***** Horrible misinformation is a bit harsh, although, to some extent yes, it is pretty awful. The fact is you won't get enough vit D from foodstuff alone, and so the sun is essential to get enough. It's not in A LOT of food though... It's more like a middle ground between your statement and the video's.
NorwegianQvirr I kind of agree that is horribly misinformed when it suppose to be a factual video. This is also such a old myth that most people should know better nowday
I have had one of my eyes' lenses replaced with an artificial one (cataract surgery) and I can definitely confirm being able to see slightly farther into UV in that eye. It's nice having only one of them removed because I can compare between the two eyes.
Interesting video. Makes me want to reassemble my TEA laser and fire it through some fresh olive oil and mint and try it on various fresh leafs. It'd be neat to see the red.
Interesting to watch the ghosting at around 3:20 mark, looks like a nice display of the image stabilisation element(s) of the lens at work perhaps? (24-105 IS, Brady?) Aside from this, another great video, Dr Meghan always explains ideas succinctly :)
Glad to see Dr Gray back on Sixty Symbols. I assume she is still a regular face on Deep Sky...though I have to admit I have not wandered over to that channel in a long while. Something I will have to remedy (after I watch this one of course).
Recently, I purchased a U.V. flashlight and never really understood how it worked, and this video explains more about U.V. light. I really wish you'd show more household items and explain why they react U.V. light they do. Really enjoyed this video!
So glad I watched this. I had never seen fluorescence demonstrated like that and I think the combination of the visual with the explanation that the energy it emits is lower because it loses some brought it together for me. Thanks!
Excellent video and a very good idea for a series of videos!! I would have liked to see more on UV absorption though. As an astronomer, it might not be the first thing on your mind. But for the general public, UV absorption of sunglasses, windows, sunscreen etc. is incredibly important.
That is a telescope image, so technically yes. But viewing it with just your own eyes, it would be far too dim to see those details. As for rotation - absolutely not. Think about it. It's 220,000 light years in diameter, a single pixel in that image is as large as thousands of entire solar systems. The period to rotate one revolution is anywhere from tens of millions to hundreds of millions of years.
Hugo Santos Indeed! And that's why Astronomy is such a humbling activity :) It should be noted that we can actually measure the rotation of the Andromeda galaxy, even if we can't see it happening directly. So we do know it rotates, just like our own galaxy.
Hugo Santos no you cannot actually see the rotation when looking at a galaxy it is way too large to notice any change in position at the small timescale that humans use.
The highest frequency of visible light is roughly twice that of the lowest freq. of visible light, making the 7 colours of visible light (like the 7 notes of the diatonic scale) basically an octave. We hear the resonance of a high C and a middle C and a low C. Were we able to see beyond the visible spectrum, would we see the resonance of hyper red and red? . (BTW,... How you were able to resist lava lamps and wakachicka music I'll never know!..)
I remembered Quinine emit longer wave length is light because the electrons jump up several energy levels when they absorb UV photons, then jump down one energy level at a time and emitting lower energy photons.
I professor of molecular biology I had was teaching us about the effects of UV light on DNA. She was also telling about the complex DNA repair system we have. One enzyme need UV light to catalyze the repair. So she joked: "you go to the beach get a little bit of mutation, then you have to go again to not get cancer because of it"
Will you guys be covering more of the electromagnetic spectrum? I'd really like to learn the basics about wifi-signals, microwaves, bluetooth etc. and how they relate to easy reception/amount of data that can be transferred etc.
It would have been cool to put some of the fluorescent stuff in the UV part of the spectrum (from what I assume is an arc lamp) to show that yes, there's UV light there.
how can i ask bradys physicist buddies a question? i saw a vid of a guy burning sea water with radio waves. were just the impurities in the sea water burning?
Brilliant! Also, I want to rave now :P Also, where is Dr. Gray from? She sounds American, but every so often I detect a bit of Irish accent...just curious :)
The only perfect conductor is a superconductor, and inside those light pretty much doesn't propagate. Or rather, it can be described as gaining a mass.
Jesse Mason The EM Field is never "not there"; even at zero energy in the EM Field it is still present. In fact it cannot reach zero energy because of natural Quantum Uncertainty, we can't ever be sure a field has reached zero energy because there could be ± some energy in the field (uncertainty). The EM Field therefore does exist everywhere at all times: inside conductors, super-conductors, and even inside black holes!
