Magical heating sword

So these magicians have been working on a new weapon for the King because he wants something to show off about. They were struggling for inspiration when they discovered a way of trapping the friction of the metal against the air inside an unobtanium steel alloy and releasing the trapped energy as heat. This heat trapping is so effective and so powerful that after a 15 minute charge time the sword can be heated to 1583 degrees celsius (2800 degrees fahrenheit). It can maintain this heat for a minute then it must have a 15 minute recharge during which time it is effectively a normal sword. The power of the sword has no direct effect on the wielder and also does not melt the sword.

So to recap the powers are

• Produces one minute of intense heat with 15 minute recharge.
• Protects user from abilities of sword.
• Protects user from other magical attacks.

Given that the sword has these powers what issues for the user will the sword give?

• Not a duplicate, but closely related: worldbuilding.stackexchange.com/questions/31968/…
– Kys
Apr 6, 2016 at 14:26
• And your sword is going to lose a lot of strength if the steel itself is that hot (not sure if this is covered under your no-melt unobtanium)
– Kys
Apr 6, 2016 at 14:28
• @Kys I was inspired by the other question you have linked. And the heat has no direct affect on the weilder or the sword. Apr 6, 2016 at 14:41
• 1583 C is very specific, any particular reason for this number? Apr 6, 2016 at 20:55
• @MichaelMcGriff Melting point of iron. Apr 6, 2016 at 21:03

Assuming, as mentioned in the question, that the user is protected from the effects of the sword, heat would not be an issue. As long as the user is holding the sword, he is protected from its heat. However, there are other issues.

Time and Convenience

If the sword heats up for only 1 minute, after 15 mins of recharging, then that's hardly efficient. That's a 15:1 ratio. Thus, seeing as a battle could last for several hours, the sword would then need at least a couple of days prior to the battle to charge. This would, of course, be an issue and a nuisance, because you may never know when the sword and its intense heat function may be needed, or for how long. With such an inefficient power output ratio, it may well be that the sword's intense heat function might rarely be used, if ever, simply because it just takes way too long to charge.

Reliability

How would the user know how much power is left in the sword, before it needs to be re-charged? It is possible that the user may come across a situation where the intense heat function is desperately needed, but activates it, only to find that there isn't enough power to heat the sword up for longer than a second. Some sort of timer should be incorporated into the sword to inform the user how much longer the sword can produce such heat.

Safe-keeping

The user may be protected from the heating effects of the sword, but not everything around him or it. The obvious housing for such a sword would be a scabbard, but then the scabbard would also have to be protected from the heat. This is so that the scabbard does not instantly explode in a cloud of ash if the sword is accidentally activated inside the scabbard. Especially because scabbards are usually made of wood, or leather. The scabbard could be made of the same material as the sword, of course, since the sword is not damaged by the heat, but that would make the scabbard very heavy. If, on the other hand, the material used to make the sword is light enough that the scabbard would not be a hindrance, then the sword itself would not have enough force when used, because it is too light.

Well, realistically, if the sword is giving off that kind of heat no one will be able to actually use it without risking tremendous harm to their own side.

That thing would kill anyone who got within meters of it. It would bake knights in their armor - friends and foes alike.

It would also start fires all around the user, which will be potentially deadly to the wielder (although the blade itself is not). If you're standing in the rain the super heated vapor might also harm you as puddles beneath your heat instantly boil.

The only way to use this relatively safely would be outdoors, in a relatively moist environment, either by yourself, or far enough from your own forces that you won't harm them. However at that point you're putting yourself in a lot of danger on the battlefield.

Unless this sword has a very specialized use (such as fighting a dragon one-on-one) it would not make a suitable weapon on the battlefield.

