cat-physics

  • Kryptaria:So much of this fic is poor Q trying to explain things in a way the agents understand.
  • Kryptaria:SO MUCH
  • zooeyscigar:ugh, i know. sorry abut that.
  • Kryptaria:No, no, no. It's perfect. That's how it should be.
  • Kryptaria:Because really, it's like trying to explain physics to cats.
  • Kryptaria:"You CANNOT jump straight up six feet in the air, then move sideways three feet!"
  • Kryptaria:Cat: *does it anyway*
  • zooeyscigar:OMG
  • zooeyscigar:best description ever

Furball is an astonishingly fat cat. She is so fat that many people, on seeing her for the first time, start impromptu comedy routines (“Is that a cat or a pumpkin? That cat’s so fat you could use it as a pillow! I’m not saying that cat’s fat, but, well, she is pretty fat, actually.” etc.) She’s a long-haired confection of orange, white and black, and is faintly reminiscent of a calico feline walrus. Her many skills include convincing everyone in the house, and some people who are just passing through, that she hasn’t been fed in weeks, and convincing gullible songbirds that a cat that heavy and spherical could never jump high enough to be any kind of danger.

Being incredibly fat means that she often sits up on a chair or a sofa, on her haunches, like a person, which can be slightly off-putting. It also means she can’t always clean herself properly. She’s developing dreadlocks.

So tonight I gritted my teeth, rolled up my sleeves, and washed her. In the sink.

When she stood bolt upright and started trying to sink her claws into the mirror above the sink to get away, I merely smiled and carried on washing her. I knew that cat-claws, while wonderful things, cannot get traction on the glass of a mirror. And that just-trimmed cat-claws can’t allow a cat the size and shape of a small walrus to climb sheer glass.

Nobody had explained these simple things to Furball, though, and she went straight up the side of the mirror.

Sooner or later, I’ll figure out how.

8

Journey into a Schwarzschild black hole.

The simplest kind of black hole is a Schwarzschild black hole, which has mass yet no electric charge or spin. This black hole geometry was discovered by Karl Schwarzschild in 1915, shortly after Einstein presented his final theory of General Relativity. The gifs above are created from a simulation depicting what you would theoretically see if you traveled towards a black hole, against a panorama of our Milky Way.

First of all, as you approach, you clearly see gravitational lensing taking place, with the black hole bending light around it. It appears to ‘repel’ the Milky Way radially, which then stretches the image transversely. The sections closer to the black hole experience greater ‘repulsion’, so the image appears to be compressed radially.

You then take note of the Einstein Ring seen around the black hole, occurring because of the bright objects lying directly behind it. Due to the aforementioned gravitational lensing, the light from these bright objects is bent around the black hole and forms this ring.

Fortunately (or maybe unfortunately), as you get closer, the trajectory of your journey does not have enough angular momentum to go into an unstable circular orbit. If you had slightly more, you would find yourself orbiting this black hole, which would, in fact, make for a fairly nice view. However, you carry on travelling towards the center.

Next, you swiftly pass through the photon sphere,where light rays can orbit the black hole in unstable circular orbits. However, you do not see anything of particular interest, but are more concerned with your forthcoming fall through the horizon. 

As you travel, you would not know at what point you fell through the black hole’s horizon. However, as you do pass through it unaware, it apparently splits in two, explained nicely by these Penrose diagrams (if you have the chance to give them a quick glance over whilst you’re hurtling towards your inevitable death). Here, space is falling faster than light, meaning you are carried inexorably inward.

Anyone who happens to be watching your spectacular journey would see you as fairly dim and red. This effect is due to red shift, with anything falling past the black hole’s horizon appearing this way to an observer outside of this point.

As you get closer and closer to the center, the black hole’s tidal forces begin to wear on you. Presuming you are travelling feet first, you feel a greater force of gravity in your lower half than up by your head. Due to these forces, you are stretched vertically and crushed horizontally; this is known as spaghettification. These forces also mean that your view of the Universe beyond is blue shifted and bright around your waist, but red shifted and dim above that; a strange sight.

Despite having been utterly torn apart from the tidal forces, a tenth of a second later you reach the black hole’s singularity, the center point of infinite curvature. Here, space and time as you know them come to an end, and so does your exciting journey.

It must be remembered that real black holes are probably much more complicated than Schwarzschild black holes; they likely spin and are not isolated, so a journey into a normal black hole could be slightly different adventure.

Credits: 

http://jila.colorado.edu/~ajsh/insidebh/schw.html

http://galaxy.phy.cmich.edu/~axel/mwpan2/krpano/

The Cat’s Paw Nebula in Infrared

Infrared view of the Cat’s Paw Nebula (NGC 6334) taken by ESO’s VISTA. NGC 6334 is a vast region of star formation about 5500 light-years from Earth in the constellation of Scorpius. The whole gas cloud is about 50 light-years across. NGC 6334 is one of the most active nurseries of young massive stars in our galaxy, some nearly ten times the mass of our Sun and most born in the last few million years.

Credit: ESO/VISTA

Physicists add ‘Quantum Cheshire Cats’ to list of quantum paradoxes

Given all the weird things that can occur in quantum mechanics—from entanglement to superposition to teleportation—not much seems surprising in the quantum world. Nevertheless, a new finding that an object’s physical properties can be disembodied from the object itself is not something we’re used to seeing on an everyday basis. In a new paper, physicists have theoretically shown that this phenomenon, which they call a quantum Cheshire Cat, is an inherent feature of quantum mechanics and could prove useful for performing precise quantum measurements by removing unwanted properties.

Read more: Phys.org
Via FQTQ

2

Today I want to talk to you about my new favourite scientist. His name is F.D.C. Willard.

F.D.C. Willard is a co-author on a single paper in the 1970s about low tempurature physics. F.D.C. Willard is also a Siamese cat. That image is his signature.

You see, a physicist named John H. Hetherington wrote a paper. He used “we” a lot when writing it. Based on the standards at the time a paper written by one person would never be accepted if it said “we” right the way through. J.H. Hetherington was far too lazy to re-type it though, so he just made up a fancy name for his cat Chester. Who was sired by a cat called Willard.

F.D.C. Willard

Felis. Domesticus. Chester. Willard.

(This is not F.D.C. Willard, just a nice example of Siamese Cat)

If this theory is correct, we may live in a web of alternate timelines

The Many Worlds Interpretation of quantum physics has been around for nearly 60 years. It’s a highly controversial idea which suggests that our world — and everything in it — is constantly splitting into alternative timelines. If it’s correct, here’s what your true existence might actually be like.

Over a hundred years ago, the discovery of quantum physics ruined the party. Our comfortable, clockwork conception of universe was thrown into disarray with the realization that, at the micro-scale, there’s some crazy funky stuff going on.

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Physics and cats, making fun with principles since 1935. Cute.

H/T: Kittens investigate Newton’s cradle (TRF)