Well, the solstice is over, but the sun is still angry with me, so to appease it, lets continue the theme of my previous post. I’m of course talking about my look at Jantar Mantar, winner of my coveted ‘scientific installations that look like amusement parks’ award. It beat out the EBR-I reactor and that one ATK rocket factory with all the built-in slides to win this award, no small feat!

As I mentioned before, Jantar Mantar was built in the early 1700s to measure the sun, time, constellations, etc. This was before the sun turned murder-mad, so it was built for a different reason than appeasement. Specifically, it was built in that time where the line between ‘Astronomy’ and ‘Astrology’ wasn’t as clearly delineated. What that meant was that if you wanted your horoscope, this would have been the place to go for the most accurate one!
…well, you know. Most accurate in that it was twice as accurate as the cheap ones, but two times zero and all that… Look, the last several astrologists I went to just gave me a sad look and just said “Buy sunscreen. It won’t help, but you might feel more in control. I’m so sorry”. I could give a better horoscope than that, or at least I could if it wasn’t for this sunburn that I think has just gone bone-deep.
Anyways, regardless of my views of astrology it takes a lot of effort and skill to construct a sundial that is accurate to within two seconds.
….And a lot of stone too, because that thing is big.

As I try to keep my 3D posts separate from my multispectral ones, I figured that I should probably follow up my 3D post with the latter. There really isn’t a lot of them, so this post will be a bit shorter. As I mentioned, I only had a very brief time at Jantar Mantar(due to carpet shopping taking priority), and really wish I could have explored it more. My hobby of taking photographs in different spectra highlighted the lack of time for me. It might take less than a minute to swap the camera filters around and change the white balance, but if I only have 20 minutes to freely explore a large area, a minute is a lot of time. This is my way of excusing the paucity of different spectra.
Here’s the Samrat Yantra again

Breaking it into the three colour channels(red, green and blue), there really isn’t anything unexpected.



and just because I like doing it, here’s a .gif of the three channels.

The sky might be lighter in the shorter(blue) wavelength than many of my Canada photos. I think the haze is the main contributor to that. There’s a lot of wood burning in India, at least in the areas where I visited, and I was in Jaipur during the dry season, so there was always a faint haze.
More interesting are the stains on the Samrat Yantra. I had wondered if they were mosses/moulds or stains from the smoke and pollution. They seem to stay the same shade in the different spectra, so I’m guessing soot stains. Mosses should be lighter in the red and green spectra(like the foliage in the background), as the photosynthetic process absorbs more shorter wavelength radiation and reflects more longer wavelength radiation. Unfortunately, I didn’t take an infrared photo here to confirm my hypothesis(by ‘confirm’, I of course mean ‘offer some slight evidence to slightly reinforce’). Instead, I just had my dual band Schott UG11 filter.

This filter blocks the visible spectrum, and is is dual near-infrared and ultraviolet… honestly, I think these photos are skewed to infrared(more due to my camera’s capabilities than the filter’s ones; the filter tries to compensate for this by blocking most infrared light). It isn’t as useful for me as a dedicated infrared filter, but it is pretty, and isn’t ‘pretty’ the purpose of science?
… no? Okay, fine. Be that way. I don’t like you either, science. Am I really arguing with the science, or is it just a bit of heat stroke?
No, no, it’s science. It’s hurt me too much in the past.
The photo does seem to suggest that the stains are from soot; foliage isn’t bright in the UG11 filter in the same way as it is for an infrared filter, but it does have a distinctive greenish tinge(There are three colours in this filter the way I set the white balance. Vegetation is green. The sky is indigo. Everything else is grey). The stains don’t have that tinge. They’re just black. I don’t have a photo ready to show, but ash and soot are dark in all the near-visible wavelengths, so the stains seem to correlate with it. Still, I wish I could have gotten a near-infrared photo.
I mean I did take a not-so-near-infrared shot, but that’s completely different.

I took this with my Seek Reveal thermal camera. Unfortunately, it has a fixed focal length, so no zooming in or out. I took two photos, and just tried to align them.
I really don’t know why I took these photos. To prove it was warm that day? I already knew that. The shady alcove in the Samrat Yantra is only 40° C, but that is in an area that would not have had any sun, only warmed from the air and the head of the sunshine diffusing through the sides. The vertical wall is slightly warmer, but not by much. It had just passed noon, so the sun had only started to shine on that side of the vertical wall, and didn’t have much time to warm it up. These were the only thermal photo I took here.
However, The Samrat Yantra is so big that the above photos were only of the west half of it. Would the other half be any different?
No. obviously not. That’s a stupid question, and I’m ashamed I wrote it out. I’m definitely blaming the heat, not my general stupidity. Still, I already took the photos, so let’s pretend it’s worth looking into.

So, the shadow is just starting to rise up the ‘dial’ on this side. If I had taken more thermal photos, I suspect this wall would be warmer than the one on the other side, just from the residual heat. I didn’t though, so here’s the colour channels.



And the gif.

