# “Hot” coffee cup **URL:** \ **Category:** Factual Questions\ **Created:** [January 20, 2024, 7:45pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406 "2024-01-20T19:45:03Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [January 21, 2024, 9:50pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/81 "2024-01-21T21:50:09Z")
See, I told you Yeti was the answer. ---
**Author:** ![Retzbu\_Tox](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/retzbu_tox/32/11829_2.png) [@Retzbu\_Tox](https://boards.straightdope.com/u/Retzbu_Tox)\ **Post date:** [January 21, 2024, 10:00pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/82 "2024-01-21T22:00:49Z")
I think you need something that heats on demand, like a mug made out of sodium metal. When you put your cold coffee in there, that baby will heat right up, I guarantee it! ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 21, 2024, 10:33pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/83 "2024-01-21T22:33:00Z")
Incidentally, the nuclear pacemakers that **outlierrn** mentioned contained maybe 150 mg of Pu238. They aren’t being made anymore, but people with them die on a regular basis. And although they’re supposed to be returned to a laboratory like Los Alamos, I suspect there are a bunch that people have forgotten about. If you can acquire 30 or so of these, you can build your nuclear coffee mug. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 21, 2024, 10:34pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/84 "2024-01-21T22:34:31Z")
I’m thinking you’ve got part of the radioactive material in the mug, and part in a coaster. When you put the mug on the coaster, they interact and heat up. When you store them separately, they don’t heat up, or at least not nearly as much. That solves the problem of the mug starting a fire or something when it’s in a cabinet. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 21, 2024, 10:47pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/85 "2024-01-21T22:47:45Z")
Unfortunately, while that strategy is effective for something large like a power plant, I don’t think it can be scaled down to coffee mug size. Power plants control their output by having a neutron moderator of some kind. Generally speaking, that slows down the produced neutrons so that they’re more likely to cause other fissions. If you want to stop the reaction, remove the moderator. The chain reaction stops because there aren’t enough neutrons going at the right speed. There are also neutron reflectors, which can reduce the size of the fissionable material you need by reflecting them back into the mass, but that still only does so much. Also, I don’t think we want to be using induced fission here (as opposed to spontaneous fission from radioactive decay). Alpha particles are one thing (eaily stopped by almost anything, as **Chronos** said); neutrons are another. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [January 21, 2024, 11:28pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/86 "2024-01-21T23:28:02Z")
These seem pretty close, albeit electrically powered. If you need a heated coffee mug in the real world, this might do. [Ember Mug² 10oz Temperature Control Smart Mug - Black : Target](https://www.target.com/p/ember-mug-178-10oz-temperature-control-smart-mug-black/-/A-79910207?ref=tgt_adv_xsf&AFID=google&CPNG=Appliances&adgroup=72-8) ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [January 21, 2024, 11:46pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/87 "2024-01-21T23:46:39Z")
> [@Dr.Strangelove](#): > > I suspect there are a bunch that people have forgotten about. If you can acquire 30 or so of these, you can build your nuclear coffee mug. I guess introducing a step that involves digging up 30 dead bodies doesn’t really make any of this significantly less plausible. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 21, 2024, 11:47pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/88 "2024-01-21T23:47:59Z")
I was thinking about putting feelers out at crematoriums. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [January 21, 2024, 11:48pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/89 "2024-01-21T23:48:48Z")
Well, I gave you the benefit of the doubt that you were planning on waiting for people to die. You can never be sure with mad scientists. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 21, 2024, 11:54pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/90 "2024-01-21T23:54:20Z")
Agreed. One of the best things about a good FQ hypothetical is just how outrageously large the hand-wavable obstacles can become. If you are going grave robbing, the hard(er) part of that effort will be that since you probably don’t have any way to trace who had/has those pacemakers, you’ll need to dig up a lot more than 30 bodies to find 30 nuclear pacemakers. Which reminds me of a horrible joke from the days when one could tell jokes about ethnic groups who were supposedly extra un-smart. > **Person 1** : Did you hear about the airliner that crashed into the cemetery near [capital city of supposedly unsmart ethnic group]? > **Person 2** : No. That’s terrible. What happened? > **Person 1** : I’m not sure but so far rescuers have recovered over 1200 bodies. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 21, 2024, 11:57pm UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/91 "2024-01-21T23:57:28Z")
