Which is larger: the number of meters across the Milky Way, or the number of cells in all humans? Explain or show your reasoning.

Some useful information: The Milky Way is about 100,000 light years across; There are about 37 trillion cells in a human body; One light year is about 10^16 meters; The world population is about 7 billion.

Respuesta :

Answer:

there are more cells in all humans than the number of meters across the Milky Way

Step-by-step explanation:

Here we are told that 1 light year is equivalent to:

[tex]1ly=10^{16}m[/tex]

We also know that the diameter of the Milky Way is

[tex]d=100,000 ly[/tex]

Therefore, the diameter of the Milky Way in meters is:

[tex]d=(100,000)\cdot (10^{16})=10^5\cdot 10^{16}=10^{21}m[/tex]

On the other hand, the world population is about 7 billion:

[tex]p=7\cdot 10^9[/tex]

Every human body has about 37 trillion cells, which corresponds to

[tex]n=37\cdot 10^{12}[/tex]

Therefore, the total number of cells in all humans is

[tex]N=np=(37\cdot 10^{12})(7\cdot 10^9)=2.6\cdot 10^{23}[/tex]

The second number is larger: therefore, there are more cells in all humans than the number of meters across the Milky Way.