TheDefected

TheDefected t1_jef4qqd wrote

Reaction mass is what some people have said, if you don't weigh much, when you connect, you're more likely to push yourself back off them than if you were heavier.

Another factor is the speed of your muscles. All things being equal, if you were lighter (and your fist/arm was too), you could make up for that with a faster punch.
Less mass in your arm, but more speed to make up for it. This is one of those Newtonian things involving collisions, if everything worked out without losses, if you wacked a 2kg ball into a 1kg ball and it transferred all the energy, the 1kg ball would shoot off at double the speed.
However, there's going to be a max speed based on your muscles, you wouldn't just be able to halve the weight of your arm and then expect it to move twice as fast. In other words, you can get faster with your punches, but there's a sort of preferred speed from your muscles which it'll tend to hang around.

eg- your muscles will move your arm in a particular speed range no matter what. Double the weight of your arm won't halve the speed, half-weight arms won't double the speed. You can add extra mass though, so if you gripped a lump of steel in your fist, you'd have a stronger punch, as there would be spare capacity in your muscles to account for the extra mass without taking a big hit in the speed to level it back out.

This part however is just one part of the whole punch, it's more like the mechanics of throwing a limp arm at someone, and doesn't account for the followthrough which would give you a stronger punch from having a heavy overall physique.

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TheDefected t1_jec6x8q wrote

Another cause/fix to it is to do with quantisation, and quantum physics.
This lead to a similar paradox called the UV catastrophe.

The premise was you could infinitely divide things, time and distance, so half of whatever measurement there is, but it turns out you can only get so far, and then it blends together in the Planck length and Planck-time.
It's not a case of just being the smallest thing currently measurable, it's more the limit on the granularity of the universe.

The UV catastrophe is what started quantum physics, the maths said that a black body (in simple words, something that radiates heat perfectly) would radiate energy at all different frequencies in differing levels. The maths divided these frequencies infinitely, and they all had at least some energy, at that would mean it would radiate infinite energy too.
It was figured out that you couldn't just divide everything infinitely, it got down to discrete quantised steps, eg mini packets or "quanta" in these levels.

The Planck length is the smallest possible division of space and distance, and you can't halve it, and the Planck time is the time it takes light to cover the Planck distance, eg the fastest possible thing covering the smallest possible distance, and it can't get smaller.

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TheDefected t1_je733mp wrote

There is a British TV show called Q.I, where they'll often deal with curious facts.
One episode did mention this, involving what was so unusual about a monk reading in silence.
I believe that was somehow noted as being unusual (since they had vows of silence) and it could then be deduced that if that was thought of as unusual, that means speaking when reading was the norm.

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TheDefected t1_j6mspzd wrote

It is a stall, but one that is recoverable (for the cobra)
The body is slammed into the air as an air brake, the first part of getting the nose up is a rapid stall to prevent the aircraft just climbing and flying up.
The aim was to maintain the altitude during this, so a rapid lift of the nose, a stall of the wings so it doesn't gain a lot of altitude and also I believe an engine set up which can still work taking in enough air to give plenty of thrust to hold the altitude.

Regaining level flight is apparently from the elevators, the nose-up airbrake is somewhat stable but once you're back on the elevators, you get more drag at the back (bottom) of the wing, and it flips the nose back down again.

So- way over the angle of attack, stall the wings so you don't gain altitude, plenty of thrust so it won't sink, plenty of drag and slowing down. Then on with the elevators, adding extra drag at the bottom (still stalled, the air isn't flowing over the wings) and it'll flip the nose back down and you recover.

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TheDefected t1_j6j063k wrote

Petrol engine - air and fuel is already mixed, compressed, and then ignited with a spark.
Diesel engine - these aren't premixed, the engine has to take the air in, compress it, and at around the time the spark would ignite, that is when a diesel has to get in all the fuel it needs.
The faster an engine turns, the shorter that window too, so you tend to reach a point where there's not enough time to squirt enough fuel in and let it burn.
Modern diesels all tend to be common rail high pressure injection, usually around 1600-2000 bar. Having that sort of pressure means you can get a lot of fuel in quickly, but it still is a struggle.
I would guess the Audi LeMans diesel GT car would run at pretty high pressures, and also since it has a lot more cylinders, it doesn't need a massive bucketload in each one.

Gas turbines constantly add fuel and air, so it doesn't have the limitation of a small window to do everything.

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