BusaDave9

I have relatives that are deaf. Some have cochlear implants that allow them to hear. These cochlear implants are possible with human technologies. Deaf people congregate around other deaf people. They often marry other deaf people. Their children are often deaf. I don't want to give specifics due to privacy issues. Do you believe what I am telling you? The same can be said for blind people. Globally, the World Health Organization estimates that over 1.3 billion people—about 16% of the world's population—experience a significant disability. https://www.who.int/news-room/fact-sheets/detail/disability-and-health I have been comparing humans to animals living in the wild. So to compare what I've stated above with similar situation in animals. I say there is nothing like these numbers in the animal kingdom. Is there a group of blind wolves living in Siberia, helping each other with food and survival? I can't prove there isn't. I can't prove the negative. I ask you to use common sense. Nearly 70% of American adults require some form of vision correction. https://www.sightconnection.org/statistics-how-many-people-wear-glasses-in-the-world/ Is there similar numbers of hawks that are nearsighted? I doubt it but I can't prove it. I ask you to use common sense. Is there a group of swallows deep in the Amazon forest that can not fly. They grow to reproductive age because of other swallows bring them food. I can't prove these groups of birds don't exist but I ask you to use common sense. Do you believe the things I have said in this post or are you just being argumentative?

Sethoflagos was asking for more information about Climate change. https://humanprogress.org/freedom-from-climate-related-death-risk/ Deaths caused by weather have gone down over 97% in the last 100 years. At the same time we are causing the extinction of many animals. Animals usually live in a very specific environment and as the climate changes many species die off. Humans on the other hand live everywhere from the tropics to the arctic circle. We evolved in Africa where it's hot. We have very little body hair and we sweat. As we moved out of Africa we have adapted with inventions and innovations. Many of these inventions are ancient. For example wearing animal skins as clothing has allowed us to live in Alaska and northern Canada. Modern inventions such as air conditioning and heating make us even more likely to survive extreme temperatures. We herd animals and grow crops. This allows us a more constant supply of food. We have invented transportation starting off with 2 wheeled wagons that allows us to bring the food from the fields to where the people are. All these things allow us to survive better than the wild animals. CharonY isn't bringing much to the conversation. He doesn't realize I am comparing humans to animals in the wild. He says "think about conditions that renders folks sterile and/or less likely to procreate." and "It is true that these are partially lessened in modern societies, but often they are not eliminated fully." Of course they are not eliminated fully. People all over the world go to fertility doctors. Wild animals don't have that option. I am saying major and minor undesirable traits are getting passed on to the next generation at a far higher rate than with wild animals. Deaf and blind people are fully expected to reach reproductive age. People with mental or physical handicaps are still able to procreate. Society itself has created an environment where people that cannot run still do not have to worry about wolves, lions or other predators killing them.

Yes, let's talk about climate change. We humans are changing the world's climate because we are extremely over populated and because we are the only species that burns fuels for our needs. Some say we are creating our own demise. I say the impact on the wild animals is far greater that our impact on humans. We'll never become extinct but we are causing many animals to become extinct. The rate that humans are dying due to the weather is going down greatly. Look it up. I'm not saying evolution works differently for humans mechanistically. Our environment is different. Give me an evolutionary trait. Tell me people with this trait ____________ are dying off more quickly than the rest of the human race. People with that trait aren't making it to reproductive age. You may find traits we die of but again compared to animals.

