics, there aren't too many distinct topics, with many concepts being the same just expressed differently (believe it or not, the conservation of momentum principle is derived from Newton's 3rd Law). So, once you surpass the initial basic conceptual hurdle, its all about doing the questions to pinpoint the small gaps in understanding. For example, you may know that 'work done' is calculated by 'force x distance' from class, but what if you encounter this question asking for the work done on object at an inclined surface? This question would make you rethink the formula and realise that the force in the work done formula has to be the PARALLEL component to the displacement. So, overall, I think this topic just comes down to doing a ton of practice questions so that you can 100% answer any

I wanted to get in a research group of another university as a second year physics student and he told me that lots of people quit because it is hard and he has lots of students, he does not need me. He told me that if I can finish the mechanics book in one month then we can talk about it. What he meant by finishing is he said I will open a page and you should be able to teach the stuff on it to me.

I said I will try, and I tried. I couldn’t. I had midterms but it is irrelevant because the problem was the book,it felt so hard to understand. It 3 days to deadline and I just understood Euler-Lagrange equation barely (as a student, it is enough I suppose but for teaching, no). I couldnt get mechanical similarity, Kepler Problem, anharmonic oscillations and canonical equations. I couldn’t even gave a glance at canonical equations.

What should i do? Should I ask for more time or say that this is the best I can do?

Sorry for my English.

I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.

Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.

Has anyone else had issues with Alpkit products?

TL;DR:
I've had enough with Alpkit and lost all trust in them and their products. Their customer service is poor too.

The longer version:

It took three of Alpkit's Carbonlite walking poles before I got a couple that seem okay, with two different (potentially dangerous) faults between the three. Alpkit assured me the faults were rare, which is why they didn't recall the products.

I've had 3 or 4 mattresses that failed. One lost air through the material itself (leading to a cold autumn camping week - my first wild camping experience - with no mattress to sleep on), and Alpkit had me repeatedly looking for a puncture in the bath. When they received the mattress, they said it was a fault that affected a very small number of mattresses, which is why they repeatedly asked me to look for a puncture before they offered the return. The other mattresses had bubbles pop up from them (literally, waking me on a couple of occasions), and Alpkit didn't refund me for one of them. I looked after them properly (e.g. not leaving them inflated inside a tent). I always thought the self-inflation was a gimmick until I actually received a mattress that did self-inflate. I bought a half-length Airo that has been okay (still only used around 10 times) but 1 decent product out of 5 is still very poor of course. The self-inflation has stopped working on it though.

I bought a few pairs of their socks, which were rubbish (bobbling, shrinking, wearing out quickly, elastic quickly going).

I bought an Alpkit Kepler merino shirt that ripped along one of the sleeve seams the first time I wore it, and after questioning, Alpkit accepted a return and confirmed it was an issue with the product. The replacement developed a hole within a week. I know merino wool can be fragile and have used Decathlon and Rohan merino tops without issue.

I kept thinking I'll stop buying from Alpkit, but when I'm looking for a new product, they often crop up as 'best buys.' What prompted this post is being annoyed with Alpkit customer service over a Balance waterproof jacket which early on didn't seem very breathable and when it rained, also turned out to be not very waterproof (and in a cold and potentially dangerous situation). They were slow to refund me for that, well over a week longer than the 2-3 days they cite. I also received no communication from them about the return (I may have wanted a replacement, for example) *

Here's the problem: : A satellite of mass 500 kg orbits the earth with a period of 6000 s. The earth has a mass of 5.97 × 10^24 kg, a radius of 6.38 × 10^6 m, and G = 6.67 × 10^-11 N ∙ m2/kg2. It wants me to find the magnitude of the gravitational force and the attitude of the Satellite.

No matter what I do on this problem I can't seem to solve it correctly. I can't use the Gravitational force formula due to the lack of r. I assumed I might be able to use the centripetal force formula since the centripetal force equals the force of gravity in this case. However, once again I don't have r. The only way I could see to get r was by using Kepler's third law, but once I solved for it, the number I got was way too big to be the distance between the earth and the satellite

My question is this: How can I find r for this problem and how can magnitude be properly found without it?

Edit: I managed to solve my problem! Thank you to everyone who posted to help me out!

Do your worst!

I'm surprised it hasn't decade.

For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.

I said "hey look, an escaPEA"

No one near me but it didn't half make me laugh for a good hour or so!

Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂

It really does, I swear!

Hey all,

I'll try and keep this somewhat brief and will probably [update: I did] fail.

I'm lucky enough to have a solid rig:

i9-9900k

64GB of 3000Mhz RAM (I do some rendering occasionally)

2TB+ Nvme SSD (PCI gen 3)

EVGA Hybrid XC3 3080

Solid 5.1 sound system

I recently got my hands on an LG C1, which is fantastic in so many ways, one of which is the included GSync which I had no idea was so damned effective until using it. I ran a 48 gbps HDMI cable between my rig and my living room and will game from there when I'm looking for an experience. I'll moonlight via a Galaxy Tab S7+ a whole heck ton around the house and will use it remotely quite often (well I used to use it remotely, resigned from my super toxic job so not so much remote use in the foreseeable future). Unfortunately Android tablets don't have the framerate or resolution dialed in [yet].

The 3080 tier lit up an hour or so for me and having been one of the first people to use 'Onlive' and have worked a bit in designing VDI stacks with Kepler accelerated cards on zero clients (basically another kind of version of building a cloud based datacenter, but I'm rusty now). I've been dialed into the concept of cloud gaming for a damn long time now and this, this right here, the 3080 tier, is the cloud gaming dream realized.

Knowing a lot of the tech behind it, I still see it as black magic right along side DLSS - it's the stuff of science fiction.

So my connection to the 3080 tier is as follows:

Latency to the Superpod: 17 to 18ms

Bandwidth: 1.2Gbps down/40Mbps up (Comcast/Xfinity)

-- Via ethernet from my rig, using the C1 TV

All games have motion blur off (I find streaming adds its own sort of motion blur and in game blur wreaks havoc on the codec the stream is using)

A quick summary between local and the service: very difficult to distinguish between local and remote on most games (I'm not a competitive gamer so keep that in mind) - I'm not seeing a lag in mouse movements unless I'm looking for it. I've tried Control, AC Odyssey, New World, Cyberpunk, AC Valhalla and with a single month Ubisoft + subscription will go through some Far Cry's, etc. over the next few days when I have time.

From what I've seen it's exactly like Moonlighting, there is about a 10 to 20 percent hit on framerates at 1440p that I take using Moonlight and this seems to be around the same exact area of performance loss with the 3080 tier.

New World was the most immediately revealing (these numbers of

Here is the potential WBCQ team for Germany. Assuming the team receives all their players, you'll see plenty of current MLB players. When putting together these teams, I am putting a best case scenario. It's called potential/projected players who might join the team, not who will join the team. The tldr will be towards the bottom if you want a quick idea on if this team will make it or not as these posts are detailed, scroll down towards the Reasons Why They'll make it to get a short version.

Just some context:

Strong: The team is a favorite to qualify for the main tournament. Everything clicks and they win a spot to qualify.

Average: A competitive team. Can hold their own against the top baseball countries but certain things have to go their way to beat them. Third or fourth place finish with a chance to challenge for the second qualifier spot in the group.

Weak: Not strong enough to qualify. Fifth or last place finish

Rotation

*Heritage Player
^Seven innings

^One Inning
* Eight Innings

|Position|Name (B)|2021 Team|

They’re on standbi

Pilot on me!!

Nothing, he was gladiator.