Karthikeyan KC

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Viewing 15 replies - 1 through 15 (of 116 total)
  •   Warm water below cold water at the beach?#10190

    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.

  •   Nuclear fission of stable elements in human body#10180

    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.

  •   Would a 100 µW/m2 electromagnetic wave reading dangerous to human health?#10172

    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 does time give? What is its factor? How do dead organisms become oil?#10163

    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.

  •   Why we need higher temperature on earth for fusion reactors?#10139

    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. :)

  •   At what depth will underwater flares still burn?#10121

    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.

  •   A green flash appeared, bright and fast, blindingly bright#10118

    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.


  •   1st law of thermodynamics and embryo#9997

    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.

  •   Does mating aluminum to steel speed up heat transfer through the steel?#9990

    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!

  •   Earth's Orbit Path & Variations#9947

    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.

  •   Earth's Orbit Path & Variations#9943

    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.

  •   Hearing light when shone on MEMS microphones?#9940

    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.

    Smartphone mic placed at an angle

    Image credit – Dominik Schnabelrauch under CC BY-NC-SA.

  •   Arclind Mindspace – A crash course platform for self-learners#10007
  •   Earth's Orbit Path & Variations#9950
  •   Why are sound waves from a moving object compressed?#9930

    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.

Viewing 15 replies - 1 through 15 (of 116 total)