Questions tagged [physics]

Use this tag for questions about the physical nature of reality and in particular claims that are strictly about the field of physics. Please use specific tags if the question is about other sciences such as chemistry. Also consider to add [electromagnetism] and [radiation] if appropriate.

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16
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3answers
2k views

Do Shade Balls conserve/save water?

In recent headlines here, here, here, it appears that Los Angeles reservoir now has 96 million "Shade Balls" to slow evaporation. I'm skeptical on a number of fronts: How much water went in to ...
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1answer
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Is it necessary to leave a pool during a thunderstorm?

Most schools and public pools have the policy of closing swimming areas during thunderstorms for fear of electrocution. I was wondering how logical or reasonable this policy is, given that most pools ...
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Breaking the bottom brick with your hands

In the movie Bloodsport, which claims to be based on a true story, the lead character is challenged to break one brick at the bottom of a stack, using only his hands. He successfully causes the bottom ...
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Man using "water as fuel" for a welding machine? (H₂O → "HHO")?

I saw a while back a YouTube video that appears to show a news report of a man who patented technology to turn water into "HHO". The video makes some big claims — 161 km (100 mi.) on 0.1 L (4 ...
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Has the speed of light significantly slowed down over the past 6,000 years?

One of the problems for young-Earth creationism is that we are seeing light from stars more than 6,000 light-years away, which implies that those stars pre-date the alleged date of the creation. To ...
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Is it not possible to swim in crude oil?

In the book Ship Breaker by Paolo Bacigalupi, one of the characters falls into crude oil and state that one cannot swim in crude oil. The character can swim in water. If true, why would you not be ...
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Does the Mount Washington wind speed record have scientific validity?

A record wind gust of 231 miles/hour was recorded in 1934, according to http://www.mountwashington.org/about/visitor/recordwind.php Wind speeds of this magnitude are commonly known to damage or ...
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1answer
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Did January 2014 American snowfall char and burn when exposed to fire?

This site, ‘Fake Snow’: Videos In Multiple States Show Strange Snow That Doesn’t Melt Normal, Burns, Smells of ‘Plastic’, shows several videos and images of people burning snow they collect from ...
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1answer
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Are ceramic heaters more efficient than convection heaters?

A colleague is trying to tell me that I should pay more and get a ceramic heater rather than a cheap convection room heater because I'll save money on electricity. I have one like this: Sure it's ...
15
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1answer
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Is Canadian PM Trudeau's explanation about quantum computing accurate?

In a recent press conference Justin Trudeau answered a journalist who asked him (initially jokingly) to explain quantum computers. He obliged with a <1 minute explanation which seems to receive ...
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1answer
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Do ultrasonic cat repellents work?

Amazon sells roughly 355 different cat repellent products but judging by the consumer ratings, most of them don't actually work -- and even those that do, could be correlation rather than causation. ...
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1answer
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Was the vertical cannonshot related by Samuel Rowbotham ever performed?

A common claim in support of "Flat Earth" models is that a cannonball fired precisely vertically drops back upon the cannon, even back down the muzzle. One such claim appears here http://www....
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Does the theory of evolution contradict the second law of thermodynamics?

I was reading about the Law of Thermodynamics, and the Second Law of Thermodynamics really interested me because the Law apparently stated that in any isolated system, the entropy of that system will ...
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Will melting icecaps and glaciers cause the ocean to rise?

I often hear people claim "global warming will cause the ice-caps to melt, and that will cause the water levels in the ocean to rise, and that will cause major world-wide flooding." Now, ignoring the ...
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2answers
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What percent of time is a rocket to the moon on the right trajectory?

I heard the following quote: "A rocket to the moon spends only 7% of the time on the correct course, the rest of the time it is off course and needs to be corrected and put back on course." This is a ...
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Does water always boil at 100°C under normal atmospheric pressure?

