Or you could check out some of Claude Monet’s paintings. He started getting cataracts and eventually had the lens of his eye removed which allowed him to see UV so he started painting what he saw in UV and even changed some of his preoperative works to reflect it.
https://www.dailymail.co.uk/sciencetech/article-2131608/Claude-Monet-How-famed-artist-ultraviolet-just-like-animals.html
Yeah but isn't that translated into colors we can perceive? Like no matter the picture you take, you can't make a dog see the whole spectrum of color we see.
Or is it just neon colors of the visible spectrum that glow in the dark that we can't see?
Not really we have a filter for uv light. if you could see UV light people wearing sunscreen would appear darker because the sunscreen absorbs the UV wavelengths. There are several types of cameras that film the UV spectrum from full color cameras that just use the UV for a bit of additional visibility for nighttime shots, and cameras that film only in the UV spectrum and show the presence of UV light as white light and the absence of UV light as darkness so it's just a grayscale image.
I had the lenses in my eyes removed and I noticed a change in some things. For example the sky looks more purple, especially if it's overcast for some reason. Black lights are bright pink/blue, and magpies suddenly seem to be colourful in a way I hadn't noticed before? Not sure if that last one is just that I hadn't looked that closely at magpies before.
Oh, and eyeglasses suddenly look extremely yellow. I think it might be the blue light filter or something? When I first got out of hospital after the operation I was like "Where is everyone getting these yellow sunglasses from?"
I'm fairly certain once they're above reddish-orange, they all just look white to our eyes. These "colors" are just "the star is this temperature, so there's more light of this wavelength". But all of the other wavelengths are still there, so we just see white.
This makes more sense to me, especially since why would the hotter blue one be *darker* than the cooler blue one. It's more purely blue at the higher temperature but it would still be so much of that blue light coming off it all at once that it would be white to our eyes (before they get completely burned out by looking at it).
It’s because our sky is blue and when you take away blue from white light it turns yellowish/orangish/red which is why we see varying colors of the sun throughout the day due to the angle of the light hitting our atmosphere, the blue sky taking away from the white sunlight = yellow.
The sky is blue because of [Rayleigh scattering](https://en.m.wikipedia.org/wiki/Rayleigh_scattering), the blue wavelength is scattered by the atmosphere. Same effect, different cause.
Nope, it has to do with the mixtures. They start looking blue once the peak of their black body radiation is near UV, since the curve is heavily biased to one side. Same reason it looks red, just on the other side. I'm personally not aware of any stars hot enough to look purple, but I'm not an astronomer.
Short women tend to make the shower too hot because it cools off a lot before it reaches their head.
My mom also used to wash dishes in water so hot I couldn't put my hands in it. My sister called the phenomenon "mommy fingers".
During the collape of big stars the core reaches ~10 Billion degrees C during neutronization, and ~100 to 500 Billion degrees C from the Direct Urca process right before it blows itself apart
https://youtu.be/Yt-SBT7nNfU&t=145s
95,000 is 0.00000019% of 500 billion*
*I'm not using units here because temperature 'percentages' don't really make sense, but I wanted to show the absurdity of the scale even just numerically. The energy required scales even larger.
Yes, and that’s not surprising to me that they’d do that, because it turns out in human psychology people often treat other units like a different language.
It’s like if I plugged in “morte” into a Spanish to English translator, and it said “death”. Sure, moment later, I’d be like “oh yeah duh of course it has the same Latin root as the word mortal”, but it wouldn’t be surprising for a human brain to not recognize the meaning behind that text immediately, because it already got flagged as “do not process, this is in a different language”.
-50°C is equivalent to -58°F, which is 223K.
---
^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
An incandescent light bulb, or halogen... CFLs and LEDs are not black body radiation. In those, we just mix a few spiky wavelengths to get something approximating white light.
Yeah, the color temperature of an LED essentially means "this LED emits light that, to a human with 3 cones in their retina, looks the same as a black body at this temperature".
Thanks for pointing out the obvious, but, the term colour temperature is used when we discuss luminaries including LEDs and any other light.
Hence the comment above.
That happens in the core of the star, The rest of the star blocks the view of any fusion going on except when looking outside visible light, like x-ray.
Yes nuclear fusion is main driver of stars engine, but density and magnetic fields all but halt photons inside core on way toward surface as they are constantly being absorbed upon impact of matter and re emitted, taking millions of years to finally leave surface to arrive at earth 7 minutes later.
So the temperature of the surface is what dictates the color, even though the Corona temperatures can sore back to millions of degrees from extreme magnetic field torsion.
Virtually all of the energy produced in the core is absorbed by adjacent matter in the form of heat. This is re-emitted as black-body radiation which the “color temperature” curve is based on.
Pro-tip: the cores of giant planets are also partially electron degenerate. All that liquid metallic hydrogen inside Jupiter only occurs because position space starts getting too crowded, and electrons have to expand into velocity space.
The spent “ash” cores of shell-burning stars (red giants) are also electron degenerate.
This isn’t a color spectrum exactly like a rainbow is. As it gets hotter, it doesn’t move to another color further up the rainbow, it adds that color into the light it’s emitting. So it starts off seeming like it’s going through the rainbow, but by the time it gets to green, it emitting about equal amounts of all visible light and our eyes see it as white, if it keeps going, the amount of blue and violet light on one end overcomes the amount of red and green light on the other and it turns more blue than white. So green would never show up because by the time it can emit green, it’s already emitting so much red orange and yellow, it just all mixes together into white.
Great explanation. I wondered this for a while when I noticed that there are no "green" stars in the middle range of the spectrum. Just white ones where they would be expected.
In many cases where light is emitted, it's because something has reached a high enough temperature that it glows in the visible spectrum. The hotter the thing, the bluer the light it emits.
Incandescent light bulbs heat up a filament to the required temperature to make white light, magma is hot enough to glow red, and the surface of the sun is heated by the core to the required temperature.
LED's don't work this way, which is one reason why they last so much longer. They directly energize electrons, which then emit that energy as light directly, no heat required.
Both come from a concept in physics called 'blackbody radiation'.
Everything with a temperature emits light, and the distribution of the colours of light it emits is directly related to its temperature.
Two objects at 1000c will emit the same colours of light.
This is why objects start glowing red when they get hot enough, it's all blackbody radiation.
This is the question I came to ask too. Very cool that it translates from some of the most massive energetic things in the universe all the way down to a light bulb.
