Ki blasts destroying the planet

[Fox666]

I think it's the same case with the Genki-Dama Goku used on Vegeta. He said it would take on Oozaru Vegeta, but couldn't take regular Vegeta. Okay, the Genki-Dama only had half of it's power, but Vegeta was 1/10 weaker!

It's just a plot shift to make the enemy look tough by surviving anything.

[Piccolo Daimao]

When Goku asserted that Namek's explosion was what caused Freeza to hold back, it's met with laughter. Add that to Freeza's later "if I get caught in the explosion I may lose a good deal of my power" or whatever and the fact that an even weaker Freeza did survive it, and I think it paints a pretty convincing picture that Goku was just talking out of his ass.

It was met with laughter because Freeza knew that he'd detonated the core, so the planet would explode in five minutes anyway. Why would Goku be talking out of his ass when he has good reason to think that Freeza could've died in the explosion, or at least been severely injured? There's nothing to contradict it. And just like you said, Freeza says, "If I get caught in the explosion, I may lose a good deal of my power."

And even Freeza said to Goku, "Will you die in the explosion? Or would you survive it, only to die in space?" If Goku's even or stronger than Freeza, why would he mention the possibility of him surviving it?

Just for reference, here are some of the quotes:

Chapter: 320 (DBZ 126), P9.2
Context: after it turns out Planet Namek didn’t blow up
Freeza: “Chih…! Did I suppress my power too much…?!”
Goku: “It’s because you were afraid of getting caught up in the planet’s explosion yourself…You screwed up. Though thanks to that, I survived…”

Chapter: 320 (DBZ 126), P10.1-4
Freeza: “Though we’ve avoided having the planet instantly explode, its core has been destroyed…Do you know what that means? Even if left alone, after 5 minutes this time there will definitely be a huge explosion, and Planet Namek will become space dust…”
Goku: “What!?...5 minutes will be enough for me to defeat you and escape in the spaceship I rode here from Earth.”

But anyway, I agree with your earlier explanation now, that it's just for the plot.

[CatouttaHell]

No amount of ki control will change the fact that blasts from characters in the Boo arc (fat Boo's Kame that made direct contact with the Earth also comes to mind) should've been more than powerful enough to destroy the Earth 100 times over. AT wrote himself into a corner with this one.

Nevermind even the Boo Arc. 530,000 Freeza could easily destroy a planet as large as Planet Vegeta, and yet in the Cell Arc you have guys a thousand times stronger confining their fight to a tiny road.

[ggf31416]

Dragon ball simply doesn't follow the our laws of physics.

I believe that the oozaru transformation and piccolo becoming a giant increased their masses. Unless oozurus are 99% compressed air or dirt taken from the enviroment, the saiyans would have to create mass to transform.
The energy required to create that mass would be equivalent to many gigatons or teratons of TNT. There is no way that child goku could have such energy. That implies that the energy/matter conversion factor is much lower (lower light speed?) than in RL(real life) . Also it would mean that the oozaru would have less energy than a base form.

However the energy required for a planet buster attack would be over 10^32 J. 1 Kg = 9 * 10^16 J, so it would require over 10^15 kg = over 1000000 millions (one trillion) tons of matter to become energy. There is no way they have so much mass and energy in their bodies. That implies that the energy/matter conversion factor is much higher than in RL.

That means that the energy/matter conversion would have to be both higher and lower than in RL, which wouldn't make sense or that the laws of conservation of energy and mass don't apply.

If our physic laws don't apply, for all we know, planets may have anti-matter cores, insulated by weak magnetic fields, that would destroy the planet if mixed with the rest of the planet as a result of a blast.

There are many problems in dragon ball. For example master Roshi's kamahameha that was able to destroy only a small montain shouldn't be able to destroy the entire moon. Also the fragments of the moon should have destroyed most of the life on Earth.

[Hellspawn28]

It's because of Ki control, and I think most fans should know this by now. If they always use their full attacks in combat then they would kill everyone on the Planet, and ending the series. The same reason why most superheros in comics like Superman, Thor, and Silver Surfer don't go all out in battle.

Like most people said, Freeza never blow up Namke because he would not get caught in the blast. I remember Viz made a error with him saying that his attack was not strong enough.

[Savage68]

The same reason why most superheros in comics like Superman, Thor, and Silver Surfer don't go all out in battle.

When they do, hardly anything significant happens. See: All-out Sentry and World War Hulk fighting each other. All-Out Superman fighting Wonder Woman. All-out Thor fighting Bor. The most you'll see is large craters and broken buildings. This brings us back to that whole "Earth has plot armor in comics because it needs to have plot armor" thing.

Like most people said, Freeza never blow up Namke because he would not get caught in the blast.

I think only one person said that.

[Bussani]

That means that the energy/matter conversion would have to be both higher and lower than in RL

Or that ki isn't a form of mass-energy.

[Kid Buu]

Are these any Cell and Buu arc examples of Ki Blasts hitting the earth and not exploding the planet?

I think Gotenks SSJ3 did it.

[Kaboom]

Are these any Cell and Buu arc examples of Ki Blasts hitting the earth and not exploding the planet?
I think Gotenks SSJ3 did it.

Yeah. At one point, Gotenks is throwing a massive barrage of blasts down at Boo who's in the ground, and Piccolo tells him to cut it out or else he'll destroy the planet.

Also earlier, SSj3 Goku and Fat Boo smack a Kamehameha back and forth. It flies off into the distance, and was said to take out a good chunk of the planet when it exploded.

[BDL]

I've debated about this recently and my speculation is : there are several types of Ki Blast which harmful to the planet and not. The Harmful one beside contains so much annihilator energy and atomic explosion effect , it has solid form. So after hit something it's not immediately explode but flying through everything till reach it's unstable form and then explode. In other words, Vegeta's Galic Gun is this type of attack . If it's fired and then maybe crush Goku's body, the blast would still in form , digging through the Earth surface into the core and then explode. Final Flash, Goku's, Gohan's and Cell's Kamehamehas show like that too. Either one is Immediately Explode Ki Blast. This one has 2 types too : Atomic Explosion Effect and not. Just like it's name, this type of attack would immediately blow up after hit target. The powerful one maybe make great explosion and damage on surface but still not enough to completely bust the planet.We've seen many of this type of attack in Manga. And there is a Ki Blast with much destructive power on target but rather harmless to the area. This one like Spirit Bomb and probably Hell Flesh and Light Grenade.

[Bussani]

And there is a Ki Blast with much destructive power on target but rather harmless to the area. This one like Spirit Bomb

Kaio warned that it can destroy the very planet you're trying to protect if you're not careful.

[BDL]

And there is a Ki Blast with much destructive power on target but rather harmless to the area. This one like Spirit Bomb

Kaio warned that it can destroy the very planet you're trying to protect if you're not careful.

Maybe if it miss the target and hit the planet.