Younes Shabany, professor in the Mechanical Engineering department at San Jose State University, writes in Heat Transfer: Thermal Management of Electronics: For example, boiling temperature of water ...
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1answer
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Did chemist Glenn Seaborg claim the Oklo reactor was man-made?

The Oklo mine in Gabon is thought to be the site of the only natural nuclear fission reactors. An Instagram video posted by Instagram user matrixdisclosure claims it was actually man-made. Nobel ...
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Is the RS-28 Sarmat missile capable of destroying an area the size of France?

The Daily Mail claims Russia has unveiled chilling pictures of its largest ever nuclear missile, capable of destroying an area the size of France. Who estimated this level of destructive power? ...
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Does earthing reduce oxidative stress and inflammation?

The other day my friend asked what I think about "earthing" claiming that their products provide electrons we used to get from walking barefoot on the earth surface and that they have positive (...
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2answers
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How can we know meteorites found on Earth came from Mars?

ALH84001 is a famous meteorite found in Antarctica. Scientists have since claimed that (1) this meteorite came from Mars (along with several other meteorites), and (2) that it contained evidence of ...
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1answer
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Does the wind direction affect the audibility of distant sounds?

There's a common (almost clichéd) claim that you can only hear some distant sound "depending on the wind direction". Here are some random examples. The local population does not have to expect ...
14
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1answer
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Are ion heaters significantly more efficient then normal electric heaters?

An ion heater manufacturer claims their ion heaters are a lot more efficient than common electric heaters: How ion boilers (heaters) STAFOR can reach COP 1,57? In solid conductors only half (...
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1answer
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Can differential friction explain a statue turning around?

Apparently in the Manchester museum, an Egyptian statue turns around while in a sealed display case. There is time-lapse footage of the statue, and in the article, Brian Cox is quoted as saying that: ...
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Can airport X-ray machines scramble Kindle screens?

According to the Daily Mail, there have been reports of X-ray machines scrambling Kindle screens, despite Amazon's claims that it is impossible. Can X-ray machines have this effect?
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Did all iron on Earth come from outer space?

According to the video 9 Shocking Facts from the Quran! Iron is not natural to the Earth. It did not form on the Earth but came down to Earth from outer space. This may sound strange but it is true....
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Are microwave hot-spots real?

So, this was originally a part of this question, but from the comments it seems like it might be beneficial to branch it. I have been told that the microwave left "hot spots" — areas in a fluid ...
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Can products that claim to to reduce electromagnetic radiation from mobile phones be substantiated?

There are some products, stickers that you put onto your mobile phone for example, that claim the following Boost your natural defenses in the presence of electromagnetic radiation (EMR) ...
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Is there hard science behind the benefits of home water softeners? [closed]

Does anyone know of any empirical studies or well-tested scientific theories on the benefits (or lack thereof) of using a home water softener? I have a water softener in my house that we installed ...
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1answer
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Did Canadian company HyperStealth invent an invisibility cloak?

This seemingly legitimate camouflage design company says it invented an invisibility cloak called Quantum Stealth that works by bending light "without cameras, batteries, lights or mirrors." http://...
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1answer
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Is the ninth wave the largest?

This famous painting by Ivan Aivazovsky is called The Ninth Wave: Wikipedia tells about the origin of the name: Both English and Russian titles refer to the nautical tradition that waves grow ...
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4answers
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Is this video from NASA proof that LENR is a real effect?

This video was hosted on a nasa.gov domain name. It talks about Low Energy Nuclear Reactions (LENR), also known as Cold Fusion. On this site it is claimed that this is proof that LENR works and that ...
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1answer
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Will liver move towards milk?

Someone here in the office reckons that if you put liver and milk in a fridge overnight, the liver somehow 'crawls' towards the milk. I am inclined to think this is rubbish but a casual trawl of the ...
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Is Columbia's Omni-Heat Reflective technology effective?

In this advertising video published by Columbia Sportswear, Omni-Heat Reflective is introduced as a technology which reduces body heat loss by reflecting body heat radiation (back to itself) using ...
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2answers
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Does the Karpen Pile work, producing continuous energy without refueling?