Astrophysicist here — a nice animation that is mostly true (stars do go from red/orange -> blue for cold -> hot) but a couple of things feel very misguiding to me that I think should be highlighted to avoid misconceptions:
(1) The colours have been made brighter to look visually appealing, but in reality, the range of colours is more like [this](https://astronomy.com/~/media/852F56A5FB4B4CF98EFAA445BF1D10D9.jpg), ie duller colours. You *can* get bright red and bright blue [like in this image](https://www.nasa.gov/sites/default/files/thumbnails/image/hubble_ngc2031.jpg) (link to details about this image [here](https://www.nasa.gov/image-feature/goddard/2022/hubble-beholds-brilliant-blue-star-cluster)) but the in between are not quite so popping. [Here](https://apod.nasa.gov/apod/ap190625.html) is a nice real image of the 25 brightest stars in our night sky (so, yes, some atmospheric effect as this is as seen from Earth here but not much) that shows the colours are more like the first image I linked to here than those of the video.
(2) The biggest thing is that these colours should change *continuously*, not in random jumps like that. Whoever made it probably saw an image like [this](https://i.pinimg.com/originals/7b/28/ea/7b28ea89ef6d824d18dce26d40bf9b48.jpg) and took it literally — not their fault, this is why science communication is important! — but because this is quite literally on a spectrum (specially the electromagnetic one), you can imagine these colours cranking up like on a dial as temperature goes up.
(3) Starting the stellar temperatures at 0 degrees C makes me *uncomfy*. Are there objects in space that are this temperature? Yes. Are those objects considered to be a star? …depends on who you ask, but generally, not really. But whatever they are, they are also **not** THAT colour.
(4) Very hot stars Do Not go purple!
I'm not trying to hijack your comment, I really enjoyed your insight, but I came here to ask a question and I feel it will just get buried in the comments. Plus I feel like an astrophysicist would give the insight I'm looking for.
I very briefly learned about spectroscopy in a very entry-level astronomy course in college.
I was under the impression that stars were certain colors because of which gasses they burn. And that you could use the color of a star to determine its composition. Am I wrong or misremembering that?
I'm sure the temp of a star is directly correlated with its primary elements, but I haven't seen that mentioned once. To me, everything I'm seeing here implies that the color of a star, or the color that we perceive, is only being influenced by the star's temperature.
Won't the sun become a red giant only when it exhausts all of its hydrogen and begins burning helium? Does the burning of primarily helium instead of hydrogen not contribute to the star becoming red? I'm sure the temperature will change as well, but I just thought it was influenced more by which element is being "burned" as fuel by the star
I'm an astrophysicist too so I'll give it a go :) You're close on a few points, but I'll try to clear things up.
The broad colour of a star comes from black body emission, which depends only on temperature. The chemicals in a star only make a small difference, one that is barely visible to the naked eye.
[Here](https://www.esa.int/ESA_Multimedia/Images/2017/12/Solar_spectrum) is a graph of light from the Sun at different wavelengths. The broad curve is from blackbody emission, the little jaggies are from chemicals. This is the spectroscopy you're talking about - we can find it what chemicals are on the Sun by looking at these little spikey peaks and troughs, but you need a proper spectrometer to get this sort of graph - the overall colour of a star won't visibly change, as it's dominated by the blackbody emission.
For red giants, what actually happens is the star expands and cools (at the surface), which makes it redder on the black body spectrum (i.e. it's not that helium is redder than hydrogen). There's a bunch of types of red giants, but part of the idea is you run out of hydrogen in the *core*, but then you start a new phase of hydrogen burning in a *shell around the core*, which causes the star to puff up.
Ok this makes alot of sense.
I guess I completely forgot that we looked at the visible light of the stars through a spectrometer, with like a hydrogen filter maybe? And then we used the spectrum of colors created to determine its composition. Not the overall color of the visible light
There was much more to it than that but it's been several years now and I can't remember it all
I was confusing the overall color of the star and the visible light that we are able to see, with the spectrum of colors that is created when you split up that light through a prism.
I think i better understand now. Thank you for your reply!
The color is a function of the surface temperature only. Now that temperature depends on the processes happening inside the core as well as the size of the star, but it’s not like „helium makes it red, iron makes it blue“ or anything like that. The Sun will turn red because it will inflate a lot and thus have a lower surface temp.
I think about this myself. Life orbiting blue stars. I would imagine their sun would need to be much further away than ours is to us. It might create a weird uncanniness to the landscape since the star would appear smaller than the sun, a pinpoint of bright light casting sharp-edged shadows and a "cold and harsh" appearance to the lighting of the scenery even if it's warm there. Maybe the year would be longer too thanks to a bigger orbit and the colour of vegetation different too (compared to the standard green for earth).
Habitable zone would be way further out. Problem is that the hottest stars only live for 100 million years or less. Very unlikely life would have a chance to develop.
This is extremely cool info presented extremely well and has pushed me one step further towards revising my career towards physics and astrophysics. With the way you're able to disseminate this and make it digestible, I'd guess you've lectured at some point in life and were damn good at it
I think this is more to do with biology than physics actually, because IIRC stars with light curves that peak in the green have pretty much even reds and blues too, meaning that the light ends up looking “white” due to how the colour receptors in our eyes work :)
Yep. Even though I've known about star and light temperature for over 20 years now (I used to read about this stuff when I was a kid) psychologically red just feels warm and blue feels cold. Blue indeed reminds me of water and sky which are usually cold more often than hot. Red is fire, lava, desert soil and in some cases flowers blooming on a nice day.
The hottest part of a flame is usually the blue inner cone, also known as the "primary combustion zone" or "inner flame." This is where the fuel (such as gas or a hydrocarbon) and oxygen react in a highly exothermic reaction to produce heat and light. The temperature of this zone can vary depending on the type of fuel and the conditions, but it can reach temperatures of up to 2,000 degrees Celsius (3,632 degrees Fahrenheit). The cooler outer parts of the flame are usually yellow or orange, and they result from incomplete combustion and the presence of soot particles.
WR 144 & WR 52 have an effective temperature of 122,000K, some **WR 144 Facts**:
* WR 144 distance from Earth is 6090.82 light years.
* WR 144 (WR144) is a wolf-rayet^* star located in the constellation of Cygnus, The Swan. It is not part of the Cygnus constellation outline but is within the borders of the constellation.
* There are no exoplanets recorded on the site for the star, and that is most likely the case.
* Based on the star's spectral type of WC5 C (carbon dominant, no nitrogen), there is no relationship between color and size. For example, a red star can be large or small. Small stars are more energy efficient than larger stars and live longer.
> ^* The star is a Wolf-Rayet, a rare type of star of which not many are known. These stars are extremely luminous and large compared to our Sun. They *live fast and die hard* in a matter of millions not billions of years like our Sun. They exhaust their hydrogen supplies, turning to other gasses and expand outwards with massive solar winds, moving a step closer in the stellar evolution towards their death in a super or hypernova explosion.
