Karthikeyan KC
Admin@karthikeyankc · Joined November 9, 2013
Aeronautical engineer, product builder, developer, science fiction author, and an explorer. I'm the creator and editor of Geekswipe. I love writing about physics, aerospace, astronomy, and technology.
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They’ll likely nuke this option in the future. Added a Gotcha to your answer.
Hi Sydney. This is a great experiment to try out to learn thermoelectric effects. By the way, the actual effect you wanted to quote is Seebeck effect (making a voltage from a temperature difference). Peltier effect is the opposite of that (current through the junction heats or cools it).
Said that, Seebeck effect is what powers the fan on your wood burner.
For your experiment, with plain aluminium and steel, you’d hardly get any voltage. Almost no power, however big you make the sheets.
Let me explain why it’s hard. The measure of the magnitude of the induced thermoelectric voltage in response to a temperature difference across material is called the Seebeck coefficient (S).
The voltage comes from how differently the two metals respond to heat. Measured against platinum, aluminium sits at about +3.5 µV/K and iron at about +19 µV/K. I’m using iron as a stand-in for steel, which shifts a little with the alloy. This gives you 15.5 µV for every degree. So across your 100°C difference that’s about 1.5 mV. In comparison, an AA battery is 1.5 V.
Size doesn’t change that number, because the voltage depends only on the temperature difference. A bigger sheet has lower resistance (because it’s basically resistors in parallel), so it can push more current. But only by letting more heat flow through it. As we know, metals are great conductors of heat, that most of it walks straight across without doing any electrical work. That’s why stove fans use a module of semiconductor pellets wired in series instead.
Ha ha, a beagle on a mission! And yes it’s absolutely a force question. I really can’t answer this fully without knowing how the latch is. But I can infer the problem thou. It seems your latch sits right at the door handle.
Which means, the ‘boop’ of her nose is a good enough force for the door. Think of the door as a big lever. The hinges are the pivot and the spot where her nose pushes is the distance from the pivot. So the entire thing acts as a lever mechanism at the door handle. The farther the handle is, the easier it will be to open the door.
Your problem is that the latch sits right next to the handle, right at the door’s edge. Slide it up the door and it’ll still be at the same distance from the hinge line, so it takes about the same pull. The beagle just have to jump higher. Move it up only if that gets it out of her reach. Also I am not sure about the adhesive and the latch itself. You can also try placing the latch in a way that it is not being peeled (like a tape being peeled from the side). If you remount it in a way where the beagle’s push slides along the surface instead of peeling it, it might withstand the load from the boop.
Or if you’re allowed to drill the door, honestly I’d skip the tape and use a latch that screws in. Pups and babies are persistent little engineers in their own way and nothing can stand their determination to open something.
Hi. A sweet smell turning up after hours opening the window? My best guess is that it’s the petrichor, despite the weather being dry, if you had watered your plants, it could cause the smell. My other guess is it could be the lingering parts of the burnt cooking smoke.
Most of the smoke would have left through the open window, but a few might have stuck to the stuff in your room. When they seep out it might give a different ‘sweet’ smell. Like the carpet, sofa, curtains, and a simple draft could bring them back in. The scientific term for this is called sorption. Basically, it’s like a sponge soaking up with a liquid, except it’s the smoke and the objects in the room in your case. Think of these things (carpets, foam sofa, bed etc) as a sponge absorbing the smoke. You can empty the air of a room in an hour or so, but you can’t wring out a sponge that fast.
So why sweet? Burnt food isn’t only bitter. If it had sugars in the food, when they overheat, they caramelise. And that could give out the smell of burnt sugar. I’d bet that’s your mystery smell.
And I do hope you do have smoke detectors, especially carbon monoxide, as they’re odourless and harmful. Stay safe and curious.
Great question, Kai. There are loads actually! Magnets are the closest thing to real-life magic you can have.
Here are my three favourite projects that’ll help you understand more about it hands-on.
- Build a motor – A battery, a nail, a copper wire, and a magnet. That’s it. Stick a small neodymium disc magnet to the flat head of an iron nail, and hang the nail’s point from the negative end of the battery (could be an AA). The magnet holds it there against the battery’s steel end. Now touch a copper wire from the battery’s positive end to the side of the magnet. The nail starts spinning! Current runs down through the nail and out through the magnet, right through the magnet’s own field, and current crossing a magnetic field gets a sideways push called the Lorentz force. It’s the same push that turns every electric motor, just without the gearbox. It all heats up fast (the battery, wire, and magnet all get warm), so keep each spin short. Then flip the magnet over, and guess which way it’ll spin before you look. Here’s a more detailed explanation on how to build the motor.
