How did the cookfire get hot enough to melt gold in Game of Thrones?In the television series Game of Thrones, Khal Drogo melts gold in a cookpot over a seemingly ordinary fire, and then pours the molten metal on Viserys' head. How could the cookfire get hot enough to melt gold?
Wikipedia says the melting point of gold is nearly 2000° F.
Reference:
"Gold"
[1] on Wikipedia
Answered here on Skeptics [1]
[1] https://skeptics.stackexchange.com/a/5868/25998Gold melts at 1064 °C, however, in jewellery, gold is often alloyed with copper ( wiki [2]). Though copper melts at 1084 °C, the alloy has a lower melting point, as you can see from the phase diagram (note that the temperature is in Kelvin, which adds ~271):
If the crown is 18k gold (¾ gold, ¼ copper), which makes an alloy that is harder than gold or copper alone, and gives a nice reddish hue to the gold, then the campfire only needs to be able to produce ~900 °C, which is achievable with the right fuel according to ...
ACCEPTED]
Khal Drogo's melting of gold [1] in what appears to be a simple cookpot, without the application of some sort of magic or a carefully stoked furnace, the melting should not have happened at all. Pure gold is simply too tough to melt with an ordinary fire.
Pure gold has a melting point of 1945 degrees Fahrenheit.
The average cooking fire even with good coals can reach approximately 650 to 700 degrees Fahrenheit.
So under this premise, it would be impossible to melt gold over a cooking fire with a standard cooking pot.
Metal °F °C Specific Gravity Weight in Troy OZ per CU IN Aluminium 1220 660 2.70 1.423 Antimony 1167 630 6.62 3.488 Beryllium 2340 1282 1.82 0.959 Bismuth 520 271 9.80 5.163 Cadmium 610 321 8.65 4.557 Carbon 2.22 1.170 Chromium 3430 1888 7.19 3.788 Cobalt 2723 1495 8.90 8.900 Copper 1981 1083 8.96 4.719 Gold 1950 1065 19.32 10.180 18K Green 1810 988 15.90 8.375 18K Yellow 1700 927 15.58 8.211 18K White 1730 943 14.64 7.712 18K Red 1655 902 15.18 7.998 14K Green 1765 963 14.20 7.482 14K Yellow 1615 879 13.07 6.885 14K White 1825 996 12.61 6.642 14K Red 1715 935 13.26 6.986 10K Green 1580 860 11.03 5.810 10K Yellow 1665 907 11.57 6.096 10K White 1975 1079 11.07 5.832 10K Red 1760 960 11.59 6.106
a primitive blacksmith forge [3] with the right kinds of coals, bellows and additives can easily reach 1400 - 2000 degrees but it takes skill, practice and the proper tools.
the melting points of a variety of metals [4] which could have been used and heated over a cooking fire limits the potential metals to tin (449 degrees Fahrenheit), lead (621 degrees Fahrenheit), a magnesium alloy (660 degrees Fahrenheit) or an aluminum alloy (at 865 degrees) Cooking at temperatures over a fire at temperatures higher than 650 degrees means most food burns beyond recognition.
If you want to be generous and make his fires raging bonfires using oaken wood (which I don't remember seeing that night) he might be able to reach 1200 degrees, but he would need a bellows and a means to raise the temperature of the fire significantly the same way a blacksmith does. At 1200 degrees he would be able to possibly melt poor quality, low-grade, golden alloys.
I am not sure why everyone is so emotional over this? The nature of writing is sometimes a writer (even if he is George R.R. Martin) is WRONG. Either through a lack of research, or an overwhelming desire to have a scene look a particular way, they may make a decision to write something and NOT care if it is physically possible. It's a choice the writer makes, it does not stop it from being outside the realm of physical possibility, nor does it make the awesomeness of the scene any less awesome. Hand-wave it away and call it "suspension of disbelief" [5] and keep enjoying the series.
This is a failure of both the writing team and the scientific support team on the set. While the scene invokes the Rule of Cool [6] trope, it fails and instead highlights " How Is That Even Possible [7]" trope.
Is there magic that would be capable of making flames hot enough to melt gold? Yes, but it is highly unlikely Khal Drogo would have had access to anyone or any technology capable of producing heat of such magnitude as easily as he did.
All Valyrian magic was rooted in blood and fire. It said they could set dragonglass candles to burning with strange, unpleasantly-bright light. With the obsidian candles, they could see across vast distances, look into a man's mind, and speak with one another though they were half the world apart. It is often said that the old wizards of Valyria did not cut and chisel stone, but worked it with fire and magic as one might work clay.
There are other users of fire magic such as the Priests of R'hllor [8] or the warlocks of the House of the Undying Ones [9] in the old city of Qarth. But given the Dothraki disposition toward magic overall, it is unlikely magic was used.
[1] https://en.wikipedia.org/wiki/GoldWitches, or maegi, are reviled as evil and unnatural.
The melting temperature of Gold is 1064.18 °C.
According to wikipedia flame temperatures as: Wood 1027 °C, Charcoal fire 750–1,200 °C
So it doesn't seem unreasonable that a pot on a coal fire could melt a Gold alloy. Note that we don't know the O2 concentration or atmospheric pressure in the world of A Song of Ice and Fire, and so these flame temperatures could be very different to our world!
