Common sense is useless in science!

[Tiberius]

Excellent video explaining how common sense is useless in science:

[Kyuuketsuki]

Brilliant!

Ta

Kyu

[theVOID]

Great video.

You the Tiberius from Athiest Blogger?

If so, your blog rocks.

[leo-rcc]

(12th August 2009 10:35)theVOID Wrote:  You the Tiberius from Athiest Blogger?

If so, your blog rocks.

He is, and yes it does.

[theVOID]

About that birthday thing:

365 days in the year
30 people in the class
1/2 chance of 2 people sharing a birthday?

I can't figure that one out.

[Tiberius]

(12th August 2009 10:35)theVOID Wrote:   Great video.

You the Tiberius from Athiest Blogger?

If so, your blog rocks.

I am. Thanks for the kind words

(12th August 2009 10:45)theVOID Wrote:  About that birthday thing:

365 days in the year
30 people in the class
1/2 chance of 2 people sharing a birthday?

I can't figure that one out.

It's known as the "Birthday paradox", but the math is quite simple. It's easier to do in reverse. Suppose that we wanted to calculate the chances that 2 people did not have the same birthday.

If you have one person in the room, they have a 365/365 chance of not sharing a birthday (since there are no others in the room). If you add another person, they have 364/365 chance of not sharing a birthday (since there are only 364 days left that are not already taken.

If you have 30 people in the room, the calculation looks like this:

365/365 * 364/365 * 363/365 * 362/365 * 361/365 * 360/365 * 359/365 * 358/365 * 357/365 * 356/365 * 355/365 * 354/365 * 353/365 * 352/365 * 351/365 * 350/365 * 349/365 * 348/365 * 347/365 * 346/365 * 345/365 * 344/365 * 343/365 * 342/365 * 341/365 * 340/365 * 339/365 * 338/365 * 337/365 * 336/365

So the probability of 2 people *not* having a common birthday out of 30 people is 0.293683757.

To get the probability of 2 people having a common birthday, you simply need to subtract our result from 1:

1 - 0.293683757 = 0.706316243

So in a room of 30 people, you have a 70.6% chance of finding 2 people with the same birthday.

Q.E.D.

You can read about the problem here: http://en.wikipedia.org/wiki/Birthday_problem

[theVOID]

Astounding.

I may have to start studying statistics.

---

Back from wikipedia...

Cool, that actually makes sense when considering pairs.

Any other good mindfucks that you lot know of?

[Tiberius]

(12th August 2009 12:19)theVOID Wrote:  Any other good mindfucks that you lot know of?

I can prove that 0.999... (recurring) is equal to 1:

x = 0.999...
10x = 9.999...
10x - x = 9.999... - 0.999...
9x = 9
x = 1

Therefore x = 0.999... = 1

More on that here: http://en.wikipedia.org/wiki/0.999...