[Lan(r)12]

UC said:

That's the single most annoying thing I've heard in a while. A forum is generally where to ask stuff that you can't figure out elsewhere or need better insight that the internet fails to provide. You're wasting everyone's time.

Also, you could have typed in everything you need to get to that wikipedia article in less words than it took to make that post.

lol
wow
Ive read it...I didnt think anyone would take that seriously....but there are things called OPINIONS that people have...even on established scientific fact.
Thats what I was searching for.
Run along now, theres a good boy.

[timetes]

so apparently lead is the most dense material on earth. So that means no lasers or infra red can go throught this material. I remember watching on TV the Russan ship that was at the bottom of a sea.......all died in this accident. But I thought they were able to see through the Lead ship?

hmmmm, cant build a house with lead! Im talking security and privacy here.:cool:

[insane_alien]

timetes said:

so apparently lead is the most dense material on earth. So that means no lasers or infra red can go throught this material. I remember watching on TV the Russan ship that was at the bottom of a sea.......all died in this accident. But I thought they were able to see through the Lead ship?

hmmmm, cant build a house with lead! Im talking security and privacy here.:cool:

lead isn't the densest, iridium and osmium are(its debatable which is denser as they are so close. and it is ever so slightly variable).

lasers and infrared can't go through a block of steel or aluminum either so i don't know why you are suggesting its a property of density.

i also don't recall any ships being made of lead, even russian ones.

[Sisyphus]

Lasers can't go through anything you can't see through (like a piece of black paper), because it's visible light. Various materials are opaque to various frequencies.

You wouldn't make a ship out of lead because it's so weak and heavy, but I'm assuming a nuclear sub would have a fair amount of lead on board surrounding the reactor.

[npts2020]

Sisyphus said:

Lasers can't go through anything you can't see through (like a piece of black paper), because it's visible light. Various materials are opaque to various frequencies.

You wouldn't make a ship out of lead because it's so weak and heavy, but I'm assuming a nuclear sub would have a fair amount of lead on board surrounding the reactor.

Yep, and even more around one on an aircraft carrier (bigger reactors) but afaik that is the only place any ship has large lead components.

[Lan(r)12]

insane_alien said:

lead isn't the densest, iridium and osmium are(its debatable which is denser as they are so close. and it is ever so slightly variable).

lasers and infrared can't go through a block of steel or aluminum either so i don't know why you are suggesting its a property of density.

i also don't recall any ships being made of lead, even russian ones.

Have they not done experimental studies to see which is more dense? Or do the published figures vary lab to lab?

[insane_alien]

we of course they've done experiments its just there are a variety of different crystal structures in the metals that can vary in the amount present which can alter the density so two different samples of the same element can have different densities. with osmium and iridium there is a fair bit of overlap.

osmium can have a slightly greater density than iridium but it is in the range of milligrams per centemeter cubed.

[GDG]

Sisyphus said:

Lasers can't go through anything you can't see through (like a piece of black paper), because it's visible light. Various materials are opaque to various frequencies.

You wouldn't make a ship out of lead because it's so weak and heavy, but I'm assuming a nuclear sub would have a fair amount of lead on board surrounding the reactor.

You've obviously never used a cutting laser. ;)

According to the EPA, nuclear subs use "steel, water tanks, and polyethylene" for radiation shielding. Probably weighs a lot less than lead (and having less mass makes the sub more manuverable).

[Sisyphus]

GDG said:

You've obviously never used a cutting laser. ;)

If it passed through, it couldn't cut, now could it?

[GDG]

Sisyphus said:

If it passed through, it couldn't cut, now could it?

It passes through: it just leaves a hole behind ;)

[insane_alien]

GDG said:

It passes through: it just leaves a hole behind ;)

by pass through it was meant that the material was transparent to it, ie, the laser goes through leaving the material unchanged.

[minus_Ph]

GDG said:

You've obviously never used a cutting laser. ;)

According to the EPA, nuclear subs use "steel, water tanks, and polyethylene" for radiation shielding. Probably weighs a lot less than lead (and having less mass makes the sub more manuverable).

The polyethylene is shielding for the neutrons. They go right through lead like it isn't there at all. The lead, if any, is for the gamma rays they go right through the polyethylene and need some element with a heavy nucleus to attenuate them.

The ideal radiation shield has both.

[Lan(r)12]

insane_alien said:

we of course they've done experiments its just there are a variety of different crystal structures in the metals that can vary in the amount present which can alter the density so two different samples of the same element can have different densities. with osmium and iridium there is a fair bit of overlap.

osmium can have a slightly greater density than iridium but it is in the range of milligrams per centemeter cubed.

Well, that asnwers the part about naturally occuring materials...but what is the limit of the density the object can have and exist on earth, synthetic or organic.

And how the heck did this become about nuclear sub-shielding? :D

[Mr Skeptic]

Organic materials are going to have a lower density, since they must contain carbon and carbon is quite light.

[SH3RL0CK]

Lan(r)12 said:

Well, that asnwers the part about naturally occuring materials...but what is the limit of the density the object can have and exist on earth, synthetic or organic.

This question has already been answered in this thread. Read posts # 2, 3, 4, and especially #8.

This post has been edited by SH3RL0CK: 6 March 2009 - 02:18 PM

[Sisyphus]

Probably should have linked to this earlier, but:

http://en.wikipedia....ents_by_density

It's too bad all the heaviest ones are so expensive/rare/dangerous/unstable, as tossing around unexpectedly heavy objects is ripe for physical comedy.

[Lan(r)12]

Sisyphus said:

Probably should have linked to this earlier, but:

http://en.wikipedia....ents_by_density

It's too bad all the heaviest ones are so expensive/rare/dangerous/unstable, as tossing around unexpectedly heavy objects is ripe for physical comedy.

You're a genius lol
And yes, "pull my finger" has got nothing on this lol

[timetes]

falcon9393 said:

I am not sure but i will take a wack at it
My guess is carbon based structures such as Fullerenes: Graphite and Diamonds:confused:

Ok....plus lead and the Iron core. Well, If I made a shield of one of these materials (except the core) to keep out harmful waves/privacy, would the out side of the shield be the "zero potential" were this new energy is made? Did that make sence.

[coke]

Sisyphus said:

Probably should have linked to this earlier, but:

http://en.wikipedia....ents_by_density

It's too bad all the heaviest ones are so expensive/rare/dangerous/unstable, as tossing around unexpectedly heavy objects is ripe for physical comedy.

wait a sec... thats list by density of elements... the most dense element is well known to be osmiun, followed by those other transition metals- platinum, gold, etc,

but osmium is not necesarily the most densest material... most densest material might be some compound

[Airbrush]

insane_alien said:

they aren't all that dense at all. lead is denser.

a quick google reveals estimates of the cores density to be somewhere about 13000kg/m3 http://pubs.usgs.gov/gip/interior/

Why complicate the density? It is far easier to visualize the density your link gave (for the Earth's lower core) as 13.1 gm/cm^3 than to gross it up to a cubic meter.

Same goes for speeds greater than 3,600 mph, better call it one mile per second. That you can visualize. Or if your audience is not in the US, call it km/second. Scientists need to consider their audience, unless they want their only audience to be other scientists. ;)