Holding Arnold's Hand

[Arc7Kuroi]

Intro
So, as per the thread title, I am holding Arnold's hand through baby's first CGT.

Calcs
So, Clover made a calc for the meteor and so did Arnold. This thread is to determine which calc is superior for use.

Personally, I believe Arnold's height assumption of 110 km is fine after checking out his source. However, I'm a bit unsure for the speed. I know for a fact Clover's mid-end ablation speed is a safe lowball since we know it ablates. I am unsure of if Arnold's calc'd speed for the meteor is cinematic timing, given that using the movie time and distance characters travel from pixel scaling in the movie would net that the characters are far slower than where they scale (super to hypersonic vs FTL). So, I would appreciate if CGM evaluated what height should be used (top of mesosphere 85 km vs top of ablation height 110 km) and what speed should be used (ablation 3 km/s vs pixel calc'd 18.8 km/s).

Votes
Clover height (85 km): Mitch
Arnold height (110 km): M3X, Therefir, Armor, Clover
Neither height: Damage (unsure atm)
Clover speed (3 km/s): Damage
Arnold speed (18.8 km/s): Clover, Therefir, M3X, Armor, Mitch (recalc speed from Clover’s height)
Neither speed:

 

[CloverDragon03]

Following

I'm just gonna let this play out, I don't have enough craps to give about this anymore

 

[Arnoldstone18]

smh.

 

[Dragoonseraphim]

Did this need to be quite so condescending?

 

[Kachon123]

Clearly a joke.

 

[Arc7Kuroi]

Doing favors for people ain't fun unless you can poke a little fun at em

 

[Arnoldstone18]

Whatever, thanks.

 

[Lynieryz]

Arc is Arnold's tooth fairy so it's justifiable

 

[SeijiSetto]

I think the pixel calc'd speed is more accurate, honestly. The reason things ablate is because atmospheric drag starts peeling back layers on re-entry, right? That works for normal sized meteors, which are typically far smaller than 81km wide, and thus have a far higher surface area:volume ratio, allowing drag to push back on them far more. Conrad's meteor asteroid (as it will henceforth be referred to) weighs far more (as mass is directly proportional to volume) compared to its frontal surface area and so drag forces compared to the weight will be FAR smaller.

This giant asteroid doesn't initially ablate upon emerging from the portal, there are no flames and you can just see waves of air being displaced around the surface of it. I think combining this with the point above is a valid case for using the pixel calc'd speed rather than assumed.

tl;dr asteroid is really ******* big, surface area to volume ratio means drag forces will do less to it, drag forces are what causes ablation, therefore using the faster speed may be valid.

 

[KingogKings777]

Whatever, thanks.

The tsundere pfp makes reading this 10x funnier.

 

[Arnoldstone18]

Bump

 

[Damage3245]

Personally, I believe Arnold's height assumption of 110 km is fine after checking out his source. However, I'm a bit unsure for the speed. I know for a fact Clover's mid-end ablation speed is a safe lowball since we know it ablates. I am unsure of if Arnold's calc'd speed for the meteor is cinematic timing, given that using the movie time and distance characters travel from pixel scaling in the movie would net that the characters are far slower than where they scale (super to hypersonic vs FTL). So, I would appreciate if CGM evaluated what height should be used (top of mesosphere 85 km vs top of ablation height 110 km) and what speed should be used (ablation 3 km/s vs pixel calc'd 18.8 km/s).

I'm fine with sticking with ablation speed.

 

[Arnoldstone18]

Any reason in particular? I’d always thought a calculated version of things were more reliable than an assumption on said things.

 

[Arc7Kuroi]

I'm fine with sticking with ablation speed.

Which height end are you fine with 110 or 85 km?

 

[CloverDragon03]

Any reason in particular? I’d always thought a calculated version of things were more reliable than an assumption on said things.

I second this. Usually calculated values > assumptions

 

[Damage3245]

The calculated value for the speed is still based on assumptions too by the way.

Which height end are you fine with 110 or 85 km?

Not sure on that.

 

[Arc7Kuroi]

I second this. Usually calculated values > assumptions

I take it you’re good with Arnold’s version atm?

