Ask a physicist anything. (7)

[Zippy the Wonderslug]

I would imagine a controlled tongue.

That, and they aren't afraid of vacuums like us.

 

[Wiccan_Child]

What keeps animals from talking like humans?

The major reason is that they simply haven't evolved to. Humans are one of a few species that can communicate ideas with sound (dolphins are, famously, another such species), and there's some debate as to why we evolved this ability.

The vervet monkey has distinct calls for different predators, and the obvious advantage is that the troop gets advanced warning if one member spots the predator. Perhaps human language evolved for the same reason - we used basic calls to identify predators or prey, and it simply got more complex.

There's also a more physical limitation, in that most animals don't have the apparatus to make complex sounds like humans can (a dog can make a variety of sounds, but is largely limited by its snout).

 

[Chalnoth]

Pop question.

Why are tires on all cars not that very long in width?

More width = more friction = less fuel economy (as Wiccan_child noted). I also strongly suspect that with a wider tire, it would be more difficult to create a tire that displaces water, so that you might be at more risk of hydroplaning.

 

[FrozenOne]

Ok I'm asking then. What happens if the laws of physics change across the universe? More specifically, the data suggested that the value of alpha may change ever so slighty, and therefore change the laws of physics.

You will need to read the article below to see what I mean.

Laws of physics may change across the universe - space - 08 September 2010 - New Scientist

I hope there will be answers from both sides of the evolution-creation debate.

 

[Chalnoth]

Ok I'm asking then. What happens if the laws of physics change across the universe? More specifically, the data suggested that the value of alpha may change ever so slighty, and therefore change the laws of physics.

You will need to read the article below to see what I mean.

Laws of physics may change across the universe - space - 08 September 2010 - New Scientist

I hope there will be answers from both sides of the evolution-creation debate.

First, I'd like to point out that this result is highly unlikely to hold up under closer scrutiny. We'll see down the road if I am wrong, but basically the main complaint for this result is that it looks a lot like they're just fitting to the noise: in essence, they're trying to see these teeny tiny spectral lines from trace amounts of heavy elements in distant quasars. Many suspect that they're not actually seeing these spectral lines at all, but are instead simply seeing random noise.

That said, if I'm wrong, if this result does hold up, then what it would basically mean in this particular instance is that the strengths of the bonds of different molecules would vary across the universe. A type of molecule that is stable here might be unstable elsewhere, and vice versa.

 

[Wiccan_Child]

Ok I'm asking then. What happens if the laws of physics change across the universe? More specifically, the data suggested that the value of alpha may change ever so slighty, and therefore change the laws of physics.

You will need to read the article below to see what I mean.

Laws of physics may change across the universe - space - 08 September 2010 - New Scientist

I hope there will be answers from both sides of the evolution-creation debate.

If the laws of physics are capable of change, we'd see it in things like radiometric decay dates. We wouldn't get such coherent dates from independent dating techniques if the fundamental laws that govern their behaviour changed. They may change, but it'd be too small to have shown up in our measurements.

Across the universe, it's harder to tell. The laws of physics may change, but there's no real concrete evidence that they do, and all the evidence says they don't.

 

[Cactus Jack]

About radiometric dating. Explain both sides. Is it or is it not accurate?

 

[NGC 6712]

About radiometric dating. Explain both sides. Is it or is it not accurate?

Yes it is accurate. You should Google this - there are some excellent articles on the web about radiometric dating.

 

[Nabobalis]

About radiometric dating. Explain both sides. Is it or is it not accurate?

There isn't two sides. It is very accurate and some methods have strict rules for when to use them.

 

[Wiccan_Child]

About radiometric dating. Explain both sides. Is it or is it not accurate?

It is incredibly accurate. One of the most compelling reasons (beyond the sheer physics of it), is that we can date the same thing using a variety of techniques - several radiometric techniques, dendrochronology, etc - and we get the same age. If these things didn't work, there's the obvious question as to why they seem to work. If the physics was wrong, if radioactive decay constants changed over geological time, then we shouldn't get agreement across the board.

But since you asked for both sides, I'll attempt to elucidate the doubters' position. They believe that there are several fundamental assumptions made by radiometric dating that invalidate it. They may even cite specious arguments like "It's circular; the fossils date the rocks date the fossils", or, "They dated a living snail and it was thousands of years old!", or, "They carbon-dated a dinosaur and it was born yesterday!". These arguments are easy to refute (this whole thread is devoted to my enjoyment to explaining common misconceptions in science), but sadly they're tenacious.

The real reason, of course, is that radiometric dating contradicts their a priori assumptions - namely, that the Earth cannot be more than several thousands of years old - and so any number of fallacious pseudo-scientific arguments are made.

 

[Zippy the Wonderslug]

Was this ever made into some fully featured, documentary film?

The beauty of pollination - YouTube

I'm trying to look online for this but I'm getting nowhere on it.

Thanks!

 

[Non sequitur]

Does decayed radium have isotopes in it?

 

[Naraoia]

Does decayed radium have isotopes in it?

Everything made of atoms has isotopes in it. Isotopes are simply atoms of the same chemical element that have different numbers of neutrons. All atoms of the same element have the same number of protons, but they may vary in their number of neutrons - hence isotopes. The term has nothing to do with radioactivity.

 

[Non sequitur]

Everything made of atoms has isotopes in it. Isotopes are simply atoms of the same chemical element that have different numbers of neutrons. All atoms of the same element have the same number of protons, but they may vary in their number of neutrons - hence isotopes. The term has nothing to do with radioactivity.

Are isotopes "in" an element?

 

[Naraoia]

Are isotopes "in" an element?

Isotopes are different kinds of an element. Not sure what you mean by "in" an element...

 

[Non sequitur]

Isotopes are different kinds of an element. Not sure what you mean by "in" an element...

Someone seems to keep saying that isotopes are in an element.

 

[Wiccan_Child]

Someone seems to keep saying that isotopes are in an element.

They would be wrong .

 

[Non sequitur]

They would be wrong .

Maybe you can word that better than I can.

 

[Wiccan_Child]

Maybe you can word that better than I can.

Pfft, I talked to graydll in that thread before. It went something like this:

Her: Causality is universal. I know this because of common sense.
Me: Causality isn't universal, as demonstrated by various quantum phenomena: radioactive decay, quantum tunnelling, the Casimir effect, etc.
Her: I could find the cause of any one of those.
Me: Go on then.
Her: "Radioactive decay is due to particles having a wavefunction".
Me: [exhaustive explanation for why this doesn't say what she thinks she says]
Her: You're just mad that I found a cause for radiation with two seconds of Google!
Me: ...

Infuriating. I still lurk there, and kudos for your tenacity, but I shan't be going back

 

[Non sequitur]

Pfft, I talked to graydll in that thread before. It went something like this:

Her: Causality is universal. I know this because of common sense.
Me: Causality isn't universal, as demonstrated by various quantum phenomena: radioactive decay, quantum tunnelling, the Casimir effect, etc.
Her: I could find the cause of any one of those.
Me: Go on then.
Her: "Radioactive decay is due to particles having a wavefunction".
Me: [exhaustive explanation for why this doesn't say what she thinks she says]
Her: You're just mad that I found a cause for radiation with two seconds of Google!
Me: ...

Infuriating. I still lurk there, and kudos for your tenacity, but I shan't be going back

Well, hopefully they abandoned it.

Now, TScott is saying, "If one wants to ask what started the decay the answer would be whatever created the unstable matter..."

I see:

cause -> noun -> effect

manufacturing plant -> car -> car starts to run

Then again, I'm not a physicist or anything...