[stereologist]

These are all solids. Dense liquids are also interesting. Some dense liquids are oils and mixtures that can be used for sorting materials. We used to use an oil to sort topaz from quartz. The quartz floated on the oil and topaz being denser sank. I recall some liquids having specific gravities of 3 or 4.

[Sisyphus]

stereologist said:

I recall some liquids having specific gravities of 3 or 4.

Mercury is also liquid at STP, and its specific gravity is about 13.5. In other words, lead will float on it, but gold will sink...

[insane_alien]

Airbrush said:

Why complicate the density?

i complicated it?

i did consider my audience. the people who use this forums most go for SI units. i posted in SI. most literature uses SI as well. heck, forum policy is to use SI.

[Airbrush]

Sorry Mr. Alien, you are correct. On second thought, I can't imagine how heavy 13.1 grams would be for something only one cubic centimeter. What I need is a common object, one that I pick up often, and the weight of that object in units I grew up with. Sorry, but I am not a scientist. I miss a lot of good science when the standard units of measure just whizz over my head. :confused:

This post has been edited by Airbrush: 31 March 2009 - 04:02 PM

[Sisyphus]

Airbrush said:

On second thought, I can't imagine how heavy 13.1 grams would be for something only one cubic centimeter. What I need is a common object, one that I pick up often, and the weight of that object. Sorry, but I am not a scientist. I miss a lot when units of measure just wizz over my head.:confused:

That's why specific gravity (which would be the same as g/cm^3) is useful, because the weight of water is something that everyone is familiar with. So, say, a gallon of that material would have the weight of 13.1 gallons of water, or about 109 pounds.

Or, since humans are very close to the density of water, a life size statue of you made of that material would weigh about 13 times what you weigh.

[Airbrush]

Thanks Sisyphus, that is the kind of stuff I like to hear. :D

[timetes]

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.

Well they seem to have some sort of other type of waves....terahertz radiation....seems to through everything ......except water and metal....
privacy gone... unless your sitting in a metal tub:eyebrow:

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coke said:

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

great....what could that compound be? Then patent it.

With all these smart people here...... what type of shielding could be used against some of this new technology that could be harmful to humans.....mico-magnetic-electrical-radiation... waves/lasers/infred etc.

What I got was.....a material without carbin as not to make the shield less dense. Steel/Water tanks/Ployethylene and apparently ...need something to attenuate them all.
:confused:

[Klaynos]

I'd suggest you want some kind of broadband metamaterial to shield well against EM radiation...

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Oh and before I forget, there are lots of things which THz radiation will not pass through, it is, as always, very frequency dependent.

[timetes]

Klaynos said:

I'd suggest you want some kind of broadband metamaterial to shield well against EM radiation...

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Oh and before I forget, there are lots of things which THz radiation will not pass through, it is, as always, very frequency dependent.

Why thank you:-) most think im nuts...lol
I just read a quote....."most say, what can not be done with science instead of what is possible with science". Very true and most are stuck on old thearys, I would assume..........Im just a mother...ohhh now a grandmother:)

An issue is "if a new invention is made, make sure it can not harm the earth and all who live here and it can be counter-acted or reversed"....just in case.

That said ....apparently they did adoped an....."Artificially engineered composite termed "metamaterial" control over a "medium" well....electomagnetic waves is what im interested in..... tunneling by "Zero" index. Ok....Polarization of electromagnetic waves using Anisotropic metamaterial...."wave retarders" " I guess it was designed for a highly efficient broadband wave retarder ..........what could that material be? Should I cover my plugs? Again.......can you make a house with it or use this in an apartment? ;)

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stereologist said:

These are all solids. Dense liquids are also interesting. Some dense liquids are oils and mixtures that can be used for sorting materials. We used to use an oil to sort topaz from quartz. The quartz floated on the oil and topaz being denser sank. I recall some liquids having specific gravities of 3 or 4.

Im not sure what type of material should be used or is being used but I found this info baluns ....
http://www.eznec.com...cles/Baluns.pdf
so there is a "possibility" that I may be feeling a wave or zap from cable wire not insilated enough.

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

topaz is a stone.....what could be used a an "insilation" in a home that dense enough to stop all types of waves. As I see that it must be a mixture of natural and man made.

This post has been edited by timetes: 26 April 2009 - 04:51 PM

[Megabrain]

What is the most dense material that can exist on Earth?

Human brain cells, there's nothing more dense than you humans!

[Airbrush]

The only way neutron star like density material could be found on Earth is to arrive here from outer space, and neutron stars cannot explode and throw pieces of themselves everywhere. Everything else crashes into a neutron star and is crushed to such density, but when neutron stars crash they merge with the energy shown by short gamma ray bursts.

[timetes]

Airbrush said:

The only way neutron star like density material could be found on Earth is to arrive here from outer space, and neutron stars cannot explode and throw pieces of themselves everywhere. Everything else crashes into a neutron star and is crushed to such density, but when neutron stars crash they merge with the energy shown by short gamma ray bursts.

thats it....gamma ray bursts.... there must be a new technology harnessing these waves for energy and or weapons.. "The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio)." quote
My question would be.....can a mirror change that wave angle and can it be stored or captured? maybe stored by satillites? I know we have detectors for them.
oh....and for the poster ,who are you if your not human LOL....

[timetes]

timetes said:

thats it....gamma ray bursts.... there must be a new technology harnessing these waves for energy and or weapons.. "The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio)." quote
My question would be.....can a mirror change that wave angle and can it be stored or captured? maybe stored by satillites? I know we have detectors for them.
oh....and for the poster ,who are you if your not human LOL....

opps....sorry my son said its impossible for gamma rays......how about solar sun burst rays.....
also, im starting to think this em zaps may be coming from the tv box, it feels like a sucking gravity and its painful. Oh and its not physical......because I used a glass of water and the water vibrated with the thumping....

[fireblast_12]

I think it can but since it will have greater gravitational pull than earth, it will cause a problem.

[Theophrastus]

On the initial subject, gallium melts at around 30 degrees celsius, and as such, its generally a less toxic alternative to mercury, though it is still mildly toxic, and stains, so one should still take care in handling it. Its density, is about 6 times that of water, so it can be used to sort stuff. If a thermometer uses a liquid metal, which isn't mercury, (mercury- free) its probably a gallium alloy, that's used. I wish I had a substantial amount of mercury or gallium. Liquid metals are pretty cool... (suddenly attains the idea to market a mercury theme park:" try our mercury slides! Just try not to get a tumour while you're at it!" Ah, neurotoxins...

In regards to the densest material, I'ld guess it to be some manner of fun radioactive element, though that would be rather unstable (for obvious reasons). Though I've heard that hydrogen at temperatures relatively near absolute zero, like those that can be achieved in a cryogenics lab, can become incredibly dense.

This post has been edited by Theophrastus: 11 May 2009 - 11:40 PM
Reason for edit: Addition of content

[Zjar]

Thank you, everyone. This thread is responsible for my having registered as a Science Forums member today, undeterred by when the conversation about dense materials and osmium blew off track. From your links, discovered some fertile things about rhenium as well.

Something particularly nice about 'permanent' online compendia is that the articles in Wikipedia have probably been improved upon my reading them this week, beyond what they contained when you posted links there 2 years ago. And threads like this one, to which conversants, including new ones, can add material with new discoveries and perspectives, are a great new way of living we're privileged to share together.

[Sisyphus]

Welcome aboard, Zjar. Glad you like the forum.

[granpa]

you people are forgetting about white dwarf material

[insane_alien]

we already covered neutron star material which is denser than a white dwarf AND explained why you couldn't really have it on earth.

[granpa]

white dwarf material is totally different from neutron star material.

also you might want to look up 'ultra-dense deuterium'