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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.

68
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4answers
14k views

Do wooden building fires get hotter than 600°C?

After the recent Notre-Dame de Paris fire, there has been a heavily re-posted tweet going around in response to an earlier claim that a golden cross did not melt or deform - due to an act of God. ...
-5
votes
0answers
84 views

Is the Infinity MG10 a working generator that consumes no fuel?

Infinity Sav are a company pushing a product, the MG10 which is available for pre-order which, they claim, can generate electricity without consuming fuel - i.e. is a free energy machine. The ...
4
votes
1answer
1k views

Can light travel at 30x the speed of light? [closed]

The claim seems to be that the researchers can make light travel faster than the speed of light. Is this true? How does it even make sense? It’s in Nature so presumably there’s something in it, but ...
58
votes
2answers
15k views

Has the laser at Magurele, Romania reached a tenth of the Sun's power?

This month the laser at Magurele, Romania became the most powerful laser in the world, according to various sources. Related: Is the laser built in Măgurele, România, the most powerful in the ...
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
votes
0answers
566 views

Does cutting paper dull a knife quickly?

This question is a follow-up to "How to test the sharpness of a knife?", my answer to it, and the comments my answer generated. Charlie Brumbaugh wanted to know how to tell when he is done when ...
8
votes
1answer
14k 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). ...
1
vote
0answers
383 views

Are two layers better at insulating body heat than one double-thickness layer? [closed]

It is almost universally recommended that wearing multiple layers of clothing is the most effective way to stay warm in cold weather, compared to one thicker layer, although there seems to be little ...
121
votes
5answers
23k views

Do atoms exist?

There are plenty of examples of people doubting ([1], [2], [3], [4], [5]) or denying ([6], [7], [8]) the existence of atoms. Is there any compelling evidence for the existence of atoms? Has anyone ...
22
votes
3answers
5k 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/...
5
votes
4answers
897 views

Does physics give a climate sensitivity to carbon dioxide of about 3°C?

A letter to the editor of the Economist from Professor Anders Levermann of the Potsdam Institute for Climate Impact Research stated the following: The IPCC’s range on sensitivity is supported by, ...
21
votes
2answers
820 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 ...
11
votes
5answers
11k views

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 ...
3
votes
1answer
788 views

Does Heads Up Texas Hold'em have more possible hands than atoms in the universe?

In the Vice (HBO) clip AI Poker Bots Are Beating The World's Best Players, it is claimed (at 2:00), that Texas Hold'em has "more possible hands than atoms in the universe". ..this competition ...
2
votes
0answers
449 views

Can ridges on the bottom of shakers be used to help with dispensing?

From https://twitter.com/LipBitinANNAmal/status/1078840770864529408 156,700 Retweets 376,681 Likes (probably not the original author): How old were y’all when you found out the ridges on the bottom ...
4
votes
1answer
528 views

Do lipid droplets in our skin create a laser?

The home page of Dr Jack Kruse, who claims to be a neurosurgeon and "optimal health educator" contains the following paragraph: There is a deep connection between thermodynamics in biology and the ...
13
votes
2answers
6k views

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 (...
21
votes
1answer
1k views

Does turning the lamp in my classroom off and on use more energy than it being turned on for 30 minutes?

My physics teacher regularly said to our class: Turning these lights [pointing to the ceiling of the classroom] off and on uses more energy than leaving them on for 30 minutes. Is this true? I ...
19
votes
1answer
17k views

“The Flat Earth Society has members all around the globe”?

When one googles "The Flat Earth Society has members all around the globe", many images appear. Some of them claim this is a post by the Flat Earth Society itself, such as this one: I wonder if this ...
1
vote
1answer
524 views

Does General Relativity bring “Cosmic Time,” which is the same for all frames-of-reference?

In a recent podcast, the philosopher William Lane Craig said that while Special Relativity taught us to doubt whether any given clock is, or whether it could be, an absolute measure of time, General ...
17
votes
2answers
34k views

Do electric heaters with open heating elements “dry the air” or “burn up oxygen”?

There is a popular belief in Russia that electric heaters with an open nichrome heating element (red hot) "burn up oxygen" and "dry the air", unlike oil-filled ones. Is it true that a Joule heater ...
23
votes
7answers
7k views

Are there technologies that provide unlimited free energy?

Many different sources claim to be able to produce "unlimited free energy". For example: UNLIMITED FREE ENERGY IDENTIFIED Company claims to have developed new technology that provides unlimited free ...
16
votes
2answers
1k views

Is redefining the kilogram useful for drug development and nanotechnology?

With the redefinition of kilogram currently underway, I see recent online articles claiming that a precise definition of the kilogram is critical for drug development and nanotechnology. E.g. BBC.com ...
72
votes
1answer
11k views

Are the claims made by Indian Ministers / personalities regarding ancient Indian inventions true?

In the past couple of years, several Indian Ministers / personalities have made claims regarding existence of modern inventions in Ancient India. Prime Minister Modi claimed that genetic science ...
3
votes
1answer
266 views

Does the Wowfixit screen protector harden phone screens?

