Recent comments in /f/explainlikeimfive

WinBarr86 t1_j6dudcp wrote

 amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid. Amorphous materials include silica glass and a multitude of other materials of different origins, such as soft glasses (like concentrated emulsions, mousses and colloidal glasses)

https://www.sciencedaily.com/releases/2008/07/080704153507.htm#:~:text=and%20lubrication%20industries.-,advertisement,its%20shape%20like%20a%20solid.

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Chaotic_Lemming t1_j6dublu wrote

A wireless jammer cannot block a wired connection. So if everything was connected with cables the internet would work. Unless they cut that cable somewhere.

Jammers work by transmitting a strong noise signal on the frequency being jammed. The wider the frequency range the more power the jammer needs to overwhelm the signals. Jammers don't actually block the signal, they just overwhelm it. Kind of like if you are talking with a friend standing next to you. In a quiet room you can hear each other just fine. The jammer acts like a loud rock concert. You are still talking, but the other person can't hear you because the surrounding noise is too loud.

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SonicKiwi123 t1_j6du7av wrote

Imagine you are trying to have a private conversation with someone who is standing two feet away from you in a silent room. You can whisper to reach other and you will both have no problem hearing each other. Now imagine you are standing further away. Much further away. You may need to yell now just to hear each other, if you are far enough away. Now imagine again, that you are back to being two feet away from each other, but this time instead of being in a quiet room, you are in a room full of the sound of jackhammers revving chainsaws horrible static sounds and people screaming, alarms blaring, any and every loud noise you can imagine all at once. Good luck trying to hear each other even if you scream back and forth even if you're standing two feet away, let alone further. There is too much interference from the loud noises covering up the actual stuff you are trying to say/hear.

Well, what a jammer does at a basic level, is essentialially create those loud noises to cover up the actual signals sent by the two transceivers trying to communicate, so that they can not "hear" each other.

Something as simple as a leaky microwave oven (as in it does not contain the microwaves within it and they leak out) can cause interference and act as a jammer to 2.4GHz wifi, as a microwave oven uses microwaves that are the same frequency of 2.4GHz. a wired connection works much differently and would be unaffected.

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WinBarr86 t1_j6dtv7l wrote

Amorphous solids like glass.

https://www.sciencedaily.com/releases/2008/07/080704153507.htm#:~:text=and%20lubrication%20industries.-,advertisement,its%20shape%20like%20a%20solid.

amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid. Amorphous materials include silica glass and a multitude of other materials of different origins, such as soft glasses (like concentrated emulsions, mousses and colloidal glasses)

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WinBarr86 t1_j6dtdh3 wrote

Amorphous means it changes.

Definition.

An amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid.Jul 7, 2008

https://www.sciencedaily.com/releases/2008/07/080704153507.htm#:~:text=and%20lubrication%20industries.-,advertisement,its%20shape%20like%20a%20solid.

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sault18 t1_j6dscmt wrote

>but doesn't alter the thermal efficiency of the engine itself

Slight correction. Hybrids like the Prius use a slightly different engine cycle than pure ICE cars. Basically, the intake valve closes later in the Prius engine so the engine doesn't compress as much air as if it intake valve closed right after the intake stroke finishes. This means the expansion ratio is greater than the compression ratio, trading power for efficiency. The addition of 2 electric Motors helps make up for some of the loss in power. The electric Motors/ generators also allow the car to control the gas engine speed and not rely on the throttle so much to do so. This allows the car to run with the throttle more open and even wide open a lot more of the time. This reduces the pumping losses since the engine is not sucking air through a restricted throttle a lot of the time. To top things off, this also reduces pressure drop that would normally happen across the throttle in a conventional ICE car, increasing the air available in the cylinder.

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vanZuider t1_j6dqnb9 wrote

The ruins that we see today often didn't stand there as ruins for 2000 years. For example, the most iconic ruin of Athens, the Parthenon temple, continued to be used, first as a Christian church, then as a mosque, for centuries (making some small alterations to it like adding a minaret). No need to tear down a perfectly good building if you can still use it.

It only became a ruin after being damaged in a war, and for the next 150 years, the Ottomans couldn't be bothered to either rebuild it nor to tear it down. Both would be a lot of work, and they didn't need the space that bad, so they just used the rubble to build a smaller mosque inside the ruins and call it a day.

Then, Greece became an independent nation, and the ruins of Ancient Greece were of huge importance to their national identity, so they removed the mosque and everything else that had been added after antiquity, and made an effort to preserve what was left of the ancient temple. What we see today is the result of that effort.

Similar stories exist for nearly all ancient ruins in European cities - they continued to be used and were integrated into newer buildings for centuries, and then beginning in the 19th century people started to remove the newer buildings, uncovering what was left of the ancient buildings, and preserving these leftovers (or sometimes attempting to reconstruct them).

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michal_hanu_la t1_j6dqdoz wrote

In practice it seems good enough for most cars. If you have an extremely special use case (eg. a police car idling by the side of the road all day), your mechanic will take that into account.

Planes, by the way, use hours, takeoffs/landings (the number of those is assumed to be the same) and, for big ones, pressurization cycles.

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