Which constant should we send to aliens?

1. Jan 24, 2005

danne89

Suppose we get contact with some aliens, which number constant should you send to test their "intelligence"?

2. Jan 24, 2005

Ryoukomaru

I would send $$\phi=1.61803399$$ - The Golden Ratio

3. Jan 24, 2005

master_coda

How exactly would we send that number? Without an encoding they could understand, it wouldn't matter what number we sent.

4. Jan 24, 2005

Well, ignoring that problem, I would say (pi^2)/6

5. Jan 24, 2005

Alkatran

e^(pi*i) + 1 = 0

6. Jan 24, 2005

WORLD-HEN

You could send them a golden rectangle.

7. Jan 24, 2005

Gokul43201

Staff Emeritus
Something simple, representation invariant and universally true, like :

** *** ***** ******* *********** *************

8. Jan 24, 2005

fourier jr

yeah, send prime numbers, just like in that movie contact

9. Jan 25, 2005

cepheid

Staff Emeritus
"The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us."

--Bill Watterson, cartoonist

10. Jan 25, 2005

gimmytang

natural constant e=2.718...

11. Jan 25, 2005

gimmytang

maybe aliens tried to contact us through microwave 200 years ago, but at that time nobody could sense that.

12. Jan 25, 2005

Chronos

Dimensionless numbers, like the nuclear fine structure constant. That would almost surely set off alarms no matter what base system they used to count. Transmit it in binary code [on-off bits]. Even a far advanced intelligence would recognize that pattern.

Last edited: Jan 25, 2005
13. Jan 25, 2005

Gonzolo

Yeah... like $$\pi$$ is so B.C. ...

14. Jan 25, 2005

Alkatran

Actually, I think a good start for the data you send is:
1010101010101010101010101010101010101010101010101010
followed by
11001100110011001100110011001100110011001100110011001100
111000111000
etc...

You know, so they know it's not random.

15. Jan 25, 2005

dextercioby

Euler-Mascheroni constant:
$$\gamma=:\lim_{n\rightarrow +\infty} (\sum_{k=1}^{n} \frac{1}{k}-\ln n)$$

$$\gamma\sim 0.577215665$$

Daniel.

16. Jan 25, 2005

danne89

The problem with this it that even chimpancies can send this sequence.

I don't think pi is good neither. Think about a gas-world, like Jupiter, where solid objects don't exist in the way we know. Would they found this number without have some motivation of real circles?

17. Jan 25, 2005

arildno

Well, all sorts of exotic numbers might do, of course (for example, Brun's constant because Brun was a Norwegian..).

However, I've yet to see any suggestions simpler and more elegant than a repeating sequence of the first few prime numbers.

18. Jan 25, 2005

arildno

ABSOLUTELY NOT!

19. Jan 25, 2005

dextercioby

WHY not,Arildno???Do you have motivation??

Daniel.

20. Jan 25, 2005

Gonzolo

There is always the Sun, and moons. I don't believe intelligent life can exist without solids. Wouldn't a zero-g ameoba tend to be round? Isn't the symmetry of a hydrogen atom round?