- Drop a magnet thru a non-magnetic cylinder – Take a long copper or aluminium pipe and drop a strong cylindrical magnet down it. It drifts down like it’s falling through honey. So what’s happening here? Neither copper nor aluminium is magnetic, so what’s slowing it? As the magnet falls, its field sweeps through the metal, and that changing field sets up swirling currents in the pipe called eddy currents. Those currents make their own magnetic field. And that pushes back against the fall. The pipe, in a sense, hates change, and the faster the magnet moves, the harder it pushes back.
- Watch an invisible field – Guess you might’ve already tried this, but this was my first ever magnet experiment as a kid. Pour some iron filings into a paper tray or a sealed plastic bag, slide the magnet underneath, and the filings line up along the field lines, like thousands of tiny compass needles. Then you can also try two magnets with their ends facing, first attracting and then repelling, and watch the pattern snap into a completely different shape. Keep the magnet under the container so the filings never touch it. Trust me, you don’t want to spend an evening picking filings off a neodymium magnet.
Have fun with it, and if you build the spinning nail, post a video of it here! Stay curious.
Hey, sorry, it took this long to answer. I’ve missed this thread totally!
The most likely answer for both of you is an electrical arc (current jumping across a small gap through the air). It builds up when two materials touch and electrons move from one to the other. But if there was a thunderstorm around, my bet is that the lightning energy got into the building through its wiring (or its pipes or metal conduits) inside its walls. Static and ball lightning are both possible too but rare.
Lightning doesn’t have to hit your building to get inside. It can come thru wires or pipes that run outside, or the ground. Once inside, it travels along the electrical, phone, plumbing, and TV systems, and along metal wires or bars in concrete walls and floors. So a spark next to a computer during a storm fits this well. And “no wiring near that location” only covers the wiring you can see. Cables and metal run inside walls and roofs too (I hope you both had it checked with an electrician. Again, sorry for the delayed response!).
During a storm, the US National Weather Service (NWS) says to stay off corded phones and away from computers, cords, and plumbing. A typical surge protector won’t protect your gear from a lightning strike, and you shouldn’t unplug things mid-storm either, as you could be struck while doing it.
But whatever it was, I hope you got an electrician to look at that spot.
Likely cause is that the water droplets are still in your headphone jack. Water in 3.5mm jack’s usually completes the circuit of the jack and makes the phone think something is connected. Dry it out! Take a cotton or a q-tip and suck out the moisture. If you have silica gel lying around, you can use it too.
Also, once you have dried the phone, you can try a soft-reset if you haven’t tried it already (press and hold volume down and the power button simultaneously).
Welcome to Geekswipe btw, @TeddyS.
We’ve added a detailed answer here.
Hey @bbtesla, welcome to Geekswipe Curiosity.
The warmth from the Sun isn’t due to magnetic field, it’s just infrared radiation. When the Sun shines, it’s beaming out of photons in all wavelengths, including infrared ones that carry heat.
These photons travel millions of kilometers through space, then the Earth’s atmosphere. Here is where clouds matter. A cloud is dense with water droplets and ice crystals that scatter and absorb much of that infrared radiation before it reaches your skin. So when the cloud obscures the sun, it’s not just hidden from view. The actual thermal energy isn’t making it to you anymore. No photons, no warmth.
Again, your magnetic field has nothing to do with it. The sensation of heat is simply your skin absorbing infrared photons and converting that energy into molecular motion, which is warmth. When clouds intercept that stream, the heat vanishes like a paused beam in a solar oven.
Hope this helps.
The whole purpose of early radio was to move audible information across space wirelessly. But if you remove sound entirely, what remains is a more fundamental truth that radio waves are just electromagnetic radiation. They are not sound. They are not inherently tied to our ears. They are physics. They are vibrations.
There’s no reason why a deaf person wouldn’t invent a radio. It’s basically understanding electromagnetism in the context of information transfer. Remote and wireless information transfer to be precise. Given that deaf persons are not exposed to sound since their birth here, they’d still perceive electromagnetism in the world. Hearing and sound are not required to understand it.
All concepts of transmission, fields, resonance, can be visually learned and experimented and definitely a deaf person is capable of inventing a radio without the analog exposure to the sense of sound.
