0

I made a Desmos Graph following the most voted answer of this question, but I'm not sure if it is correct, because it suggest that the formation of the Sun happened shortly after it would have crossed the galactic plane, but the Sun did not exist before that. Is that possible?

The line is part of a cosine function

Zeniel Danaku
  • 11
  • 2
  • 1
    First, your $x$ is wrong. The universe isn't even $\sim 57$ billion years old. Please edit your question to correct it. – WarpPrime May 28 '21 at 00:28
  • 1
    Probably not. The sun is executing radial epicyclic motion around the galactic center, so its distance increases and decreases periodically. The question you are referring to does not say anything about radial motion, so anything you have plotted on that basis must be wrong. – AtmosphericPrisonEscape May 28 '21 at 00:34
  • See https://www.desmos.com/calculator/exeupoixbq – WarpPrime May 28 '21 at 00:38
  • @fasterthanlight ok, but where is the Sun now? if I mark x=4.6*10^9 the graph show that the Sun is going down, towards the galactic plane, where the post I mentioned states that the Sun is currently going up. – Zeniel Danaku May 28 '21 at 01:16
  • @fasterthanlight again, and I quote "As the Sun is currently above the plane and moving upwards, and each cycle takes about 70 million years with an amplitude of 100pc, it will be roughly 30 million years before we cross the plane again" The "correction" you made marks the sun as going down. – Zeniel Danaku May 28 '21 at 01:48
  • The graph I made had a cycle of 70 (millions of years) and an amplitude of 100 (parsecs) – Zeniel Danaku May 28 '21 at 01:49

1 Answers1

2

Unfortunately, what you are trying to do is not possible. We do not know the details of the Sun's motion or the Galactic potential precisely enough to make a prediction of exactly where the Sun was 4.5 billion years ago.

The amplitude and period of the oscillatory motion that I specified in my answer to the previous question is known now to of order 10%. If you extrapolate backwards for more than a few cycles then the phase could be anything.

In addition, the Sun has likely changed its radial position in the Galaxy during its life. If so, then the amplitude and period of the vertical oscillatory motion will also have evolved.

ProfRob
  • 151,483
  • 9
  • 359
  • 566