According to Wikipedia, the Karpen Pile is: claimed by some to be a battery that has provided continuous energy for over 60 years, making the Karpen Pile either a supremely effective method of ...
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2answers
958 views

Are there no two snow crystals alike?

I remember vividly that when i still was young, I'd examine the snow as it dropped on my winter cloths. Every time I was amazed by the nice textures I discovered. Now many years later, I'm wondering ...
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1answer
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Has Reidar Finsrud created a perpetual motion machine?

I found some websites claiming a Norwegian artist (Reidar Finsrud) created a true perpetual motion machine. Perpetual motion is a concept that would violate both the first and second thermodynamics' ...
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1answer
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Was the periodic table discovered in a dream by Dmitri Mendeleyev?

Did Dmitri Mendeleyev conjure the organization of elements into the periodic table in a dream? Among the several places I've seen this suggested is the review of a book (that I haven't read) on ...
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2answers
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Does getting a running start increase your vertical jump?

Many people believe that a run-up helps them to jump higher. Is this true? (While it seems natural to do this, I'm having trouble believing that horizontal speed can help one jump vertically.)
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1answer
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Did Israel install cameras that can see through clothing on the Temple Mount?

In this article Salah Abu Agrafa, a worshipper at the Temple Mount claims: “They took away the metal detectors, but they replaced them with X-ray cameras that can look at our women naked.” ...
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1answer
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Does Orgone Energy exist?

I have discovered a claim going around that says everything is surrounded by "Orgone Energy" which is a universal life force. Products have arisen from this theory such as a "Cloudbuster", a device ...
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1answer
555 views

Can big earthquakes trigger a domino effect?

Can one earthquake trigger another? For instance, the quake in New Zealand, then the one in China and finally the big one in Japan. This does not count aftershocks, but separate earthquakes in ...
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2answers
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More stars than grains of sand?

This article http://news.bbc.co.uk/2/hi/science/nature/3085885.stm claims: Astronomers in Australia say there are 10 times more stars in the visible Universe than all the grains of sand on the ...
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1answer
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Can magnets damage LCD screens?

My guitar teacher once told me that leaving a magnet near a LCD screen will affect it. I was skeptical because I guess that he believes that because magnets can affect CRT screens. Here are some ...
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1answer
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Subway magnetic fields and laptop hard drives

I just heard a story of a guy who took the subway to transport his company's off-site data back-ups for storage. When the time came for restore after a disaster, the data was corrupt and erased. ...
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1answer
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Is this a way to survive a lightning strike?

source Text in the image (clockwise): Crouch down low like a baseball catcher. Get as low as you can. The nearer you are to the ground, the less likely you are to be struck by lightning. But ...
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5answers
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Are there more 40-moves chess games than atoms in the universe?

I read this tweet recently: "There are more possible games of chess lasting 40 moves than there are atoms in the entire universe. Intriguing to know." I find this highly doubtful. Could ...
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1answer
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Is the pale blue dot Earth?

Is the pale blue dot Earth in the image taken by Voyager? What I'm wondering is, why is there no other thing visible in the frame(like sun, other planets etc.,). How is the camera able to capture only ...
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3answers
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Is carbon-14 still increasing in the atmosphere?

One argument used to support the idea that the age of the earth is on the order of 10,000 years old (the 'young earth hypothesis') is that radiocarbon dating is confounded by the fact that the levels ...
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1answer
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Is it possible to stack liquids of different density scale on top of each other?

I came across q picture on the net and now I'm skeptical that it's possible. I know liquids from different density scale wouldn't mix easily but stacking them on top of eachother with perfectly ...
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1answer
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Does aluminum foil safeguard your credit card from RFID attacks?

Evidence against Does Aluminum Foil Stop Identity Theft? Some sources say that if you actually have an RFID-enabled credit card, aluminum foil does the same job, if not better, than an expensive RFID-...