We happen to now understand that the classical picture is wrong. You seem like a smart guy, why would you use a wrong model of reality? There is only one kind of light (not many forms with one being "normal light"), that comes in packets called Photons with varying wavelengths [color] and energies. Metals are typically opaque and shiny for other QM reasons (see photo-electric effect, etc.); not all metals are totally opaque, not all metals are shiny.
Rob Laquiere Because it can work as a well enough for the situation you care about. Do you care about the coriolis force when throwing a ball out for a dog?
I suppose I don't, but the fact remains that it is still there. I do typically leave out insignificant effects when doing calculations so you are right.
Is there a limit to how short and how long a wavelength can be? I would assume shortest possible wavelength is close or equals planck length, while longest possibke wavelength is only limited by the size of the universe 😊
Maybe show some Jablonski diagrams, they are pretty illustrative. Also, if you like fluorescence, search for videos on BODIPY, they're really nice and colourful :)
Very Nice Video, could have even more science in it, other then making things glow. Brady, could you make a series of Videos covering every spectrum of light? Would highly appreciate it. Thanks
I can't help but wonder if the range of colors we see is by chance. It happened to be the most useful range for random attributes that previously made no difference to evolution, but once an efficient range was found for those random attributes, evolution was bound to them. It makes me wonder if we do discover alien life, if they would even see in the same color range as us. Maybe they will be gray because their actual color is outside of our vision range.
I'm having an incredibly difficult time placing Dr. Gray's accent / regional inflection. She sounds like she may have been born in Scotland but then moved to Canada or something. Certainly different glottal stops than would be used in Scotland or Ireland or the US or Canada, but certain words like "borrow" and "process" strongly indicate some Canadian influence. Anyway, she is a good speaker. Thank you for the video.
Sixty Symbols I would like to know whether UV light is considered ionizing or non-ionizing radiation. The sources I have checked seem somewhat contradictory. They usually state that most types of UV light is non-ionizing, but when checking what frequencies of light are considered non-ionising, UV C in particular & according to some sources UV B as well. Seem to fall in frequencies related to ionizing radiation. Like I said, contradictory. Thanks for your help.
The pre-roll ad won't leave the screen. Its done and now it won't go away - just frozen on the last image. So I can't watch the vid. I've gotten out and reopened the video twice and it plays the pre-roll commercial for 1800 contacts and then stops.
in molecular biology, we use special chemical dyes that bind to DNA. upon binding, they fluoresce, and we can detect DNA like this and quantify the concentration, size and abundance of DNA! if you are interested in seeing cool pictures, google 'DNA electrophoresis'. standard practice for all molecular biologists exploring DNA molecules. thanks!
Can you tell the purity of olive oil with the black light? Just asking because some companies mix other oils (canola) in with the olive oil claiming it to be 100% pure.
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
Dr. Meghan Grey is extremely good at explaining physics. Keep up the good work!
*****
Lucky you! :D
She's class.
Dr. Grey will see you now :)
+Alex H You lucky son of a gun. Big envy! :)
Even better at cooking and cleaning
Congratulations to Paul for finally making it into one of these videos! He's helped me a lot when I've been in the labs, great guy.
3:00 We do get vitamin D from our food, most people just don't get enough of it.
***** Horrible misinformation is a bit harsh, although, to some extent yes, it is pretty awful. The fact is you won't get enough vit D from foodstuff alone, and so the sun is essential to get enough. It's not in A LOT of food though... It's more like a middle ground between your statement and the video's.
***** to be fair, they are astronomers not nutrition experts
I bought vitamin d because I live far north and we don't get a lot of sun during these months. I just hope they work lol
NorwegianQvirr I kind of agree that is horribly misinformed when it suppose to be a factual video. This is also such a old myth that most people should know better nowday
***** thanks!
I am so glad she is back. I don't even know her name but I have such a wicked crush on her. It's ridiculous.
Eric Stone Thanks. .
HHahahaha :)
Why is Dr. Gray so perfect?
An especially nice video. Thanks to everyone, but especially to Paul for his on-point light-switching skills.