• The bit about the user being immune to the blades effect cancels your first point. Apr 6, 2016 at 14:39
• @Bellerephon - missed that bit. Updated my answer. Apr 6, 2016 at 14:40
• Thanks for the edit. I think it can have an upvote know. Apr 6, 2016 at 14:49
• "That thing would kill anyone who got within meters of it. It would bake knights in their armor - friends and foes alike." Citation needed. The melting point of steel is is only a little bit below this temperature and a puddle of molten steel doesn't instantly kill the steel working standing around it and looking at it. Light bulb filaments reach 2550 degrees Celsius and they don't kill everyone standing under them. Apr 6, 2016 at 19:41
• Agree with Shufflepants. Note the blacksmith is not dead or on fire in the photo he has provided, and though by itself it is somewhat anecdotal, I can attest that blacksmiths have historical precedent for not bursting into flames or burning to death. Downvoted until reasonable explantion/sources cited. Apr 6, 2016 at 21:51

The melting point of stainless steel is 1363 degrees Celcius and molten steel is unpleasant to be around, but it's not going to kill everyone around it. Here's a guy standing next to a bunch of it:

Just because an object is a certain temperature doesn't mean it instantly makes everything around it the same temperature. After all, the surface of the sun is 5498.85 degrees Celsius, but it's not that hot here on Earth. The filament in a light bulb can reach 2550 degrees Celsius but that's not how hot your room is (I hope).

Probably the biggest issue that a user of this sword is going to face is just how bright the sword will be. It'd be quite distracting, and using it at night is going to leave the user and those around him fairly blind until the bright spots in their vision dissipate and their eyes adjust.

Also, since the temperature is a couple hundred degrees hotter than the melting point of steel, there's a slight chance that if you try to stab an armored opponent with this sword while it's activated or slightly after it's turned off that it'll melt the edges of the armor you've pierced a little and then cool before you withdraw it resulting in a natural weld making it a little hard to pull your sword out. It probably wouldn't be a very clean weld or melt the armor very much, but it might take a good yank. "Whoever pulls my sword out of my enemy's corpse gets to be king for a day!"

There would be spontaneous combustion of nearby flammables, including papers, lacy curtains , clothing, and fancy hairdos. Nearby wax would slump and drip. Anyone standing nearby would be driven back by this intense heat.

It would look quite impressive, if blinding, from a distance.

• Would a lot of this not be an advantage in a fight though. If I activate this sword it will blind and confuse my opponent and drive them back giving me a chance to kill them. Apr 6, 2016 at 14:23
• Sure. But any nearby friendlies, including bodyguards, are also rushing to leave your surroundings. Apr 6, 2016 at 14:44
• I guess it would work if I was isolated or in a duel. Apr 6, 2016 at 14:46
• Sorry, not remotely true (necessarily). Depends on the emissivity of the sword. A blackbody will radiate ~100 kW, but when cold it will be, well, black. Which is completely uncool for a sword. A sword should be shiny, right? Reflective? If its reflectivity is 99%, its emissivity is 0.01, and I only radiates about 2 kW. Nasty in a confined space, not so much outdoors. Apr 6, 2016 at 15:32
• @WhatRoughBeast Black swords, new trend. Apr 6, 2016 at 19:20

The heat from the sword will boil the moisture present in any nearby rocks, causing them to explode. Any moisture present in your surroundings will also boil, filling the air with clouds of scalding steam. The superheated steam-filled air would also rapidly expand and begin to race away from you, at least until the clouds of steam surrounding you reached an equilibrium temperature with the blade.

Essentially, activating the sword would release a small pyroclastic flow full of shrapnel. This would kill anyone nearby, friend or foe. Do not activate at parties.

• This still seems like an advantage in a battle as your army could easily take out many enemies with one soldier. Apr 6, 2016 at 15:06
• "The heat from the sword will boil the moisture present in any nearby rocks, causing them to explode. " Citation needed Apr 6, 2016 at 19:37
• the heat from, the sword is not appreciably heating anything it is not in direct contact with.
– John
Dec 14, 2020 at 6:46

Well if the sword protects the user form it's self then I don't see many Issues with it. However the user has to have some way of activating the enchantment. Maybe by saying a particular phrase, word or spell.