Collapsing Star Roaring Cannon

[NikHelton]

The calculation for the destruction of the surface uses a standard shock wave pressure of 1.37895 bars or 20 psi of pressure. However, why do we use standard pressure for such large-scale attacks? From what I found in open sources, the pressure of a 1 megaton nuclear bomb at the moment of detonation reaches a peak of 17,000 MPa 10 meters from the epicenter and up to 5,000 Mpa in the hot air area. With this, we can get much better results. But can it be used?

 

[AkumaNoHissatsu]

bump

 

[KLOL506]

The calculation for the destruction of the surface uses a standard shock wave pressure of 1.37895 bars or 20 psi of pressure. However, why do we use standard pressure for such large-scale attacks? From what I found in open sources, the pressure of a 1 megaton nuclear bomb at the moment of detonation reaches a peak of 17,000 MPa 10 meters from the epicenter and up to 5,000 Mpa in the hot air area. With this, we can get much better results. But can it be used?

I believe the 20 psi is a low-ball for acquiring "near-total fatalities" values and for busting up concrete buildings and stuff.

 

[NikHelton]

Could you call the calc group members? According to such calculations, CSRS gives a great result

 

[KLOL506]

Could you call the calc group members? According to such calculations, CSRS gives a great result

I mean, the values you stated for your MPa values come from nuclear bombs, CSRS has no evidence of being nuclear. So I'm not sure if using those pressure values is a good idea for CSRS.

 

[NikHelton]

This applies to shock waves, but is it true when it comes to an explosion that will destroy the surface of the planet and turn everything in its path to dust?

 

[KLOL506]

This applies to shock waves, but is it true when it comes to an explosion that will destroy the surface of the planet and turn everything in its path to dust?

I suppose you could start by looking for pressure values on non-nuclear explosions that could cause that much damage.

 

[NikHelton]

All sources mention a nuclear explosion

 

[KLOL506]

All sources mention a nuclear explosion

Well that sucks.

 

[NikHelton]

Давление детонации — Википедия

ru.wikipedia.org

 

[NikHelton]

I was able to find it. Using the detonation pressure of the same TNT, we will get 18,000 Mpa

 

[KLOL506]

Давление детонации — Википедия

ru.wikipedia.org

Heh. Finally.

BTW, a google search tells me that detonation pressure of explosives can range from 10 to over 140 kilobars. 10 kilobar is 1000 MPa and 140 kilobar is 14000 MPa.

 

[NikHelton]

W = 20037500^3*((27136*10000+8649)^(1/2)/13568-93/13568)^2 = 11,725762 Zettaton = Low 5-B

And if you use the maximum value that you found, then this is

W = 20037500^3*((27136*140000+8649)^(1/2)/13568-93/13568)^2 = 165,52448 Zettaton = 5-B

 

[ByAsura]

To my knowledge, it's not uniform for nukes or meteors. The epicentre is 50-100 psi.

Edit: Misspoke hear, I meant near the epicentre. It decreases considerably from the epicentre.

 

[KLOL506]

W = 20037500^3*((27136*10000+8649)^(1/2)/13568-93/13568)^2 = 11,725762 Zettaton = Low 5-B

And if you use the maximum value that you found, then this is

W = 20037500^3*((27136*140000+8649)^(1/2)/13568-93/13568)^2 = 165,52448 Zettaton = 5-B

Oh Jesus, that's... pretty high, isn't it?

 

[KLOL506]

To my knowledge, it's not uniform for nukes or meteors. The epicentre is 50-100 psi.

Source for the psi values?

 

[NikHelton]

To my knowledge, it's not uniform for nukes or meteors. The epicentre is 50-100 psi.

Давление детонации — Википедия

ru.wikipedia.org

These are the pressure values of the explosives that I found. We don't have to refer to a nuclear explosion and a meteorite to get a good result.

 

[ByAsura]

Source for the psi values?

Here, here, here and here. Keep in mind, these are airbursts, but this outright proves my point using the epicentre isn't reliable. Conservation of energy is a thing, and would actually be even worse on ground level.

Давление детонации — Википедия

ru.wikipedia.org

These are the pressure values of the explosives that I found. We don't have to refer to a nuclear explosion and a meteorite to get a good result.

Firstly, why would small chemical explosives (probably their direct epicentre, as well) be preferable to actual large-scale shockwaves? In fact, Boros' attack was going to happen thousands of metres above ground level, so it's directly comparable to an airburst.

Secondly, although these results are consistent from what I could find, somebody botched that page. 18,000 MPa is equal to 2610679.3 psi, 180 kilobars is 2610.68 psi. Each result is either a thousand times lower or a thousand times higher.

 

[KLOL506]

Secondly, although these results are consistent from what I could find, somebody botched that page. 18,000 MPa is equal to 2610679.3 psi, 180 kilobars is 2610.68 psi.

Sounds like your converter's broken, I used this simple converter, 180 kilobars is 2610679.28413 psi. 1 kilobar is 1000 bars, so 180 kilobars is 180000 bars, and as you can quickly guess, 180000 bars is 2610679.28 psi.

 

[NikHelton]

Strange. I used a converter and it shows that 1 Mpa = 10 bar

 

[ByAsura]

@KLOL My mistake, then (well, more the google calculator), but all of the other overpressure results I've found for explosives are hundreds of times lower.

@Nik 1 MPa = 1 million bars.

