Cold Definition and 419 Threads

When I was inspecting the house that I later bought about ten years ago, it was the winter time. It was cold outside. I wanted to run the air-conditioner to test that it would cool the house off effectively, but my realtor asked me not to. She said that it would damage the air-conditioner to...

I've been trying for 45 minutes and doing research but I can't even find a start to how to approach this. :( [Mentor Note: New user reminded to always show their work on schoolwork problems. That work is shown in a subsequent post below]

Is it possible to estimate the number of hot and cold spots of average diameter of 1° in a full-sky map of the CMB?

I have a cube with a volume of 1000m3 at an initial temp of 290K. The bottom side (10m by 10m) is open to the ambient air. I put this cube into a huge fridge and cool the whole volume by 5K. I close the open side by placing a cover on it. This cube has now got a volume of air at a temperature of...

I have been reading about the Ranke-Hilsch vortex tube. Details of the explanation tend to differ somewhat among different sources, but it got me thinking about the following thought experiment. Air enters a tube of about 0.5 x 4 cm cross section. It passes through a section that is channelized...

Hey there, I honestly don’t know if this is the right place for this, but I figured I would ask. lets say you are going to take a bath, but someone just took a shower and you know your hot water heater will be running low on the goods. Just for arguments sake, let’s say you have just enough...

Went for a 20-minute walk to the bus stop. The temperature was

How do we know that cold neutrinos do not make up 100% or a large percentage of the dark matter content in the universe? In my mind, the only way to prove that dark matter is not simply cold neutrinos would be to measure the density of cold neutrinos in the universe and then calculate the...

This thread is meant to discuss a topic that arose in https://www.physicsforums.com/threads/is-there-a-theoretical-size-limit-of-a-planet.1045983/ in a more precisely specified, idealized way. Further details: 1) Standard model + GR assumed, no other theories intended for this...

My refrigerator is on the minimal setting but still freezes the vegetables a little bit. It didn't do that a week ago. I'm renting and moving out in a few days so I'm not going to do anything drastic. How about wrapping my veggies in a blanket? I never understood the physics of those...

Manufacturer information: Interior material: stainless steel Exterior materials: Stainless steel Keeps cold liquid for: 24 hours Keeps hot liquid for: 12 hI was looking for a thermos bottle and came across a situation that I'm having a hard time answering. Why is the cold keeping time different...

In another well directed chemical analysis of fossils, a research group has indications that some but not all dinosaurs were warm blooded (endothermic), although some (Stegosauri and Triceratops) had apparently reverted to being cold blooded (ectothermic). In addition, it seems that the flying...

I've built an insulated chamber to protect a sensitive instrument at freeze temperatures in the winter. The instrument is mounted on a telescope, so the heat inside the chamber will slowly dissipate in the ambient. A digital PID thermostat is used to keep the temperature at a safeguard level...

cold start-: system requires huge amt of current user data to make accurate predictions early rater-: new user hasn't rated many items to make predictions. both same? isn't it?

cold start-: system requires huge amt of current user data to make accurate predictions early rater-: new user hasn't rated many items to make predictions. both same? isn't it?

I was in doubt if this is the right chapter to place this thread, but it seems there are many talents just here. "we were observing from a decent distance through optics. The weather was frosty, clear, calm. When хххххх appeared from under the arch of the house (he was хххххххх to walk to the...

Oymyakon is cold, but not that cold https://nypost.com/2021/12/03/fears-children-could-freeze-to-death-in-worlds-coldest-town/here is the Sun article they credited but failed to convert the temps https://www.the-sun.com/news/4196960/fears-children-freeze-temperatures-drop/The Siberian village...

Hi In some projects, I saw that hot and cold water tanks have been used for open circuit cooling towers. What is the need to use these tanks?

THIS POST TITLE IS MISLEADING. I paraphrased/lifted from the jpost. com article but did not read the research article. @Ygggdrasil graciously points out the error in post #3 below. Thanks...

I'll trade a cold for Covid-19 any time! https://www.medicalnewstoday.com/articles/a-common-cold-virus-may-help-fight-covid-19 Cheers, Tom

I finally brought in a heater and kept it at about 30C for 3 hours. It still smells like uncured offgassing. Will it ever cure or did the freezing/prolonged cold ruin it and i have to remove it?

I recently finished reading Paul Davies book The Eerie Silence, which is a book about the SETI (Search for ExtraTerrestrial Intelligence) project. In The Eerie Silence, Davies says that scientists using radio telescopes to search for radio messages from space aliens set their radio telescopes...

I understand that based on what I have read online quantum computers are required to be close to absolute zero because it introduces less error. Is it because brownian motion due to thermal agitation of molecules reduces with temperature?

