Can a 10 kg iron ball travel at the speed of light break through the earth?

First of all, the 10kg iron ball can not be accelerated to the speed of light; second, it has nothing to do with the mass, but whether there is quality.

Not to mention 10kg iron ball, even if a tiny dust reaches the speed of light, it is the weight that the whole universe can not bear.

How do we understand the speed limit of light

According to the theory of relativity, the energy needed to make a mass object reach the speed of light will be infinite. However, even if the universe is vast, there is no room for an infinite amount of energy.

Because of the law of conservation of energy, energy will not be created out of nothing and will not disappear for no reason. It will only change from one form to another. If we want to use the infinite energy to accelerate a dust particle to the speed of light, is it not equivalent to squeezing out the universe?

It's incredible that the vast universe was crushed by a grain of dust!

Therefore, in the macro world, the universe does not allow mass matter to reach the speed of light, but this does not mean that the relative speed of two objects can not exceed the speed of light. For example, galaxies outside the observable universe are far away from us at super light speed.

That is to say, all matter can not exceed the speed of light, which refers to the speed of the object moving in the background of space and time. If space-time itself is moving (or it shouldn't be called motion), then there is no limit.

For example, in the collapsed black hole space-time, when light crosses the visual interface and approaches the singularity, according to the relativistic field equation, the time term will become negative and the negative value will increase continuously. When infinity approaches the singularity, the time term tends to be negative infinity, while the space term starts to decrease and tends to 0. In other words, space is transformed into time, or even into negative time.

What does negative infinity mean? No one is not sure, but some people say that objects falling into a black hole will move towards the singularity at a speed infinitely close to the speed of light, but will never reach the singularity.

In fact, the reason why the speed of light is the upper limit of the speed of matter in our universe is because of the limitation of three-dimensional space. If we want to break through the limit of three-dimensional space, we must break the limit of three-dimensional space, but once the limit of three-dimensional space is broken, it will be locked into the singularity. However, even if the collapse speed of the singularity of a black hole breaks the absolute speed of light, we can not observe it at present.

What happens if the iron ball is accelerated regardless of energy?

I dare to change the angle to explain.

If the iron ball is always provided with accelerated energy, when the speed of the iron ball is close to the speed of light, even if the vacuum temperature is only 3k, the iron ball will become like a furnace, burning the three-dimensional structure of the iron ball.

From this point of view, the speed of light means that light has no three-dimensional structure at all. To some extent, the three-dimensional structure may be a more fundamental speed limit than mass. The micro particles such as protons, neutrons and electrons can not reach the speed of light, which means that they still have a certain three-dimensional structure.

Therefore, if the iron ball wants to reach the speed of light, it can only take off the "three-dimensional body" and burn it to become a little light sprinkled on the earth. The earth just increases its temperature just like bathing in the sun.

Or become high-energy neutrinos, passing through the earth, leaving no trace at all.

Generally speaking, the speed of light only applies to intangible objects, which are incompatible with tangible three-dimensional objects such as iron balls.