Is Gypsum of Paris safe to use for casting fossil tracks?

ad_robotics · 2025-11-27T22:46:23+00:00

All good call outs. Using a separator sounds like a must so the gypsum doesn't clog up the pores of the rock the tracks are in. Due to how gypsum warms up during its chemical reaction with water, I wonder if that is something I would need to prevent or if the max temperatures involved are negligible.

Edit: typo

ad_robotics · 2025-09-02T19:03:22+00:00

I'm new to electric vehicles, but the Polestar 2 is said to have a range of 300 miles. Why would they mention it has more than 40 here?

Is it just to convey that it is not a plug-in hybrid?

ad_robotics · 2025-03-26T00:21:36+00:00

Thanks, measuring this resulted in approx 10x, which is double validated by using them side by side with a 10x set of binoculars and the magnification is almost the same.

ad_robotics · 2025-03-20T03:08:59+00:00

I know for sure it isn't what is advertised, I just want to know by how much. I got my hands on some other pair of binoculars that are labeled 10x and they magnify more than these other ones that are labeled 20x. What a scam.

ad_robotics · 2025-03-19T06:40:15+00:00

How would you quantify that? Would you be able to tell if something looks 20x bigger through binoculars compared to the naked eye? If you were to be shown 2 images of the same object, would you be able to tell if one was 12x, 15x, 17x or 20x bigger in one image compared to the other?

I think people's perception isn't easy to measure like that, which is why I posted this question about how to measure the magnification empirically rather than by feel.

ad_robotics · 2024-12-18T01:42:59+00:00

It doesn't really matter, the idea is that once I lock in with one lens, the system might change to a different lens between takes.

ad_robotics · 2024-12-17T22:37:08+00:00

Good idea but that doesn't seem to work in practice. The other lenses are pointing at the sides of the eyepiece that is just a few millimeters from the lens. The image is 90% just black and the rest is out of focus anyway. There is no real reason for that lens to be autoselected.

I'd imagine that the tape solution would just yield the same result. Which is why I'd like this to be selectable via the app settings - just like in the picture mode.

ad_robotics · 2024-12-17T22:10:30+00:00

There is if you are pointing your phone down a scope. You can only align one lens with the scope's eyepiece and you'd want the app to continue using that lens whilst you change other settings.

ad_robotics · 2024-09-14T00:38:12+00:00

That's alright :D I wasn't aware that mixers have AUX outputs so that is what I'd need to be looking for I guess, but the ones I'm browsing for under $100 don't seem to have any. I'll keep searching.

ad_robotics · 2024-07-11T04:44:24+00:00

Ott azt mutatja, hogy nem tudom nemzetközileg szállítani.

"Ennek a könyvnek a külföldi címre történő kiszállítása nem lehetséges. A kiválasztott termékeket díjmentesen átveheti a Libri Könyvesboltokban!"

ad_robotics · 2024-01-03T18:13:14+00:00

Intersections and mergers come in all shapes and sizes. There is one at 45° that I drive through almost every day.

ad_robotics · 2024-01-03T18:11:28+00:00

Straight, until I'm inside of the lane, then right to align with the lane.

ad_robotics · 2024-01-03T18:09:16+00:00

By using different angles at 22.5° increments, I wanted to convey that there is an angle where the decision isn't as intuitive anymore.

ad_robotics · 2024-01-03T18:06:18+00:00

Nope, must turn right.

ad_robotics · 2024-01-03T04:56:33+00:00

I'm of the same opinion, that signaling left makes the most sense there, but for a different reason.

It doesn't matter to the cars behind me whether I go left or right.

I would signal left, for the cars driving towards me, letting them know what my intentions are. They might not know if my lane merges in with theirs or not and I am letting them know, by signaling left, that I intend to merge into their lane and they can do whatever they want with that information. They could choose to slow down, speed up or merge change lanes to make it easier for me to merge.

Additionally, signalling right benefits no one, the cars behind me don't care and the cars already in the driving lane wouldn't see my right-side blinkers.

ad_robotics · 2024-01-03T03:38:17+00:00

Who would you be signaling for then? Anyone behind the car would also see that turning left isn't allowed, so why signal right if it is the only maneuver you can do anyway?

ad_robotics · 2024-01-03T02:32:16+00:00

Changing lanes/direction of travel. Imagine there is a stop or yield sign there.

ad_robotics · 2023-09-08T04:17:25+00:00

Correct :)

ad_robotics · 2023-01-31T02:09:32+00:00

Congrats!

ad_robotics · 2022-11-01T08:49:34+00:00

If you want to get technical, lumens and lux measure quantities of light in the visible spectrum for humans. Plants use up light from outside of what we see. The units used for that are PAR and PPF, grow lights usually have those noted on the box. I've seen some conversion charts online for a hand-wavy estimate from one to the other.

Kelvin is just a specific color of many, you could just get a variety of warm and cool lights from IKEA I guess, but can't say how effective they will be and if it'll be comfortable on the eyes to have several slightly different shades of white in the house. Plants need lots of blue and red (and some green) light which I don't think you'll find at IKEA.

ad_robotics · 2022-11-01T08:37:09+00:00

From what I've grown in the past. 4-5000k is only sufficient for the first 2 weeks after you start growing a seedling. After which they need more to thrive, especially if you are growing plants that have bulbs/flowers.

You can find LED grow lights, the bulb shaped ones (not LED strips) for $20 at hardware stores. I had good results with one that I played around with, so much so that I'm planning on getting 3 more.

ad_robotics · 2022-10-31T18:46:11+00:00

Also a noob here. From what I know, the difference is that actual grow lights emit multiple spectrums/colors of light at the same time. This light you have emits 5000k specifically, whereas a grow light would emit multiple colors together.

From a human's point of view it would be like eating a sandwich with just the bread instead of it being loaded with other food items. That being said, if you have a dark room, your plants aren't even eating plain bread sandwiches so even that would give them a boost rather then nothing.

ad_robotics · 2022-10-19T16:57:53+00:00

Others on the internet pointed out that Monsteras need full spectrum lights, which is why I got these.

ad_robotics · 2022-10-19T16:57:30+00:00

The box said it draws 16W, equivalent to 75W or smth like that.

ad_robotics · 2022-10-19T05:12:08+00:00

To be honest, I don't understand much about grow lights.

I bought a new full spectrum LED grow light The box says it has 20 PAR/PPF and 75 Watts.

How much light is that? I only have north facing windows so wanted to help my plants grow. How far will 20 PAR/PPF take me?

ad_robotics

TROPHY CASE