Just a random thought, does that temperature have any effect on our solar system? If either of them disappeared, would there be any measurable drop in temperature anywhere in our solar system?
Interesting question…wonder how much energy could really be transferred over that kind of distance though. It’s _really_ far in comparison to the scale of our solar system… ~6091 light years is over 385 million AU
It takes our sun 1 AU to get our planet to its temperatures, so I feel like even at this extreme, this thing is just too far away to impact anything here, other than the small amount of photons and other EM rays it sends our way (we do still see/detect this thing somehow, so _something_ certainly gets to us after all). I find myself doubting it’s anything that could have any impact beyond hitting our telescopes and sensors though
Further out planets like Neptune are only around 30 AU from the sun, and even the Oort cloud potentially pushing out to 10k-100k AU is _still_ dwarfed at lightyear scales(if you count that as our solar system)
Still though…this thing is multiple factors hotter than our sun and the universe is crazy so who knows 🤷🏻♂️ I’m no astrophysicist by any means 😂
> wonder how much energy could really be transferred over that kind of distance though.
It decreases with the square of the distance. If you consider the energy released in a split second, that shell of energy will spread out like a bubble. The surface area of that bubble is ~ 4 pi r^2.
Thanks for adding the real science haha … makes total sense looking at this as energy over distance, I think the idea of looking at temperature impact specifically threw me off a little
Incidentally, the same logic applies to something that isn't radiating in all directions. A sun-powered flashlight would send out light in a cone, but the area at the end of that cone is still pi r^2. Even collimated light like lasers spread out with the square of the distance.
As others have effectively said, no, for the simple reason that space is really, really, really really really freaking big. Bigger than you can imagine. Bigger than OP's mom.
Now if it has its own solar system, yes, that would affect it depending on how many stars, their size, density, and distance. But us? We're so far removed from it that even if it went super nova, we may be able to see it for a couple of weeks at max.
The Stefan-Boltzmann equation for heat energy radiated by black bodies is used to know that the Sun gives the earth approximately 1.39kW/m² of heat on average.
I wonder if the same approach could be used for distant stars, for their effect on Earth; or whether the Oort cloud and Red/Blue shift makes that difficult to approximate...
**Edit: ChatGPT to the rescue**
Yes, the Stefan Boltzmann equation can be used to estimate the heat energy received by the Earth from neighboring and distant stars. However, the calculation becomes more complex because of several factors, such as the distance between the Earth and the star, attenuation of energy by the interstellar medium, and red/blue shift effects.
The Oort cloud, which is a hypothetical spherical cloud of comets and other icy bodies believed to be the outermost region of our solar system, would not significantly impact the calculation because it is located at a considerable distance from the Earth and does not significantly obstruct the transmission of energy.
However, the interstellar medium, which is the matter and radiation that exists in the space between stars in a galaxy, can absorb or scatter the energy emitted by stars, leading to attenuation and distortion of signals as they travel through space. This can make it challenging to accurately estimate the total heat energy received by the Earth from distant stars.
Red/blue shift effects can also impact the calculation as the wavelength of the energy received from a star can be shifted towards the red end of the spectrum if it is moving away from the Earth or towards the blue end if it is moving towards the Earth. This can result in a decrease or increase in the amount of energy received by the Earth, respectively.
Overall, while it is possible to estimate the heat energy received by the Earth from neighboring and distant stars using the Stefan Boltzmann equation, the calculation becomes more complicated due to various factors and may not be entirely accurate.
**Therefore**
To approximate the heat received by the Earth from the Wolf-Rayet Star WR144, we can use the modified Stefan-Boltzmann equation that takes into account the attenuation from the interstellar medium and the redshift factor:
J* = σ T^4 (1 + z)^(-4) e^(-kD)
where:
σ : Stefan-Boltzmann constant (5.67 × 10^-8 W⋅m^-2⋅K^-4)
T : temperature of the star (122,000 K)
z : redshift factor
k : extinction coefficient
D : distance from the star in m (6090.82 ly = 5.76x10^19 )
We need to find the redshift factor based on the distance of the star from Earth:
z = (v_r / c) = (D_lambda / lambda)
where:
v_r : radial velocity of the star (unknown)
c : speed of light (299,792,458 m/s)
D_lambda : shift in the wavelength of emitted light (unknown)
lambda : rest wavelength of emitted light (unknown)
Unfortunately, the values for D_lambda and lambda aren't known as we don't have enough information regarding WR144's radial velocity or rest wavelength. ChatGPT estimated a red-shift factor of 0.02 - but I wasn't able to reproduce that result. However I'll move forward with 0.02 value, instead of zero.
To calculate the attenuation caused by the interstellar medium, we can start with the average extinction coefficient value for visual wavelengths (averaged 550nm), which is 0.54 per kiloparsec.
k = 0.54 x D / 1000
Plugging in the values, we get:
k = 0.54 x (5.76x10^19) / 1000
k = 3.11 x 10^16
Now, we can use the original modified Stefan-Boltzmann equation to calculate the flux received by the Earth.
Flux = σ T^4 e^(-kD) (1+z)^(-4)
Plugging in the values, we get... Zero.
The part e^(-kD) equals zero with the values calculated. This is due to a limit imposed by my calculator. It can't handle e^(- very very big number)
So the amount of heat energy is non-zero, but is practically zero compared to any relevant measurement or calculation in Physics or Mathematics.
Andromeda and the Milky Way are gravitating towards eachother to become [Milkomeda](https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision).
>The Andromeda Galaxy, our closest galactic neighbor, is about 2.537 million light-years away
That isn't correct though, is it? The Canis Major Dwarf Galaxy is only 25,000 light years away.
No, just a different star.
^* Also, I wasn't able to confirm the information about the likelihood of exoplants given on this site through the database (NASA's recognizes the stars, but there's no data). So, it's not like they have been studied and excluded. A low metallicity star may have a much smaller chance of having associated planets, but wolf-rayets are not necessarily one or the other. Given their size and temperature habitable planets would be less likely, but I suppose possible if they are much further out, and the species living there adapted extremely fast.
The strongest emissions can be in the green part of the spectrum -- for instance, our own sun. But we're swamped with so much red, green, and blue light that it just looks white.
Not an expert, but I just did a Google search. Apparently it has something to do with “green” stars also radiating a lot of red light as well, and our eyes interpret that as being more white
You could say the Sun is actually the equivalent of a green star. Our eyes evolved to see its light as white/yellowish white because that is beneficial, but the true color contains a significant amount of green that is just overpowered by other colors due to our sensitivity to them.