Nice effect of passing the camera across the spectrum at the end Brady! Love your vids and especially those featuring Dr. Gray.
I have had one of my eyes' lenses replaced with an artificial one (cataract surgery) and I can definitely confirm being able to see slightly farther into UV in that eye. It's nice having only one of them removed because I can compare between the two eyes.
That blue picture in the video at 1:33 is a picture of "Cygnus Loop" for the ones interested.
thanks!
Being the RUSH fan, he is- Moriarty would catch that.
I didn't know that but I am interested. Thank you.
One of the best presentations I have ever had the pleasure of watching.
Much appreciated, thank you.
So, the olive oil must emit more heat than the tonic water, because of the energy difference, right?
Interesting video. Makes me want to reassemble my TEA laser and fire it through some fresh olive oil and mint and try it on various fresh leafs. It'd be neat to see the red.
very interesting , thanks & keep making those vid's about light in all its glory !
Wouter Tomme so are you saying "Thanks for Enlightening us!"?
Interesting to watch the ghosting at around 3:20 mark, looks like a nice display of the image stabilisation element(s) of the lens at work perhaps? (24-105 IS, Brady?)
Aside from this, another great video, Dr Meghan always explains ideas succinctly :)
Around 5:19 you can see her top glowing because of the interaction of the UV light and the fabric whitener washed into her clothes.
One of the best science clips I've seen in the past year.
Glad to see Dr Gray back on Sixty Symbols. I assume she is still a regular face on Deep Sky...though I have to admit I have not wandered over to that channel in a long while. Something I will have to remedy (after I watch this one of course).
Recently, I purchased a U.V. flashlight and never really understood how it worked, and this video explains more about U.V. light. I really wish you'd show more household items and explain why they react U.V. light they do. Really enjoyed this video!
I love listening to clever people talk about something they are really interested in. It's even better when I am too. Have a subscription.
Onion juice also glows under blacklight. Works as a homemade invisible ink
I really enjoy the way she explains things.
What type of lamp and what size of prism did you use to project such a vivid bright spectrum?
Best explanation of fluorescence that I have heard. It's neat to know about the olive oil and tonic water.
So glad I watched this. I had never seen fluorescence demonstrated like that and I think the combination of the visual with the explanation that the energy it emits is lower because it loses some brought it together for me.
Thanks!
4:00 Should you not use eye protection when dealing with UV lights?
Excellent video and a very good idea for a series of videos!!
I would have liked to see more on UV absorption though. As an astronomer, it might not be the first thing on your mind. But for the general public, UV absorption of sunglasses, windows, sunscreen etc. is incredibly important.
"Schweppes gave us no money making this video...
but we're not stopping them from giving us some." :P
Cool, I rarely don't get lost at points in some of these videos but I really enjoy them.
woah, really well explained, I could listen all day!
Think this is one of their best videos. Learning buckets.
6:21 Parents know where that little tightly-sealed container came from.
Only if they used them lol
Dr Megan is so pleasant to hear speak. More vids with the good Dr please Brody
GREAT idea for a Bradyseries! Looking forward to a trip across the EM spectrum.
"Hot young stars" made me chuckle.
8:52
That is a telescope image, so technically yes. But viewing it with just your own eyes, it would be far too dim to see those details.
As for rotation - absolutely not. Think about it. It's 220,000 light years in diameter, a single pixel in that image is as large as thousands of entire solar systems. The period to rotate one revolution is anywhere from tens of millions to hundreds of millions of years.
Mythricia Wow. Things are so huge out there. I can't even... how... wow.
We are just a bit of dust on all this!
Hugo Santos Indeed! And that's why Astronomy is such a humbling activity :)
It should be noted that we can actually measure the rotation of the Andromeda galaxy, even if we can't see it happening directly. So we do know it rotates, just like our own galaxy.
Hugo Santos no you cannot actually see the rotation when looking at a galaxy it is way too large to notice any change in position at the small timescale that humans use.
The highest frequency of visible light is roughly twice that of the lowest freq. of visible light, making the 7 colours of visible light (like the 7 notes of the diatonic scale) basically an octave. We hear the resonance of a high C and a middle C and a low C. Were we able to see beyond the visible spectrum, would we see the resonance of hyper red and red?
