How big is a billion?

Yitzhak Rabin

When we are talking about billions of euros, which billion are we using?

Is it a) 1,000,000,000
b) 1,000,000,000,000

Because as I understand it, there are two different systems, one which uses a, and the other one b.

Fremen

The one with twelve zeros after it (a million million) is an old-fashioned English term. The modern convention is to name numbers in multiples of 1,000.

So:

1,000 - thousand
1,000,000 - million
1,000,000,000 - billion
1,000,000,000,000 - trillion
1,000,000,000,000,000 - quadrillion

You can see what these numbers look like in terms of cash here:
http://www.funny-potato.com/trillion-dollars.html

bnt

I remember, from school days, that they wanted to call 10^9 a Milliard, but this has pretty much gone now and everyone uses the American system.

Michael Collins

Just on a more qualitative level, I suspect a lot of people are wondering just how much a billion is due to all these "billions" we keep hearing on the news regarding bailing out the banks etc. I heard this way of showing just how big a billion is:

Imagine you get 1 euro every second, after 12 days you'd have 1 million, but it'd be 33 years before you'd have 1 billion!

sponsoredwalk

here is also a historical difference between billions, trillions, and so
forth. Americans use billion to mean one thousand million (1,000,000,000),
whereas in the UK, until the latter part of the 20th century, it was used
to mean one million million (1,000,000,000,000).
http://en.wikipedia.org/wiki/American_and_British_English_differences

:rolleyes:
Now it's [latex] 1 \ x \ 10^9 \ = \ 1 , \ 000 , \ 000 , \ 000 [/latex].

You'll have to accept an apology from Richard Feynman on this particular
question:

I wish to apologize for something that is not my responsibility: Physicists
and scientists all over the world have been measuring things in different
units, and causing an enormous amount of complexity. As a matter of
fact, nearly a third of what you have to learn[SIZE=-1] 1[/SIZE] consists of different ways
of measuring the same thing, and I apologize for it. It's like having money
in francs, and pounds, and dollars... with the advantage over money that
the ratios don't change, as time goes on.

For example, in the measurement of energy, the unit we use here is the
joule (J), and a watt (W) is a joule per second. But there are a lot of
other systems to measure energy. There are at least three different ones
for engineers, which I have listed here.[SIZE=-1]2[/SIZE]

The physicists do something else when they want to talk about the energy
of a single atom, instead of the energy of a gross amount of material.
The reason is, of course, that a single atom is such a small thing that to
talk about its energy in joules would be inconvenient. But instead of taking
a definite unit in the same system (like 10[SIZE=-1]-20 [/SIZE]J), they have unfortunately
chosen, arbitrarily, a funny unit called an electronvolt (eV), which is the
energy needed to move an electron through a potential difference of one
volt, and that turns out to be about 1.6 10[SIZE=-1]-19 [/SIZE]J. I am sorry that we do
that, but that's the way it is for the physicists.

The chemists also talk about the energy per atom. Since they don't use
the atoms individually but large blobs of them, in cans and barrels, they've
chosen a certain number of atoms as a unit. This number of things is
called a mole (mol), and it is 6.023 10[SIZE=-1]23 [/SIZE] objects. The more precise
definition, which is now correct or soon[SIZE=-1] 3[/SIZE] will be, is that one mole of
carbon-12 atoms has a mass of exactly 12 grams. A mole is just a certain
number of things. So, instead of giving the energy per atom, the chemists
give the energy per mole. It's good, therefore, to know how much energy
is a mole of electronvolts. In other words, if each atom had one
electronvolt of energy, a large number of atoms would have a reasonable
amount of joules, namely 96500 joules per mole. Incidentally, a mole of
electrons has a total charge of 96500 coulombs (C); these numbers are
equal for a reason you have to figure out.[SIZE=-1]4[/SIZE][SIZE=-1]
[/SIZE]
Now, there is an additional unit that the physical chemists use, the
kilocalorie per mole (kcal/mol), and 23 of those is an electronvolt per
atom. [ 23 kcal = 96500 J ]

Finally, unfortunately, you have another system for measuring masses.
The mass of an atom, from a chemist's point of view, is given by the mass
of a mole of these atoms. For example, the mass of carbon-12 is called 12
"atomic mass units" (u), because a mole of carbon-12 "weighs" 12 grams
(or rather "has 12 grams of mass"). One atomic mass unit represents one
gram for every mole of objects, one gram per mole. We can measure that
in electronvolts also. "You can't measure mass in electron volts!"[SIZE=-1] 5[/SIZE] Sure
you can, because of the relation E = mc[SIZE=-1]2 [/SIZE]... It is useful to know how
much energy corresponds to the consumption of one atomic mass unit of
material: That turns out to be about 931 million electronvolts (MeV).

Incidentally, the rest mass of a proton is 938 MeV, while the rest mass of
an electron corresponds to 0.511 MeV. The number 938 differs from 931,
because a proton has a mass of about 1.008 amu.

I am sorry about the confusion produced by all these systems of units.
I left out, obviously, a large number of different things. For example,
when measuring luminous[SIZE=-1] 6[/SIZE] energy, the lumen (lm) is used, which
corresponds to about 1.5 mW of power in the "most visible" light, around
5500 Å (ångströms). It's all very annoying, but don't worry about it now.

When you need to measure light, just look up in a book what a lumen is.
That's an unfortunate fact that we measure things in a whole series of
different kinds of units. This causes a lot of confusion.
It's too bad, but I have already apologized, and there is nothing else
I can do...
http://www.numericana.com/answer/feynman.htm