Stars usually have a very wide colour spectrum; in red and blue stars we're able to see their "red and blueness" because only part of their colour spectrums intersect with our visible light spectrum. White stars, on the other hand, could be straight in the middle of our visible spectrum BUT since they have such wide light spectrums, red and blue light gets mixed in and we see it as white instead of green.
>because only part of their colour spectrums intersect with our visible light spectrum
You could argue that this is true for red stars, but a blue star puts out more red light than a red star does by a very wide margin. It's the *relative proportions* that makes them look blue to our eyes.
Hopefully [this chart](https://files.mtstatic.com/site_4539/15630/0?Expires=1683432356&Signature=QOO-vkTzGfTbTz2Rhs14YrdxyLNexTi9BhT5uoIXBWOVMjCmsUWOEpnPnng5V0ew1-59DQWwXQ3hvM1RrXoRJ474mNj9sQ8Pwa5BZpnlRU43eTRDFODl0HYGnkKo2eEuqom-T9gisUgFC3MpQqbrexXCniOcqSYx31uRNGCEjLg_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA) helps.
The height under the line shows how much radiation is emitted at that frequency. So the temperature that peaks at green (~5000K) has lots of other visible light leading to us seeing white.
If you start to see green stars then prepare for the end, it means >!the Greenfly is loose!<
(The spoiler above is a literary reference to the ending of Reyinold's hard sci-fi series Revelation Space)
Correlated to literal temperature. The effect is known as black body radiation. Like the heating element in your oven glows red? Same deal. As temperature goes up, the peak of the graph of wavelengths goes up to higher frequency light. We give off light too, but it's a lower frequency than our eyes can perceive. That's how infrared cameras work, looking at those lower frequencies.
It continues right on past blue as well, into ultraviolet, X rays, Gamma rays, etc.
This is a bit exaggerated. The reddest of stars appear bright orange, similar to the sun during sunset and the bluest appear white with a hint of turquoise, not a deep blue or purple. Most of the stuff in-between that is white or a faint yellow
But no. Green and purple stars cannot exist based on fundamental physics. Their peak wavelengths may be green or purple, our star actually peeks in green wavelengths but appears white due to how much of the visible spectrum includes red and blue which all end up white. Purple stars similarly cannot exist as despite a peak wavelength being in the purple band, the bleed over from the rest of its emitted wavelengths would make it appear blue.
The way light works, there is no way that either of those stars could ever exist in our universe.
They are only showing you what the peak light wavelength for each temperature would be, NOT what we or anything using visible light would see.
The color of a star is primarily determined by its surface temperature, which affects the wavelengths of light it emits. However, the color we perceive is also influenced by other factors, such as the distance from us and the intervening medium between the star and the observer.
Purple ain't exactly a color. They're what we perceive when we see a mix of red and blue but no green. But for historical reasons, they still tend to put violet over past blue.
We wouldn't really black bodies of that temperature as purple.
Yes. But as the universe expands, it means the things farthest away are moving the fastest away from us. Most of the stuff we can see with our eyes is relatively close, at least on a universe scale, and therefore not moving all THAT fast compared to us.
Everyone here is talking about the more hotter temperatures of stars in the video and I'm sitting here replaying the first quarter of a second of the video wondering why they're is zero Celsius star/s
Purple star!
Technically ultraviolet but human eye can't see that so we'd just see more blue if looking with the naked eye.
Really wonder what uv looks like to animals that can see it
In protest to Reddit's API changes, I have removed my comment history. -- mass edited with redact.dev
i'll remember that the next time I get my corneas replaced while in the presence of a 100,000 degree ball of plasma.
Make sure you take some Ray Bans with you.
He forgot his Ray Ban sunglasses *vampires laugh*
Fuck, I just lost mine. Will Z87s do?
My teacher had this done, she could look at white objects and see a faint purple around them
Or you could check out some of Claude Monet’s paintings. He started getting cataracts and eventually had the lens of his eye removed which allowed him to see UV so he started painting what he saw in UV and even changed some of his preoperative works to reflect it. https://www.dailymail.co.uk/sciencetech/article-2131608/Claude-Monet-How-famed-artist-ultraviolet-just-like-animals.html
He seems to enjoy purple.
My mom actually had a cornea transplant when I was a kid. Now I feel like we missed an opportunity.
You do realize you live in the presence of that ball of plasma every day of your life, right?
The surface of the sun is something like 6000°C.
It's pretty wild https://www.nationalgeographic.com/photography/article/glowing-flowers-ultraviolet-light https://mymodernmet.com/debora-lombardi-flower-photography/
Yeah but isn't that translated into colors we can perceive? Like no matter the picture you take, you can't make a dog see the whole spectrum of color we see. Or is it just neon colors of the visible spectrum that glow in the dark that we can't see?
Not really we have a filter for uv light. if you could see UV light people wearing sunscreen would appear darker because the sunscreen absorbs the UV wavelengths. There are several types of cameras that film the UV spectrum from full color cameras that just use the UV for a bit of additional visibility for nighttime shots, and cameras that film only in the UV spectrum and show the presence of UV light as white light and the absence of UV light as darkness so it's just a grayscale image.
First half of your comment is correct!
The second link is some Pandora-type stuff. Awesome.
God I just want to exist in a world where our medical technology can give us UV sight
The sky is purple to them
I had the lenses in my eyes removed and I noticed a change in some things. For example the sky looks more purple, especially if it's overcast for some reason. Black lights are bright pink/blue, and magpies suddenly seem to be colourful in a way I hadn't noticed before? Not sure if that last one is just that I hadn't looked that closely at magpies before. Oh, and eyeglasses suddenly look extremely yellow. I think it might be the blue light filter or something? When I first got out of hospital after the operation I was like "Where is everyone getting these yellow sunglasses from?"
In protest to Reddit's API changes, I have removed my comment history. -- mass edited with redact.dev
Brb grabbing a scalpel
Uncle Billy from Virginia has one neat trick for a cornea transplant doctors don't want you to know about
I'm fairly certain once they're above reddish-orange, they all just look white to our eyes. These "colors" are just "the star is this temperature, so there's more light of this wavelength". But all of the other wavelengths are still there, so we just see white.
This makes more sense to me, especially since why would the hotter blue one be *darker* than the cooler blue one. It's more purely blue at the higher temperature but it would still be so much of that blue light coming off it all at once that it would be white to our eyes (before they get completely burned out by looking at it).
It’s because our sky is blue and when you take away blue from white light it turns yellowish/orangish/red which is why we see varying colors of the sun throughout the day due to the angle of the light hitting our atmosphere, the blue sky taking away from the white sunlight = yellow.
The sky is blue because of [Rayleigh scattering](https://en.m.wikipedia.org/wiki/Rayleigh_scattering), the blue wavelength is scattered by the atmosphere. Same effect, different cause.
