What happens when a needle hits the Earth at the speed of light?

With classical physics, you would expect nothing to happen.

The mass of an average needle is around 1 gram, or around 0.001 kg.

The mass of our planet is an immense 5.9 x 10^24 kg.

The needle is moving at the speed of light, or around 300,000,000 m/s.

The Earth is moving at a much lower speed, 30,000 m/s.

And if you use conservation of momentum, you will find that there is literally no reaction between the two. Although the needle is moving at such a high speed, the mass of the Earth is so comparatively immense.

However, with relativity, as an object approaches the speed of light, its momentum approaches infinity.

Because of this, it doesn’t matter what the mass or velocity of the object the particle at the speed of light is striking, since it has infinite momentum, the collision will result in a massive loss of kinetic energy.

And such a wave of kinetic energy, combined with the impact of the collision, will probably destroy our planet and all life on it.

So let’s hope that a harmless needle doesn’t suddenly get a grudge against our planet and decide to attack it.

This information was taken from Quora. Click here to view the original post.

Can you imagine a single needle to be so dangerous?

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What are your thoughts on this subject?
Maridel Lemming
Wouldn’t the needle burn up, moving that fast towards the earth? Like the junk that falls now?
May 28, 2020 4:12PM
Jo Farrell
Having read the article and some of the comments, I think it would make a great story line for a film. 😄
May 23, 2020 4:39PM
Wyla Reedy
I have a little trouble believing this. How could you get a needle to go that fast? How big would it have to be? What would it be made of? Etc.
May 6, 2020 2:56PM
Prakash George
The Theory of Relativity put forth by Einstein's equation of mass-energy equivalence says that mass and energy are inter-convertible. It is postulated that any mass attaining the speed of light is converted to energy. A 'needle mass' converted to energy need not cause any such damage.
May 5, 2020 4:07PM
arnoldburke, Who said it was outside the atmosphere?
May 1, 2020 7:37AM
jjbjjc, nobody said it was coming from outer space.
May 1, 2020 7:36AM
Carol Butler
I will now officially stop worrying about the nuclear arsenals of such places as North Korea , Russia, and other enemies. Thanks!
May 1, 2020 2:58AM
It would take too much energy to accelerate a solid object to the speed of light to make it feasible but it's a good thought experiment, thanks.
May 1, 2020 2:32AM
Ha-ha-ha! Very funny and knowing Mama Gaea would not allow it. Naughty needle. Thank you for a physics lesson Quiz Folks. Be well and safe.
Apr 30, 2020 11:23PM
Yolanda Solis
Interesting but not likely to happen!
Apr 30, 2020 10:26PM
It would burn up prior to impact.
Apr 30, 2020 7:53PM
Donald McBurney
don't believe it.the needle wouid pass through so quickly we wouldn't know it.math on subjects like this is complex and it is just theory about infinite mass and can't be proven.
Apr 30, 2020 5:25PM
At the speed of light a needle would most likely be destroyed by the atmosphere before it reached the ground, just an observation from a high school drop out.
Apr 30, 2020 4:55PM
I've had a lot of experience with science and I enjoy testing theories. I know it's strange, but a needle will cause a tremendous bang!
Apr 30, 2020 3:32PM
nfridaymoose, This is not a question of your religious beliefs, but a question about theory. They are mutually compatible. Don't be so quick to say Jesus all of the time.
Apr 30, 2020 3:30PM

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