Questions tagged [light]

for questions about claims based on, or related to, visible light.

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Does too much artificial lighting result in increased crime and safety problems?

According to a Washington Post article, Nebraska's tourism board is applying for dark sky certification for the Merritt Reservoir State Recreation Area. As part of their application, they are ...
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14 votes
1 answer
5k views

Does switching the lights off help avoiding mosquitoes?

This Travel Stack Exchange answer states something I long considered for granted (probably because my parents told me so): if you want to avoid mosquitoes, switch off the light. Opening the window ...
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5 votes
1 answer
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 ...
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15 votes
1 answer
995 views

Are car headlights getting brighter?

This news story in Popular Science asks whether car headlights are getting brighter and concludes they are not: So are headlights actually getting brighter? The short answer is no—although there was ...
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3 votes
0 answers
234 views

Does UV-A light from sunlight damage our vision?

Ultraviolet (UV) light is divided into wavelength bands. UV-A is the 315-400nm. The American Optometric Association claim that UV-A may cause injury to the eye: WHAT PART OF THE UV RADIATION IS ...
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3 votes
0 answers
197 views

Does light pollution matter for Insect declines and agroecosystems?

Recently it was claimed that the increase in artificial light at night was a significant contributor to the 'ecological armageddon' of decreasing insect populations. It was further argued that the ...
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5 votes
3 answers
890 views

Are blue lights giving people cancer?

A recent article in Gizmodo reports: Researchers have linked the modern form of LED street lighting to higher rates of breast and prostate cancer, in a grim development that could have ...
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2 votes
0 answers
496 views

Speed of light not constant as measured by many scientific / research groups, but averaged & politically standardized? [closed]

In banned/ removed TEDxTalk, The Science Delusion - Rupert Sheldrake at TEDx Whitechapel, the speaker has talked about various things but I am focused on the "constants" such as "light" that he has ...
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  • 253
16 votes
1 answer
63k views

Can a lightbulb once inserted into your mouth be safely removed?

There is a viral video going around that repeats a claim I've heard before about getting a light bulb stuck in your mouth Graphic reads, The bulb shape allows it to be put into the mouth, but ...
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42 votes
1 answer
3k views

Do LED light bulbs last as long as claimed by the manufacturers?

Manufacturers routinely claim that their LED light bulb can last from 20,000 hours to 50,000 hours: Anecdotes, such as this one suggest otherwise. Daily mail wrote: More than a quarter did not ...
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8 votes
1 answer
1k views

Should I refrain from putting my clothes to dry outside on a full moon?

This website (French) explains: N'étendez jamais votre linge de couleur un soir de pleine lune. En effet, ces nuits sont plus froides que les autres et font poindre une rosée contenant du peroxyde ...
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12 votes
1 answer
4k views

Are people physically sensitive to light from LEDs over other sources?

The Irish Independent details the claims of a woman saying she is sensitive to LED light, and that it causes her nausea. The article explains that neurologists, opticians and ophthalmologists found ...
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15 votes
1 answer
833 views

Do blue lights on railway platforms reduce suicide?

Does the installation of blue lights at specific locations on station platforms reduce the incidence of suicide... at that location? using that particular method ('suicide by train')? overall? The ...
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5 votes
0 answers
255 views

Does the "Re-Timer" device help to alleviate "winter blues"?

The Re-Timer website states: Re-Timer is a wearable light therapy device for Winter Blues. Winter Blues is a low-mood experienced primarily during the winter months. Symptoms can include loss of ...
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7 votes
1 answer
1k views

Do fluorescent lights use more power to turn on?

I have been told time after time that at school if you are not going to leave the room for more than 10 minutes to keep the lights on instead of turning them off because the amount of power it takes ...
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30 votes
2 answers
2k views

Does the phase-out of incandescent light bulbs measurably reduce overall electrical power consumption?

Many countries are phasing out incandescent light bulbs. For example, in the European Union, various types of classic light bulbs have been removed from the market in the last years. The claim is that ...
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17 votes
2 answers
8k views

Do LED lights of any colour damage your eyes?

There is a Daily Mail article from May 2013: Do 'environmentally friendly' LED lights cause BLINDNESS? In the article, they specifically focus on blue LED lights and the wavelength of this light ...
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6 votes
0 answers
211 views

Does milk sold in a store with good product turnover lose a significant amount of Vitamin B2 from light exposure?

Anchor New Zealand has just released a milk bottle with a black plastic layer to protect the milk from exposure to light, and thus from loss of "taste and goodness". Their chart: from their website ...
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11 votes
1 answer
432 views

Does fluorescent lighting in schools correlate to increased illness and behavior problems?

A morning talk radio program was discussing Scotopic sensitivity syndrome and made the claim that in schools where fluorescent lighting had been replaced with indirect non-fluorescent lighting had ...
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8 votes
1 answer
703 views

Do light boxes help Seasonal Affective Disorder?

Light boxes are sold as a treatment for seasonal affective disorder (SAD) and seasonal mood swings. The claims listed are: Helps to ease seasonal mood swings and winter depression, and help ...
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27 votes
3 answers
12k views

Can blue light from LCD panels cause damage to the eyes?

In Japan there is quite a fad about LCD blue light filtering and how they might help reduce eyestrain, etc. The web site of a major computer accessory manufacturer has an English-language press ...
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8 votes
1 answer
4k views

Can blue light therapy contribute to Age-related Macular Degeneration?

High-intensity, broad-spectrum light has been an effective therapy for Seasonal Affective Disorder (SAD). More recently and less proven blue light therapy has stemmed from the discover of ganglion ...
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3 votes
3 answers
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 ...
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14 votes
2 answers
11k views

Do Valkee bright light headsets reduce SAD symptoms?

This is old news in Finland by now, but I don't know if these products are well known elsewhere yet. The idea of Valkee headsets is bright light therapy with a twist—the light is channeled through ...
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48 votes
2 answers
34k views

Is a spotlight like the Bat-Signal possible?

In the Batman movies, Batman is called when a powerful yellow spotlight with the bat drawing is projected in Gotham City's clouds. The unique drawing then become very clearly visible in the clouds on ...
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16 votes
1 answer
8k views

Do fluorescent lights cause stress?

I have heard that fluorescent lights are generally bad for you. The explanations range from the light being in the blue area of the spectrum: The signature "glow" of fluorescent lighting is ...
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28 votes
1 answer
7k views

Is it preferable to use a computer in a darkened room?

In his latest blog post, Jeff Atwood states: We computer geeks like it dark. Really dark. Ideally, we'd be in a cave. A cave … with an internet connection. The one thing that we can't abide is direct ...
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