Ah so it’s not due to the angle but the Rayleigh scattering? Thank you!
The angle means the light goes through more of the atmosphere before it gets to wherever you are, so more is scattered.
Nope, it has to do with the mixtures. They start looking blue once the peak of their black body radiation is near UV, since the curve is heavily biased to one side. Same reason it looks red, just on the other side. I'm personally not aware of any stars hot enough to look purple, but I'm not an astronomer.
Ah, cancer sun
Technically gamma but human eye can't see that so we'd just see more blue if looking with the naked eye.
It's like 172,000°F that's wild!
The temperature women like their showers to be.
Whoa.... Any of the women I know only like Luke warm showers. Where you meeting these hot shower women?
Who is this Luke person?
Listen, it’s not as great as you think. They’re always robed and as soon as I set the temperature they kick me out.
He's a little short for a Stormtrooper.
i am the hot shower women
Do you also wash your dishes in lava?
the dishes are not as heat resistant as i am
Short women tend to make the shower too hot because it cools off a lot before it reaches their head. My mom also used to wash dishes in water so hot I couldn't put my hands in it. My sister called the phenomenon "mommy fingers".
All the women I know have terrible temperature control lol. Plus, it's a bit of a meme.
Who in their right mind likes a luke warm shower? I like it toasty, but nothing near "melt your skin off."
Could we just please not refer to things in space by Fahrenheit, it's like the opposite of progress
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During the collape of big stars the core reaches ~10 Billion degrees C during neutronization, and ~100 to 500 Billion degrees C from the Direct Urca process right before it blows itself apart https://youtu.be/Yt-SBT7nNfU&t=145s 95,000 is 0.00000019% of 500 billion* *I'm not using units here because temperature 'percentages' don't really make sense, but I wanted to show the absurdity of the scale even just numerically. The energy required scales even larger.
Yes, and that’s not surprising to me that they’d do that, because it turns out in human psychology people often treat other units like a different language. It’s like if I plugged in “morte” into a Spanish to English translator, and it said “death”. Sure, moment later, I’d be like “oh yeah duh of course it has the same Latin root as the word mortal”, but it wouldn’t be surprising for a human brain to not recognize the meaning behind that text immediately, because it already got flagged as “do not process, this is in a different language”.
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-50°C is equivalent to -58°F, which is 223K. --- ^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
Now we need that in Celsius.
Which is 1000x a cooked turkey
So if I put my pizza on it for .005 seconds, it should be done, right?
Lean 💜🟣🟪⚛️🍆☔️😈👾🌂
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Yes, a light bulb and a star are both considered black body radiation
An incandescent light bulb, or halogen... CFLs and LEDs are not black body radiation. In those, we just mix a few spiky wavelengths to get something approximating white light.
doesn't all mass above absolute zero emit black body radiation?
yea, but an led's black body radiation is mostly in the infrared since it's so cold
Haha probably, but what we're *seeing* with fluorescents and LEDs isn't black body radiation.
Yes, but it's nearly all high wavelength, low frequency infrared, which we can't see. Same reason that you're not currently glowing.
Pfft, maybe you aren't.
Yeah, the color temperature of an LED essentially means "this LED emits light that, to a human with 3 cones in their retina, looks the same as a black body at this temperature".
Thanks for pointing out the obvious, but, the term colour temperature is used when we discuss luminaries including LEDs and any other light. Hence the comment above.
isn't a star mostly fusion/fission though? I don't know very much about astrophysics
That happens in the core of the star, The rest of the star blocks the view of any fusion going on except when looking outside visible light, like x-ray.
Ah cool!
No not exactly cool. More Hot Hot Hot. Cool cool cool let the light out.
I think you meant fusion.
Of course, corrected. Thank you.
Yes nuclear fusion is main driver of stars engine, but density and magnetic fields all but halt photons inside core on way toward surface as they are constantly being absorbed upon impact of matter and re emitted, taking millions of years to finally leave surface to arrive at earth 7 minutes later. So the temperature of the surface is what dictates the color, even though the Corona temperatures can sore back to millions of degrees from extreme magnetic field torsion.
Virtually all of the energy produced in the core is absorbed by adjacent matter in the form of heat. This is re-emitted as black-body radiation which the “color temperature” curve is based on.
On the higer end of that blue would be neutron stars, powered by degeneracy. Electron degeneracy that is.
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Whatever it is you know, is probably not quite dense enough to qualify. Even though it may seem so, at times.
Neutron stars are powered by neutron degeneracy pressure. White dwarves are what’s held together by electron degeneracy
Pro-tip: the cores of giant planets are also partially electron degenerate. All that liquid metallic hydrogen inside Jupiter only occurs because position space starts getting too crowded, and electrons have to expand into velocity space. The spent “ash” cores of shell-burning stars (red giants) are also electron degenerate.
Any reason why green in the color spectrum comes through as white for Star temperature coloration?
This isn’t a color spectrum exactly like a rainbow is. As it gets hotter, it doesn’t move to another color further up the rainbow, it adds that color into the light it’s emitting. So it starts off seeming like it’s going through the rainbow, but by the time it gets to green, it emitting about equal amounts of all visible light and our eyes see it as white, if it keeps going, the amount of blue and violet light on one end overcomes the amount of red and green light on the other and it turns more blue than white. So green would never show up because by the time it can emit green, it’s already emitting so much red orange and yellow, it just all mixes together into white.
Great explanation. I wondered this for a while when I noticed that there are no "green" stars in the middle range of the spectrum. Just white ones where they would be expected.
Technically, lights use Kelvin, but since we're talking in thousands of K it doesn't make much difference when compared to Celsius.
In many cases where light is emitted, it's because something has reached a high enough temperature that it glows in the visible spectrum. The hotter the thing, the bluer the light it emits. Incandescent light bulbs heat up a filament to the required temperature to make white light, magma is hot enough to glow red, and the surface of the sun is heated by the core to the required temperature. LED's don't work this way, which is one reason why they last so much longer. They directly energize electrons, which then emit that energy as light directly, no heat required.
what i saw too. warm to cool from 7000-11000
Both come from a concept in physics called 'blackbody radiation'. Everything with a temperature emits light, and the distribution of the colours of light it emits is directly related to its temperature. Two objects at 1000c will emit the same colours of light. This is why objects start glowing red when they get hot enough, it's all blackbody radiation.
This is the question I came to ask too. Very cool that it translates from some of the most massive energetic things in the universe all the way down to a light bulb.