 

[Arc7Kuroi]

Not sure on that.

Alrighty

 

[Arnoldstone18]

The calculated value for the speed is still based on assumptions too by the way.

But in this case it’s the basic distance/time for the initial speed. There’s no assumption in that. Even the final speed uses a formula without any assumptions imo.

I take it you’re good with Arnold’s version atm?

No he’s not picking, he’s just stating what we’ve always done tbh. Unless there’s a valid reason otherwise.

 

[CloverDragon03]

The calculated value for the speed is still based on assumptions too by the way.

What assumptions? Distance isn’t assumed. And as for time, if anything, the time is a lowball

 

[CloverDragon03]

I take it you’re good with Arnold’s version atm?

For speed, yes. I made it clear that if there was an actually reliably calculated speed, I’d take that option

 

[Therefir]

Obviously calculating the speed of the meteor is preferred over assumed values.

We should be focusing on the 85 km vs 110 km value.

The calculated value for the speed is still based on assumptions too by the way.

Are you trying to say the meteor wasn't located at an altitude of 85/110 km during its creation? What would you suggest to use?

 

[Damage3245]

Are you trying to say the meteor wasn't located at an altitude of 85/110 km? What would you suggest to use.

I'm not saying where the meteor is or isn't. I was just pointing out that it is still an assumption.

 

[CloverDragon03]

I'm not saying where the meteor is or isn't. I was just pointing out that it is still an assumption.

Again… What assumptions? Distance? No. Timeframe? It’s the absolute lowest you could take it

Way more reliable than slapping on an assumed speed

 

[Arc7Kuroi]

I think what Damage is getting at is this:

We make an assumption on the height of the meteor (85/110 km) then using that assumption we get the size of the meteor, and from the size Arnold got speed. So, I’m guessing he’s saying that the origin of the speed comes from the assumed height, which in and of itself is correct.

I wonder if it’d be better to use the curvature scale for the meteor size and then use that meteor size to get speed. Since you don’t really assume a height for curvature scaling. Thus the meteor size wouldn’t come from an assumed value. Thoughts?

 

[Damage3245]

I think what Damage is getting at is this:

We make an assumption on the height of the meteor (85/110 km) then using that assumption we get the size of the meteor, and from the size Arnold got speed. So, I’m guessing he’s saying that the origin of the speed comes from the assumed height, which in and of itself is correct.

Yeah, you got it.

 

[CloverDragon03]

I wonder if it’d be better to use the curvature scale for the meteor size and then use that meteor size to get speed. Since you don’t really assume a height for curvature scaling. Thus the meteor size wouldn’t come from an assumed value. Thoughts?

Curvature scaling gets really scuffed though ngl

 

[Arc7Kuroi]

Curvature scaling gets really scuffed though ngl

I haven’t really looked into that method, so explain it to me

 

[Arnoldstone18]

We should be focusing on the 85 km vs 110 km value.

Okay so I used the height of 110 as a lowball because that’s when an object undergoes ablation beyond >3km/s. 85km was chosen because that’s the top of the mesosphere, meteors undergo ablation (display visible streaks of light) at that height. But something was wrong. Initially the meteor does not undergo ablation at 85km despite falling at speeds greater than >3km/s so I decided to use the highest point meteors have been shown to undergo ablation which is 110km as a lowball.

This is supported by the fact that the man who summoned the meteor stood by the initial height the meteor came from, experienced Zero gravity as he was dying. So the meteor definitely came from heights greater than the mesosphere before falling into heights above the mesosphere to experience friction and undergo ablation where Asta stops it.

 

[Therefir]

I wonder if it’d be better to use the curvature scale for the meteor size and then use that meteor size to get speed. Since you don’t really assume a height for curvature scaling. Thus the meteor size wouldn’t come from an assumed value. Thoughts?

I think this method should be given a try, if such images with the curvature do exist.

 

[SeijiSetto]

Curvature scaling can in-fact get massively scuffed, depending on how much of Earth is in the panel.

I've done calcs with it before and the corrected diameter ended up being under half of Earth's diameter.

 

[Arc7Kuroi]

I think this method should be given a try, if such images with the curvature do exist.