I didn't say natural selection is all there is to evolution. I asked what the main cause of evolution is in humans? I said "The main cause of evolution in animals is natural selection. Mutations cause variation but natural selection causes certain traits to be passed on to the future generations." Genetic drift is not very predominant in large populations such as humans. You brought up reproductive success. Humans are the only species that practices birth control. People can control how many offspring they have. Even people with undesirable traits have children. Almost everyone can have reproductive success. And please, please, please keep in mind I am comparing human evolution to the evolution of wild animals in each of these topics. I never said caring for the weak is unknown for wild animals. I am comparing humans to wild animals. I say humans are the most compassionate animals in the world. If someone is having a hard time getting food most government have assistance programs for the poor. There are also non-government charities for assistance. If a community is starving in some part of the world other countries will send in aid. This is not fool proof. Sure people still starve but once again I am comparing to wild animals. 200 years ago people might have 8 children and only 4 might make it to adulthood. It's worse for animals. Now most human babies are expected to survive to adulthood. Excellent point that supports my viewpoint. The environment we live in allows us to proliferate. We no longer have any predators that actually hunt humans. In animals they must be able to get their food. For a predator that means they must be faster than thier prey. Prey must elude predators. Each animal must be able to survive in their environment. In humans we no longer need to hunt our own food. If someone doesn't have enough food it's because they don't have a job, or their job doesn't pay enough. Now there are all kinds of jobs for all kinds of talent. If you don't have a good job you probably won't die (or at least not at the rate of wild animals). Welfare or charities should help.

The main cause of evolution in animals is natural selection. Mutations cause variation but natural selection causes certain traits to be passed on to the future generations. That's how it works for wild animals but what drives evolution in humans? For humans I wouldn't say we have survival of the fittest. As a matter of fact, I'd go so far as to say it's survival of everyone. Maybe I exaggerate, but only slightly. Hear me out. Traits that make life hard, are not dying off due to natural selection, or at least not nearly as much as with animals living in the wild. I have a relative that has excellent hearing. She married a man who also has excellent hearing. They had 3 children that are all deaf. Being deaf is a death sentence for animals living in the wild. Whether predator or prey, senses must be acute. But for humans it doesn't matter if you have major or minor birth defect, or are blind or deaf, you are still fully expected to reach reproductive age. The oldest deaf son married a deaf woman. They had a baby. They were ecstatic to find out that their baby was also deaf. Deafness thrives in humans. So does blindness and other major genetic defects. Lots of people have genetic defects that make it hard to walk, let alone run. Many people need a wheelchair to get around. When you go to the store or almost any public building, the nearby parking spots are all reserved for handicap people. A bird that can't fly will never live to reproductive age. If a deer gets a broken leg it will die. Animals will evolve so their bones won't break too easily. But they don't evolve to have bones that never, or almost never break. Evolution never produces the perfect animal. (an unbreakable bone would be too heavy) On the other hand, a human might get in a horrible accident. It is absolutely astounding what modern doctors can do to save a life. If you are bedridden in the hospital for weeks, don't worry, wolves won't get you. You'll be taken care of and fed until you are back on your feet. If you lose a limb, doctors can reattach it. If they can't you can get a prosthetic limb. So, what is the main driving force behind human evolution if natural selection has so much less impact on us than animals living in the wild?

My question pertained to torque and differentials. Yes, a tank's track gets such good traction it doesn't need a differential but that's not what I asked. It's like someone asking about how an airplane flies and you say "don't ask about airplanes, helicopters are much better because they can land in more locations." We're on a different topic now. I don't know what more to say. Yes, a tank gets good grip. I try to get good grip with my jeep by putting on larger tiers with an aggressive tread but I can't put a track on my jeep and even if I could it's not allowed because they tear up the trails and roads.

Grip alone is not always the answer. A 2 wheel drive car may have a problem with grip, especially off road. A locking differential will help and four wheel drive helps. You are saying a tank has great traction. That's true, tracks help tremendously. A tank has such good traction (grip) that it almost never gets stuck. In a tank grip alone is good enough. I say grip alone is not always the answer because many vehicles don't get excellent grip. When a tire starts to spin that's when the type of differential is important. Off-roaders like to have locking differentials to apply torque to the wheel with the best traction.

I'd rather not confuse this thread with talk about how a tank works but since you brought it up. The engine of a tanks turns the drive sprockets at the rear of the track (marked in red here). This is where the engine applies torque to the track to propel the tank. All the rest of the wheels are idle wheels. The yellow are road wheels with suspension. The blue is tension wheels for the mechanic to adjust how tight the track is. and that's all I have to say about that.

