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 ...
3
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1answer
822 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
298 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, ...
11
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1answer
886 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 ...
12
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2answers
9k 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.)
9
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0answers
525 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 is ...
4
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1answer
385 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 ...
34
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2answers
14k 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
146 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 ...
9
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2answers
1k 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
321 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
663 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
847 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
638 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
5k 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 ...
5
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1answer
430 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 ...
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2answers
4k 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
398 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
249 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 ...
35
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2answers
4k 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
858 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 ...
55
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1answer
26k 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 ...
48
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1answer
7k 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?
5
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2answers
2k 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
767 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 ...
41
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2answers
20k 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 ...
12
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1answer
4k 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. But ...
23
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1answer
2k 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 comments ...
2
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0answers
114 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 ...
8
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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 ...
8
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2answers
922 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 ...
48
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2answers
10k 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
250 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 ...
32
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3answers
15k 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
4k 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
791 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 ...
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0answers
244 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
22k 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). ...
7
votes
1answer
623 views

Do directional tread patterns on tires reduce hydroplaning?

Treaded car tires are said to be better at avoiding hydroplaning than smooth tires (slicks) in the rain. In particular, directional treads are thought to be the best. The following is an example of ...
28
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5answers
12k views

Is the "Back to the future" Huvr board real?

This website is promoting a hovering skateboard. As far as my knowledge can tell, this seems fake. The only two known technologies I know of which can hover like that are magnets and quantum ...
6
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2answers
416 views

Is 'Higgs Boson' called the 'God Particle' because of a book by Leon Lederman?

Why is 'Higgs Boson' called the 'God Particle'? According to Forbes The name was the invention of Leon Lederman, himself a great physicist, who used it as the title of a popular book in 1993. Is ...
24
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3answers
6k views

Do tinfoil hats protect against any sort of radiation?

Delusional conspiracy theorists are commonly portrayed as wearing tin-foil hats to protect against mind-control rays from sinister organisations such as [goverments/aliens/NSA/CIA/FBI/liberals/...
4
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2answers
1k views

Can people run on water?

There have been a few videos around since as far back as 2010 that people can run on water. This is less commonly called Liquid Mountaineering. This is apparently a new sport but I have only ever seen ...
1
vote
1answer
6k views

Will wrapping a bottle in a wet paper towel make it chill faster?

Example of the claim: Take a couple paper towels and wrap them around your beer, then douse it in water. It should be soaked but not dripping (you don't want ice forming in your freezer). Air is ...
30
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1answer
3k views

Can the health of an alkaline battery be determined by bouncing it?

I was just sent a YouTube video, which appears to demonstrate that one can determine the "health" of a battery (current voltage, useful lifetime remaining, etc.) by bouncing it on a level surface. A ...
9
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1answer
969 views

Is there a letter from Bohr about the 1950 Nobel prize?

César Lattes had some important participation in the discovery of the the pi meson, but the Nobel prize was awarded to Cecil Powell alone. There are claims that Niels Bohr left a letter explaining ...
15
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1answer
3k views

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 ...
16
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1answer
1k views

Is the 500-mile email case true?

According to the author of this story, an improperly configured email server had too strict timeout settings which effectively limited its communication radius to 500 miles. The author states it's ...
5
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1answer
3k views

Does the Theradome Laser Helmet deliver around 7 J/cm2 to the head?

The Theradome Laser Helmet is claimed by its manufacturers to promote healthy hair growth. In this infographic, they claim it delivers energy to the skull at a concentration of 6.959 j/cm2 - ...
21
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5answers
164k views

Is this tealight-flowerpot heater more efficient than just tealights?

This article at the Daily Mail describes a small heater based on tealights and flowerpots. It claims that [the system] "make[s] the heating more efficient" (I assume in comparison to just tealights) ...