Readers reply: is a ‘negative microwave’ – a device that quickly cools food and drink – possible?

11 months ago 139

Ive been grappling for decades astir however you’d get a “negative
microwave” to work, a instrumentality that precise rapidly cools things specified arsenic nutrient oregon drinks without having to pre-fill it with thing that’s already cold. I recognize galore of the reasons wherefore it’s adjacent intolerable but is it really impossible? Maybe quantum physics tin mysteriously bash it. George Stewart

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Readers reply

I judge the astir promising method to chill nutrient oregon portion rapidly would beryllium to enactment the plate/cup/glass successful a container from which aerial could beryllium pumped. The resulting accrued evaporation of h2o would transportation distant heat. Advantage: No chemic contamination, nary ample magnetic fields etc, nary request for the pressured retention of gas. Drawback: depending connected the applied debased pressure, evaporation whitethorn effect successful the detonation of parts of the repast 1 wants to cool, drinks could boil and spill over, which means that for information reasons, the unit driblet should beryllium limited. This method would beryllium inefficient for adust food.

Alternative method: the plate/cup/glass could beryllium placed successful a measurement wherever pressurised aerial from a retention vessel is allowed to expand. Just similar a CO2 occurrence extinguisher cools, the expanding state (which should beryllium ambient aerial for information reasons) would beryllium precise cold. Drawback: cooling would beryllium achieved implicit a accelerated airflow, which whitethorn beryllium inconvenient if 1 wants to support a repast connected a sheet oregon a liquid successful a cup. The ample thermal gradients progressive whitethorn beryllium destructive for the repast oregon the sheet (especially if crystal enactment occurs). A banal of pressurised ambient aerial would beryllium required.

Maybe the safest method is inactive simply to hold for the repast to chill down “naturally” portion talking with a bully person. Michael Bremer

A blast chiller is the appliance you need. No quantum physics: it is simply a benignant of ace refrigerator. Use of blast chillers is prescribed successful European restaurants, but it is not uncommon successful backstage households. I americium Italian and my hubby has precocious bought one. When helium cooks excessively overmuch lasagne, helium uses the blast chiller to chill it down quickly, stopping bacterial growth. Food volition past longer, it volition beryllium safer and erstwhile you reheat it, it volition sensation overmuch much better. Valeria Andreoli

Plunging nutrient into liquid helium volition bash the occupation for you. It’s what is utilized to chill the MRI scanners successful hospitals. At a guess, I would accidental each clip you utilized it successful a home room would outgo astir £50, truthful if you deliberation it’s worthy it, there’s your answer. Terry Eaton

Microwave ovens vigor nutrient by colliding microwaves with h2o molecules, breathtaking the electrons and making them lukewarm up nutrient and drink. This vigor needs to beryllium removed successful immoderate mode to de-excite the electrons. In quantum mechanics, this could beryllium achieved by expanding the wavelengths of electron vibration, making them oscillate little vigorously, truthful theoretically it is possible. But, arsenic we each know, vigor people goes from lukewarm to cool. Warm things chill to the ambient somesthesia arsenic governed by 2nd instrumentality of thermodynamics. So, I deliberation the question is: what is the constituent of creating a antagonistic microwave if the arrow of clip dictates that things volition chill people anyway? Elvis

This has been known since the 17th century, acknowledgment to Robert Boyle. Hold the unit changeless and alteration the pressure; somesthesia drops. Increase the pressure, and the somesthesia rises. Takes a batch of vigor to bash it though. Kevin Aston

I’ve been grappling with this thought for galore years. Tinkering successful the plot shed hasn’t produced immoderate results yet. Once you person solved this, possibly you tin assistance maine with my different project, the acheronian torch, which projects a tract of “no light”. David Sogan

Sure, it’s possible, but not with microwaves. Instead usage liquid pressurised state that is released into a vacuum cooling chamber. This volition make a precise frigid situation owed to the state expanding its volume. Google “the coldest spot successful the universe”, and you volition find it’s a rapidly expanding state unreality with little somesthesia than the remainder of the universe. The effect tin among others beryllium felt erstwhile you refill a lighter with butane gas. The refiller vessel volition get precise cold. OJ Nordhagen, Norway

I’m a atomic idiosyncratic with a physics PhD. As you person been grappling with this for a while, I ideate you person done immoderate probe yourself truthful forgive maine if I rehash worldly you person learned. Microwaves vigor nutrient arsenic the electromagnetic radiation interacts with the h2o molecules successful the food. This wavelength interacts with antithetic vibrational modes successful the molecule wrong the food, the vigor from the microwave excites the molecule and causes it to vibrate faster. This heats the food. It particularly interacts with hydrogen bonds, specified arsenic water, hydrocarbons successful lipid etc.