.
(BTW,... How you were able to resist lava lamps and wakachicka music I'll never know!..)
Love the new style of Sixty Symbols, keep it up, Brady :)
4:43 So that's how they man Nuka Cola Quantum.
Blood Beryl Sorry. I should have put a trigger warning on my comment then.
Blood Beryl nuka cola isn't real
shune84 don't bring me back to reality **runs away crying**
Blood Beryl Evidently in your own unique universe that has been constructed from your own ideas and cognitive processes.
Schweppes, please pay these folks some money. Scientists need more funding, and Gin!
I might be late to notice but I really appreciated the video quality and filming in this one! (Thanks Brady)
Meghan is just great, nice to see her again! :) Thanks for another good video!
How come at like 8:55 to the end, the lights in the background change colour as the angle changes? What is that!
it is the thing that was casting the rainbow at the beginning of the video
Love this channel
Nice to see Dr Meghan Gray again!
Very interesting and well explained. Thanks.
Was this filmed by J.J Abrams?
I remembered Quinine emit longer wave length is light because the electrons jump up several energy levels when they absorb UV photons, then jump down one energy level at a time and emitting lower energy photons.
Love Dr Meghan Gray's videos :)
Great video!
Fluorescence is also an important analytical technique and so could have been discussed in a chemistry video as well!
In what form is the mint that was added to the olive oil? Would like to do this kitchen experiment with my kids 😊
I professor of molecular biology I had was teaching us about the effects of UV light on DNA. She was also telling about the complex DNA repair system we have. One enzyme need UV light to catalyze the repair. So she joked: "you go to the beach get a little bit of mutation, then you have to go again to not get cancer because of it"
Another example of fluorescence is the brightener in laundry detergent. Clearly visible on Dr. Grey’s vest.
This was interesting! Especially near the end of watching the cosmos through UV.
I'm glad to see Dr. Meghan Gray doing good and well. It felt like I hadn't seen her on here in years..
Will you guys be covering more of the electromagnetic spectrum? I'd really like to learn the basics about wifi-signals, microwaves, bluetooth etc. and how they relate to easy reception/amount of data that can be transferred etc.
Wow!
Excellent I absolutely your videos.
Please keep posting
Hello lovely Dr. Grey! Where have you been?
Is the fact that wavelenghts are larger towards slower frequencies the reason bass can't be heard well on small earbuds?
You could tell what their light source is in the first part of the video by the emission lines in the spectrum. Looks like fluorescent lighting to me.
Awesome video, can't wait to see what they will talk about when it comes to Gamma rays, also microwaves.
oh i thought i was watching DeepSky Videos until she held up the note that said SixtySymbols hahaha
It would have been cool to put some of the fluorescent stuff in the UV part of the spectrum (from what I assume is an arc lamp) to show that yes, there's UV light there.
7:54 TIL that Chris Pratt emits UV light.
Her shirt glows, too. 5:18
how can i ask bradys physicist buddies a question? i saw a vid of a guy burning sea water with radio waves. were just the impurities in the sea water burning?
Thanks Paul!
\o/
Dr Gray is back!
Brilliant! Also, I want to rave now :P
Also, where is Dr. Gray from? She sounds American, but every so often I detect a bit of Irish accent...just curious :)
I believe she's American. The accent you're hearing might be acquired from living in the UK.
Brandon Shaffer
Maybe. Apparently, American + a bit of Nottingham = Irish to my ears XD
She's Canadian, but lives in Nottingham.
Nillie
Ah! Well, Canadian and American accents are pretty much the same...unless you're French Canadian...then you're the best Canadian in the land...
IceMetalPunk Canada _is_ part of America (just not those United States of America). ;)
Thumbs up for Paul
What if there is no EM field present? (Say inside a conductor.) How then does light propogate?
The only perfect conductor is a superconductor, and inside those light pretty much doesn't propagate. Or rather, it can be described as gaining a mass.
Jesse Mason The EM Field is never "not there"; even at zero energy in the EM Field it is still present. In fact it cannot reach zero energy because of natural Quantum Uncertainty, we can't ever be sure a field has reached zero energy because there could be ± some energy in the field (uncertainty). The EM Field therefore does exist everywhere at all times: inside conductors, super-conductors, and even inside black holes!