I think it is because the fire was burning very hot "HollyWOOD" :-)
Alternatively, perhaps the gold was cheapened by adding lead (or silver/some other alloy such as in the Archimedes story). Lead was often used, make objects feel heavy like true gold and be gold coated but were cheaper to make.
Why this might have worked here:
Gold melts at ~1948F.
Lead melts at ~621F.
Wood goes through several stages before burning. As temperature increases, moisture boils off. At 450 degrees F, wood particles form volatiles, which produce the flames we see. At 750 degrees F combustion becomes possible. An oak log needs between 200 and 400 degrees to maintain combustion and burns at a maximum of 900 to 1100 degrees.
Hence an average cookfire (say a good boy scout campfire) can get to an average of 900-1000. Easy enough to melt lead. If it has an extremely good bed of coals and the right pitch to get a good draft going, you might get to 1200 or so. But, you would still be several hundred degrees Farenheit short of melting pure gold. Even silver takes ~1700 which would be really pushing it on a regular cookfire.
More likely it is because the t.v. producers simply took the story as originally written back in 1996 and never bothered to fact checked the author's claim to see if it would work. I remember reading this scene back in Asimov's when it first came out. I remember thinking at the time it was hogwash and I haven't changed my mind. However, it is still a brutal image.
Easiest answer is that gold in ASOIF has a different melting point than gold in our world, just as seasons in that world are not the same as seasons in our world.
Second easiest, is that it's not gold, but a fake gold made with a metal with a low melting-point. Khal Drogo might have been duped by an unscrupulous trader, or he used fake gold to add to the insult. "Why, the 'golden crown' isn't even gold at all!"
Real gold in our world, when it's melted, glows yellow, a typical cooking pot (cast iron or copper) would also melt in the tempuratures required to melt gold, and those tempuratures can't be reached on a campfire anyway. Even in a furnace, the time required to melt gold is far greater than the time it took in the show.
It might have been a gold alloy rather than pure gold. There's a chart at http://www.engineeringtoolbox.com/gold-alloys-melting-points-d_1434.html listing the lowest possible melting points of various alloys of gold plus one other metal (the melting point depends on the ratio of the two, but the temperatures listed are those for an "eutectic mixture", which is defined as "the mixture at such proportions that the melting point is as low as possible.") The lowest temperature is a gold/thallium alloy which melts at only 268 degrees Fahrenheit, and other reasonably low ones are gold/lead which has a melting point of 419 Fahrenheit, and gold/bismuth which melts at 466 fahrenheit (in real history, both lead [1] and bismuth [2] have been used since ancient times, so it's plausible they'd be available in the world of Game of Thrones). The numbers on this page [3] and this one [4] suggest that over 800 celsius, or around 1500 fahrenheit, would be a reasonable conservative estimate for the temperature of an open wood fire, so it should easily be able to melt nearly all the eutectic alloys on that page (the only ones above 1500 are manganese, sodium, and uranium).
[1] http://www.scientificamerican.com/article/ancient-roman-lead-melted-down-explore-frontiers-physics/Not as shown.
As noted by others, the melting point of gold is (depending on its purity) between 900°C and 1070°C, see the table below.
Metal °F °C Specific Gravity Weight in Troy OZ per CU IN Aluminium 1220 660 2.70 1.423 Antimony 1167 630 6.62 3.488 Beryllium 2340 1282 1.82 0.959 Bismuth 520 271 9.80 5.163 Cadmium 610 321 8.65 4.557 Carbon 2.22 1.170 Chromium 3430 1888 7.19 3.788 Cobalt 2723 1495 8.90 8.900 Copper 1981 1083 8.96 4.719 Gold 1950 1065 19.32 10.180 18K Green 1810 988 15.90 8.375 18K Yellow 1700 927 15.58 8.211 18K White 1730 943 14.64 7.712 18K Red 1655 902 15.18 7.998 14K Green 1765 963 14.20 7.482 14K Yellow 1615 879 13.07 6.885 14K White 1825 996 12.61 6.642 14K Red 1715 935 13.26 6.986 10K Green 1580 860 11.03 5.810 10K Yellow 1665 907 11.57 6.096 10K White 1975 1079 11.07 5.832 10K Red 1760 960 11.59 6.106
The various sources such as the same question on Skeptics.SE [1] and a similar question (silver instead of gold) somewhere else [2] put the heat of a campfire between 500-1000°C, to 1100-1200°C for large fires. Assuming the melting pot was in the fire or very near to it (to have enough heat transferred), it could be possible, depending on the purity of the gold.
So yes, it should be possible in theory.
However, Wikipedia puts the colour of steel [3] at orange at that temparature. So the pot in which the gold was melted, should have been glowing red hot at the very least, as seen in the following image.
Also, the pot was not in the fire but above it, and from the meat being cooked on it, the fire doesn't look hot enough (the meat would've been charred).
So yes, it should (theoretically) be possible, but not as shown.
[1] https://skeptics.stackexchange.com/q/5849/16121
"Patient: Doctor, it hurts when I do this!" "Doctor: Then don't do that.":) - TLP