I’m not saying there aren’t ways of speeding up the process. Alternatively, you can [break into a weapons lab posing as a medical research facility, replace the plutonium suspension with shampoo, and smuggle it out with an RC car](https://www.imdb.com/title/tt0091472/) (would it surprise anyone that this was a favorite movie of mine as a kid?). ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 22, 2024, 12:04am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/92 "2024-01-22T00:04:16Z")
Another option is to steal the material from decrepit Russian lighthouses: > **[Radioisotope Thermoelectric Generators - Bellona.org](https://bellona.org/news/nuclear-issues/radioactive-waste-and-spent-nuclear-fuel/2005-04-radioisotope-thermoelectric-generators-2)** > > UPDATED April, 2005. To read the previous version of November, 2003, click here. Not sure if that’s easier or not. Surely there’s a black market for these things. They’d be mildly useful as a dirty bomb, though IMO there are better options. Maybe there are some Libyans I can contact. ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [January 22, 2024, 12:18am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/93 "2024-01-22T00:18:35Z")
Unfortunately. Would they necessarily be of a most stimulating variety, you think? Fuel cells? Boondockers would love those. Or a small portable generator sized nukie suitcase! Harbor Fright here we come! ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [January 22, 2024, 12:27am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/94 "2024-01-22T00:27:22Z")
> [@Dr.Strangelove](#): > > I was thinking about putting feelers out at crematoriums. I was thinking of an episode of a CSI show where they realize that all of the murder victims had nuclear pacemakers, and at the end of the episode break in on a guy holding a bulky coffee cup. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 22, 2024, 2:08am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/95 "2024-01-22T02:08:05Z")
How about americium? We can harvest it from all the discarded smoke detectors. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 22, 2024, 2:16am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/96 "2024-01-22T02:16:17Z")
I considered that. But Americium-241 only produces about 0.1 W/g: [https://iopscience.iop.org/article/10.1088/1742-6596/1689/1/012063/pdf](https://iopscience.iop.org/article/10.1088/1742-6596/1689/1/012063/pdf) So we need around 25 grams in this case. According to Wikipedia, there’s only around 0.29 micrograms per smoke detector, so you’d have to disassemble around 86 million smoke detectors. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 22, 2024, 2:25am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/97 "2024-01-22T02:25:02Z")
I thought most nuclear pacemakers were betavoltaic, using tritium? ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 22, 2024, 2:26am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/98 "2024-01-22T02:26:40Z")
The later ones were, but the early ones were thermoelectric: [http://large.stanford.edu/courses/2015/ph241/degraw2/](http://large.stanford.edu/courses/2015/ph241/degraw2/) ---
**Author:** ![outlierrn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/outlierrn/32/3005_2.png) [@outlierrn](https://boards.straightdope.com/u/outlierrn)\ **Post date:** [January 22, 2024, 2:55am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/99 "2024-01-22T02:55:48Z")
Just to be clear, everything I know about this topic I gleaned from looking up the RTG scenes from **The Martian**. I would have assumed that in addition to wildy impracticable, the answer to the OP would have included highly illegal (and maybe it does), so I was surprised to see the bit about pacers. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [January 22, 2024, 3:55am UTC](https://boards.straightdope.com/t/hot-coffee-cup/996406/100 "2024-01-22T03:55:08Z")
> [@Czarcasm](#): > > Coffee is made up of water and ground coffee beans. Even if you found a safe and simple way to keep the coffee at a constant hot temperature, you still have the problem of steam escaping and turning what is left to **sludge**. that would be your NESCAFE (R) , > [@Darren\_Garrison](#): > > I was thinking of an episode of a CSI show where they realize that all of the murder victims had nuclear pacemakers, and at the end of the episode break in on a guy holding a bulky coffee cup. … reading the SDMB , > [@Dr.Strangelove](#): > > The later ones were, but the early ones were thermoelectric: > [The History of Nuclear Powered Pacemakers](http://large.stanford.edu/courses/2015/ph241/degraw2/) those were also the reason for Breshnevs broad shoulders … [Previous page](https://boards.straightdope.com/t/hot-coffee-cup/996406.md?page=4) [Next page](https://boards.straightdope.com/t/hot-coffee-cup/996406.md?page=6)