Introduction

Which weighs more, a ton of feathers or a ton of gold? Your System 1 might immediately intuit that gold is heavier, while your System 2 would probably reason that a ton of anything weighs the same: a ton. The full answer, as you might guess by this post's existence, is more complicated.

A ton of tons

Living in the United States, a ton means 2000 pounds to me. However, there are at least 3 common definitions of ton used today:

  1. A long ton: used in the UK, 2240 pounds
  2. A short ton: used in the US, 2000 pounds
  3. A metric ton (tonne): used in the International System of Units, 1000 kilograms

Apparently, the ton longweight is another type of ton historically used in the iron industry. I don't care about the iron industry from a few centuries ago.

The answer is whatever you want, depending on where you are

As a quirk of linguistics, since “ton” and “tonne” are pronounced the same, if you asked this question verbally, you could generate at least 4 versions:

In the US (a short ton weighs1 less than a metric ton):

  1. … a tonne of feathers, or a (short) ton of gold? (feathers weigh more)
  2. … a (short) ton of feathers, or a tonne of gold? (gold weighs more)

In the UK (a long ton weighs more than a metric ton):

  1. … a tonne of feathers, or a (long) ton of gold? (gold weighs more)
  2. … a (long) ton of feathers, or a tonne of gold? (feathers weigh more)

4 versions! How did we let this happen? Think of the children!

Another version

Perhaps we could re-word the question to be less ambiguous: which weighs more, a pound of feathers or a pound of gold?

Because someone is out to get you, specifically you, the troy weight system exists. The troy system is used to measure precious metals. The troy pound is lighter than the avoirdupois pound, the one that normal people actually care about.

So the answer is deterministic this time: the pound of feathers weighs more, as long as you aren't normalizing the units for comparison.

Yet another version:

Then, surely, mercifully, an ounce of feathers also weighs more than an ounce of gold?

No! Did we not just state that someone is out to get you? By some anti-miracle, the troy ounce is heavier than the avoirdupois ounce! Screw you!

Conclusion

The world of units is a world of darkness.

  1. Some people might take issue with my use of the word “weigh” since the ton is a measure of mass. Get out of here, high school physics teachers! ↩︎