Posts Tagged‘charge’

Struggling Against Static Electricity.

Everyone knows the standard static electricity experiment. You grab yourself a perspex rod and a wool cloth and, after some vigorous rubbing (often with a few innuendos thrown in), suddenly your perspex has the ability to attract pieces of paper. Most people will also understand the mechanism of action, the transference of charge that leaves the rod negatively charged and the cloth positively charged. What most people won’t know however is that friction isn’t required to generate a static charge. This is what can lead to hilarious situations like the one in the video below:

So if friction isn’t a requirement for generating a static charge how do these address labels get it? The answer is actually pretty interesting and has to do with the way adhesives work. For these address labels the adhesion comes from a chemical reaction, meaning that the address labels had a form of bond with the backing before they were torn apart. When this bond is broken both materials will gain or lose electrons, depending on where the material sits on the triboelectric series. I’d hazard a guess that the material that the address labels is made up of tends more towards the negative end of the spectrum, meaning that bin holds a strong negative charge.

This is what is responsible for the labels floating around in a seemingly random fashion before ejecting themselves out onto the floor. The effect wouldn’t have been immediate, each label would only carry a small negative charge, however past a certain point the negative field would have become big enough to repulse the small weight of each of the labels. If they were so inclined they could throw a positively charged piece of plastic in there and they’d all be attracted which would also be pretty interesting.

Or, if you wanted some real fun, if they rubbed their head with a balloon and then dunked themselves in there all the labels would gleefully stick to them. Not that that proves much, just that it’d be hilarious to see someone with shipping label backing stuck to them.

The Nikola Phone Case is Bunk.

I understand that a basic understanding of circuit fundamentals isn’t in the core curriculum for everyone but the lack of knowledge around some electrical phenomena really astounds me. Whilst most people understand the idea of radio waves, at least to the point of knowing that they power our wireless transmissions and that they can be blocked by stuff, many seem to overestimate the amount of power that these things carry. This misunderstanding is what has led several questionable Kickstarter campaigns to gain large amounts of funding, all on the back of faulty thinking that simply doesn’t line up with reality. The latest incarnation of this comes to us in the form of the Nikola Phone Case which purports to do things that are, simply, vastly overblown.

nikola phone caseThe Nikola Phone Case states that it’s able to harvest the energy that your phone “wastes” when it’s transmitting data using it’s wireless capabilities. They state that your phone uses a lot of power to transmit these signals and that only a fraction of these signals end up making their way to their destination. Their case taps into this wasted wireless signal and then captures it, stores it and then feeds it back into your phone to charge its battery. Whilst they’ve yet to provide any solid figures, those are forthcoming in the next couple weeks according to the comments section, they have a lovely little animated graph that shows one phone at 70% after 8 hours (with case) compared to the other at 30% (without case). Sounds pretty awesome right? Well like most things which harvest energy from the air it’s likely not going to be as effective as its creators are making out to be.

For starters the the idea hinges on tapping into the “wasted” energy  which implies that it doesn’t mess with the useful signal at all. Problem is there’s really no way to tell which is useful signal and which isn’t so, most likely, the case simply gets in the way of all signals. This would then lead to a reduction in signal strength across all radios which usually means that the handset would then attempt to boost the signal in order to improve reception, using more power in the process. The overall net effect of this would likely be either the same amount of battery life or worse, not the claimed significant increase.

There’s also the issue of battery drain for most smartphones devices not being primarily driven by the device’s radio. Today’s smartphones carry processors in them that are as powerful as some desktops were 10 years ago and thus draw an immense amount of power. Couple that with the large screens and the backlights that power them and you’ll often find that these things total up to much more battery usage than all of the radios do. Indeed if you’re on an Android device you can check this for yourself and you’ll likely find that the various apps running in the background are responsible for most of the battery usage, not your radio.

There’s nothing wrong with the Nikola Phone Case at a fundamental technological level, it will be able harvest RF energy and pump it back into your phone no problem, however the claims of massive increases in battery life will likely not pan out to be true. Like many similar devices that have come before it they’ve likely got far too excited about an effect that won’t be anywhere near as significant outside the lab. I’ll be more than happy to eat my words if they can give us an actual, factual demonstration of the technology under real world circumstances but until then I’ll sit on this side of the fence, waiting for evidence to change my mind.

The Universe’s Strange Preference for Matter.

In the beginning, the one where time itself began, the theory goes that matter and antimatter were created in equal amounts. When matter and antimatter meet they annihilate each other in a perfect transformation of matter into energy which should have meant that our universe consisted of nothing else. However, for some strange reason, the universe has a small preference for matter over antimatter, to the tune of 1 parts in 10 billion. This is why our universe is the way it is, filled with billions of galaxies and planets, with the only remnant of the cataclysmic creation being the cosmic microwave background that permeates our universe with bizarre consistency. The question of why our universe has a slight preference for matter has puzzled scientists for the better part of a century although we’re honing in on an answer.

ALPHA Antimatter TrapIf you had the ability to see microwaves then the night sky would have a faint glow about it, one that was the same no matter which direction you looked in. This uniform background radiation is a relic of the early universe where matter and antimatter were continuously annihilating each other, leaving behind innumerable photons that now permeate every corner of the known universe. What’s rather perplexing is that we haven’t observed any primordial antimatter left over from the big bang, only the matter that makes up the observable universe. This lack of antimatter means that, for some reason or another, our universe has an asymmetry in it that has a preference for matter. Where this asymmetry lies though is still unknown but we’re slowly eliminating its hiding spots.

The Antihydrogen Laser Physics Apparatus (ALPHA) team at CERN has been conducting experiments with antimatter for some time now. They have been successfully capturing antiprotons for several years and have recently moved up to capturing antihydrogen atoms. Their approach to doing this is quite novel as traditional means of capturing antimatter usually revolve around strong magnetic fields which limit what kinds of analysis you can do on them. ALPHA’s detector can transfer the antihydrogen away from their initial capture region to another one which has a uniform electric field, allowing them to perform measurements on them. Antihydrogen is electrically neutral, much like its twin hydrogen, so the field shouldn’t deflect them. The results have shown that antihydrogen particles have a charge that’s equivalent to 0, showing that it shares the same properties as its regular matter brethren.

This might not sound like a much of a revelation however it was a potential spot for the universe’s asymmetry to pop up in. Had the charge of the antihydrogen atom been significantly different from that of hydrogen it would’ve been a clue as to the source of the universe’s preference for matter. We’ve found that not to be the case so it means that the asymmetry exists somewhere else. While this doesn’t exactly tell us where it might be it does rule out one possibility which is about as good as it gets in modern science. There’s still many more experiments to be done by the ALPHA team and I have no doubt they’ll be significant contributors to modelling just similar matter and antimatter are.