Pretty much anything I could have said here I already said above. Still, I’m pretending there’s some point to this, so lets just copy and paste the above and pretend that it’s an original observation.
” The photo does seem to suggest that the stains are from soot; foliage isn’t bright in the UG11 filter in the same way as it is for an infrared filter, but it does have a distinctive greenish tinge(There are three colours in this filter the way I set the white balance. Vegetation is green. The sky is indigo. Everything else is grey). The stains don’t have that tinge. They’re just black. I don’t have a photo ready to show, but ash and soot are dark in all the near-visible wavelengths, so the stains seem to correlate with it. Still, I wish I could have gotten a near-infrared photo. “
And yeah, here’s another dual band photo too.

And to copy and paste… no I can’t be bothered to scroll up. It’s too hot. Foliage green, soot not green. Stains maybe soot. Okay. done. Lets go on to something new.
Okay, this is the… astronomy thingy… Is the sun exploding now? I’m can only feel burning and I’m really thirsty. Just hang on, taking a drink.

That’s better. It’s only heat. I survived hotter in Death Valley. anyways, it’s one of the Rashivalaya Yantra instruments. There’s one for each astrological sign, and I can’t remember which one this was.




I think it’s the same stone as the Samrat Yantra, but maybe at least from a different quarry. The walls of the Samrat Yantra are painted, but the dial isn’t, and it seemed slightly of a different shade. It looks like a lot of the instruments are made of marble, and for ones that aren’t, the portion designed to be read is of marble too.
Here’s the Rashivalaya Yantra with the UG11 filter. Enjoy while I wet down my t-shirt again.

That’s better. It felt just as good the last three times I wetted it down. Anyways, you can tell that the Rashivalaya Yantra is of different materials than the floor. There’s still a few stains here, and they still look grey/black. Wait, my T-shirt is dry again. Give me a second.

Sorry, I just went for a dunk in the river and… oh. You went on without me. No, no, that’s fine. It’s not like I own this website or anything. No, no, look at the colour channels, don’t mind me.




Is that good? Can I continue? The Samrat Yantra is in the background, and you can get a sense of scale here. Anyhow, the missing paint on the Ram Yantra is most noticeable in the blue channel and almost invisible in the…
What’s a Rama Yantra? I didn’t mention it last time? Well, what do you expect when you get ahead of me?
The Ram Yantra is that stonehenge-looking thing in the centre of the photo; it’s one of the instruments I didn’t have time to look at or get a 3D photo of.

There’s actually two of them; the right side of the farther one is visible behind the nearer one. They have a central pillar not visible in the photo; the position of the pillar’s shadow gives the angle and position of the sun at any given time. If the pillar’s shadow falls into one of the gaps, well… that’s what the other Rama Yantra is for; the gaps in one correspond with the walls of the other. On the right side, you can see the missing paint. Of course, these are both useless when the sun goes down… I really wish the sun would go down… I think it is exploding, now that I’m looking at it. Going swimming again. Yeah, go ahead, look at the next one.

THE RIVER IS DRY AND THE FISH ARE ON FIRE! I think I’m skipping swimming for now. The UG11 photo shows little variation in the colour of the Rama Yantra; the paint is the same shade as the unpainted(or older paint?) section. By the way, I mentioned that I didn’t spend much time switching filters. Time is short, especially when the sun is planning to murderr you and burn your… no, that’s the present, not 2017. It was only 38° then, not the… 38°? That can’t be right.
Anyhow, this was where I did make one switch, from the Schott UG11 filter to my Zomei 680 nm infrared filter. This filter is just outside the visible spectrum, offering the best colours of my infrared set.

I was a bit farther away when I took this photo, but still, there isn’t and difference in the colours of the Rama Yantra. More interestingly, I did get a photo of the Samrat Yantra’s stains. Definately not moss or moulds; they are much darker than the vegetation, without that pale blue colour. They’re the black of ash, which is the same colour as my sunburn now. I think maybe I should go inside, but the laptop has melted to my lap, which has melted to the chair.
I’ll figure it out after this last batch of photos. I’m going through them quick, as I think my IQ is dropping in the heat. If I can survive this, I need to keep smart enough that I don’t forget how to open a door. Again.

Here’s the other Rama Yantra. In front of it is another instrument I didn’t talk about last time, the Chakra Yantras. From what I understand, the Bar through the circle points north. In the centre of the bar is a hole; a sighting tube can be placed in the hole and rotated; the position on the circle will tell what degree it is at. It is used to find the angle of inclination and declination for planets and stars and…
No, that’s it. I can’t do it. I think my brain just shut down my mathematical skills to conserve energy. I don’t understand what I just wrote anymore. Lets do… you know… colour thing.



Wait, was red supposed to be first…dunno…here’s the color thingie… no, the moving one with the name nobody can pronounce.

The metal is pretty much the same shade in all three channels. There’s nothing else really special, except for the exit sign. Is that an ancient astronomy tool too, or is just the photo hinting at my future. Should I walk into the light now? I don’t want to; it looks hot.

Finally, another Zomei 680 nm filter. The foliage is a nice cool blue, but it’s a hot day so the black metal is still dark, and hot. so, so hot.
I’m going to try to get indoors now. The door is several metres away, and the sun is looking at me. If I don’t make it, tell the astrologists… tell them I understand now, and I should have bought sunscreen. I’m not giving back my refund though.
Oh yeah. The above photos were taken with a modified Canon Rebel T3i camera. Sorry. gotta die now.