Ask a physicist anything. (5)

[Cabal]

Why not? H and H[sup]-[/sup] are both elements, even to you, yet they behave differently: the latter, for instance, can be manipulated by EM fields, unlike the former. Does that mean ionized monoatomic Hydrogen is a different element to neutral monoatomic hydrogen?

Moreover, isotopes of Hydrogen (such as deuterium and tritium) behave differently to Hydrogen, and these differences have proven very useful. But does that mean isotopes of Hydrogen count as different elements?

Are we talking specifically about chemical differences here? I would say they're comprised of the same element as they haven't changed proton number.

Regarding ions, I'd just call them ions, seeing as elements must be neutral - it would be a misnomer to call them elements.

(I suspect however that I'm basing my argument on a faulty definition of element that I was taught - possibly a pre-Dalton one *ulp*)

 

[LittleLambofJesus]

Are we talking specifically about chemical differences here? I would say they're comprised of the same element as they haven't changed proton number.

Regarding ions, I'd just called them ions, seeing as elements must be neutral - it would be a misnomer to call them elements.

(I suspect however that I'm basing my argument on a faulty definition of element that I was taught - possibly a pre-Dalton one *ulp*)

Ion cannon - Wookieepedia, the Star Wars Wiki

An ion cannon was a weapon which fired highly ionized particles or highly ionized plasma.

YouTube - Adywans Empire Strikes Back Revisited - Hoth Ion Cannon Shot

 

[Wiccan_Child]

Are we talking specifically about chemical differences here? I would say they're comprised of the same element as they haven't changed proton number.

Regarding ions, I'd just called them ions, seeing as elements must be neutral - it would be a misnomer to call them elements.

(I suspect however that I'm basing my argument on a faulty definition of element that I was taught - possibly a pre-Dalton one *ulp*)

So, to you, 'element' is a synonym for 'atom'?

 

[Cabal]

Ion cannon - Wookieepedia, the Star Wars Wiki

An ion cannon was a weapon which fired highly ionized particles or highly ionized plasma.

 

[Cabal]

So, to you, 'element' is a synonym for 'atom'?

To me, elements are comprised of atoms, i.e entities which still have individually consistent chemical properties. If two or more atoms are bonded into a molecule* and it changes its chemical properties from that of a single atom, then it's not longer technically an element. Any homonuclear molecule of any kind does not merit that label.

(I know this is a STUPID argument, but why aren't diatomics et al. on the periodic table of the elements, hm, HM? )


* and I think the definition of this depends on the type of bonding, so I'm not necessarily convinced that all solids comprised of the same kind of atom (like a block of gold, say) are molecules.

ETA: I mean, just to make this more confusing, wiki's definition of molecule (which is all I'm using for the moment also) involves covalent bonding only.

http://en.wikipedia.org/wiki/Molecule

I was under the impression ionic bonds counted but...hey. Maybe that "ask a chemist anything" crack wasn't too inappropriate here after all

 

[Wiccan_Child]

To me, elements are comprised of atoms, i.e entities which still have individually consistent chemical properties. If two or more atoms are bonded into a molecule* and it changes its chemical properties from that of a single atom, then it's not longer technically an element. Any homonuclear molecule of any kind does not merit that label.

(I know this is a STUPID argument, but why aren't diatomics et al. on the periodic table of the elements, hm, HM? )

Historical reasons

* and I think the definition of this depends on the type of bonding, so I'm not necessarily convinced that all solids comprised of the same kind of atom (like a block of gold, say) are molecules.

ETA: I mean, just to make this more confusing, wiki's definition of molecule (which is all I'm using for the moment also) involves covalent bonding only.

Molecule - Wikipedia, the free encyclopedia

I was under the impression ionic bonds counted but...hey. Maybe that "ask a chemist anything" crack wasn't too inappropriate here after all

Wikipedia's definitions seem to be drawn from a) Encyclopaedia Britannica, and b) Chemistry textbooks. I move to disregard Wikipedia's opinion on this

 

[Cabal]

Historical reasons

I mean, not to harp on, but given your remark about melting points, if that's the case then every single possible arbitrarily sized lump of any type of identical atoms is its own element which would make the periodic table rather impractical

Wikipedia's definitions seem to be drawn from a) Encyclopaedia Britannica, and b) Chemistry textbooks. I move to disregard Wikipedia's opinion on this

Yes, I'm not wild about using it anymore. Then again, I was also using my half-remembered definitions from chemistry. In secondary school. So I think I fail harder there....