Yes, if a tire can't grip it can't apply torque and propel the vehicle. But when one tire has grip and the other doesn't that's when the design of the differential makes a difference. When one tire on an open or regular differential has no grip then neither tire can propel the vehicle. (Torque is limited by the tire with the worst traction) When one tire on a locking differential has no grip then the one tire with grip can propel the vehicle. (Torque is delivered to the tire that has traction)

Yes, I agree. When the vehicle is stuck no work is being done. When it starts to move lets not try to talk about which tire is doing the work. Then I'd like to talk about torque applied to the wheels.

With an open differential, when one tire is spinning and the other is not. BOTH tires are helping push the car. You can say push. You can say torque. You can say load or work. You can say whatever you want but both tires help the car get moving. People see the one tire spinning and they think this one tire is the only one doing any effort to move the car. This is not true. Both tires are helping out EXACTLY the same amount. Thought experiment: Lets say someone is trying to turn the tire on dry pavement. He has a long torque wrench on the hub of the wheel. He may be pushing with all his might and the tire is not turning. He is still applying torque. If he had just a little more help he might be able to move the car. This is not how the engine applies torque. It applies it through the differential . With an open differential it applies torque equally to both wheels no matter what.

Yes, people misunderstand torque, power and energy .... and I would like to add speed. Sure it takes energy to spin a tire but that doesn't mean it's applying that energy (or torque) to the ground. For that reason I say for this discussion it is best to imagine the weight of the wheel can be disregarded. Imagine it doesn't weigh anything. I disagree with your sentence I underlined. Lets say we've got an open differential and one tire is on glaze ice. You can't apply much torque to this tire before it starts to spin. Lets say only five foot pounds of torque can be applied before it spins on the ice. The other tire that is on dry pavement is also getting exactly the same amount of torque (5 foot pounds) but this is still not enough to move the jeep. This is why I say an open differential ALWAYS applies the same amount of torque to both wheels. On the other hand a locking differential will, at times, apply all the torque to the one tire with the best traction. For example lets say a tire on a jeep comes off the ground due to very rough terrain. (Imagine he's in 2 wheel drive, I don't want to think about what the other axle is doing). In this case the tire on the ground is getting all the torque and can still propel the jeep. I say no torque can EVER be applied to ANY tire that is off the ground. This is true if you have an open differential or a locker. All my off-road buddies disagree with that last statement. If the jeep has an open differential the tire off the ground would be spinning fast. My friends would say the spinning tire would have lots of torque. "Go grab that tire, Dave. You'd go flying up into the tree tops." 1. A spinning tire of any weight will be hard to stop. This is why I prefer to say it has neglectable weight for the sake of discussion. 2. If the spinning tire isn't pressing against the ground it CAN'T be applying any torque. To disagree would be to disagree with Newton's 3rd law, to every action there must be an equal and opposite reaction. To explain my last point it would be like me going into a gym and bench pressing an empty bar bell. If I were to yell out "I am pressing up with 300 pounds of force." Everyone would yell "BS!" It's not possible. Then lets say a couple of guys were to put 300 pounds of weight on the ends of my bar bell while I am holding it above me. Now I sure as hell better be able to hold up 300 pounds or that bar bell will come crashing down on my chest. On the other hand lets say I can bench press 300 pounds (a lie) and when that much weight is put on my bar bell I continue to do repetitions. Now everyone would say "WOW he can press up that hard. I guess he was always pressing up with 300 pounds of force like he said." NO NO NO just because I CAN bench press 300 pounds doesn't mean I was when there were no weights on my bar bell. This is all hypothetical, I'm a wimp and can't bench press 300 pounds.

