average life expectancy vs. time of human existence

[cpa77]

I'm not sure if this is the correct thread so pls forgive me if it is not. I am trying to figure out how to calculate the equivalency of one human life (80 years) to humans' time on earth (6 million). basically if 6 million years were equal to 80 years, what would one year equal? my goal is to compare 11000 years (out of 6 million) to how much time that would equate to in the average human life span. I want to do the same for life on earth (3.5 billion years).

 

[Dr.Peterson]

One year would be represented by 1 6-millionth of 80 years. That is, divide 80 by 6,000,000 to get the number of years.

Then you'll want to convert that to minutes. Give it a try. (The effort is good for you.)

 

[cpa77]

thank you! so 0.000013333333333 would equal one year. I would divide that number by 525,600 (the amount of minutes in a year)?
that is 0.000000000025368 would equal one minute?

 

[Dr.Peterson]

I think you're going in the wrong direction.

If 6,000,000 real years were represented by 80 years, then 1 real year is represented by 80/6,000,000 = 0.00001333 years. Now you want to know how many minutes there are in 0.00001333 years, right? The answer will be a larger number, not a smaller number.

 

[cpa77]

ok. so if 0.00001333 represents one year, what does that number equate to in measurements of time? You mentioned minutes so I'm assuming you have an idea but I do not really know how to figure that out. ultimately I need to figure out this:
if 6m years = 80 years
then
10,000 years = ??

 

[cpa77]

I did one equation where 10k years equaled 2.65 days but I am not sure I did that correctly

 

[cpa77]

another time I reached the conclusion that 10k years equaled about 12 hours but again, I do not know if I am using the correct formula

 

[Dr.Peterson]

Okay, I'll just do it for you.

If 6,000,000 real years were represented by 80 years, then 1 real year is represented by 80/6,000,000 = 0.00001333 years. Now you want to know how many minutes there are in 0.00001333 years, right? The answer will be a larger number, not a smaller number.

To convert 0.00001333 years (you keep citing the number without the unit, which I think is the cause of your difficulty) to smaller units, we multiply by the appropriate factors. First, to days:

[MATH]0.00001333\text{ years}\times\frac{365.24\text{ days}}{1\text{ year}} = 0.0048699\text{ days}[/MATH]​

To convert that to hours:

[MATH]0.0048699\text{ days}\times\frac{24\text{ hours}}{1\text{ day}} = 0.1168768\text{ hours}[/MATH]​

To convert that to minutes:

[MATH]0.1168768\text{ hours}\times\frac{60\text{ minutess}}{1\text{ hour}} = 7.012608\text{ minutes}[/MATH]​

So your one year is represented by about 7 minutes of a person's life.

Now multiply any of these values by 10,000 to get to your goal. I suggest using years (it will be a fraction) or days.

Another approach would be to skip the one year part, and just use one proportion directly:

[MATH]\frac{10,000}{6,000,000} = \frac{x}{80}[/MATH]​

May I ask: Do you ever use proportions or units? If not, then you really shouldn't even be asking this question, because you'll probably use the results incorrectly if you don't understand them.

 

[cpa77]

Sorry, I do not see an instance where I failed to refer to the unit... maybe I’m just misunderstanding what you mean but I mentioned years, days and hours every time. Thank you for your help, I believe the answer I was looking for was approximately 48 days.

 

[Dr.Peterson]

Yes, it's about 49 days (48.7, rounded up).