World Science Scholars

41.3 Implications for Mass: Intuitive Explanation

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    • Imagine a factory has created two identical blocks of wood. One of the blocks is stationary next to you, while the other has been set in motion and is speeding by you. What would you say about the density of the moving block compared to the stationary block?

      Hint: The density of an object is its mass divided by its volume.

    • Density of the block will increase as d = m/v
      so as mass increases with increasing velocity and length is lorentz contracted
      thus both factor will lead to increase in density

    • Because length at rest is divided by gamma, the density at rest will be multiplied by gamma squared.

    • Seems like the density will go up because of Lorentz contraction and mass increasement.

    • As mass increases we know density increases

    • The density of the block would increase by a factor of (gamma)^2 due to Lorentz contraction by a factor gamma and increase in mass by a factor of gamma

    • I agree the density should increase. Interesting how quickly that would happen, as the mass is increasing and the volume would be decreasing because the length would contract as well.

    • The block is Lorenz contracted (in the direction of the speed, 2 other measurements stay the same), so the volume decreases by a factor of gamma. The mass is increased by a factor of gamma. Which means that the density, whici is mass divided by volume, increases by a factor of gamma^2.

    • If volume decreases for the same amount of mass, then we know density must increase. Here we have an increase of mass and a reduction of volume, both by a factor of gamma, therefore density for the moving block is greater than the block at rest from a stationary POV.

    • Relativistic mass grows with velocity.

      Approaching the Einstein speed of light, mass grows incredibly.

      SRT allows mass to transform.

      Mass divided by volume, the density of the block set in motion will be greater than the one at rest.

      Both blocks of one gallon or near 4 litres and the mass of 10 kg each allows us to see their 10 kg divided by 4litres= 2.5 kg/l for densities.

      Both blocks at 2.5 kg/l but one at rest, the other swinging around on a centrifuge.

      The faster the centrifuge, the heavier the 10 kg.

      10 kg at 100 kg near lightspeed becomes 100 kg divided by 4 litres. This is 25 kg/litre, a very larger number.

      This would add to NASA ethics of over-designing Voyageur 1 & 2 to withstand relativistic mass.

      Escape velocities from ESI (earth similar inventory) exoplanets do not seem yet to approach the speed of light for construction purposes, but then again, the B2 bombers have to reach a critical speed before going into the aEther, invisibility, and being able to hover infinitely.

      This is a huge structural problem for planetoids evolving but more so for star evolution.

      Black holes are fast and therefore must relativistically be dense. White holes? I dunno… Where is Prof. Carlo from France on this? 🤭

    • EMCee squared huh. Faster equals heavier, so I should stop to weigh in so I’ll weigh less? And take a run to gain weight? I know no-one can run at relativistic speed, the concept is nice though. don’t you think?

    • Based on special relativity, the density of the moving block of wood would appear to be higher compared to the stationary block of wood as observed by an observer at rest relative to the stationary block.
      According to special relativity, as an object approaches the speed of light, its mass appears to increase, and its length appears to contract in the direction of motion. This phenomenon is known as relativistic mass increase and length contraction or Lorentz contraction.
      When the block of wood is set in motion and sped by the stationary block, its mass will be greater compared to its rest mass. At the same time, it will undergo length contraction along its direction of motion. It means that the moving block of wood would appear shorter compared to the stationary block when observed by an observer at rest relative to the stationary block. It arises due to the relative velocity between the stationary and moving blocks. As a result, the moving block’s dimensions along the direction of motion would be reduced, leading to a decrease in its volume.
      As a result, the mass of the moving block of wood will increase, and its volume will decrease. Therefore, the ratio of mass to volume, which defines density, will be higher for the moving block than the stationary block, as observed by an observer at rest relative to the stationary block.

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