We happen to now understand that the classical picture is wrong. You seem like a smart guy, why would you use a wrong model of reality? There is only one kind of light (not many forms with one being "normal light"), that comes in packets called Photons with varying wavelengths [color] and energies. Metals are typically opaque and shiny for other QM reasons (see photo-electric effect, etc.); not all metals are totally opaque, not all metals are shiny.
Rob Laquiere Because it can work as a well enough for the situation you care about. Do you care about the coriolis force when throwing a ball out for a dog?
I suppose I don't, but the fact remains that it is still there. I do typically leave out insignificant effects when doing calculations so you are right.
Great analogy to just hearing a few instruments in an orchestra and just looking for visible light in astronomy.
The avian and insect (and plant) world makes great use of the UV spectrum. Check it out some time. It's amazing!
The video started with a Durex ad and i thought, "Well this is an interesting start to a sixty symbols video..."
Is there a limit to how short and how long a wavelength can be? I would assume shortest possible wavelength is close or equals planck length, while longest possibke wavelength is only limited by the size of the universe 😊
Well the energy limits the shortest wavelength, hence photons.
IamGrimalkin well.. yes, but is there a known limit? ☺
Ill Carl Electroweak unification might count as an upper limit, as you can't really distinguish "light" anymore.
Looking forward to more videos about the electromagnetic spectrum!
Cool video!
And her dress glows!!
An awesome vid!
Maybe show some Jablonski diagrams, they are pretty illustrative.
Also, if you like fluorescence, search for videos on BODIPY, they're really nice and colourful :)
Proud to be an alumnus of Nottingham University :) 69-72
Very Nice Video, could have even more science in it, other then making things glow.
Brady, could you make a series of Videos covering every spectrum of light? Would highly appreciate it.
Thanks
Fun and informative! Keep it coming! :D
I see Dr Gray on twitter all the time now xD gotta love technology!
I can't help but wonder if the range of colors we see is by chance. It happened to be the most useful range for random attributes that previously made no difference to evolution, but once an efficient range was found for those random attributes, evolution was bound to them.
It makes me wonder if we do discover alien life, if they would even see in the same color range as us. Maybe they will be gray because their actual color is outside of our vision range.
Thanks Paul
She's Canadian, it's qui-nine, not qui-nene.
Laundry detergent also works great!
I'm having an incredibly difficult time placing Dr. Gray's accent / regional inflection. She sounds like she may have been born in Scotland but then moved to Canada or something. Certainly different glottal stops than would be used in Scotland or Ireland or the US or Canada, but certain words like "borrow" and "process" strongly indicate some Canadian influence. Anyway, she is a good speaker. Thank you for the video.
That was a very good explanation of the er spectrum!
2:30, stare at the white wall to the right of her, the visible light spectrum on the left will disappear.
Interesting! Thanks
Thanks paul!
what is the amount of energy stored in a photon of uv spectrum ?
A medical condition called aphakia?
Sixty Symbols
I would like to know whether UV light is considered ionizing or non-ionizing radiation. The sources I have checked seem somewhat contradictory. They usually state that most types of UV light is non-ionizing, but when checking what frequencies of light are considered non-ionising, UV C in particular & according to some sources UV B as well. Seem to fall in frequencies related to ionizing radiation. Like I said, contradictory.
Thanks for your help.
The pre-roll ad won't leave the screen. Its done and now it won't go away - just frozen on the last image. So I can't watch the vid. I've gotten out and reopened the video twice and it plays the pre-roll commercial for 1800 contacts and then stops.
in molecular biology, we use special chemical dyes that bind to DNA. upon binding, they fluoresce, and we can detect DNA like this and quantify the concentration, size and abundance of DNA! if you are interested in seeing cool pictures, google 'DNA electrophoresis'. standard practice for all molecular biologists exploring DNA molecules. thanks!
Can you tell the purity of olive oil with the black light? Just asking because some companies mix other oils (canola) in with the olive oil claiming it to be 100% pure.
The first i in quinine (i.e. the one following the u) is a short i in English.
Since purple/white light is the only color light that will turn a radiometer. What happens to a radiometer under ultraviolet light?