I enjoy taking my Jeep up into the mountains on rough trails. I have gotten into an argument with some of the others that also enjoy this pastime. I was hoping you guys could settle a dispute about locking differentials. Background I think this is mainly a science question. You don't have to know much about cars but you do need to know the following: Open Differential This is the most common differential found in almost all cars and trucks. Lets say a car with an open differential has the left tires on dry pavement. The right tires are in snow covered ice. If you have an open differential and you hit the gas your right tire would just spin in the ice and snow. Your left tire on the dry pavement will not turn. You're stuck. Locking differential These are not common. Sometimes they are found in off-road vehicles or in race cars. With a locking differential both tires on the axle turn in unison. In the same scenario, your right tires are in snow covered ice and your left tires are on dry pavement, you hit the gas. Now you can accelerate briskly. Because you have tires on the dry pavement you don't get stuck. The Debate Most people say an open differential will, at times, send all the torque to the one tire with the worst traction. And a locking differential will send torque to both tires equally. I say this is almost exactly opposite of the truth. I say an open differential will always apply torque equally to both tires on the axle. And I say a locking differential will, at times, send all the torque to the one tire with the best traction. So what do you guys say? Am I right or is everyone else wrong? I don't want to explain my reasoning until I hear from others.

That reminds me of a cartoon I saw years ago. It was 2 astronauts standing on another planet looking at their own shadow. But the shadow was only their skeleton. One of the astronauts says "I don't like the looks of that." I wish I could find that on the internet. It would be much better than me describing it.

I agree. It's kinda hard to wipe that from your memory.

https://www.youtube.com/watch?v=UnyHMSz7JDE https://www.youtube.com/watch?v=UnyHMSz7JDE

^ ^ ^ I didn't understand that picture until I saw the image was titled "Genetics.jpg"

What? ? So my weed wacker is as powerful as a horse?? My car is more powerful than 200 horses???????? I know a gasoline engine can maintain power without getting tired but seriously. 200 horses can be pretty powerful. Or imagine not being able to pull a riding lawn mower unless you have 20 horses. Is this some kind of joke? Oh yes I guess I didn't pay attention to the thread.

Come on EdEarl, this is ridiculous. No thinking adult believes babies are brought by storks. On the other hand, if the Bible were to say we were brought here by storks, then a large percentage of the public would believe that beyond all logic. To believe otherwise would mean eternal damnation for doubting the Bible.

Two scientists walk into a bar. The first scientist says ‘I’ll have a glass of H2O” The second scientist says ‘I’ll have a glass of H2O Too" The second scientist dies of Hydrogen Peroxide poisoning.

A cop with a drug sniffing dog said to me "This dog tells me you're on drugs." I said "I'm on drugs? Your the one talking to dogs." The rest of the day didn't go very well.

A farmer named Malcom had a car accident. In court, the trucking company's fancy lawyer was questioning Malcom. "Didn't you say, at the scene of the accident, 'I'm fine?" asked the lawyer. Malcom responded, "Well, I'll tell you what happened. I had just loaded my favorite mule, Bessie..." "I didn't ask for any details", the lawyer interrupted. "Just answer the question. Did you not say, at the scene of the accident, 'I'm fine!'?" Malcom said, "Well, I had just got Bessie into the trailer and I was driving down the road....." The lawyer interrupted again and said, "Judge, I am trying to establish the fact that, at the scene of the accident, this man told the Highway Patrolman on the scene that he was just fine. Now several weeks after the accident he is trying to sue my client. I believe he is a fraud. Please tell him to simply answer the question." By this time, the Judge was fairly interested in Malcom's answer and said to the lawyer, "I'd like to hear what he has to say about his favorite mule, Bessie". Malcom thanked the Judge and proceeded. "Well as I was saying, I had just loaded Bessie, my favorite mule, into the trailer and was driving her down the highway when this huge semi-truck and trailer ran the stop sign and smacked my truck right in the side. I was thrown into one ditch and Bessie was thrown into the other. I was hurting, real bad and didn't want to move. However, I could hear ole Bessie moaning and groaning. I knew she was in terrible shape just by her groans. Shortly after the accident a Highway Patrolman came on the scene. He could hear Bessie moaning and groaning so he went over to her. After he looked at her, and saw her fatal condition, he took out his gun and shot her between the eyes. Then the Patrolman came across the road, gun still in hand, looked at me and said, "How are you feeling?" "Now what would you say?"