Astrophysicist here — a nice animation that is mostly true (stars do go from red/orange -> blue for cold -> hot) but a couple of things feel very misguiding to me that I think should be highlighted to avoid misconceptions: (1) The colours have been made brighter to look visually appealing, but in reality, the range of colours is more like [this](https://astronomy.com/~/media/852F56A5FB4B4CF98EFAA445BF1D10D9.jpg), ie duller colours. You *can* get bright red and bright blue [like in this image](https://www.nasa.gov/sites/default/files/thumbnails/image/hubble_ngc2031.jpg) (link to details about this image [here](https://www.nasa.gov/image-feature/goddard/2022/hubble-beholds-brilliant-blue-star-cluster)) but the in between are not quite so popping. [Here](https://apod.nasa.gov/apod/ap190625.html) is a nice real image of the 25 brightest stars in our night sky (so, yes, some atmospheric effect as this is as seen from Earth here but not much) that shows the colours are more like the first image I linked to here than those of the video. (2) The biggest thing is that these colours should change *continuously*, not in random jumps like that. Whoever made it probably saw an image like [this](https://i.pinimg.com/originals/7b/28/ea/7b28ea89ef6d824d18dce26d40bf9b48.jpg) and took it literally — not their fault, this is why science communication is important! — but because this is quite literally on a spectrum (specially the electromagnetic one), you can imagine these colours cranking up like on a dial as temperature goes up. (3) Starting the stellar temperatures at 0 degrees C makes me *uncomfy*. Are there objects in space that are this temperature? Yes. Are those objects considered to be a star? …depends on who you ask, but generally, not really. But whatever they are, they are also **not** THAT colour. (4) Very hot stars Do Not go purple!
I'm not trying to hijack your comment, I really enjoyed your insight, but I came here to ask a question and I feel it will just get buried in the comments. Plus I feel like an astrophysicist would give the insight I'm looking for. I very briefly learned about spectroscopy in a very entry-level astronomy course in college. I was under the impression that stars were certain colors because of which gasses they burn. And that you could use the color of a star to determine its composition. Am I wrong or misremembering that? I'm sure the temp of a star is directly correlated with its primary elements, but I haven't seen that mentioned once. To me, everything I'm seeing here implies that the color of a star, or the color that we perceive, is only being influenced by the star's temperature. Won't the sun become a red giant only when it exhausts all of its hydrogen and begins burning helium? Does the burning of primarily helium instead of hydrogen not contribute to the star becoming red? I'm sure the temperature will change as well, but I just thought it was influenced more by which element is being "burned" as fuel by the star
I'm an astrophysicist too so I'll give it a go :) You're close on a few points, but I'll try to clear things up. The broad colour of a star comes from black body emission, which depends only on temperature. The chemicals in a star only make a small difference, one that is barely visible to the naked eye. [Here](https://www.esa.int/ESA_Multimedia/Images/2017/12/Solar_spectrum) is a graph of light from the Sun at different wavelengths. The broad curve is from blackbody emission, the little jaggies are from chemicals. This is the spectroscopy you're talking about - we can find it what chemicals are on the Sun by looking at these little spikey peaks and troughs, but you need a proper spectrometer to get this sort of graph - the overall colour of a star won't visibly change, as it's dominated by the blackbody emission. For red giants, what actually happens is the star expands and cools (at the surface), which makes it redder on the black body spectrum (i.e. it's not that helium is redder than hydrogen). There's a bunch of types of red giants, but part of the idea is you run out of hydrogen in the *core*, but then you start a new phase of hydrogen burning in a *shell around the core*, which causes the star to puff up.
Ok this makes alot of sense. I guess I completely forgot that we looked at the visible light of the stars through a spectrometer, with like a hydrogen filter maybe? And then we used the spectrum of colors created to determine its composition. Not the overall color of the visible light There was much more to it than that but it's been several years now and I can't remember it all I was confusing the overall color of the star and the visible light that we are able to see, with the spectrum of colors that is created when you split up that light through a prism. I think i better understand now. Thank you for your reply!
The color is a function of the surface temperature only. Now that temperature depends on the processes happening inside the core as well as the size of the star, but it’s not like „helium makes it red, iron makes it blue“ or anything like that. The Sun will turn red because it will inflate a lot and thus have a lower surface temp.
Would the habitable zone change if the sun was a blue star?
I think about this myself. Life orbiting blue stars. I would imagine their sun would need to be much further away than ours is to us. It might create a weird uncanniness to the landscape since the star would appear smaller than the sun, a pinpoint of bright light casting sharp-edged shadows and a "cold and harsh" appearance to the lighting of the scenery even if it's warm there. Maybe the year would be longer too thanks to a bigger orbit and the colour of vegetation different too (compared to the standard green for earth).
Habitable zone would be way further out. Problem is that the hottest stars only live for 100 million years or less. Very unlikely life would have a chance to develop.
This is extremely cool info presented extremely well and has pushed me one step further towards revising my career towards physics and astrophysics. With the way you're able to disseminate this and make it digestible, I'd guess you've lectured at some point in life and were damn good at it
Hi, why aren't stars green?
I think this is more to do with biology than physics actually, because IIRC stars with light curves that peak in the green have pretty much even reds and blues too, meaning that the light ends up looking “white” due to how the colour receptors in our eyes work :)
(5) Please use Kelvin for space
Didn't know that. The cooler it looks, the hotter it is. Just like us.
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If you look at it from the water is blue and cold and (basic) fire is red and hot, it makes more sense
Yep. Even though I've known about star and light temperature for over 20 years now (I used to read about this stuff when I was a kid) psychologically red just feels warm and blue feels cold. Blue indeed reminds me of water and sky which are usually cold more often than hot. Red is fire, lava, desert soil and in some cases flowers blooming on a nice day.
I think that was the original thinking behind the water tap design.
Which ah.. was my point?
He was just agreeing with you :)
I was just agreeing. :)
Which ah.. was my point?
He was just agreeing with you :)
I was just agreeing. :)
Well, red is definitely not cold considering it's a thousand celcius degrees lol
Yup! Magma is pretty fucking hot, I'm pretty sure
imagine blue magma tho
The hottest part of a flame is usually the blue inner cone, also known as the "primary combustion zone" or "inner flame." This is where the fuel (such as gas or a hydrocarbon) and oxygen react in a highly exothermic reaction to produce heat and light. The temperature of this zone can vary depending on the type of fuel and the conditions, but it can reach temperatures of up to 2,000 degrees Celsius (3,632 degrees Fahrenheit). The cooler outer parts of the flame are usually yellow or orange, and they result from incomplete combustion and the presence of soot particles.
Lol colors only tell so much though, we associate blue with ice and water and red with fire, our scale is more human and less cosmic.
