Can You Go Fast Enough to Get Enough Mass to Become a Black Hole?

Disclaimer: Before we start, it’s worth pointing out that the mass of something isn’t actually affected in any way by the speed at which it is traveling, despite what you’d find in the outdated teachings and textbooks of the past. Einstein’s theory of Special Relativity disproved this theory long ago, yet it’s still widely believed that speed affects mass, and for a while, it was taught this way in schools and colleges. I may not be Einstein himself, but in this article, I’m going to explain why this is fake news, and why you cannot go fast enough to get enough mass to become a black hole.

So, Did The Scientists Get It Wrong?

If you skipped a few too many science lessons in high school, let me just remind you that science is one heck of a complicated subject where theories are proved and subsequently disproved.

All. The. Time. 

Doesn’t anybody remember when we thought the earth was flat? Or when Pluto was still a planet? This isn’t the first time, and I’m sure it isn’t the last either.

The likely reason behind the widespread belief that speed affects mass is because ‘relativistic mass’, which is not the same as regular mass, could potentially actually gain mass as it gains speed. It seems a natural leap from here to assume humans can become a black hole… doesn’t it?

I won’t go off on too much of a tangent, but it’s essentially the confusion of these two totally different masses that misleads the majority of people who believe that speed affects mass.

If an Object Doesn’t Gain Mass, What Does It Gain?

We established pretty early on that objects do not, in fact, gain any mass as they gain speed, and therefore cannot become a black hole but one thing they do gain is kinetic energy.

Again, for the science class truants among us, the kinetic energy can be added to the rest energy of an object (which is, interestingly, in its mass) to tell you its total energy.

What is Relativistic Energy?

The following is the equation for relativistic energy:

E = MC2/(1-V2/C2)½

In this equation, E stands for the relativistic energy, M stands for mass (which doesn’t change, don’t forget!), C represents the speed of light (which is 299,792,458 m/s, in case you were wondering), and V is the speed of the object.

When an object is still, V = 0, leaving E = MC2.

So, you can use this equation to work out the mass-energy equivalence. The rest energy would therefore equal MC2, indicating that the rest energy is contained within the mass.

And That Means...

In equation speak, it means:

EK = MC2 (1/(1-V2/C2)½ -1)

In English, this translates to the fact that as the speed increases, the kinetic energy increases also.

It shows that EK is the reset energy taken off of the total energy, but it also reinforces that the mass of the object does not change.

Fun fact: even when an object is traveling at speeds that are almost as fast as the speed of light in a vacuum, said object will have an infinite amount of kinetic energy.

However, this doesn’t apply to objects that have mass due to the amount of energy required, but objects with mass can still achieve speeds that are pretty impressive.

More on Mass!

An object’s mass refers to two things:

  1. The amount of resistance an object has to acceleration - objects with a larger mass accelerate at a reduced rate when there is force being applied.
  2. The ability of an object to react to gravity and work within its limitations. The greater the object’s mass, the greater force it will experience from its gravitational field.

No matter how fast an object is traveling at, its resistance to acceleration is not altered nor is its ability to feel the pull of gravity, and therefore neither is the mass affected by fast speeds.

Einstein said it first, but it’s been backed up by scientists and experiments which prove this to be true ever since, which is why you’re hearing it from me, now.

What About Turning Into a Black Hole? Is It Possible? Give Me Answers!

Here it is, the answer to the question you’ve all been waiting for…


Unfortunately (but I mean also luckily, I guess?) objects, and therefore humans, cannot gain enough speed or travel fast enough that they would get enough mass to turn into a black hole.

It’s literally not at all possible on account of not being able to gain mass through speed.

Even if you hit speeds that matched the speed of light, it would still make no difference to your mass levels and you’d be no closer to becoming a black hole than if you were sat on the sofa watching a Netflix film about space - it’s not like there aren’t plenty of those.

How Do black Holes Form?

There’s still a lot to learn about the things that go on above us up in the night sky and beyond, but one of the most commonly known and understood causes for a black hole is when a large star reaches the end of its life cycle and collapses in on itself as it implodes.

You might be surprised to learn that a black hole doesn’t actually claim any space, but it does have a mass which would have belonged to what was formerly a star.

Despite not taking up literal space, black holes become ‘larger’, or more massive to use the technical term, as they consume the matter that surrounds them.

As you’ll have probably seen in a space movie or two, anything that crosses over the horizon of a black hole is unlikely to return.

They continue to grow and expand, enfolding anything from stars, planets, spaceships that find themselves in the wrong place at the wrong time, and even other black holes, until they evolve into a supermassive black hole.

Gordon Watts