Philosophy Discussion Forums | A Humans-Only Club for Open-Minded Discussion & Debate

[Felix]

In a spacecraft, all liquids are stored in sealed containers that have straws (drinking tubes) attached to them - so no wine chalices or sloshing wine. In the film footage I saw in which Neil was watching Buzz drink his wine through a tube and consume his host cracker (that's Host, not Hostess), he did look like he was anxious to get out the door - can't imagine why.

[Steve3007]

In that particular instance there was indeed a chalice, donated by Buzz Aldrin's Presbyterian church.

https://www.history.com/news/buzz-aldri ... lo-11-nasa

It was, I've read, the only time that an open container of liquid has been consumed anywhere other than the Earth.

[Felix]

Hmm, as I said, in the film footage I saw, filmed inside the landing module, he drank the wine from a tube, it didn't show him pouring anything. I figured the chalice was just symbolic, that he didnt actually use it.

[Jonathan A Bain]

Its curious that the given commonplace explanation of how the moon formed is certainly wrong.

We are typically told that a mars-size object impacted the Earth and the impact resulted in
the moon forming. The problem is that if any object is broken off from the Earth, it can only
have two direct results. Either it returns to its point of impact, or it is ejected beyond escape
velocity, in which case it never returns. In order for an impact to put a body into orbit, there
would need to be a very precise collision with a fourth body at just the right amount.

Now such a coincidence is possible; albeit unlikely. But the problem is that it is virtually
impossible for a whole series of such impacts resulting in all the moons in the solar system
having such uniform orbits. All the major moons are very close to the ecliptic plane,
and all the largest bodies orbit in the same direction, with orbits that are very close
to being circular. We almost never see very elongated, eccentric, highly elliptical orbits
when it comes to moons. Non-uniform orbits, like those of comets, would be the norm
if the moons all formed as a result of random impacts.

So regardless of whether the moon is in a coincidental orbit or not, its formation process
has not been understood by the scientific community at all.

[Sy Borg]

It has been shown that the relative homogeneity of the Moon and the Earth means there must have been a giant impact with the hypothetical proto-planet, Theia. The chances of it being a captured body with very similar composition are therefore extremely low.

The intruder was smashed into bits and the debris field would have orbited the Earth as a ring, which is what happens with such impacts at first.

It's been determined that such a ring would have orbited the Earth for a century afterwards (shorter than I would have intuitively expected) before it coalesced into the early Moon. The young Moon was very much closer to the Earth then than it is today and may well have been scorched by the Earth, which would have been glowing hot from the collision.

Re: the OP, you will find that the size of the Moon and Sun in the sky are very similar to the size of your thumbnail held out at arms' length.

[Steve3007]

The problem is that if any object is broken off from the Earth, it can only have two direct results. Either it returns to its point of impact, or it is ejected beyond escape velocity, in which case it never returns.

What is the evidence on which the above claim is based? I'm sure I've seen computer models demonstrating it not to be true.

[CIN]

Re: the OP, you will find that the size of the Moon and Sun in the sky are very similar to the size of your thumbnail held out at arms' length.

Proof that God has opposable thumbs.

[Sy Borg]

Re: the OP, you will find that the size of the Moon and Sun in the sky are very similar to the size of your thumbnail held out at arms' length.

Proof that God has opposable thumbs.

He also has long grey hair and a long grey beard - basically Galdalf without the hat, including opposable thumbs with which he holds his staff and the reigns of Shadowfax.

Re: the OP.

... the Saturn V remains the tallest, heaviest, and most powerful (highest total impulse) rocket ever brought to operational status, and holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 140,000 kg, which included the third stage and unburned propellant needed to send the Apollo Command/Service Module and Lunar Module to the Moon.

Given that the mass of the moon is 7.34 × 10²² kilograms. If the Egyptians had a rocket as powerful as the Saturn V, it would need to make approximately 523,000,000,000,000,000 trips to construct the Moon. You would think that a space program of that scale would have left some traces behind ...

[Felix]

You would think that a space program of that scale would have left some traces behind....

Word (heiroglyphic) is that Ra ordered Konshu to destroy all the evidence.

[Felix]

Oh, I am in trouble now, I misspelled Khonsu's name, I hope he doesn't send his mummy after me!

[Steve3007]

Re: The conversation about God's almighty opposable thumbs between CIN and Greta.

If it were true that God made the sun to be about the same apparent size as His almighty thumb when viewed from Earth, it's interesting to note that the apparent size of the sun in the sky is dictated by its actual size and distance which dictates the amount of radiation we receive from it per unit time which dictated, in all sorts of ways, the way in which life evolved on Earth which dictated the evolution of humans which dictated the size of our opposable thumbs which dictated the size of the thumbs we gave to our God (or the other way around, according to preference) which (according to our premise here) dictated the apparent size of the sun...

So there's kind of a circular "Terminator's One Surviving Arm" thing going on there. But not a whole arm. Just a thumb.

[Sy Borg]

Felix, it appears that you are saying that the Sun god sent the Moon god to destroy evidence of the Moon herself being artificially made. Of course, it seems so obvious now that you mention it!

Steve, what about those with, say, Marfan Syndrome, or those who generally have very long arms and thin fingers?

[Jonathan A Bain]

The problem is that if any object is broken off from the Earth, it can only have two direct results. Either it returns to its point of impact, or it is ejected beyond escape velocity, in which case it never returns.