Reading over the curvature page, idk if the outer space shot would qualify, since the meteor is in front of the horizon. Might be able to correct for that with some trig tho

Edit: maybe it’s close enough to the horizon tho, idk what are measuring stick for near the horizon is

 

[Arnoldstone18]

Yeah, you got it.

The lesser assumptions the better. Using too many assumed parameters is just weird. And it’s not as if the assumed heights doesn’t have backing from what the movie gave us.

So yeah let’s discuss which assumed height the most likely. I personally propose 110 for reasons mentioned here and on my calc blog.

 

[Therefir]

Okay so I used the height of 110 as a lowball because that’s when an object undergoes ablation beyond >3km/s. 85km was chosen because that’s the top of the mesosphere, meteors undergo ablation (display visible streaks of light) at that height. But something was wrong. Initially the meteor does not undergo ablation at 85km despite falling at speeds greater than >3km/s so I decided to use the highest point meteors have been shown to undergo ablation which is 110km as a lowball.

Your method does make sense, ablation occurs below 110 kilometers, since only at that altitude are the atmospheric layers dense enough for ablation to occur.

@CloverDragon03 You seem to be fine with calculating the speed but not using the distance of 110 km, why is that?

 

[Arnoldstone18]

Your method does make sense, ablation occurs below 110 kilometers, since only at that altitude are the atmospheric layers dense enough for ablation to occur.

@CloverDragon03 You seem to be fine with calculating the speed but not using the distance of 110 km, why is that?

Also I’d like to mention that in my blog Clover and I calculated, the speed at 85km but it still gave speeds higher than ablation. However the initial state of the asteroid wasn’t reflecting that (it’s not on fire). Hence the 110km since that’s the highest points ablation occurs.

I’m not sure what Clover thinks tho.

 

[Therefir]

@Arnoldstone18 According to this source, meteors such as the Draconids in October, fall to about 70 km before they heat up enough to glow.

This is because the Draconids are much slower than other meteors, falling at 20 km/s.

The height in the atmosphere at which a meteor begins to glow (ablation) depends on its arrival speed.

The meteor in question is slower than the Draconids, meaning it would need to fall below 70 km to actually begin to ablate.

 

[Therefir]

Since even assuming this meteor was formed at 110 kilometers above the surface only gives us a speed of 17.47 km/s, Clover's height might actually be more accurate.

So I would either go with 85 or 70 kilometers for the height, 110 km is only applicable for faster meteors.

 

[Arc7Kuroi]

Therefir brings up a good point. Since drag has some component proportional to velocity, “slower” meteors will ablate closer to earth than “faster” ones. Can I assume you’re for Clover’s height then Therefir, but using a calculated speed?

 

[Therefir]

Can I assume you’re for Clover’s height then Therefir, but using a calculated speed?

I'm fine with that height, the mesosphere is known to be the place where most meteoroids actually become meteors.

 

[Arnoldstone18]

@Arnoldstone18 According to this source, meteors such as the Draconids in October, fall to about 70 km before they heat up enough to glow.

This is because the Draconids are much slower than other meteors, falling at 20 km/s.

The height in the atmosphere at which a meteor begins to glow (ablation) depends on its arrival speed.

The meteor in question is slower than the Draconids, meaning it would need to fall below 70 km to actually begin to ablate.

This is interesting… but to be fair those meteors are the size of rocks and pebble. Your source also says the angle at which the meteor falls is also a factor. However, I just realized after researching that the bigger issue is the fact that we are using meteor logic for this.

Thee confusion stems from the word “meteor”. The object we are actually analyzing is actually an “asteroid” which goes from hundreds of meters to kilometers in size. A meteor is often just Little Rock’s of debris from a comet.

This Asteroid’s calculated initial speed is at least 13km/s at a height of 85km. It’s massive and heavy so it will continue to accelerate as opposed to draconids that are probably cm to a few m in length. And it should experience great friction upon its decent so much that it begins to burn at the front.

Maybe we shouldn’t be focusing on a meteor’s speed sources for an asteroid. Infact maybe we shouldn’t be using any type of logic we would use for meteors for an asteroid. Let’s start using asteroid logic on asteroids. Which should affect the density btw. What do you think?