To cool, we would person to extract vigor from the food. This is simply a small trickier and produces vigor arsenic a byproduct. One method is the laser. Negative temperatures person been produced successful the lab, but don’t effect successful a acold entity arsenic you would want. A much feasible method would impact utilizing acold liquids and pumping vigor away, conscionable similar a almighty fridge. Perhaps a speedy blast of nitrogen state astatine utmost acold temperatures would bash it. At my enactment we usage cryogenic temperatures, if it was imaginable to chill an entity indirectly utilizing a antagonistic microwave instrumentality we would privation to know! Rose Brown

A fig of methods could beryllium utilized to guarantee that the surface of the food/object radiates vigor and receives minimal incoming vigor (eg, chill the walls of a metallic instrumentality it’s successful to adjacent implicit zero.) These volition rapidly chill the object’s aboveground (“flash freezing”). However, determination is not – and cannot beryllium – immoderate method to chill the interior of the entity different than by conduction of its vigor to the outside. A microwave sends electromagnetic vigor to the interior, but determination is nary specified happening arsenic antagonistic vigor (except successful weird contexts). MartinMellish

No, and the elemental crushed is due to the fact that of the 2nd instrumentality of thermodynamics. It’s the lone carnal process that isn’t fundamentally symmetrical (in this universe, anyway) and truthful is often regarded arsenic defining the arrow of time. It fundamentally states that entropy (disorder) volition ever summation successful an isolated system. Heating increases entropy, you are moving with the earthy inclination of the universe, truthful it’s casual – propulsion immoderate vigor (eg, microwaves) astatine thing and it conscionable becomes much entropic without immoderate further work. Cooling, connected the different hand, means putting much bid (decreasing entropy) into a system, moving successful the other absorption the beingness wants to go, arsenic defined by thermodynamics, truthful that’s a batch of further enactment (and truthful energy) needed to trim entropy (ie chill it) arsenic summation it (heat it) by the aforesaid degree. HaveYouFedTheFish

If you enactment vigor into something, nary substance however you bash it, it’s not going to go colder. As acold arsenic I understand, a fridge works by having vigor successful the aerial of the container moving connected immoderate worldly successful the fridge, thereby cooling the aerial inside. Overall the surrounding aerial becomes warmer than if you hadn’t turned connected the fridge; if you near the doorway unfastened (a atrocious idea) it wouldn’t chill the room. So adjacent successful that case, though you enactment vigor into the instrumentality and it is cooling something, wide a fridge is heating things up.

If you could reverse time, however, you could conscionable usage a regular microwave device. You enactment your blistery nutrient into the microwave, hold till the microwaves person near the nutrient to beryllium absorbed by the instrumentality surrounding it and instrumentality retired your acold food. somehowrational

I’m definite that astir 30 years agone they had a contraption successful Thresher’s off-licence that you could inquire them to enactment your vessel wrong to chill it rapidly. If I retrieve correctly, it rattled a batch successful the process. I person sometimes wondered what happened to those machines and wherefore determination is nary modern equivalent. HotBurrito

The thought of utilizing fluorescence to chill a worldly nether optical excitation was initially projected successful the 1920s, past theoretically validated by Landau successful 1946. As George Stewart expected, it relies connected quantum mechanical principles: if a laser is utilized to thrust electrons into excited states with non-equilibrium occupancies, past the electrons tin sorb phonons (wave-like structural vibrations that transportation vigor successful materials) earlier relaxing to a debased vigor authorities by emitting a higher-energy photon (fluorescing). This results successful a nett vigor nonaccomplishment from the worldly and is known arsenic “anti-Stokes fluorescence”: for a amended statement (and an illustration of cooling a macroscopic entity from country somesthesia to -182C), see here.

However, if this cooling process is to outweigh the accustomed heating effects caused by electromagnetic question absorption, past the worldly that is being irradiated indispensable person an highly precocious quantum efficiency. This means that the electrons indispensable travel precisely the close series of excitation, absorption and emission, alternatively than absorbing the vigor from the laser by non-radiative dissipation. To date, I judge this has lone been conclusively demonstrated utilizing ultra-high purity glasses featuring uncommon world ions. (In the past decade, scientists person claimed to execute akin laser cooling successful definite semiconductors and perovskites, but the experiments person not been reproduced and stay controversial.) So I americium acrophobic that anyone attempting to chill their gazpacho with a laser volition astir apt beryllium disappointed. furry_marmot

The reply present is, I think, counterintuitive. Rather than recruiting the precise finest and astir dedicated brains successful academia and manufacture to probe a solution to this puzzle, you request to assemble a clump of feckless erstwhile subject students who person each been thrown retired of university. That way, the squad is definite to execute zero degrees and volition truthful beryllium an unqualified success. ThereisnoOwl