How do you collect a lot of data about the ionosphere? Well, you could use sounding rockets or specialized gear. Or maybe you can just conscript a huge number of cell phones. That was the approach taken by Google researchers in a recent paper in Nature.
The idea is that GPS and similar navigation satellites measure transit time of the satellite signal, but the ionosphere alters the propagation of those signals. In fact, this effect is one of the major sources of error in GPS navigation. Most receivers have an 8-parameter model of the ionosphere that reduces that error by about 50%.
However, by measuring the difference in time between signals of different frequencies, the phone can estimate the total electron current (TEC) of the ionosphere between the receiver and the satellite. This requires a dual-frequency receiver, of course.
According to the Sapir–Whorf hypothesis, our language influences how we think and experience the world. That’s easy to imagine. Certainly our symbolism of mathematics influences how we calculate. Can you imagine doing moderately complex math with Roman numerals or without zero or negative numbers? But recently I was reminded that technological media also influences our perception of reality, and I have a Hackaday post to thank for it.
The post in question was about color TV. When I was a kid, most people had black and white TVs, although there were color sets. Even if you had a color set, many shows and movies were in black and white. Back then, many people still shot black and white film in their cameras, too, for many reasons. To make matters worse, I grew up in a small town, reading books from the local library that were ten or twenty years behind the times.
At some point, I read a statistic that said that most people dream in black and white. You may find this surprising, as I’ll bet you dream in color. It turns out, how people dream may have changed over the years and still and motion photography may be the reason.
The Post
In the post, I posed a question I’ve thought about many times: Did people dream in black and white before the advent of photography? It was kind of an off-hand remark to open the post, but many people reacted to it in the comments. They seemed surprised that I would ask that because, of course, everyone dreams in color.
I asked a few people I knew who also seemed very surprised that I would assume anyone ever dreams in color. But I was sure I had been told that sometime in the past. Time to hit the Internet and find out if that was incorrect or a false memory or something else. Turns out, it was indeed something else.
A scientific paper from 2008 held the answer. It turns out that science started asking questions like this in the early 1900s. Up through the 1940s, people overwhelmingly reported dreaming in black and white, at least most of the time. Color dreams were in the minority, although not unheard of.
Then something changed. Studies that occurred in the 1960s and later, show exactly the opposite. People almost always dream in color and rarely in black and white. Of course, that correlates well with the rise of color photos, movies, and television. What’s more is, while there is no scientific evidence gathering about earlier times, there is a suspicious lack of, for example, a Shakespeare quote about “The gray world of slumber…” or anything else that would hint that the writer was dreaming in black and white.
Interpretation
Judging from the paper, it seems clear that most people agree that color media played a role in this surprising finding. What they can’t agree on is why. It does seem unlikely that your dreams really change based on your media consumption. But it is possible that your recollection changes. This is particularly true since the way researchers acquired data changed over that time period, too. But even if the data doesn’t show that you dreamed in black and white, it did show that you remembered dreaming in black and white.
For that matter, it isn’t clear that anyone understands how you experience dreams visually, anyway. It isn’t like the back of your eyelids are little movie screens. You don’t actually see anything in a dream, you only remember seeing it.
The Question
If something as simple as black-and-white movies and TV can change how we perceive dreams, you have to wonder how much tech is changing our reality experience in other ways. Do we live differently because we have cell phones? Or the Internet? Will virtual reality alter our dream lives? It would be interesting to fast-forward a century and see what historians say about our time and how strangely we perceive reality today.
Normally, you think of things casting a shadow as being opaque. However, new research shows that under certain conditions, a laser beam can cast a shadow. This may sound like nothing more than a novelty, but it may have applications in using one laser beam to control another. If you want more details, you can read the actual paper online.
Typically, light passes through light without having an effect. But using a ruby crystal and specific laser wavelengths. In particular, a green laser has a non-linear response in the crystal that causes a shadow in a blue laser passing through the same crystal.
Nowadays, if you want to delay an audio signal for, say, an echo or a reverb, you’d probably just do it digitally. But it wasn’t long ago that wasn’t a realistic option. Some devices used mechanical means, but there were also ICs like the TCA350 “bucket brigade” device that [10maurycy10] shows us in a recent post.
In this case, bucket brigade is a euphemism calling to mind how firemen would pass buckets down the line to put out a fire. It’s a bit of an analog analogy. The “bucket” is a MOSFET and capacitor. The “water” is electrical charge stored in the cap. All those charges are tiny snippets of an analog signal.
When we first looked at [Anders Nielsen’s] EEPROM programmer project, it was nice but needed some software and manual intervention and had some limitations on the parts you could program. But through the magic of Open-Source collaboration, revision 2 of the project overcomes all of these limitations and—as you can see in the video below—looks very polished.
If you recall, the programmer is in a “shield” format that can plug into an Arduino or — if you prefer a retrocomputer — a 6502uno. Along with hardware improvements from the community, [Henrik Olsson] wrote Python software to handle the programming (see the second video below).
Imagine this. A young person comes to you wanting to get started in the electronic hobby. They ask what five things should they buy to get started. Make your list. We’ll wait. We bet we can guess at least two of your items: a multimeter, and a soldering iron. [LearnElectroncsRepair] recently showed us a review of the Zotek Zoyi ZT-N2 which is a soldering iron and a multimeter in one unit. You can watch the video review below.
Honestly, when we heard about this, we didn’t think much of the combination. It doesn’t seem like having your probe get red hot is a feature. However, the probe tip replaces the soldering iron tip, so you are either soldering or measuring, but not both at the same time.
We’ll be honest. Measuring Forth words per second doesn’t seem like a great benchmark since a Forth word could be very simple or quite complex. But we think the real meaning is “up to 400 million words per second.” There was a time when that level of performance would take a huge computer. These days, a simple board that costs a few bucks can do the trick, according to [Peter Forth] in an online presentation.
The key is the use of the Milk V Duo and some similar boards. Some of these look similar to a Raspberry Pi Pico. However, this chip on board has two RISC V cores, an ARM core, and an 8051. There’s also an accelerator coprocessor for vector operations like AI or video applications.