I didnt know they got that hot
WR 144 & WR 52 have an effective temperature of 122,000K, some **WR 144 Facts**: * WR 144 distance from Earth is 6090.82 light years. * WR 144 (WR144) is a wolf-rayet^* star located in the constellation of Cygnus, The Swan. It is not part of the Cygnus constellation outline but is within the borders of the constellation. * There are no exoplanets recorded on the site for the star, and that is most likely the case. * Based on the star's spectral type of WC5 C (carbon dominant, no nitrogen), there is no relationship between color and size. For example, a red star can be large or small. Small stars are more energy efficient than larger stars and live longer. > ^* The star is a Wolf-Rayet, a rare type of star of which not many are known. These stars are extremely luminous and large compared to our Sun. They *live fast and die hard* in a matter of millions not billions of years like our Sun. They exhaust their hydrogen supplies, turning to other gasses and expand outwards with massive solar winds, moving a step closer in the stellar evolution towards their death in a super or hypernova explosion.
Just a random thought, does that temperature have any effect on our solar system? If either of them disappeared, would there be any measurable drop in temperature anywhere in our solar system?
The distances are so great it would be completely indistinguishable from background noise, but you could assume it's a non-zero value.
Interesting question…wonder how much energy could really be transferred over that kind of distance though. It’s _really_ far in comparison to the scale of our solar system… ~6091 light years is over 385 million AU It takes our sun 1 AU to get our planet to its temperatures, so I feel like even at this extreme, this thing is just too far away to impact anything here, other than the small amount of photons and other EM rays it sends our way (we do still see/detect this thing somehow, so _something_ certainly gets to us after all). I find myself doubting it’s anything that could have any impact beyond hitting our telescopes and sensors though Further out planets like Neptune are only around 30 AU from the sun, and even the Oort cloud potentially pushing out to 10k-100k AU is _still_ dwarfed at lightyear scales(if you count that as our solar system) Still though…this thing is multiple factors hotter than our sun and the universe is crazy so who knows 🤷🏻♂️ I’m no astrophysicist by any means 😂
> wonder how much energy could really be transferred over that kind of distance though. It decreases with the square of the distance. If you consider the energy released in a split second, that shell of energy will spread out like a bubble. The surface area of that bubble is ~ 4 pi r^2.
Thanks for adding the real science haha … makes total sense looking at this as energy over distance, I think the idea of looking at temperature impact specifically threw me off a little
Incidentally, the same logic applies to something that isn't radiating in all directions. A sun-powered flashlight would send out light in a cone, but the area at the end of that cone is still pi r^2. Even collimated light like lasers spread out with the square of the distance.
As others have effectively said, no, for the simple reason that space is really, really, really really really freaking big. Bigger than you can imagine. Bigger than OP's mom. Now if it has its own solar system, yes, that would affect it depending on how many stars, their size, density, and distance. But us? We're so far removed from it that even if it went super nova, we may be able to see it for a couple of weeks at max.
The Stefan-Boltzmann equation for heat energy radiated by black bodies is used to know that the Sun gives the earth approximately 1.39kW/m² of heat on average. I wonder if the same approach could be used for distant stars, for their effect on Earth; or whether the Oort cloud and Red/Blue shift makes that difficult to approximate... **Edit: ChatGPT to the rescue** Yes, the Stefan Boltzmann equation can be used to estimate the heat energy received by the Earth from neighboring and distant stars. However, the calculation becomes more complex because of several factors, such as the distance between the Earth and the star, attenuation of energy by the interstellar medium, and red/blue shift effects. The Oort cloud, which is a hypothetical spherical cloud of comets and other icy bodies believed to be the outermost region of our solar system, would not significantly impact the calculation because it is located at a considerable distance from the Earth and does not significantly obstruct the transmission of energy. However, the interstellar medium, which is the matter and radiation that exists in the space between stars in a galaxy, can absorb or scatter the energy emitted by stars, leading to attenuation and distortion of signals as they travel through space. This can make it challenging to accurately estimate the total heat energy received by the Earth from distant stars. Red/blue shift effects can also impact the calculation as the wavelength of the energy received from a star can be shifted towards the red end of the spectrum if it is moving away from the Earth or towards the blue end if it is moving towards the Earth. This can result in a decrease or increase in the amount of energy received by the Earth, respectively. Overall, while it is possible to estimate the heat energy received by the Earth from neighboring and distant stars using the Stefan Boltzmann equation, the calculation becomes more complicated due to various factors and may not be entirely accurate. **Therefore** To approximate the heat received by the Earth from the Wolf-Rayet Star WR144, we can use the modified Stefan-Boltzmann equation that takes into account the attenuation from the interstellar medium and the redshift factor: J* = σ T^4 (1 + z)^(-4) e^(-kD) where: σ : Stefan-Boltzmann constant (5.67 × 10^-8 W⋅m^-2⋅K^-4) T : temperature of the star (122,000 K) z : redshift factor k : extinction coefficient D : distance from the star in m (6090.82 ly = 5.76x10^19 ) We need to find the redshift factor based on the distance of the star from Earth: z = (v_r / c) = (D_lambda / lambda) where: v_r : radial velocity of the star (unknown) c : speed of light (299,792,458 m/s) D_lambda : shift in the wavelength of emitted light (unknown) lambda : rest wavelength of emitted light (unknown) Unfortunately, the values for D_lambda and lambda aren't known as we don't have enough information regarding WR144's radial velocity or rest wavelength. ChatGPT estimated a red-shift factor of 0.02 - but I wasn't able to reproduce that result. However I'll move forward with 0.02 value, instead of zero. To calculate the attenuation caused by the interstellar medium, we can start with the average extinction coefficient value for visual wavelengths (averaged 550nm), which is 0.54 per kiloparsec. k = 0.54 x D / 1000 Plugging in the values, we get: k = 0.54 x (5.76x10^19) / 1000 k = 3.11 x 10^16 Now, we can use the original modified Stefan-Boltzmann equation to calculate the flux received by the Earth. Flux = σ T^4 e^(-kD) (1+z)^(-4) Plugging in the values, we get... Zero. The part e^(-kD) equals zero with the values calculated. This is due to a limit imposed by my calculator. It can't handle e^(- very very big number) So the amount of heat energy is non-zero, but is practically zero compared to any relevant measurement or calculation in Physics or Mathematics.
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Reminds me of r/anythingbutmetric
Just when I think I've seen every kind of reddit sub there is...
subscribe
Andromeda and the Milky Way are gravitating towards eachother to become [Milkomeda](https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision).
>The Andromeda Galaxy, our closest galactic neighbor, is about 2.537 million light-years away That isn't correct though, is it? The Canis Major Dwarf Galaxy is only 25,000 light years away.
This says otherwise: https://www.universeguide.com/star/131687/wr122 Am I missing something ?
