/sci/ - Science & Math

He's an ethologist and evolutionary biologist, just skim over the physicsy bits.

The number of reached planets should be (effectively) proportional to the volume of expansion, which would work out to the radius cubed.

This, of course, is proportional to the time since the broadcast cubed.

Unfortunately that damned inverse-square law makes the signal exponentially insubstantial as higher distances are achieved.

Inverse square law

>>3085651
The total number of planets reached is <span class="math">\propto r^3[/spoiler] ("volume the radio signal is boundary of), but the number of planets currently reached is <span class="math">\propto r^2[/spoiler], since the wavefront is a spherical surface.

>>3085676 inverse-square law makes the signal exponentially
>x^(-2) = exp(-x)

>>3085664
>Implying he publishes shit without checking
>Implying biologists are unaware that volume rises as r^3 and area as r^2
>Implying you know physics better than Dawkins

>>3085651
First the number of planets reached so far will be something about N~r^3, after that, when r is about the thickness of the galaxy, N~r^2, than N~r^d, where d is something between 1 and 2 (as far as I remeber, it's the dimension of space on galactic level).

>>3085690
I'm used to using the term "exponentially" to mean "dramatically." Forgive me.

>>3085720
People make mistakes dude. I was reading a physics book where the guy passively labeled Aluminum as element 14. It happens.

His point, and Dawkins's, are intact.

>>3085720

Hey, you know, I'm just looking at it occupation-wise. I would give Dawkins some leeway about topics in evolution and other biological science shit like that, but if it's something else he doesn't officially specialize in, I would hold him in no higher regard than a typical college student writing a research paper.

>>3085758
Well that's wrong, so make yourself unused to it.

(While we're at it, quantum leaps are pretty awfully small.)

Right then.

I thought it might be important because I watched a documentary voiced by Morgan Freeman (apparently he knows a lot about black holes). It said that entropy had been shown to increase by the square and not the cube (of radius I suppose) as might be expected for a volume, and this led to discovery of the holographic principle. You see the apparent relation.

>>3085782
How about you relieve your draconian insistence and allow someone to make a mistake of common parlance once in a while. Was my point invalidated? No.

>>3085786
The surface of an event horizon goes like the radius squared, so this is not a surprise.

>>3085651
Something a lot of people tend to gloss over is the inverse square law in relation to our radio broadcasts.

Yeah, in 2000 years, our broadcasts will have reached pretty far, but I seriously doubt you'd be able to pick us out from the background noise unless you were specifically looking right at us.

>>3085720
>Baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaawkins
>Biology

It's like I'm really in the 70s

>>3085791
You had as much of a point as "the moon is made of cheese", so no, your point was not invalidated.

>>3085796
That's why we should broadcast and search in the "water hole." That would improve our chances of contact by a shitload.

>>3085804
>The moon is made of cheese
>There is a dropoff of broadcast signal effectiveness as distance increases
>Same validity

I'm sorry, I usually don't keep tabs on tripfags. Is this guy always this much of an asshole?

>>3085818
With that attitude when somebody corrects you I see a golden future in science for you, woohoo

>>3085826
I thought "forgive me" was a great response to being corrected.

>>3085690
>>3085676 inverse-square law makes the signal exponentially
>x^(-2) = exp(-x)

Are you saying that -2 doesn't qualify as an exponent? That doesn't sound right to me.

>>3085879
Polynomial: <span class="math">x^n[/spoiler], exponential: <span class="math">n^x[/spoiler]. (Depends on the application over which domain of n you consider the polynomial case polynomial, e.g. it's sometimes convenient to call <span class="math">x^{-2}[/spoiler] polynomial as well, although mathematically wrong)

>>3085879
Exactly. Which is why I said it. I'm used to "exponentially" referring to a behavior that uses an exponent that's greater than one (or less than -1).

Recently I've realized that it specifically refers to a set base with an EXPONENT that's in terms of x. This still produces a diminishing or inflating curve but the behavior is different. "Exponentially" has a pretty specific definition.

So I made a slip up, and so did you. Note the two extremely different ways in which were notified of our error.

Also note that "golden future in science" can specifically refer to "quasar field research while browsing /sci/" so it's certainly not a bad thing.

>>3085776
People do indeed make mistakes, but this fact does not have anything to do with what I was arguing against, which is the poster's idea that Dawkins doesn't know basic geometry. Even if Dawkins made a mistake, it has nothing to do with the fact that it's not evbio he was talking about. "skim over the physicsy bits" is bullshit.

>>3086041
Yup. And I should have quoted the person YOU quoted instead of quoting YOU.

Mistakes all up in this bitch.

Don't just skim over the physicy bits, don't bother reading the entire thing, all he does is restate and redefine the obvious in a pseudo-intellectual shelf-filler coffee-table novella format, with the short chapters and thick margins.

Don't get me wrong, there's nothing wrong with using layman's terms to explain something, but he doesn't just do this, he oversimplifies, so it's a shit book on par with the da vinci code.

>>3085782
>>3085804
>>3085826

stop being such an aspie.

>>3086093
I forgive you <3