That is an interesting observation, Colin. There could be a few reasons. I just read about upwelling, thanks to you. So it could be the primary reason, as you mentioned you were on the beach. Upwelling is basically the wind movements (parallel to the shoreline) displacing the warm water on the surface of the ocean, where the cold water wells up to replace it. Combine the effects of this with currents or local seabed heating, you might have felt warmer down than at the top. Do share the location where you experienced this and probably we could figure out more. I hope this answers your question to a degree.
Hi Christopher,
To expand on what’s nuclear fission is, it’s the reaction where you split an atom into two or more atoms by bombarding a neutron into it. However, only heavier elements (that have 92 or more protons) can undergo nuclear fission as they are unstable and easy enough to ‘break’ them.
The ones you listed are lighter elements (with less than 92 protons) and are very stable, hence they wouldn’t undergo fission. And if you split them, it would only absorb energy rather than release it.
Maybe you can fuse hydrogen to create a fusion reaction, but you’d need the temperature and pressure conditions to be like the one at the core of the Sun to do that.
Still, for the sake of curiosity, you can get the total energy from the mass of the human body. Considering an average of 60 kg, using e = mc2, the energy from the elements that make up an average human body is 5.3 x 1018 J. Compared to this, the energy from the Tsar Bomba detonation is 2.1 x 1017 J.
Hi Chris,
First and foremost, please take care of your health. Please consult your doctor for any ailments you’re experiencing.
As for your question, you haven’t mentioned the probable source and type of radiation. Assuming it’s non-ionising radio waves, 100 µW/m2 is way lower than the ICNIRP recommended exposure levels for radio waves, which is 2,000,000 µW/m2 (for 30 – 400 MHz). And given it’s a very short 2-second pulse every 10 mins, it couldn’t harm you.
The source could be any of your electronic devices—a WiFi router, Bluetooth devices, security camera, or a mobile tower nearby. If you are being exposed to low-intensity non-ionising radiation from these devices, it is very unlikely to cause any issues to your health.
But if you believe you are being exposed to unsafe radiation levels or high-power microwaves (which could actually cause tissue heating under long exposures), check with an engineer, a local authority, or someone from the occupational health department and confirm if any high-power sources are nearby.
Hope this helps. :)
What time do organisms that get buried underground is a long series of several biochemical chemical reactions. Once organisms get buried, it’s a game of temperature, pressure, and bacteria that goes on for millions of years.
Let’s look at the typical timeline of an organism that gets buried.
First, the oxygen gets cut off once the buried organism is at a certain depth. This oxygen-free environment kicks off the anaerobic bacterial decomposition of the organic matter. Decomposition basically breaks down complex molecules of organic matter into simpler molecules. It becomes an insoluble matter called Kerogen if given a few thousand years.
These simpler molecules could be hydrogen and carbon, forming the hydrocarbon compound. The heat and pressure determine the type of hydrocarbon formed based on how the organic matter sinks through the layers. With the right temperature, pressure, and depth, a mix of solid, gaseous, and mostly liquid hydrocarbons would be formed over time (millions of years). This mixture is what you’d call petroleum (or crude oil). Technically this process is called Catagenesis.
So, the ‘time’ component acts as a very slow cooker that builds up pressure and heat. There’s a lot of factors involved, mind you. So ‘time’ plays the dominant role here, patiently facilitating all the right conditions like sinking, decomposition, heat, and pressure to form Kerogen, eventually Catagenesis, and trapping the oil in a reservoir. Time is the crucial ingredient here.
You’re right. Fundamentally for nuclear fusion to occur on Earth, you need very high temperatures and pressure so that the hydrogen isotopes (basically two protons) overcome their mutual repulsion to fuse together.
At the core of the Sun, the pressure is extreme (26.5 x 10^15 pascal) due to the gravitational force of the hydrogen and helium. And this pressure contributes more to creating a viable condition for the fusion.
On Earth, however, you cannot create such high pressure. The highest pressure we could possibly achieve in our fusion reactors is around 2.5 x 105.
The denser and hotter the plasma is the more chances of fusion to occur. Hence, on earth, we make the plasma hotter than the core of the sun and try to achieve high densities (which means we are trying to achieve higher pressures too).
I hope this helps, Shamil. Thanks for visiting Geekswipe. :)
It depends. It should burn as long as the oxidizer and fuel are in contact and enough heat is provided to ignite it. The primary challenge might be the heat you’ll need for ignition. For effects of temperature and pressure, you’ll need to consider the phase changes of the oxidizer and fuel compounds used, how it affects their thermal properties as well. For depths like Mariana Trench (108 Mpa and 1 °C), I think an underwater flare would probably work if you provide enough heat to ignite it in the first place.
