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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71 views

Can a cheap knife perform as well as an expensive knife in a sharpness test? [on hold]

I'd immediately dismiss it, but many people in the /r/gif subreddit, on imgur and others seem to agree. Let's just say that for this example, if one steel is better than the other, paying more gets ...
4
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0answers
189 views

Can StoreDot batteries be charged in two minutes?

CNET writes: StoreDot's system, which you can see in action in the video [at the link], uses a different chemical makeup to traditional batteries. We saw a modified Samsung Galaxy S5 go from 15 ...
8
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2answers
740 views

Did Stephen Hawking say that blackholes don't exist?

According to this article and this one, the theory about black holes is all false. A while ago, Indian astrophysicist Abhas Mitra studied and discovered that black holes are not what they were ...
16
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1answer
383 views

Do setback thermostats cause more energy to be used, and does the heating type matter?

It was first brought to my attention by a local HVAC Contracting company, that a programmable/setback thermostat would actually cause my home heating system to use more energy, and hence for me to ...
12
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0answers
526 views

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 ...
21
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1answer
5k views

Did Albert Einstein say “the only reason for time is so that everything doesn't happen at once”?

The quote The only reason for time is so that everything doesn't happen at once. is attributed to Einstein with some regularity. (For example, Google returns 47,700 results, of which all except ...
3
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0answers
329 views

Did Thomas Edison kill elephant Topsy?

It is largely believed that Edison electrocuted lot of animals to prove that AC current was dangerous. There is a video on youtube that goes to show that Edison killed Topsy. But in Wikipedia I found ...
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0answers
104 views

what is the prognosis for effects of being struck by lightening and how do I prevent being struck again when living next to a large body of water? [closed]

I live in Australia in a 2 story house overlooking a big river about 3 kms from its outlet to the sea. My bed is close to the window upstairs looking over the river and its a small bedroom. Last night ...
21
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1answer
769 views

Do trackers hold their ears to the ground?

There is a trope (in movies and cartoons and elsewhere) of Native American (or other) trackers are sometimes depicted as listening to the ground to presumably hear far away horses or other animals ...
5
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1answer
417 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 ...
3
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1answer
508 views

Does sealing electrical outlets reduce heating costs?

I stumbled upon this blog post which claims that installing foam gaskets and plugging your electrical outlets with plugs will reduce your heating costs by reducing air leakage. Is this true?
2
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0answers
235 views

Can Magic Leap deliver its claims about their future augmented reality product?

Magic Leap has been very outward with their public face regarding their upcoming augmented reality product. They've been promising a great deal, and the media has hyped up their image as a result, ...
10
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1answer
641 views

Do extreme homeopathic dilutions still retain quantities of the starting materials?

This Indian Institute of Technology Bombay press release quotes some research papers which claims to prove that homeopathic remedies do retain original substances even when diluted. The paper ...
7
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1answer
1k views

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.)
7
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0answers
135 views

Does an avocado ripen faster in a paper bag?

I've always heard that an avocado could ripen faster if put in a paper bag. These claims can be found in many places on the internet : The best way to ripen avocados How to ripen an avocado Here ...
3
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1answer
248 views

Can a strong solar storm knock out our power grids for months?

It's often said that a strong solar storm can burn out the biggest transformers which would take months to replace. If these transformers are so critical, I can't believe they don't have any safety ...
20
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2answers
5k views

Did Manahel Thabet develop a groundbreaking formula to measure distance in space without the use of light?

I stumbled upon the Wikipedia page of Manahel Thabet recently. Here are some extracts from the Wikipedia page. "At the age of 25, she earned her first PhD in Financial Engineering magna cum laude, ...
1
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0answers
101 views

Can the concussion of a .50 calibre bullet from a sniper shot kill you even if the bullet misses? [duplicate]

I've heard before that if a sniper shot a .50 calibre bullet at you from a great distance and missed, but the bullet went past your head, that the concussion from the bullet flying by could still kill ...
8
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2answers
602 views

Can bouncing batteries tell you if they are charged or not?

I saw this article this morning, and while it seemed fairly legitimate, I was skeptical about it. The claim is that if you drop a battery (flat end down) it will bounce higher/longer if the charge is ...
2
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0answers
181 views

Do holes in pot lids make water boil faster? [closed]

The responses to this reddit post make me think that it is a popular belief that holes in pot lids make water boil faster. The claim is that by lowering pressure, the water boils at a lower ...
4
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1answer
457 views

Do you need specialist filters to look at the sun?

During the UK's recent solar eclipse we were constantly reminded that we should never look directly at the sun because it could damage your eyesight permanently, that you should only look at the ...
2
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0answers
381 views

Could you survive a vertical 100m drop in a BMW hatchback? [closed]

In Mission Impossible Ghost Protocol, at 116:42, Ethan Hunt (played by Tom Cruise) drives a BMW 1181 hatch off of an auto car transporter: He was wearing his seatbelt: And the air bag deploys: ...
2
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0answers
179 views

What formula gives the solunar periods of the Solunar Theory? [closed]

Disclaimer This is a precursor to the question "Is the solunar theory real?" - which I'm hoping to answer. So I fully understand if you don't believe that the question lives up to the forum's ...
2
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2answers
525 views

Water swirl according to hemisphere: video

I'm aware of the previous answer to this question. But my question is concretely about this video. Is it fake? How?
6
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1answer
1k views

Does putting our head to the ground remove “positive electromagnetic charges”?

A few Muslim friends claimed that putting your head to the ground like what you would do during Muslim prayers helps you by discharging your head from positive electromagnetic charges. I personally ...
2
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0answers
115 views

Could a grid-iron football deflate due to weather conditions? [closed]

My dearest New England Patriots won the Super Bowl this year. From a physics standpoint, is it plausible that the footballs were slightly under-inflated due to atmospheric pressure? Bill Nye claims ...
5
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1answer
362 views

Did Thales conduct experiments in electricity?