 

[NikHelton]

Convert MPa to bar - Conversion of Measurement Units

Do a quick conversion: 1 megapascals = 10 bars using the online calculator for metric conversions. Check the chart for more details.

www.convertunits.com

 

[NikHelton]

Absolutely all converters say that 1 MPa is 10 bar

 

[ByAsura]

Sorry, my dinosaur brain read bar as pascal when you first said it.

Still, my other points stand. These kinds of PSI aren't uniform.

 

[NikHelton]

Could you then help find a detonation pressure that can be used?

 

[KLOL506]

Sorry, my dinosaur brain read bar as pascal when you first said it.

Still, my other points stand. These kinds of PSI aren't uniform.

the lowest I found was 10 kilobar (10000 bar) or 145037.7 psi or 1000 MPa (Once again check the link I shared)

 

[ByAsura]

the lowest I found was 10 kilobar (10000 bar) or 145037.7 psi or 1000 MPa (Once again check the link I shared)

I was talking to Nik there. I just misread something he said.

Could you then help find a detonation pressure that can be used?

As I said, 50-100 psi.

Also, it turns out the difference of hundreds is quite literally due to explosive overpressure varying by hundreds. Still, though, wide-spread explosions are more likely than the epicentre of powerful chemical explosives.

 

[NikHelton]

It is difficult for me to provide English-language sources, but I found information supporting 18,000 Mpa of TNT

Давление детонации — Карта знаний

Давле́ние детона́ции — давление во фронте детонационной волны в заряде... Заходите на сайт, чтобы узнать подробнее.

kartaslov.ru

 

[ByAsura]

That's not really support. It's just copy-pasted from the same source.

Like I said just above, though, they actually vary by hundreds of times. It's fine.

 

[NikHelton]

I was talking to Nik there. I just misread something he said.

As I said, 50-100 psi.

Also, it turns out the difference of hundreds is quite literally due to explosive overpressure varying by hundreds. Still, though, wide-spread explosions are more likely than the epicentre of powerful chemical explosives.

If it can't be used for Boros, then can it be used for the feat of Genos and Psykos, who created a colossal explosion in the shape of a sphere?

 

[ByAsura]

That depends, but I'd be tempted to say yes. Genos especially because even the fringes of his fireballs vaporize rock.

What did you have in mind specifically, if I may ask?

Edit: For a 15-metre fireball like I calculated the HoE feat as, it gets almost 9 kilotons. But that's assuming 15-metres is the radius and not the diameter (it decreases to a little over 1.1 kilotons with a 7.5 metre radius). A 100-metre fireball (50 metres in radius) will get just under 330 kilotons.

 

[KLOL506]

k bois, I helped as much as I could, now I disappear into the void, lemme know if you need anything else

 

[NikHelton]

That depends, but I'd be tempted to say yes. Genos especially because even the fringes of his fireballs vaporize rock.

What did you have in mind specifically, if I may ask?

Edit: For a 15-metre fireball like I calculated the HoE feat as, it gets almost 9 kilotons.

 

[NikHelton]

The diameter of the explosion was 3644 km

 

[ByAsura]

I don't want to say it's completely wrong, but the perspective is horrendous.

To give an example, continents look massive on a globe because the edges recede with the curve of the Earth. Flat maps counter this problem. It's like putting an apple in front of a basket ball to make it look a lot larger.

Plus, most of the explosion wouldn't be calculable if you were right. Almost 100% of the planet's atmosphere is concentrated 100 kilometres above the surface. The explosion variables are very, very different above the Karman line.

 

[NikHelton]

All the lines on the perspective clearly converge. Why is it bad?

 

[ByAsura]

It's not straight above the Earth from that perspective, it's much closer to the audience than the line of the horizon.

Like I said, if you get a basketball and put an apple closer to you and above the basketball, the apple will look much bigger than it actually is.

Edit: Solar eclipses are another good example, but it's even more warped in this example.

 

[NikHelton]

w = 0.61 * V ^ 2

I found a formula for wind pressure that gives values in Pascals.

Assuming certain time ends for which Boros destroys the planet, we can get the result.

 

[Qawsedf234]

However, why do we use standard pressure for such large-scale attacks?

That's the minimum overpressure needed to kill things like humans rather consistently iirc.

As for the other stuff with the Russian site, that's not how shockwaves work. With that much force The Earth wouldn't bounce the waves it would fold under them. So it's a rather massive energy highball.

 

[NikHelton]

The standard formula for destroying the earth's surface, which was a low-ball for CSRS Boros, looked like this:

W = 20037500^3*((27136*1.37895+8649)^(1/2)/13568-93/13568)^2 = 6.46570851e+17 tons of TNT or 646.57085 Petatons (Multi-Continent level)

We use a pressure of 1.37895 bar or 20 psi, but judging by these data https://www.atomicarchive.com/science/effects/overpressure.html this is the pressure generated by a shock wave at a speed of 502 miles per hour. However, with such a speed, the wave would cover the Earth only in a day.

Boros' feat implies a faster time character, but since this is only a test calculation that can be rejected, I will take 30 seconds as the high end, although it should be much higher.

Earth's radius = 6371 km;

Wave speed = 6371000/30 = 212366 m/sec;

w = 0.61 * V ^ 2 is the wind pressure in pascals

w = 0.61 * 212366^2 = 27510583953 pascal = 275105 bar

W = 20037500^3*((27136*275105 +8649)^(1/2)/13568-93/13568)^2 = 325 Zettaton = 5-B