The WOWFIXIT web-page offers a product where you wipe a liquid over your phone screen and polish it. They claim the result will make your protect your phone screen from scratches: One of the many ...
8
votes
2answers
2k views

Did all iron on Earth come from the outer space?

According this 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. ...
103
votes
5answers
6k views

Are personal electronics a risk to commercial aviation?

Are personal electronics (of present or recent past; e.g. cell phones, mp3 players, iPads) a risk to commercial air travel? Is the typical request to "turn off all personal electronic devices" based ...
18
votes
2answers
7k views

Are electric chairs powered by generators connected to the mains in the same building?

There's an episode in The Green Mile movie where the death row servicemen rehearse the upcoming execution that is done using an electric chair. One of them says (quoted from here): Roll on one. [...
24
votes
3answers
3k views

Does the radioactivity on Hiroshima's soil affect radiometric dating?

I heard several times from creationists that now, if scientists would examine the land in Hiroshima, it will tell them it is millions of years old all because of the atom bomb. And because of that ...
65
votes
1answer
8k views

Antistatic bracelet without a ground connection

Last winter in Japan, some of my friends were buying bracelets like this, that claim to prevent or reduce static shocks: Here is an advertisement picture describing how it is supposed to be used, ...
19
votes
2answers
5k views

Is Nikola Tesla the only scientist to successfully create ball lightning?

Related: Is there any scientific proof that ball lightning is real? Someone passed along this The Oatmeal comic about Tesla. It's quite interesting and entertaining. I was curious about a lot of the ...
18
votes
2answers
3k views

Can a man fall faster than the speed of sound?

I have heard that a man can fall faster than the speed of sound, and survive, by jumping from 36,000 meters; a free fall that, it seems, lasts ten minutes after the jump. Is it true?
4
votes
0answers
447 views

Does this video show a sonic boom through a sun dog?

This YouTube video purports to be of a rocket launch from the Kennedy Space Center in 2010. It shows a rocket reaching the speed of sound, and creating a sonic boom at the same time as the rocket ...
11
votes
1answer
2k views

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 ...
14
votes
1answer
3k views

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 ...
2
votes
0answers
382 views

Does carrying or consuming onions help to prevent heatstroke and/or reduce your body temperature?

Will consuming onions help to reduce your body temperature, or prevent heatstroke? Some common variations of this claim include applying onion juice to your skin, or even just carrying an onion in ...
2
votes
3answers
3k views

Evidence for the absolute speed of light

I'm wrapping my mind over Einstein's Special Relativity. He postulates an abolute speed of light which concludes (in my perspective) to several illogical paradoxes. Is there any evidence, that the ...
20
votes
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 ...
7
votes
1answer
3k views

Does Heattech clothing generate heat?

Uniqlo sells HEATTECH heat-generating clothing. When HEATTECH absorbs body moisture, tiny droplets generate heat. Thermographs clearly show that HEATTECH maintains more warmth, more evenly over ...
34
votes
2answers
11k 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, ...
4
votes
1answer
998 views

Is the laser built in Măgurele, România, the most powerful in the world?

Some news websites, including Romanian and non-Romanian ones, claim that the laser built in Măgurele, România (which is going to be used starting today), is the most powerful (and in other sources the ...
12
votes
1answer
962 views

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.” ...
35
votes
2answers
3k 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 ...
3
votes
0answers
1k 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 ...
-1
votes
1answer
532 views

What evidence would remain of the use of atomic/nuclear weapons 26,000 years ago? [closed]

In his 1998 book, Yellow Sky: an alternative perspective about the human condition and history, Kenneth Lipton argues that high radon levels in southeastern Pennsylvania may provide evidence of prior ...
220
votes
4answers
26k views

Does hot water freeze faster than cold water?

Is it true that hot water freezes faster than cold water and if so, what practical applications have there been found for this phenomenon?
-4
votes
1answer
445 views

Is there compelling proof against an alternative to the law of conservation of energy? [closed]

The law of conservation of energy states that energy cannot be created or destroyed, but changed into different forms, which I've never found entirely compelling. It's impossible to measure the energy ...
10
votes
2answers
729 views

Did thirteenth century scholars attempt to determine the congealing of oil by reading Aristotle?

In "The Production of Knowledge" William Starbuck presents the following anecdote (without providing its source). Is this anecdote based on a real historically traceable incidence? During the ...
3
votes
1answer
632 views

Electro-osmotic pump to keep bunker dry

Supposedly the latest tech in keeping water out of (historically significant) bunkers is electro-osmotic pulse technology. EOP is based on the principle of electro-osmosis—the movement of a liquid ...
4
votes
1answer
526 views

Does each doubling of CO2 cause a 2-4°C increase?

Professor Henrik Svensmark argues that cosmic rays have a strong influence on cloud formation and hence climate change. In 2016 he predicted global warming was over. He was recently the lead author of ...