Many school texts and other popular sources claim Thales of Miletus conducted experiments in electricity, showing amber to attract feathers, for example, supposedly. However, I can find no verifiable ...
8
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2answers
1k views

Did astronauts leave footprints on the moon?

Our Young-Earth Creationist physics teacher stated that he does not believe that man actually stepped on the moon. That topic has been well covered here. One of his arguments, however, was that ...
0
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1answer
278 views

Is a human on a bike more efficient than a fish in water? [closed]

Long ago, an enthusiastic cyclist claimed to me that a human on a bike was more efficient than a fish in water. Is this true? I would guess that the relevant measure of efficiency would be something ...
3
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0answers
181 views

Is it possible to make it rain in the desert by burning cactus fields? [closed]

The Karl May's book Winnetou III describes Old Shatterhand crawling almost dead trough the Llano Estacado desert. Near perishing, he encounters enourmous field of dry cactuses. Then he burns the ...
33
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2answers
1k views

Did Thomas Edison test 1600 materials for the filament of his light bulb?

From this webpage: In 1879, after testing more that 1600 materials for the right filament, including coconut fiber, fishing line, and even hairs from a friend's beard, Edison and his workers ...
11
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1answer
361 views

Do calcified water heaters use more energy?

It is very often claimed (by both government energy efficiency experts and water-heater sellers/service people) that calcified heating elements in electrical water heaters lead to much higher energy ...
49
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1answer
6k views

Is Starlite a hoax?

About 40 years ago, Maurice Ward, a hairdresser and amateur chemist, developed a plastic that was said to be resistant to extreme heat. Able to withstand a laser beam that could produce a temperature ...
45
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1answer
6k views

Did Benjamin Franklin perform an experiment by flying a kite in a lightning storm?

Is there any credible evidence that Benjamin Franklin actually did his famous kite experiment?
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2answers
923 views

Is this CCTV video about a chair moving by itself in Essex theatre fake?

from various sources around the internet Daily Mail Is this theatre haunted? CCTV footage captures the spooky moment a chair moves all on its own... hours after a medium's show Get ready to feel ...
8
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1answer
434 views

Can lightning bring down a plane?

Some early reports by witnesses to the Air Algérie Flight 5017 crash claim that lightning caused the plane to crash: A GROUP of herders who say they saw Air Algerie flight AH5017 crash claim it ...
39
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2answers
6k views

Is it safe to stand by the windows during a thunderstorm?

There is widespread belief in my culture that we should not stay near door or windows during lightning. So people advise others to stay inside house with doors and windows closed to be safe from ...
2
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1answer
436 views

Did the Curiosity Rover take its own hands-free selfie?

Time Magazine had an article with a photographic portrait of the Curiosity Rover on Mars, attributed to NSA/JPL. Here's another version: This photos seems like it would be impossible to take. I ...
12
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1answer
735 views

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. ...
20
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1answer
833 views

Does sleeping naked in a sleeping bag keep you warmer?

The most popular question on outdoors.SE is Is it warmer to sleep naked in a sleeping bag? Now, all the answers over there are not properly researched and it was suggested in one of the ...
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0answers
86 views

Is there a non-ionizing, non-heating mechanism by which cell phones can damage sperm? [closed]

I'm aware that a similar question has been asked before, but I'm hoping my questions are different enough to warrant a new post. Does the presence of a cellphone affect sperm count or heart rate? I ...
6
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1answer
2k views

Is our moon moving away from earth?

I was reading articles on the Moon and I came across this article which states that the Moon moves away from Earth at the rate of 2.5 CM/Year whereas in the other article it states that it moves away ...
5
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1answer
343 views

Did the isolation condensors fail at Fukushima Daiichi? Was human error involved?

The reactors at the Fukushima Daiichi nuclear power plant in Japan were overflowed by a tsunami following the Tohaku earthquake of 2011. Consequently, a power outage at the station disabled the ...
47
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2answers
9k views

Will a bullet be split in half if it hits a butter knife that is fixed in place?

I was reading a manga, and I saw this: So I was wondering. Will a bullet be split in half if it hits a butter knife that is fixed in place? Have there been experiments to test that?
4
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0answers
216 views

Is a weaver's knot more secure with both ends on the same side?

There are two different ways one can make a weaver's knot. One has both ends on the same side (a) the other on opposite sides (b). Pictures and a statement "the two free ends should end up on the ...
21
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1answer
4k views

Did the Quran predict the speed of light?

It appears to be popular to claim that the Qur'an predicted the speed of light before it was scientifically well understood. Although none of the sources state that outright, that is what they imply. ...
16
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2answers
3k views

Does GPS use General Relativity?

Sources on the internet claim that the GPS system requires Relativity to work (xkcd). I've searched information about the GPS system, how it works and how it was set up, reading information from many ...
6
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1answer
521 views

If the viewable part of lightning goes from the ground up, why does it look like lightning goes from the sky down? [closed]

According to here, it seems like the visible portion of lightning comes from the ground up; however I watched some slow motion YouTube videos, and it is clear that the lightning appears to be ...
1
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0answers
199 views

Can a plastic tent keep contaminants out and emulate a safe clean room?

I was reading an article on why opening the cover of a hard drive was a bad idea. In the article, the author mentions that the safest way to open the cover of a hard drive was to do it in a class 100 ...
7
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1answer
5k views

Do water molecules change when you talk to them?

I've heard that saying something nice in front of water changes the water molecules shape into a nice shape and saying something bad in front of it makes the molecules align in a bad order (ugly one). ...