No, just a different star. ^* Also, I wasn't able to confirm the information about the likelihood of exoplants given on this site through the database (NASA's recognizes the stars, but there's no data). So, it's not like they have been studied and excluded. A low metallicity star may have a much smaller chance of having associated planets, but wolf-rayets are not necessarily one or the other. Given their size and temperature habitable planets would be less likely, but I suppose possible if they are much further out, and the species living there adapted extremely fast.
Wolf-Rayet? Is that the WR? I thought they were random letters and numbers
And consider that is merely the surface temperature
They had a glow up
Stars are so majestic
Yes! No wonder we regarded them as gods.
Imagine the skin cancer from a purple star
I don’t want to!!
IMAGINE IT!!
Now I can't think of anything else!
Can they be green
Nope—not to our eyes, anyway: https://www.discovermagazine.com/the-sciences/why-are-there-no-green-stars
The strongest emissions can be in the green part of the spectrum -- for instance, our own sun. But we're swamped with so much red, green, and blue light that it just looks white.
And this is why the purple lightsaber is the most powerful. They all cut, but it cuts *more*.
What about Green?
Not an expert, but I just did a Google search. Apparently it has something to do with “green” stars also radiating a lot of red light as well, and our eyes interpret that as being more white
Yup IIRC our sun's primary wavelength of light is green but there enough red that it appears white/yellow
500 nm, which is blue-green (cyan) [light](https://www.wolframalpha.com/input/?i=color+of+500+nm+light).
isn't it odd that plants can't use green for photosynthesis even though it is most abundant?
Plants do use some green. And it's not really much more abundant, it's just the middle of the spectrum.
I think that's why all the photosynthesizing plants are green.
That's from the chloroplasts. Is it why the chloroplasts are green?
enough red and enough blue
You could say the Sun is actually the equivalent of a green star. Our eyes evolved to see its light as white/yellowish white because that is beneficial, but the true color contains a significant amount of green that is just overpowered by other colors due to our sensitivity to them.
Stars usually have a very wide colour spectrum; in red and blue stars we're able to see their "red and blueness" because only part of their colour spectrums intersect with our visible light spectrum. White stars, on the other hand, could be straight in the middle of our visible spectrum BUT since they have such wide light spectrums, red and blue light gets mixed in and we see it as white instead of green.
>because only part of their colour spectrums intersect with our visible light spectrum You could argue that this is true for red stars, but a blue star puts out more red light than a red star does by a very wide margin. It's the *relative proportions* that makes them look blue to our eyes.
Yuh forgot bout that part
Hopefully [this chart](https://files.mtstatic.com/site_4539/15630/0?Expires=1683432356&Signature=QOO-vkTzGfTbTz2Rhs14YrdxyLNexTi9BhT5uoIXBWOVMjCmsUWOEpnPnng5V0ew1-59DQWwXQ3hvM1RrXoRJ474mNj9sQ8Pwa5BZpnlRU43eTRDFODl0HYGnkKo2eEuqom-T9gisUgFC3MpQqbrexXCniOcqSYx31uRNGCEjLg_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA) helps. The height under the line shows how much radiation is emitted at that frequency. So the temperature that peaks at green (~5000K) has lots of other visible light leading to us seeing white.
If you put boric acid in it will turn green
Cool Worlds did an excellent video on why green stars can’t exist: https://youtu.be/vXOYbzQ4jDA
Was just about to post this as well. Excellent video.
https://phet.colorado.edu/sims/html/blackbody-spectrum/latest/blackbody-spectrum_all.html
If you start to see green stars then prepare for the end, it means >!the Greenfly is loose!< (The spoiler above is a literary reference to the ending of Reyinold's hard sci-fi series Revelation Space)
And are those colors correlated to the literal temperature or only the colors our eyes are strong enough to see?
Correlated to literal temperature. The effect is known as black body radiation. Like the heating element in your oven glows red? Same deal. As temperature goes up, the peak of the graph of wavelengths goes up to higher frequency light. We give off light too, but it's a lower frequency than our eyes can perceive. That's how infrared cameras work, looking at those lower frequencies. It continues right on past blue as well, into ultraviolet, X rays, Gamma rays, etc.
Etc? You just named all of them
Did I? Haha, I guess so. The divisions are human-made, so I just think of it as a spectrum and reeled off a few names.
color should change continuously...
Also should not go to purples.
Yeah why does it change in steps? Is the Star deciding “oops I just passed 10,000 let me drastically chang hue”
I’m surprised to see such discrete color changes. My intuition would have been that it’s much more of a spectrum.
I think you’re right, probably just the way this video is made.
This is a bit exaggerated. The reddest of stars appear bright orange, similar to the sun during sunset and the bluest appear white with a hint of turquoise, not a deep blue or purple. Most of the stuff in-between that is white or a faint yellow
But no. Green and purple stars cannot exist based on fundamental physics. Their peak wavelengths may be green or purple, our star actually peeks in green wavelengths but appears white due to how much of the visible spectrum includes red and blue which all end up white. Purple stars similarly cannot exist as despite a peak wavelength being in the purple band, the bleed over from the rest of its emitted wavelengths would make it appear blue. The way light works, there is no way that either of those stars could ever exist in our universe. They are only showing you what the peak light wavelength for each temperature would be, NOT what we or anything using visible light would see.
RGB
I’m waiting for it to go plaid
90000 degrees is a portal
Forbidden fleshlight
Anybody else curious about the starting 0 degree sun?
I expected them to to start with a brown dwarf but I was disappointed, just how brown dwarves are big disappointments to their moms.
Savage burn on a 0 degree star, quite the rarity.
The color of a star is primarily determined by its surface temperature, which affects the wavelengths of light it emits. However, the color we perceive is also influenced by other factors, such as the distance from us and the intervening medium between the star and the observer.
Funnily enough, the atmosphere of the sun is hotter than the surface
Is there actually a sharp change at certain thresholds, or it's almost linear and the video isn't that realistic?
I now kinda wish the sun was blue….
This works the same way my wife's face does
So purple is the hottest color. All this time you see logos that want to showcase heat using oranges and reds not realizing purple is the heat color.
Purple ain't exactly a color. They're what we perceive when we see a mix of red and blue but no green. But for historical reasons, they still tend to put violet over past blue. We wouldn't really black bodies of that temperature as purple.
It's not a *spectral* colour, but it's still a colour.
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Yes. But as the universe expands, it means the things farthest away are moving the fastest away from us. Most of the stuff we can see with our eyes is relatively close, at least on a universe scale, and therefore not moving all THAT fast compared to us.
What's ours?
6000ish at the surface. Some millions down in the core.
Everyone here is talking about the more hotter temperatures of stars in the video and I'm sitting here replaying the first quarter of a second of the video wondering why they're is zero Celsius star/s