So I've been hunting google for an answer but i cannot find a definitive one. If 0 Kelvin is the coldest temperature and it is where atoms cease to move does this mean that a photon in a vacuum is the hottest particle because it is in turn moving at the fastest speed possible? Second question...

Is it because of increase in pressure on my blood vessels due to cold weather outside?

My water heater has an issue. I still get cold water, but is that safe to drink if the water heater is not working? Thanks!

Neeleman, M., Prochaska, J.X., Kanekar, N. et al. A cold, massive, rotating disk galaxy 1.5 billion years after the Big Bang. Nature 581, 269–272 (2020). https://doi.org/10.1038/s41586-020-2276-y Abstract Massive disk galaxies like the Milky Way are expected to form at late times in traditional...

What are standard quantitative measurements of wringability? What is the quantitative limit between wringing and cold welding? What are the basic reasons of weakness at wringing/cold welding fault?

Hi, Can i know how having cold meals daily effects out health in long term? Thank you

I understand that cold fusion is an ever lasting energy but could some one exsplain it to me i have only heard of it.

Is it possible that the big bang started with ice, starting a tiny ice particle in a cold quite chaos , which grew into a giant ball of ice to eventually explode and through cold friction bring heat and start the light and speed to create all. It would seem more logical to get ice out of a dark...

Can anybody get me a cold fussion bottle to experiment with? Where would you get the heavy water they use?your not what you think you are what you think is what you are.

1) According to the first law of thermodynamics, when an object is brought into contact with a cold object, a process takes place that brings about an equalization of the temperature of the two objects, but why? why not from cold to hot?2) What exactly is entropy? I know it is the disorder of...

Will stone cold steve austin return at NO WAY OUTINDIA

http://www.nytimes.com/2002/03/05/science/05BUBB.htmlMore on the feud over cold fusion. Is it soup yet?A wake to imagination! {^,^}

I understand that if there is a type of laser that can make something cold instead of hot.How is this done?I understand that a photon has an energy of E=hv. v being the light frequency.Okay, Is v=c/wavelength where c=light speed.If that�s the case, when a laser hits an atom, the latter should...

An interesting paper is about to be published in the highly-respected journal called Science. It reports on a simple, tabletop method of creating nuclear fusion. You can read about the findings at the Washington Post website...

This is a follow up to the post about 'nothing' existing in the universe. When our universe gets very old, say trillions years from now, everything should have decayed and we're left with a cold dark universe, which for all practical purposes, has ceased to exist.But in reality, it will still...

i'm currently working on a formula on cold fusion, i'm no scientist, i'm just 12 years old... any ways here is my thoery; scientist need a brake, simple every day video gamers andintalectual kids in gifted class in a physics website (me) and every day workers can contribute to major research...

i always read that the universe was very hot after the big bang, right before the first star formed. i just read this article on space.com that said it wasn't. what do you think?::Kyle

Why is it that battery tends to leak in cold environments?Chense

The particle accelerator slated for 2006 in CERN - the Large Hadron Collider, according to some calculations, may be capable of producing thousands of microscopic black holes about 5000 times heavier than a proton.In any case, microscopic black holes, lasting only a fleeting moment because they...

I need a liquid which is inexpensive and readily available to common consumers. It must not freeze and maintain a temperature of >40 degrees F when passed through eighth inch plastic tubing by some sort of pumping device in an environment of temperatures as low as -20 degrees F. Any ideas?

I'm currently doing work on cold fusion and i need some info!!!! i need just as much info i can get....PLEASE HELP!!!!!!!!!!!!! thank you in advancehe who fights monsters finds that he himself is not a monster... you stare into the abyss, and the abyss stares back at you.-Fredrich Neitchzie

why does hot water rise and cold water sink

If I want to boil an egg, should I use the hot water from the faucet or the cold water?I know there is something similar about freezing water.

What is cold fusion and how does it work?I am temporarily out of my mind... Will be returning momentarily.

this is an earlier post from nanotech ideas, I thought it should have it's own post for more specific consideration.The meager beginnings of a cold fusion engine built with a hydrogen trap�1. Build a spherical chamber several atoms in diameter.2. Let an aperture exist on the top of the chamber...

can we make cold plasma. i heard that plasma is high energy gas, but does not neccesarily have to be heat energy. any comments

gr-qc/0111107Title: Cold Dark Matter from Dark EnergyAuthors: Aharon Davidson, David Karasik, Yoav LedererThe above paper can be found on:arXiv.org Physics e-Print archiveIt has not been refereed or submitted to a journal. Is there anything real in it? If so, it might be a major breakthrough...