Although there's nothing like making your own encyclopaedia by stealing from ANOTHER encyclopaedia....class act, wiki

 

[Biologist]

If you write everything as zeros, then you'll have wiped it clean - but it'll be unusable.
What actually happens when you delete something (e.g., by emptying the recycling bin) is that you simply designate the piece of drive that held the information as 'writeable' - in other words, the computer is free to put new information where the old information was kept.

But until the computer's decided to put anything there, the old information still exists. There are programs out there which can pull 'deleted' files back from the grave - provided there's enough still there. I once did that to my entire music collection (curse you iTunes!), and I got it all back, with only a few glitches in some obscure tracks.

BUT

You can also download industrial-strength Incinerators: they scramble the data of the thing you want deleted using various random number generators. I think seven full 'scrambles' constitutes a military-grade deletion.

Cool stuff

The best thing to do is whole disk encryption. That way you can decommission the whole drive in a fraction of a second just by deleting the pre-boot loader.

 

[pgp_protector]

The best thing to do is whole disk encryption. That way you can decommission the whole drive in a fraction of a second just by deleting the pre-boot loader.

For the Harddrives I must prevent anyone from getting the data on, I find thermite quite effective

 

[Wiccan_Child]

I mean, not to harp on, but given your remark about melting points, if that's the case then every single possible arbitrarily sized lump of any type of identical atoms is its own element which would make the periodic table rather impractical

Ah, but it's not its own element. O[sup]-[/sup], O[sub]2[/sub], and O[sub]3[/sub], are all of the same element: Oxygen.

Yes, I'm not wild about using it anymore. Then again, I was also using my half-remembered definitions from chemistry. In secondary school. So I think I fail harder there....

Although there's nothing like making your own encyclopaedia by stealing from ANOTHER encyclopaedia....class act, wiki

Wikipedia is the only 4th party source

 

[mzungu]

Seriously, why isn't there an Irelandium yet?

*grumblgrumblgrumbl*

That's because they have not discovered Leprechaunium yet!

 

[Cabal]

That's because they have not discovered Leprechaunium yet!

Or to give it its technical name, "gold"

 

[mzungu]

Or to give it its technical name, "gold"

Ah! Yer a gentleman and a scholar ye are!

 

[Steffenfield]

I know I've asked this before, but once more, could you please explain how this intense phenomena is possible?

I'm having a hard time understanding how a wave of water can just instantly freeze like this.

Thanks.

 

[Wiccan_Child]

I know I've asked this before, but once more, could you please explain how this intense phenomena is possible?

I'm having a hard time understanding how a wave of water can just instantly freeze like this.

Thanks.

As far as I know, these are just phenomena that happen to resemble 'frozen waves', and aren't actual waves that suddenly froze in that shape - rather, they built up slowly over a long period of time.

Ironically, the images you post are hosted on a site called Hoax-Slayer.com You can read their own debunking here.

 

[LittleLambofJesus]

Originally Posted by Cabal Or to give it its technical name, "gold"

That's because they have not discovered Leprechaunium yet!

YouTube - Bonanza's Hoss and the Leprechauns

 

[Cabal]

As far as I know, these are just phenomena that happen to resemble 'frozen waves', and aren't actual waves that suddenly froze in that shape - rather, they built up slowly over a long period of time.

Ironically, the images you post are hosted on a site called Hoax-Slayer.com You can read their own debunking here.

I'm sure these particular ones could well be gradual formations as you say - but would it be possible for a large body of supercooled water to form, which has a tendency to suddenly freeze?*

*I suspect yes in theory, no in practice - the thought just occurred....

 

[Wiccan_Child]

I'm sure these particular ones could well be gradual formations as you say - but would it be possible for a large body of supercooled water to form, which has a tendency to suddenly freeze?*

*I suspect yes in theory, no in practice - the thought just occurred....

You could supercool on a large scale, but it's exponentially more difficult as you scale it up from, say, a Coke bottle in the fridge. You couldn't get something that shape either. And, the ice would be an opaque white, not that translucent blue you see in the 'frozen waves'.

Possible, but very difficult.

 

[GrowingSmaller]

Could dark matter be gravity from the future that travells FTL? Aaaaaw, why not?

 

[mzungu]

Could dark matter be gravity from the future that travells FTL? Aaaaaw, why not?

Your question is wrongly put. For something to come from the future it has to have a past and thus gravity must exist today if it is to be present in the future!