What is the evidence on which the above claim is based? I'm sure I've seen computer models demonstrating it not to be true.

An ellipse always returns to its starting point.
Are you saying orbits are not ellipses?

Your recollection is likely not based on real gravity equations,
rather there are vague diagrams originating from centuries
past wrongly depicting a cannonball going into orbit.

One of my gravity algorithms is currently ranked
1st out of over 3 million at google
for the search "binary orbit software".

Although not exactly the question of this topic,
solving for n-body-gravity with numerous interacting
gravity fields is actually a far more advanced algorithm
than a single body orbit - which can only be an ellipse,
or the object reaches escape velocity.

[Steve3007]

Steve, what about those with, say, Marfan Syndrome, or those who generally have very long arms and thin fingers?

Good point! I guess we have to assume that God has/had thumb sizes and arm lengths that were broadly similar to the average genetically healthy adult human.

An ellipse always returns to its starting point. Are you saying orbits are not ellipses?

Well, no, in my post back there I wasn't saying that. I was asking you a question. But since you ask, no, orbits generally are not ellipses. That's Kepler's idealisation for two body systems. If orbits were all perfect ellipses then Neptune would not have been discovered, because its discovery was due to calculations based on observations of orbital perturbations of already known planets using Newton's (not Kepler's) laws.

So a more general solution is the application of Newton's laws and a more general solution than that is Einstein's laws. As you know, the application of those laws to systems of three bodies or more has to be numerical, using finite time steps.

Clearly a situation in which a large body impacts with another large body and they both partially or wholly vapourize and/or break into an extremely large number of pieces is not a simple two body problem. So, although this doesn't in itself show your conclusion to be wrong, I don't think that the justification for that conclusion is that a body following an elliptical path always returns to the same point. We know, for example, that it is dynamically possible, in an orbital system described by Newton's laws, for a body to be ejected from that system such that it never returns.

Your recollection is likely not based on real gravity equations, rather there are vague diagrams originating from centuries past wrongly depicting a cannonball going into orbit.

I'm pretty sure they're based on modern computer simulations of Newton's laws applied to large numbers of mutually gravitating particles. I've written some simpler ones myself at various times. More complex ones appear to have been used to model collisions of large bodies to show such things as the formation of ring systems and satellites. I'll try to find some examples online, but there have been numerous gravitational simulations written over the years.

One of my gravity algorithms is currently ranked 1st out of over 3 million at google for the search "binary orbit software".

I searched for it and found this:

http://www.flight-light-and-spin.com/binary-orbits.htm

I presume that's it? Looks good. Very interesting. I'd be interested to see some of the code that does the calculations. In your explanation...

http://www.flight-light-and-spin.com/ma ... roblem.htm

...you talk about using a "quantum of time". I presume what you're talking about here is simply the use of a finite (small but non-zero) time step in the calculations? This is what is done in all numerical computer simulations of physical systems which can't be solved analytically. Not just planetary orbits. It's also used in physics engines in computer games.

To start writing a numerical simulation of many mutually gravitating bodies is essentially quite simple. It's a numerical solution to Newton's law of gravitation:

F = Gm₁m₂ / r²

For each time step, and for each body, as an initial first order approximation, you simply work out the acceleration of each body using the above equation and F = ma, add the acceleration to the velocity and add the velocity to the position. This is the simplest possible form of numerical integration. Then you can start optimising by using higher order numerical integration methods like Runge–Kutta methods and so on.

As far as I can tell from your explanation on your website, this first approximation is what you did. It is a standard first approximation for solutions to this kind of system. I can see why you used the thing you refer to as a "holding matrix" in order to calculate all momentum changes before calculating all position changes, but I don't think this is a fundamental innovation. It doesn't alter the fact that the number of gravitational interactions to be calculated is proportional to the square of the number of bodies ((n² - n) / 2, I think), and it doesn't alter the fact that the accuracy of the model will always be dependent on the size of the finite time step chosen and the method of numerical integration chosen.

There are various other more complex algorithms, such as "particle-in-cell" algorithms, and various special case simplifications, that can reduce the required computing time for very large systems of particles such that it doesn't increase with the square of the number of particles. But there's always a trade-off between general applicability, accuracy, computing time and complexity of the algorithm.

Although not exactly the question of this topic, solving for n-body-gravity with numerous interacting gravity fields is actually a far more advanced algorithm than a single body orbit -which can only be an ellipse, or the object reaches escape velocity.

It's not necessarily a more advanced algorithm. The difference is in the way in which the problem can be solved: numerically or analytically. In an analytical solution to a problem, it is possible to write an equation that precisely defines the entire state of the system at any time t:

State = F(t)

In three-or-more-gravitating-body problems this cannot be done. Instead, the system has to be evolved from an initial time, t₀ by numerical integration.

But, at heart, the algorithm representing the numerical solution to the problem is pretty simple. It's the successive optimisations of the algorithm, and/or the use of simplifying assumptions for special cases, to yield more accurate models for a given amount of computing time that adds the algorithmic complications. As a general rule, if computing time is unlimited, algorithms can be relatively simple.

The interesting part, I think, is when you start to think about chaotic systems in which the inaccuracies of numerical solutions to problems blow up so large so quickly that no amount of computing power can keep up. But I guess that really is straying off topic.

[Steve3007]

Here's one of various videos showing small excerpts from computer simulations of impact scenarios: