Is there a speed of heat?

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Offline bizerl

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Is there a speed of heat?
« on: 16/07/2012 01:26:22 »
When trying out my new stainless steel frypans, I noticed they heat up and cool down much faster than my old ones. Is there a measureable speed at which heat radiates through a material, and what is the quality of the material that would influence such a speed?

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Offline Geezer

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Re: Is there a speed of heat?
« Reply #1 on: 16/07/2012 02:59:13 »
The rate at which heat travels through metals is known as thermal conduction. For metals, their ability to conduct heat is similar to their ability to conduct electricity. For example, aluminium and copper are both good electrical and thermal conductors.
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #2 on: 16/07/2012 19:45:45 »
Not quite.
The speed at which a change in temperature moves through something is related to the thermal diffusivity. It is possible to have two objects with the same thermal conductivity but for heat to travel faster through one than the other.
http://en.wikipedia.org/wiki/Thermal_diffusivity
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Offline Geezer

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Re: Is there a speed of heat?
« Reply #3 on: 16/07/2012 21:15:21 »
Rats! Another gap in my education.
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Offline evan_au

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Re: Is there a speed of heat?
« Reply #4 on: 28/07/2012 09:14:26 »
The thickness of the material also matters; thinner=faster to heat up.

Some pans have a copper core, and will heat up more quickly & evenly - but these cost more, so I would expect it to be clearly stated on the label...

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Offline chris

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Re: Is there a speed of heat?
« Reply #5 on: 29/07/2012 09:26:07 »
To rub some ointment on Geezer's wounds and to add a little extra clarification, as Geezer has highlighted, in general the reason why metals tend to be good conductors of heat - as well as electricity - is down to their crystal structure.

Metals are considered to be a lattice of positive ions (nuclei) in a sea of electrons. These electrons can move freely, swapping between the different positive centres. As Chemistry World science writer Mike Brown eloquently put it to me, "you can think of it like a troop of atomic jugglers - the metal nuclei - lobbing skittles (electrons) back and forth amongst themselves."

The consequence is that, when a metal is heated, the kinetic energy (vibrations) of the electrons increases. And because they are free to move, they can collide with other particles (both electrons and ions) over greater distances and transmit these vibrations through the material, which is why heat is well conducted.

The freedom of the electrons to move also accounts for the high electrical conductivity. Ionic materials, where the electrons are not free to move in this way, tend to be poorer conductors as a consequence.

Someone else can explain why graphite has the conduction properties that it does.

Chris
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #6 on: 04/08/2012 22:06:59 »
Never mind graphite, how do you explain diamond?
It's a very good conductor of heat, but it can't be because of a sea of moving electrons because diamond is an excellent electrical insulator- there are no free electrons.
(BeO and a few other materials have the same property)
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Offline chris

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Re: Is there a speed of heat?
« Reply #7 on: 06/08/2012 09:21:39 »
Indeed - my brain exploded before I could even begin to think about how to explain that! What do people think might be going on in diamond?
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #8 on: 06/08/2012 13:21:04 »
Well, Wiki says this
http://en.wikipedia.org/wiki/Thermal_conductivity#Lattice_waves
but I'm not convinced.
We all know that the phonons were the "villains" in an obscure Dr Who episode in the mid 1970s.
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Offline evan_au

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Re: Is there a speed of heat?
« Reply #9 on: 07/08/2012 12:12:18 »
In a very hard material such as diamond, the speed of sound can be very high. Heat is just vibrations of the atoms, and this can travel at a similar speed.

Diamond is made up of several isotopes of carbon. Using isotopically pure carbon increases its thermal conductivity - said to be the highest of any material.
http://en.wikipedia.org/wiki/Material_properties_of_diamond#Thermal_conductivity

Presumably the varying isotopic concentrations of natural diamond scatter and diffract the phonons as they pass through the crystal, just like crystal boundaries and impurities do in other materials.

Heat pipes also work quite well, but they use boiling and condensation to transfer the heat, so they only work over a very narrow range of temperatures. Because they rely on physical movement of a vapour, the velocity of heat transfer is fairly low.
http://en.wikipedia.org/wiki/Heat_pipes
« Last Edit: 07/08/2012 12:31:37 by evan_au »

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Offline evan_au

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Re: Is there a speed of heat?
« Reply #10 on: 07/08/2012 12:59:08 »
We feel Infra-Red radiation as heat, and this travels at the speed of light.

Of course, in a material transparent to IR, the speed of light is somewhat less than it's usual value in a vacuum - but a photon beats a phonon!
« Last Edit: 07/08/2012 13:01:44 by evan_au »

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #11 on: 10/08/2012 02:25:41 »
Never mind graphite, how do you explain diamond?
It's a very good conductor of heat, but it can't be because of a sea of moving electrons because diamond is an excellent electrical insulator- there are no free electrons.
(BeO and a few other materials have the same property)

Diamonds are an amazing substance. Diamonds actually change the emission of heat to some other form of emission. I have never had the time or the equipment to tell you exactly what that emission is. However it was taught to me, that way by a master machinist. I believe there are even a few more modern scientists that have also confirmed this. Engineers in the electrical field, have also used diamonds in this way to remove heat from electrical components. It is documented but only in obscure pamphlets.

Years ago they used to use a phosphorous compound to harden metal. It worked by altering the emission from hot glowing metal to be hardened, from a heat emission to a light emission. It glowed white hot when it was applied to the red metal to be hardened. It worked extremely well. Phosphorous is an extreme poison, that may have lead to it being taken off the market.

Light removes much more energy from a part, then heat. You can kind of witness this, when you light a light bulb, with low voltage, or under voltage, it glows red. When you raise the voltage it glows yellow or nearly white or blue. Showing you which emission removes more energy. It actually uses velocity as the principle, but I am new to the forum and I do not want to rock too many boats.

The phosphorous hardening compound works in a similar way, instead of raising the amount of energy in the part, you offer the energy, a very exited path to drain the energy or abundance of particles in the part, very quickly.

The direction of heat as was mentioned makes a very big difference, by heating a part halfway between the two ends of the part, it makes it possible to heat one end much more quickly, and even limit the heat that makes it to the cold end of the part. When you heat the center of the part, you send heat out towards the end you want to heat. By the time the heat from the end you are trying to heat, can reverse the flow, of the heat moving towards it. The end you are heating heats up without being able to transfer the heat to the rest of the part.

It is an old welders trick to weld a part that is to big to just weld with the equipment you have.

If you dip the heated end, of a piece of aluminum that is heated on one end by welding process, or bending process, into a bucket of water very quickly, the heat will move very quickly towards the cold end of the aluminum, enough to burn your hand in seconds of quenching. Yet on the same part heated the same way but not quenched, the cold end will not even get hot, before it cools in air. To me that is a phenomena.

Some stainless pans have an aluminum disk inside the pan. It is manufactured inside the stainless pans bottom. To keep the heat even in the pan and to speed the heating of the pan.


                      Sincerely,

                            William McCormick



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Offline damocles

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Re: Is there a speed of heat?
« Reply #12 on: 11/08/2012 04:30:28 »
Diamond is not alone in being a non-conductor with very high thermal conductivity and diffusivity. The alkali metal oxides, lime, magnesia, and beryllium oxide are other examples from many (and they are much cheaper and more practical than diamond!

Beryllium oxide is favoured as the ideal heat sink because it has a large heat capacity to go along with its high conductivity and diffusivity. Unfortunately it is a very dangerous substance to handle. Magnesia (magnesium oxide) is nearly as good.
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #13 on: 11/08/2012 12:47:42 »
I think the problem with William McCormick's post is that it's essentially nonsense.
Fro example, while he writes that "Light removes much more energy from a part, then heat."
In fact about 3% of the power supplied to a light bulb is dissipated as light. The other 97% is lost as heat.
Heat removes about  33 times more energy in this case than light does.
If you reduce the voltage then the re comes a point where the filament is too cool to emit light, but it still gives heat.
In this case light is utterly incapable of removing energy from the filament, but heat still does it just fine.

Phosphorus compounds are still used in hardening some steels, but the effect is due to interstitial pinning of the lattice- nothing to do with light emission.
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #14 on: 11/08/2012 13:38:18 »
Heat does not travel far. Infrared does. Are you saying that infrared is heat, and not light?

It really is neither. Infrared red light, will pass through an opaque raw computer chip wafer, without heating the wafer, making it seem not at all like heat. It will heat flesh just on the other side of the wafer though. Much like you would expect light to do after passing through a glass window. So perhaps we just have to agree on what infrared is?

When you raise the voltage to a light bulb, it can no longer just give off heat, to remove energy, heat is no longer capable of removing the abundance of energy in the filament. The filament in a quest to remain a filament, starts to emit light and infrared heat. As well as UV, and even X-rays as the light gets brighter and brighter, before it destroys itself. You can only put a few watts to a light bulb before it gives off light.

Our sun is a giant carbon laser, it is white if viewed outside of our atmosphere, the only reason that heat from the sun reaches us, is because it travels as light, UV, and of course X-rays. Those rays can penetrate just about any single wall material we try to block them with, after you leave the earths atmosphere.

Heat does not travel in a vacuum well, because there are so few air particles to transfer the actual heat. A light bulb transmits energy by way of light, and infrared.

If they are currently measuring this in some other way, or calling infrared, heat, I would love to hear about it.

                      Sincerely,

                            William McCormick


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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #15 on: 11/08/2012 13:43:29 »
Please don't waste the forum's bandwidth with gibberish like "Our sun is a giant carbon laser"

You may also want to look at this
http://en.wikipedia.org/wiki/Radiant_heating
Radiant heat does exist.

"When you raise the voltage to a light bulb, it can no longer just give off heat, to remove energy, heat is no longer capable of removing the abundance of energy in the filament. " is still nonsense
Most of the energy lost from the filament is lost as heat.
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #16 on: 11/08/2012 14:17:45 »
So you are saying that infrared light, is classified as heat not light?

True radiant heat is infrared at a certain frequency or wave length. It works very much like light. An infrared emitter is used. The heaters in the Quiznos sandwich ovens are infrared.

The terminology in the field of building and for use by the homeowner is often vague and unscientific. A standard hydronic radiator, mounted at the base of a wall, called base board heat, in a home. Is usually powered by a gas or oil burning system, that heats water that is circulated through pipes to the base board heat. Sometimes solar or electric heat, is used to heat hot water for the baseboard heater.

The baseboard radiator, does not actually radiate much at all, rather it, is a convection device. Air has to pass over aluminum fins to transfer the heat to the air.

The hydrocnic hot water heated floor system, is also called radiant heat, however again it uses convection to take the heat from the floor and heat the rest of the room. They basically lay PEX tubing, Cross-linked polyethylene, commonly abbreviated PEX or XLPE, in the floor up and down the length of the floor. They run hot water through it.

The sun is surrounded by carbon dioxide, it has been printed in books of learning for many years that way. What do they say it is now? Would you like me dig some of them up?
 


                      Sincerely,

                            William McCormick

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #17 on: 11/08/2012 14:31:50 »
The heaters in the Quiznos ovens are just filaments surrounded by pure silicon. The rays pass through the silicon and heat the sandwich. Silicon is such a good insulator against heat, that is how we know that it is infrared passing through the silicon, not just heat.

                      Sincerely,

                            William McCormick 


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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #18 on: 11/08/2012 14:51:14 »
"So you are saying that infrared light, is classified as heat not light?"
yes, so is that wiki page; and so do you.
"True radiant heat is infrared at a certain frequency or wave length."

I know that most so called "radiators" actually transfer heat by convection and advection, but that's nothing to do with the fact that you were wrong to say that light transfers more heat. In the great majority of cases the reverse is true by a big margin.

Silicon is actually quite a good conductor of heat and, especially when it is hot, a good conductor of electricity too so I rather doubt that "The heaters in the Quiznos ovens are just filaments surrounded by pure silicon."
However because there's no easy way for me to check on  some particular sandwich seller's equipment in another country I can't be certain.

However if you mean that they are surrounded by silica (like these ones)
http://en.wikipedia.org/wiki/Infrared_heater#Quartz_heat_lamps
that's another matter.
Some thing like Quinzo's which isn't accessible to 95% of the world's population isn't a good choice of example.

Silica is a reasonably good conductor of heat anyway, so your point isn't valid.

And this "The sun is surrounded by carbon dioxide, it has been printed in books of learning for many years that way. What do they say it is now? Would you like me dig some of them up?"
is just bollocks.

The sun is surrounded by the corona, the solar wind and a vacuum.
Not only are those in fact made largely of hydrogen, but any CO2 there would get destroyed by the high temperature.

I can't imagine where you got such a silly idea as that the sun is surrounded by CO2.
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #19 on: 11/08/2012 15:41:35 »
I believe what I said is highly accurate, for the purpose I said it. Light is necessary to create the infrared emission from the element. You just cannot do it without the light. Meaning as you increase the power to the element, it naturally starts emitting rays designed to carry away more energy. And they do.

When I create a very powerful ARC through pure argon, using a couple thousand watts, of power, there is a pinpoint heat generated, in very close proximity to the ARC,  however most of the rays, leave the area, as light and UV.  There is almost no infrared. So I have to contest that heat is reliving the area of energy.

Regular heat does not pass through silicon without heating it, infrared rays do. Now I was taught that infrared is a form of light. It certainly is not regular heat.

On the other side of the coin infrared is ineffective at moving the veins of a radiometer, if no white light is present. If there is the slightest white light present, then the infrared will move the veins of the radiometer and at amazing speeds.

Certainly the terminology leaves something to be desired of no matter which way you look at it. I don't think that infrared is neither light or heat myself. But I do not see why we cannot make communication about it better.

                      Sincerely,

                            William McCormick

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #20 on: 11/08/2012 15:55:02 »
http://en.wikipedia.org/wiki/Infrared

This kind of states that infrared is light. But I am not someone to argue about the poor definitions we use in real life. I know I could die from the poor definitions, any day on the job.

Often people in an attempt to make something clear, use the two terms interchangeably and not on a scientific level that is probably ok. It leads to mislabelling though.

I was really just trying to hone in on the actual workings of the universe. We would need to be on the same page of the exacting differences of the two rays, to from an agreement.

                      Sincerely,

                            William McCormick

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Offline damocles

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Re: Is there a speed of heat?
« Reply #21 on: 11/08/2012 16:23:17 »
Out of interest I tried to look up some thermal conductivities in my reference books. For different types of material they are expressed in all kinds of different weird and inconvenient units. However, with a bit of application of conversion factors, here is what I have come up with. It may be of interest.

The units of these numbers are W/cm/K, and the temperatures are close to ambient. The materials are single crystal, glassy, or hard rolled.

Silver         4.29
Copper       4.01
Gold           3.19
Aluminium   2.37
Silicon       1.5
Iron           0.80
Platinum    0.72
------
Sapphire (corundum, aluminium oxide)      0.354
Topaz       0.18
Quartz      0.08
Marble      0.05
------
Diamond   22
BeO          2.1
MgO         0.35

That might help put a perspective on some of the discussion.
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #22 on: 11/08/2012 16:49:14 »
I believe what I said is highly accurate, for the purpose I said it. Light is necessary to create the infrared emission from the element. You just cannot do it without the light. Meaning as you increase the power to the element, it naturally starts emitting rays designed to carry away more energy. And they do.

When I create a very powerful ARC through pure argon, using a couple thousand watts, of power, there is a pinpoint heat generated, in very close proximity to the ARC,  however most of the rays, leave the area, as light and UV.  There is almost no infrared. So I have to contest that heat is reliving the area of energy.

Regular heat does not pass through silicon without heating it, infrared rays do. Now I was taught that infrared is a form of light. It certainly is not regular heat.

On the other side of the coin infrared is ineffective at moving the veins of a radiometer, if no white light is present. If there is the slightest white light present, then the infrared will move the veins of the radiometer and at amazing speeds.

Certainly the terminology leaves something to be desired of no matter which way you look at it. I don't think that infrared is neither light or heat myself. But I do not see why we cannot make communication about it better.

                      Sincerely,

                            William McCormick
I'm starting to think you are trolling.
Nobody else is going to believe that you are accurate. That nonsense about the Sun being a laser or surrounded by CO2 will make sure of that.
Light is not needed to generate IR.
IR LEDs and an ordinary light bulb run at low voltage prove this.
So this "Light is necessary to create the infrared emission from the element. You just cannot do it without the light." is plainly wrong.



 "Meaning as you increase the power to the element, it naturally starts emitting rays designed to carry away more energy. And they do."
Doesn't make sense because the radiation (IR or visible) wasn't designed at all.


If you look here, you can see the emission spectrum from an argon arc lamp. (btw, It's not an abbreviation so it isn't written in capitals)
http://www.pre.ethz.ch/facilities/vortec/
As you can see, much, if not most of the radiation emitted is IR


"Regular heat does not pass through silicon without heating it, infrared rays do."
Will you please learn the difference between silica and silicon.

This
"On the other side of the coin infrared is ineffective at moving the veins of a radiometer, if no white light is present. If there is the slightest white light present, then the infrared will move the veins of the radiometer and at amazing speeds. "
Is just not true.



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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #23 on: 12/08/2012 05:22:33 »
I believe what I said is highly accurate, for the purpose I said it. Light is necessary to create the infrared emission from the element. You just cannot do it without the light. Meaning as you increase the power to the element, it naturally starts emitting rays designed to carry away more energy. And they do.

When I create a very powerful ARC through pure argon, using a couple thousand watts, of power, there is a pinpoint heat generated, in very close proximity to the ARC,  however most of the rays, leave the area, as light and UV.  There is almost no infrared. So I have to contest that heat is reliving the area of energy.

Regular heat does not pass through silicon without heating it, infrared rays do. Now I was taught that infrared is a form of light. It certainly is not regular heat.

On the other side of the coin infrared is ineffective at moving the veins of a radiometer, if no white light is present. If there is the slightest white light present, then the infrared will move the veins of the radiometer and at amazing speeds.

Certainly the terminology leaves something to be desired of no matter which way you look at it. I don't think that infrared is neither light or heat myself. But I do not see why we cannot make communication about it better.

                      Sincerely,

                            William McCormick
I'm starting to think you are trolling.
Nobody else is going to believe that you are accurate. That nonsense about the Sun being a laser or surrounded by CO2 will make sure of that.
Light is not needed to generate IR.
IR LEDs and an ordinary light bulb run at low voltage prove this.
So this "Light is necessary to create the infrared emission from the element. You just cannot do it without the light." is plainly wrong.



 "Meaning as you increase the power to the element, it naturally starts emitting rays designed to carry away more energy. And they do."
Doesn't make sense because the radiation (IR or visible) wasn't designed at all.


If you look here, you can see the emission spectrum from an argon arc lamp. (btw, It's not an abbreviation so it isn't written in capitals)
http://www.pre.ethz.ch/facilities/vortec/
As you can see, much, if not most of the radiation emitted is IR


"Regular heat does not pass through silicon without heating it, infrared rays do."
Will you please learn the difference between silica and silicon.

This
"On the other side of the coin infrared is ineffective at moving the veins of a radiometer, if no white light is present. If there is the slightest white light present, then the infrared will move the veins of the radiometer and at amazing speeds. "
Is just not true.

Here is a proof that at one time many did learn that CO2 surrounds the sun, and that its incandescence is what creates the very bright light. The yellow color of the sun through our atmosphere, might be explained by carbon as the source. Helium is of a red band, and so is hydrogen if I am not mistaken. Carbon and Co2 have that yellow spectrum.

This is pre-world war two stuff, before the government openly announced that they would hide the secret of the atom from earth. Maybe Russia was fearful of how the Americans and English, were going to get the secret of the atom, out of their heads, so they started the cold war. Ha-ha.

I wasted about an hour looking for another source I have somewhere. I just could not find it, I will keep looking. This publication below is from General Motors Corporation. It was a very fascinating booklet given to the public to learn about automobiles and the substances that make them work. You can see they talk about explosives in a booklet made for the whole family. Things were very different before the war. Ha-ha Explosives were an American thing, at this time.

Your link to the argon arc lamp is broken.

Not all infrared is heat, and certainly an argon arc emission has heat, up close to it, however most of its energy except for up close, is turned into light and UV.

When they say that 9 percent of the energy that hits earth from the sun is UV. That does not mean that the energy needed to create that UV is not 80 percent of the energy created by the sun and the effects on the sun. You have to have an open mind about this, because it is never, or rarely discussed.

As far as needing light to create Infrared, at any distance from the bulb, from an incandescent light bulb filament, you will need some light to do it. That is the point, when you up the wattage to the bulb, it gives off light to remove the energy. Just the infrared emission is no longer enough.





                      Sincerely,

                            William McCormick
« Last Edit: 12/08/2012 05:26:06 by William McCormick »

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Offline damocles

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Re: Is there a speed of heat?
« Reply #24 on: 12/08/2012 06:10:20 »
Will, I am sorry but your posts really are cloud cuckoo land nonsense and non-science
Quote
Here is a proof that at one time many did learn that CO2 surrounds the sun, and that its incandescence is what creates the very bright light. The yellow color of the sun through our atmosphere, might be explained by carbon as the source. Helium is of a red band, and so is hydrogen if I am not mistaken. Carbon and Co2 have that yellow spectrum.
• CO2 decomposes into CO and O around 3000°C, and CO to C and O around 4000-5000°C. The temperature in the neighbourhood of the sun's "surface" (photosphere) is around 10000°C. All materials are atomic or single atom cations at that temperature; no molecules can exist.
• In my local, relatively unpolluted atmosphere, the sun's colour is white. "yellow" is a technical term used by astronomers to categorize a star's surface temperature, and to express subtle variations in perceived star colour in observations. It is also the actual colour of the observed sun in conditions where there is a lot of atmospheric scattering by particles.
• The visible line emission spectra of hydrogen and helium are totally irrelevant to any of the considerations here -- visible light emitted by the sun is an incandescence spectrum associated with a "blackbody" radiation around 10,000 °C, not an atomic emission spectrum.
• The visible band emission spectrum attributed to carbon dioxide (1) is not yellow, and (2) could not be present in sunlight anyway because carbon dioxide simply cannot exist anywhere near the sun.

Quote
This is pre-world war two stuff, before the government openly announced that they would hide the secret of the atom from earth. Maybe Russia was fearful of how the Americans and English, were going to get the secret of the atom, out of their heads, so they started the cold war. Ha-ha.

Hmm ... I am now coming around to thinking that you are trolling as BC suggests above. Linking wacky non-science with a government conspiracy is par for the course. The 'Ha-ha' at the end is not!
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #25 on: 12/08/2012 12:36:01 »
The carbon arc lamp, is capable of temperatures up to 10,000 degrees. Carbon boils at around 6,500 degrees Fahrenheit. Boiling Carbon in a vacuum, with no oxygen may be what we are seeing.

Consider water boils at 212 degrees Fahrenheit, yet 800 degree Fahrenheit steam, is nothing to get excited about.

There is material still around about the temperature in an ARC, Union Carbide put the temperature of a Tungsten ARC in Argon at 35,000 degrees Fahrenheit.

The use of Carbon ARC cutting and welding was much more popular before, tungsten TIG welding was introduced. There are some wild temperatures obtained using carbon ARC.




                      Sincerely,

                            William McCormick 

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #26 on: 12/08/2012 13:11:19 »
It is kind of funny, I go through a lot of trouble to bring people information that they at least should have, if not know. And I often do get accused of wanting to get people angry. It is just ridiculous. As scientists, or individuals who are striving to becoming scientists, there should only be interest in finding truth.

That document I presented is just an interesting document that is part of American history. Is it so agitating to you that you have to accuse me of some sort of game or charade to get attention? That is an attack on my character, and there is no sound reason for it.

If you check out this document, you will see during the war they decided that individuals on earth should not have the secret of the atom or the atom bomb. There was no conspiracy because they came out and said it. If you come out and tell people their government is going to make them as stupid as wood, there is no conspiracy. In the peoples defense they just thought the government was going to hide the bomb, not the atom. You know governments they are not always to smart, or truthful.

http://www.rockwelder.com/explosives/Hiroshimahalfton.PDF


Here is a short movie, it shows TIG welding. In the finale part of the film, the third demonstration, you are watching a tungsten electrode melt and boil. Using less then 100 amps of power. That is the power of an ARC.

In that third demonstration the particles of electricity are leaving the stainless steel work piece and hitting the electrode. That polarity is the same polarity that is used in ARC welding.

http://youtu.be/dYReqtnmM4Q

                      Sincerely,

                            William McCormick 

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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #27 on: 12/08/2012 14:07:37 »
Damocles,
did you have any trouble with the link I posted to the arc spectrum?
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Offline CZARCAR

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Re: Is there a speed of heat?
« Reply #28 on: 12/08/2012 16:51:24 »
Kirchoff's law?

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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #29 on: 12/08/2012 17:27:35 »
Kirchoff's law?

What about it?
It's certainly no going to support William's assertion that the moon is made of green cheese or whatever it was that he said.
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #30 on: 12/08/2012 18:13:56 »
Kirchoff's law?

What about it?
It's certainly no going to support William's assertion that the moon is made of green cheese or whatever it was that he said.

You and I might just have a communication problem. I do not believe you would hate the things I know, and do everyday. I think coming at you with a different language may be causing a problem.

Today I checked out that link and it worked well. Last night I got a link broken on it.

I am not sure what point you are making though. Again most of that 100 KW of that lasers input, is going away as light not heat. With 100 kw of heat I can melt a hundred pound block of aluminum in seconds.

The infrared heaters are actually surrounded by quartz, or silicon dioxide, it is silicon.

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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #31 on: 12/08/2012 18:56:12 »
Is there any way of getting you to read what you type and see if it makes sense?
For example, the page I cited
http://www.pre.ethz.ch/facilities/vortec/
is about an arc lamp and not a laser (and "arc" still doesn't need capital letters).

If you look at the diagram you will see that there is a lot of effort dedicated to cooling it- because it really does generate more heat than light.

As for "The infrared heaters are actually surrounded by quartz, or silicon dioxide, it is silicon. "
You plainly have no idea what you are talking about. Since it is silicon dioxide it isn't silicon.
It's like saying the Hindenburg flew because it was full of water.
« Last Edit: 12/08/2012 20:37:09 by Bored chemist »
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #32 on: 12/08/2012 20:10:48 »
ARC in America used to stand for (Anode, Rectified, Cathode). The people that went to the moon, used these terms to describe the usually white, blue or purple, excited self inducting gas cloud created by electricity, that gives off light. 

It turns out that Benjamin Franklin was totally correct on his views of electricity. Modern science labels batteries and cathode ray tubes backwards. Benjamin Franklin replaced Du Fays theory, of two types of electricity, and rightly so. Since that time colleges have flip flopped on the subject, incorporating a little of everyone's wrong theories into the finale catastrophe.

Benjamin Franklin did create the first transistor and he turned lightning on and off with it. Benjamin Franklin did fly a kite in a lightning storm. Using a piece of silk to isolate himself from the kite string. All the myths about that being impossible are coming from people that should know better.

A carbon laser is created with an ARC. An argon laser is created with an ARC. That is just how it is.

                      Sincerely,

                            William McCormick


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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #33 on: 12/08/2012 20:35:38 »
Nope it didn't.
Since, in the history of the world only a couple of dozen people have been to the moon their point of view wouldn't really count for much.
Also the word was in wide use before then
This patent from 1898 (rather a long time before NASA)
http://www.google.com/patents?id=gjVMAAAAEBAJ&printsec=abstract#v=onepage&q&f=false
 is for an alternating current arc lamp so there's plainly no rectification involved. The invention of the word is credited to Sir Humphrey Davy. He didn't know anything about rectification.
A quick look on Google suggests that only welders use that construct.

"It turns out that Benjamin Franklin was totally correct on his views of electricity"
Nope
http://en.wikipedia.org/wiki/Fluid_theory_of_electricity

"Benjamin Franklin did create the first transistor and he turned lightning on and off with it. "
Nope (and just plain silly no such transistor exits, even today.).

"A carbon laser is created with an ARC."
as far as I know the only carbon lasers are xray lasers and are created with a small atom bomb. Details are sketchy.

"An argon laser is created with an ARC."
Nope,
"The typical noble gas ion laser plasma consists of a high-current-density glow discharge in a noble gas, "
from
http://en.wikipedia.org/wiki/Argon_laser#Argon_laser

(and as far as I can tell, CO2 lasers do the same.)
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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #34 on: 13/08/2012 03:17:18 »
My father worked at Grumman Aero Space. The people that built the Lunar module, the only vessel that performed flawlessly each time in actual space, not just high orbit.

It did so because they understood the ARC, friction, vacuum, compression, magnetism, ambient radiation, electricity, induction, you name they had it.

Have you ever looked at AC current, it is just DC current, changing direction, a set number of times a second. Nothing more to it, nothing fancy about it. Each half cycle of the AC current, creates an ARC when you create a short through air. Each cycle creates two ARC's, first on one electrode then the other. That is the only difference between pure DC and AC. Alternating current just means alternating DC current.

There is one more thing I have to throw at you, this is Benjamin Franklin's claim to fame. He found that by using points and flats, that he could easily dissect electricity, and decipher which way it was going. And how and why ARC's are formed. I am talking about the physical shape of the electrodes. One is pointed one is flat.

Did you see that movie I posted earlier. I made that to show people how electricity works. In the first part of that movie, the torch is charged (-) like on a modern American car battery. Pure DC current. You might note that except to initiate the ARC with a high frequency system that cuts out after an ARC is formed, the beam is totally silent. There is no ARC, or arc sound, that is a silent Anode beam. Because the flat work piece does not boil off and create an ARC. 

In the second part of the movie I feed the torch with AC current. You can hear the 120 cycles created from the 60 hertz power, messing with the audio.

As I explained there is an ARC formed, and you can see that the tip of the torch starts to melt, or balls up because it is being hit with electricity from the work piece or flat shaped electrode. AC creates very high surface heat, and does boil the surface of the flat metal work piece. Giving you 120 hertz.

In the last part of the movie the torch is charged (+) as marked on a modern American car battery. Pure DC current. You can see that there is also an ARC noise. You can see that the tungsten melts and even starts to boil, it recedes into the torch. Because the tungsten does not boil as much as a steel consumable electrode, the tungsten actually melts faster then a consumable steel electrode. Because the Tungsten is hardly boiling, it is not self cooling. The consumable steel ARC rod, boils and cools the rod. So you get a super hot ARC ray created at the tip of the consumable rod.

If you watch that a few times you will see that I am telling the truth.

http://youtu.be/dYReqtnmM4Q

Sorry I did not get back to you sooner I was welding up a set of railings for a friend. I made some shop drawings about three weeks ago, and bent it up two weekends ago, and yesterday and today between doing laundry, I welded them up. Now it is back to work tomorrow, Ahhhhhh. 





                      Sincerely,

                            William McCormick




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Offline damocles

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Re: Is there a speed of heat?
« Reply #35 on: 13/08/2012 04:33:28 »
Damocles,
did you have any trouble with the link I posted to the arc spectrum?

No.

Why do you ask?
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Offline damocles

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Re: Is there a speed of heat?
« Reply #36 on: 13/08/2012 04:55:57 »
If you check out this document, you will see during the war they decided that individuals on earth should not have the secret of the atom or the atom bomb. There was no conspiracy because they came out and said it. If you come out and tell people their government is going to make them as stupid as wood, there is no conspiracy. In the peoples defense they just thought the government was going to hide the bomb, not the atom. You know governments they are not always to smart, or truthful.

There was never a "secret of the atom". The discovery of nuclear fission was down to Hahn & Strassmann in Germany and Meitner and Frisch in Sweden in the year before the 2nd world war started. It was openly published in the science literature.

See http://en.wikipedia.org/wiki/Nuclear_fission#History

Any chemist or nuclear physicist could easily tell from the information on the public record that nuclear fission was a branched chain reaction, and therefore potentially explosive. The only secret that the US government wanted to or would have been able to keep was a series of secrets about how to go about engineering the basic science to produce a bomb. There are about 7 or 8 features of the nuclear fission reaction that make this engineering quite tricky and problematic.

So there was certainly a secret of the bomb, indeed several of them. But secret of the atom? Not at all clear what you are getting at here, nor what its relevance to this particular topic is. But the way it has been told certainly sounds conspiratorial -- especially the bit about the Russians going haha!
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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #37 on: 13/08/2012 21:51:11 »
My father worked at Grumman Aero Space. T

Sorry I did not get back to you sooner I was welding up a set of railings for a friend. I made some shop drawings about three weeks ago, and bent it up two weekends ago, and yesterday and today between doing laundry, I welded them up. Now it is back to work tomorrow, Ahhhhhh. 

                      Sincerely,

                            William McCormick





My mum taught on of the Spice girls and, like you dad's job, that also has absolutely nothing to do with the issue.

Unless your dad was using the word arc before My Davy, he's misusing it.

Nice railing.
It must be a right pain in the neck doing all that cutting to 6 digit accuracy. Do you have your own interferometer to check the pieces?
Also, how good is your air conditioning?
I find that temperature changes of just 1 degree alter the lengths of bits of steel by 15 parts in a million or so and Aluminium is even worse.

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

Damocles, I just wondered, given that William had struggled with it. He seems not to have understood much of it.

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #38 on: 13/08/2012 23:27:47 »
If you check out this document, you will see during the war they decided that individuals on earth should not have the secret of the atom or the atom bomb. There was no conspiracy because they came out and said it. If you come out and tell people their government is going to make them as stupid as wood, there is no conspiracy. In the peoples defense they just thought the government was going to hide the bomb, not the atom. You know governments they are not always to smart, or truthful.

There was never a "secret of the atom". The discovery of nuclear fission was down to Hahn & Strassmann in Germany and Meitner and Frisch in Sweden in the year before the 2nd world war started. It was openly published in the science literature.

See http://en.wikipedia.org/wiki/Nuclear_fission#History

Any chemist or nuclear physicist could easily tell from the information on the public record that nuclear fission was a branched chain reaction, and therefore potentially explosive. The only secret that the US government wanted to or would have been able to keep was a series of secrets about how to go about engineering the basic science to produce a bomb. There are about 7 or 8 features of the nuclear fission reaction that make this engineering quite tricky and problematic.

So there was certainly a secret of the bomb, indeed several of them. But secret of the atom? Not at all clear what you are getting at here, nor what its relevance to this particular topic is. But the way it has been told certainly sounds conspiratorial -- especially the bit about the Russians going haha!

That is what you read, and learned.

However if you look at what Benjamin Franklin had discovered about matter and the particle of electricity. And the advancements some, not all, Americans made in science. You would know that the actual Hiroshima bomb, did in fact weigh just under a half ton. The duplicate of the bomb, dropped on Hiroshima, sat on display at West Point for many years. I believe they removed the display, shortly after I visited West Point.

When the Freedom of information Act was introduced in the seventies. They released the video of the women actually making those bombs. Women in hair nets. Complete with the substances and weights needed to build one. On public funded television.

My facetious question might be, "Was that the cover up of the bomb, and the atom, or was that the bomb and atom released?"

I am not saying believe me or trust me. I am saying give a possible truth a chance. Ask yourself this, why did we need the freedom of information act, to uncover zero secrets? Why were most of the secrets about pre-world war two weapons. This bomb I am mentioning was around before World War Two.

The half ton Hiroshima bomb, was in fact not made with highly radio active material. Only slightly radio active fuel oils. That is why they did hide the bomb, and the atom. When you release 7,600,000 BTU's in a fraction of a second, you get a blast, like the one at Hiroshima.

The bomb casing was some type of metal that although faintly developed a brown or reddish tint, on the welds, it did not rust. That could mean chrome-molly, or manganese steel, or even titanium. I did not test it.

The core of the bomb was a metal sphere filled with 25 pounds of ammonium nitrate with many precision detonators all around the sphere, all aiming at the center of the core. Each detonator had an equal length wire to each one, so that they would all fire exactly at the same time. The core was suspended by chain in the center of the bomb. A lot of women with hair nets were making them.  The core was suspended so it would stay in the center of the bomb casing and the oil payload in the bomb casing.

The oil was a high BTU oil, again I do not have the exact specifics of the oil, something like a #6 fuel oil or rosin oil, perhaps even a creosote oil.

When you try to blow oil apart, from the inside, you increase the pressure upon the oil so suddenly that, it almost solidifies. Very similar to doing a belly flop into water. For a split second that waters surface is almost as hard as cement. The water cannot be displaced fast enough.

The oil, for a split second, becomes an unmovable ojbect. It has to do with the physics of start change and stop. During that time, the core and the oil reach temperatures of the sun. Leveling just about anything within a quarter mile radius. Of course horrid effects move out much further. But the actual total devastation area is about a quarter mile radius. Which is to this day a very, very powerful bomb.

If you have ever detonated asphalt you know the power of asphalt. You just have to electrically or chemically shock asphalt to detonate it. Asphalt has much less BTU's then #6 fuel oil. #6 fuel oil is over two hundred times more powerful then asphalt.

Years ago here on the Island high performance race shops had a couple of cars detonate rather violently. What took place was a race engine trying to move oil at a velocity, the viscosity of the oil would not allow. They eventually filmed a race motor, with a plexi glass oil pan, and found that oil would at very high RPM's get pressed to the spinning crank shaft. Instead of naturally being thrown off, by the centrifugal forces. These shops developed oil scrapers, that not only kept this from happening but also gave them more horse power.

Science has been dictated by government, through grant monies and tax breaks for many generations now here in America. This is not conspiracy, rather fact.

I have heard many times now, that science is above petty politics. Well if that is true, scientists would not be taking grant monies from such people. The truth is money comes from the printing press, so if you want money that is where it will come from. The banks currently control the press, government has always been in control of the banks, and also the money.

Poverty is a tool, not a scientific reality that just happens. The government uses it for many purposes. Government does not repair poverty, because it makes people easier to control.

The government just does things by the book using our ignorance to steer us wherever it is convenient. The government does not like to get caught in a conspiracy, unless the false conspiracy, is better then the real one.

 

                      Sincerely,

                            William McCormick


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Offline damocles

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Re: Is there a speed of heat?
« Reply #39 on: 14/08/2012 06:41:38 »
...(SNIP)...
That is what you read, and learned.

However if you look at what Benjamin Franklin had discovered about matter and the particle of electricity. And the advancements some, not all, Americans made in science. ***(COMMENT 1)***
You would know that the actual Hiroshima bomb, did in fact weigh just under a half ton. The duplicate of the bomb, dropped on Hiroshima, sat on display at West Point for many years. I believe they removed the display, shortly after I visited West Point. ***(COMMENT 2)***

When the Freedom of information Act was introduced in the seventies. They released the video of the women actually making those bombs. Women in hair nets. Complete with the substances and weights needed to build one. On public funded television.

My facetious question might be, "Was that the cover up of the bomb, and the atom, or was that the bomb and atom released?"

I am not saying believe me or trust me. I am saying give a possible truth a chance. Ask yourself this, why did we need the freedom of information act, to uncover zero secrets? Why were most of the secrets about pre-world war two weapons. This bomb I am mentioning was around before World War Two.
***(Comment 3)***

The half ton Hiroshima bomb, was in fact not made with highly radio active material. Only slightly radio active fuel oils. That is why they did hide the bomb, and the atom. When you release 7,600,000 BTU's in a fraction of a second, you get a blast, like the one at Hiroshima. ***(COMMENT 4)***

The bomb casing was some type of metal that although faintly developed a brown or reddish tint, on the welds, it did not rust. That could mean chrome-molly, or manganese steel, or even titanium. I did not test it.
***(Comment 5)***

The core of the bomb was a metal sphere filled with 25 pounds of ammonium nitrate with many precision detonators all around the sphere, all aiming at the center of the core. Each detonator had an equal length wire to each one, so that they would all fire exactly at the same time. The core was suspended by chain in the center of the bomb. A lot of women with hair nets were making them.  The core was suspended so it would stay in the center of the bomb casing and the oil payload in the bomb casing.
***(COMMENT 6)***

The oil was a high BTU oil, again I do not have the exact specifics of the oil, something like a #6 fuel oil or rosin oil, perhaps even a creosote oil.

When you try to blow oil apart, from the inside, you increase the pressure upon the oil so suddenly that, it almost solidifies. Very similar to doing a belly flop into water. For a split second that waters surface is almost as hard as cement. The water cannot be displaced fast enough.

The oil, for a split second, becomes an unmovable ojbect. It has to do with the physics of start change and stop. During that time, the core and the oil reach temperatures of the sun. Leveling just about anything within a quarter mile radius. Of course horrid effects move out much further. But the actual total devastation area is about a quarter mile radius. Which is to this day a very, very powerful bomb.

If you have ever detonated asphalt you know the power of asphalt. You just have to electrically or chemically shock asphalt to detonate it. Asphalt has much less BTU's then #6 fuel oil. #6 fuel oil is over two hundred times more powerful then asphalt.
***(COMMENT 7)***

... (snip) ...

Science has been dictated by government, through grant monies and tax breaks for many generations now here in America. This is not conspiracy, rather fact.

I have heard many times now, that science is above petty politics. Well if that is true, scientists would not be taking grant monies from such people. The truth is ...(SNIP)...

***(Comment 8)***


(1) Ben Franklin was in many ways and in many areas a great man. His contribution to the science of electricity was important at the time it was made, but has since been shown to be flawed in many ways, and has been superseded by new experimental results and deeper insights. Ben Franklin's work on electricity has been relegated to the historical archive, where it rightly belongs.

(2) There was surely no "duplicate" of the bomb that was dropped on Hiroshima? A replica maybe? Is the fact that the display was removed shortly after your visit significant? Did you ask too many inconvenient questions?

(3) It is quite unclear at this point whether you are talking about the Hiroshima bomb, or a production line of pre world war 2 bombs, or whether you believe, incredibly, that both were the same.

(4) I know that the Hiroshima bomb did contain a payload of highly radioactive material -- specifically U-235 at a very high level of enrichment.
---(a) An ex-colleague and friend of mine was a leading British mass spectrometrist who was fairly directly involved with the calutrons that were used for isotope separation, and has talked about it on more than one occasion.
---(b) The United States Government has been in no position to manipulate the information about the radioactive heritage of the Hiroshima neighbourhood -- neither to exaggerate it nor to diminish it.
---(c) No conventional bomb of a half ton could match the yield (i.e. energy output) of the Hiroshima bomb. The blast (i.e. energy output per unit time = peak power) could possibly have been matched by a conventional bomb through the sorts of effects you describe, though even that is doubtful. Total damage is best represented by the yield rather than the blast.

(5) One of the real secrets of the bomb was the use of beryllium as a neutron reflector in the casing of the bomb and design considerations around that. What that has to do with reddish coloration around the welds I have no idea. Maybe there was some iron somewhere as well?

(6) Another of the real secrets of the bomb is the need for a design to get several smaller pieces of U-235 to come together with perfect timing to make a single piece of U-235 large enough to trigger the explosive branched-chain reaction. Even a few milliseconds out and the uranium mass will simply melt and evaporate and melt the casing, and make a huge and dangerous mess without exploding. The sort of arrangement described here may well be an accurate representation of the conventional explosion required to initiate the nuclear explosion in a uranium bomb. I do not know.

(7) Half a ton of fuel oil or asphalt has a maximum chemical energy release of about 21 GJ, or about 20 million Btu. The yield of the Hiroshima explosion has had several estimates ranging between about 65 and 210 TJ, meaning 60 to 200 billion Btu, or 3000-10000 times larger. Of course the fuel oil payload of the Hiroshima bomb would not have been close to half a ton if the whole bomb weighed only half a ton.
Fuel oil 200 times more powerful than asphalt? yes. 200 times more energetic? no -- about the same. Fuel oil can be reacted in a very short time with high peak power; asphalt can not.

(8) I tend to agree with the sentiment and fact expressed here, but have cut off discussion of the rest of your post because this is strictly a science discussion, and discussion of your politics, which I do not agree with, is not the business of this forum.

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Offline CliffordK

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Re: Is there a speed of heat?
« Reply #40 on: 14/08/2012 06:57:45 »
William,

Are you denying the existence of atomic bombs, or that two were dropped on Japan at the end of WWII?

Fat Man, a relatively small atomic bomb by today's standards weighed just over 5 tons, with a blast yield of about 21,000 tons of TNT.

Little Boy weighed a little under 5 tons, with a blast yield of about 16,000 tons of TNT.

Little Boy was detonated at about 1,968 feet, and destroyed buildings in about a 2 mile diameter circle, killing about 66,000 people, and injuring another 69,000 people, and potentially leading to 200,000 fatalities. 

There is no conventional bomb weighing about 5 tons that could come close to that amount of destruction.

Your article above suggested that gasoline (or various oils) have a higher explosive content than TNT.  While that may be true, the caveat is that petroleum fuels require a stoichiometric ratio of an oxidizer (air) to be compressed and detonated with the fuel.  It is not sufficient to squirt hot oil into the air, but for an explosion, both the fuel and oxidizer must be compressed.  Explosives such as TNT or nitroglycerin do not require an additional oxidizer.  Likewise solid rocket fuels also include their own oxidizer as they must perform at high altitude where air is not readily available.  Keep in mind the LEO/GER oxidation/reduction reactions may be considered oxidation with other elements behaving similarly to oxygen.

So, consider two explosives.
A stick of dynamite immersed in a 5 gallons of oil, encased in heavy metal such as a propane tank with no trapped air.
A stick of dynamite encased in a tight fitting steel pipe.

The dynamite in the oil will not have sufficient oxidizer available, and will be no more powerful than the dynamite in the pipe.  In fact, the oil bath might absorb some of the blast, lowering the overall blast content.  The oil, of course, might burn causing a secondary fire, but not explosion.

As far as back to the topic with heat.
You may wish to read about Planck's Law..  Hot objects will emit light with a peak intensity at a wavelength corresponding to the temperature, but will emit that light over  many wavelengths.  Objects on Earth with temperatures between 0°C and say 40°C will emit light in the infrared range. 

The sun with a much hotter temperature, around 5500°C will also emit some IR, but its peak intensity is with much shorter wavelength EM, in the middle of the visible light spectrum.

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Offline bizerl

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Re: Is there a speed of heat?
« Reply #41 on: 14/08/2012 07:38:42 »
The original question was raised in regards to heat applied at one end of a material, affecting the other end. I was interested in how that happens. Thanks for all those who answered. The turn taken by the "conversation"  ;) has raised another question, relating to this.

Obviously a nuclear explosion makes a vast amount of matter very, very hot very, very quickly. So is this the "thermal diffusion" of air working really well?, or just the incredibly hot reaction? It seems to me if it was placed in even something like diamond (which seemed to be the best thermal conductor), the heat would not radiate as quickly as in air.

Also, when you guys say "light", do you mean "electro-magnetic radiation"? I was led to believe that all light is electro-magnetic radiation, but not all electro-magnetic radiation is actually light.

In terms of heat vs infrared, I always thought that the effect of IR was heating (like a microwave), but that heating could occur without IR as well. The discussion has now made me think that perhaps IR is the expression of a transference of energy, which is felt by us as heat.

I have no links or formulas to back up anything I have said, just the musings of a curious mind.

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Offline CliffordK

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Re: Is there a speed of heat?
« Reply #42 on: 14/08/2012 08:30:59 »
Here is a list of thermal conductivities.  I didn't realize that Diamond was so high up on the list.  Aluminum or Copper are quite high, but much lower than the diamond.  Silica aerogel is near the bottom for thermal conduction, at least for solids.



Vacuum Thermoses, of course, use use the lack of conduction/convection through a vacuum to keep their contents hot.

All light is Electromagnetic Radiation (EM), or photons.  However, the EM spectrum covers a range of wavelengths.  It is essentially the same as light, but we define different ranges of wavelengths from high energy gamma rays to x-rays to UV to visible light to IR to microwaves to radiowaves (which can have wavelengths of several feet or more).  Our eyes are only sensitive to a narrow band of the "visible light".

So, if you think of a hot electric stove burner.  If you touched a diamond, or a piece of copper or aluminum to the hot stove burner, the conduction would be fast and hot. 

If you held your hand a foot above the stove burner, you would have slower conduction of heat through the air to your hand (conduction & convection), although the surrounding air would eventually be warmed which you would feel when you would put your hand near the burner.  As well as the hand being heated by infrared (or red) heat radiant heat.  But, the transfer of heat through the air is slow, so you wouldn't want to suspend your kettle even a few inches above the electric burner.

A piece of glass (or double-paned glass) above the burner might block the convection/conduction heat and you would be left with pure radiative heat.

Note, you can have a steel kettle with a steel handle, and not get burned (too badly at least).  But, a copper kettle with a copper handle would get the handle too hot too quickly, and transfer that thermal energy to your hand too quickly.  Copper or aluminum cookware, however, is good for even heat distribution.

I did try soldering/welding silver once.  It was a pain because of the rapid heat conduction throughout the whole piece.
« Last Edit: 14/08/2012 08:34:52 by CliffordK »

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Offline William McCormick

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Re: Is there a speed of heat?
« Reply #43 on: 14/08/2012 21:57:22 »
My father worked at Grumman Aero Space. T

Sorry I did not get back to you sooner I was welding up a set of railings for a friend. I made some shop drawings about three weeks ago, and bent it up two weekends ago, and yesterday and today between doing laundry, I welded them up. Now it is back to work tomorrow, Ahhhhhh. 

                      Sincerely,

                            William McCormick





My mum taught on of the Spice girls and, like you dad's job, that also has absolutely nothing to do with the issue.

Unless your dad was using the word arc before My Davy, he's misusing it.

Nice railing.
It must be a right pain in the neck doing all that cutting to 6 digit accuracy. Do you have your own interferometer to check the pieces?
Also, how good is your air conditioning?
I find that temperature changes of just 1 degree alter the lengths of bits of steel by 15 parts in a million or so and Aluminium is even worse.

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

Damocles, I just wondered, given that William had struggled with it. He seems not to have understood much of it.

That is actually to three digits iof accuracy, Or thousands of an inch. It is the default of the cadd drawing program.

I can output those to 1/16ths or even 1/32ths of an inch about all that is practicle. But the truth is that our tape measures are in 16ths of an inch, so we hardly ever practice 1/32ths. So hearing 11/32ths kind of throws us.

But having always done machining we are familiar with thousandths of an inch and where they fit within 16ths of an inch. So I just convert the hundredths place, to a spot within the 1/16 mark. There are aproximately six hundredths of an inch between sixteenths of an inch.

But another reason the three places are a good default is that if you are making a spacer to put between pieces you are placing, you will need accuracy to thousandths of an inch.

Myself and an Austrlian fellow created the macro that automatically measures each section within a concatinated line. So I just touch the line and it places those measurements at each break point. So I can lay out the marks on the pipe while it is straight. It takes me 30 minutes to draw the pipe rail and stoop. 30 minutes to bend the pipe. And then about eight hours to fabricate. Without the macro and drawing. It would take me two or more hours to lay it out and the two railings would never match so exactly. So it is just for speed ease and accuracy I do it that way.

I knew Roy Grumman, met him when I was 1 1/2 years old. He got down lower then me and looked up at me, gave me a real mans hand shake and welcomed me to the plant. He used to pay for family picnics that were pretty cool.

We had the technology to go anywhere, but slavery and the price of real estate do not profit from a real space program. So they cancelled any hope of it.

Sending this from my iPhone, please excuse typos.


                             Sincerely,


                                William McCormick

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Offline Bored chemist

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Re: Is there a speed of heat?
« Reply #44 on: 14/08/2012 22:21:13 »
OK, so now we know that you can't even count.
104.372 has 6 digits (and 3 places of decimals).

"When you release 7,600,000 BTU's in a fraction of a second, you get a blast, like the one at Hiroshima. "
Nope, you get about ^ J or about 2 tons of TNT equivalent.
It would make roughly as much mess as a V2 rocket did (That was 1 ton so 7,600,000 BTU would give a slightly bigger crater if it was released suddenly enough).
It would take out a few buildings, but it wouldn't demolish a good chunk of a city.

Hiroshima was not a ton of oil catching fire.
This is the effect of 300 tonnes of petrol , largely premixed with air catching fire and progressing from a deflagration to a detonation.
http://en.wikipedia.org/wiki/2005_Hertfordshire_Oil_Storage_Terminal_fire

Death toll nil.

To say that the bomb dropped on Hiroshima was 300 times less mass of a fuel which doesn't explode readily is not only absurd, but an insult to those who died there .
I'm happy to excuse the typos, but I find it very hard to excuse your delusional ramblings.
Please disregard all previous signatures.

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Offline JP

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Re: Is there a speed of heat?
« Reply #45 on: 14/08/2012 22:54:59 »
Modnote:
Ok guys, let's keep it science, as per forum policy.  We'll step in and moderate the discussion if it gets too far off topic, especially if it tends toward conspiracy theories.

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Offline alimeeabey

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Re: Is there a speed of heat?
« Reply #46 on: 14/06/2016 10:06:03 »
Silicon is semiconductor material. Due to its good heat transfer properties, it has huge application in the aluminum and steel industry and uses large amounts of silicon in alloys. The rate of heat transfer is dependent on the temperatures of the systems and the properties of the medium through which the heat is transferred. But its main application is in Semiconductor industry as silicon wafer used in various microprocessor devices.
newbielink:http://www.wafernet.com/thermal-oxide-silicon-wafers.htm [nonactive]