The likely explanation is that you might have seen a meteor. The green glow could be attributed to the chemical composition of the meteor itself.
Thanks! :) Excited and hyped!
Hi Ben,
It’s not. Your existence is the result of energy transfer and not energy creation. Biologically you evolved from a zygote — a cell, which is an open thermodynamic system with its own state variables like volume, pressure, temperature, etc. That zygote did not come into existence by magic. It’s from the fertilization of the sperm cell and the egg cell. Energy is just transferred from the surrounding to the system and vice versa, changing the state variables. It is conserved during the process.
As the mother consumes food, they breakdown and gets converted into energy (metabolism) which helps in cell division that forms the embryo, which develops into a fetus, and then into the baby you.
Hope it’s clear now.
Hi! Welcome to Geekswipe. For your question, of course, the answer is yes. Aluminium has a high thermal conductivity than steel. So the aluminium radiator certainly helps. And with the added benefit of another radiator with a much larger surface area, you can expect a faster convective heat transfer. Larger the surface area and higher the conductivity of the heat exchanger, the faster the heat transfer is.
If you wouldn’t mind, can you post the picture of your setup? Just curious!
I am glad I could help.
It may be, however, that the earth’s wobbles month by month and year by year are too slight to be measured.@m1-6eek-5w1pe, you are right. The perturbations are too small if measured within a certain period of time. So for the long run, it is an iterative process where we will revise the celestial coordinate systems including all the perturbations at certain reference points in time. You might know these points as epochs.
I rather assumed that these changes are measured and recorded.Yes, they are. And you can compute them for future dates as well. You can find them in an astronomical ephemeris. You can find one at NASA’s Solar System Dynamics website. But this one shows the data you need with J2000.0 as the reference epoch. For your case, you will need a similar calculator but one that uses up-to-date equinox data. Perhaps NASA’s SPICE is what you are looking for. Found a geometry calculator based on the SPICE data as well.
Hello Geoffrey. Yes, all the planets in the solar system revolve around the sun close to a disk-like plane with a little inclination and eccentricity. For Earth, the orbital inclination is about 7 degrees related to the Sun’s equator. The eccentricity of the orbit is 0.0167. And you’re right, the orbit does change over time and this can be recorded.
And as we observe and record everything from the Earth, we keep our Earth’s plane as the reference plane and call it the ecliptic. We observe other celestial objects relative to this ecliptic. So, for the orbital motion of the Earth relative to Sun, we can simply track the Sun’s position throughout the year. The coordinate system is called the ecliptic coordinate system. It can either be geocentric like the above case or heliocentric.
And as mentioned, there will be significant changes in the orbit over a longer time—but like in thousands of years. As it involves other planets in the solar system, it’s an n-body problem. The orbital change will be due to perturbation effects. From planets like Venus and Jupiter heavily affecting the eccentricity of the Earth. The precession of the Earth. The axial tilt. And other complex orbital perturbations along with any unexpected celestial activity that affects the solar system. We call the cyclical effect on Earth as the Milankovitch cycles. Hope this is what you are looking for.
Hi! This is very interesting. Maybe it’s not photoelectric effect at all. Could it be because of the thermal effects? Try playing with the intensity of the laser perhaps. Also, how are you generating the frequency? And maybe the other factor could the phone itself. The laser could be aimed at the hole where you assume the mic is, but on some smartphones, the mic is placed at an angle to avoid accidental damage—like when someone uses the mic hole to eject the SIM tray instead.
Image credit – Dominik Schnabelrauch under CC BY-NC-SA.
And…there’s no such thing as a “sound wave”? It’s **just** air, just the atmosphere we know, but vibrating?
Spot on! Yep. Sound is just the air molecules vibrating at different frequencies. It’s a pressure wave. No, nothing new is released into the air, because it’s the air that is vibrating in the first place. If there’s no air, there won’t be any medium for this vibration (sound) to happen. This is why you can’t hear sound in space.
Also, in the case of light, it is the oscillations of electric and magnetic fields — one of the fundamental properties of the universe and it does not need a medium to propagate. Whereas, the sound is a compression wave, oscillation of air particles. It is just a property of the medium (air). In other words, for sound waves to exist, you need a medium like air or water. Electromagnetic waves exist because the universe fundamentally has it.
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