Thursday, April 26, 2018
Saturday, August 19, 2017
Thursday, August 17, 2017
Thursday, January 16, 2014
Ceramics Bending Behaviour
Ceramic has many holes in its surface, it is not
really solid. When a force is applied on a ceramic material, on bending,
its top surface become concave due to compression stress while the bottom
surface of the material is stretched. At point where compression is maximum on
top, in the meanwhile at the same point, at the lower bottom surface, tension
is maximum and from that point, material shatter.
References:
External Link
References:
External Link
Sunday, December 1, 2013
How to Fall Asleep in Less Than 30 Seconds
Does it take you a while to fall asleep at night? Do you find your mind dwelling on various thoughts before you’re able to finally drift off and relax into sleep? Do you find that you just aren’t sleepy enough when it’s time for bed?
Realize that if it takes you 15 minutes on average to fall asleep each night, that’s more than 91 hours per year that you’re wasting. This is the equivalent of spending more than two 40-hour workweeks just lying in bed waiting to fall asleep.
And if you have insomniac tendencies and take more than an hour to fall asleep each night, you’re spending more than nine 40-hour weeks on that pointless activity — every year. That’s a tremendous amount of wasted time.
If you’d like to change this situation, keep reading. I’ll explain the details and share a process for training your brain to fall asleep almost instantly when you’re ready to go to bed.
Drop Caffeine (at Least Initially)
First, if you drink coffee, tea (including green tea and white tea), yerba mate, cola, or any caffeinated beverages on a semi-regular basis, this method won’t work very well at all, so I strongly recommend that you get off all caffeine for at least 2 weeks before you attempt to make improvements in this area.I also advise that you drop chocolate during this time as well, including cocoa and cacao, since those contain stimulants too.
Even a small cup of coffee in the morning can disrupt your ability to fall asleep quickly at night. You may also sleep less restfully, and you’ll be prone to awaken more often throughout the night. Consequently, you may wake up tired and need extra sleep.
Simply eliminating all caffeine from your diet can improve your sleep habits tremendously. So if you haven’t already done that, please do that first before you attempt the training method I explain later in this article.
If you really love your caffeine though, the good news is that it’s okay to add it back once you’ve gone through this adaptation training. It will still disrupt your sleep a bit, but once you’ve mastered the habit of being able to fall asleep in 30 seconds or less, then most likely you’ll still be able to continue the habit even if you consume some caffeine during the day.
Train Your Brain to Fall Asleep Faster
A decade ago it might have taken me 15-30 minutes to fall asleep most nights. Sometimes it would take more than an hour if I had a lot on my mind. And very occasionally I could fall asleep within 5 minutes or less if I was very sleepy.
Today it’s fairly normal for me to fall asleep within 30 seconds or less, and often I’m able to fall asleep in less than 1 second. My best is probably around 1/4 of a second.
How do I know this? Because I have a witness that tells me how long I was out. I also know that I was sleeping because I awaken with the memory of a dream. If my sleep time is only a second or a fraction of a second, then it’s obviously a very short dream. Some time dilation occurs though, so a 1-second dream may feel significantly longer… perhaps as if 5-10 seconds have passed within the dream world.
Is this narcolepsy? No, narcolepsy is very different. I don’t just fall asleep at odd times throughout the day, and I don’t have excessive daytime sleepiness. Most days I don’t take any naps. One thing I do have in common with narcoleptics is that I can start having dreams immediately when I fall asleep, whereas most people don’t enter the dream state for at least an hour. I regard this as a positive adaptation though, not a problem or defect.
I can’t normally force myself to sleep when I’m not at all sleepy. But when I’m ready to go to sleep, I can go to sleep very quickly without wasting time trying to fall asleep.
I’m not able to do this 100% perfectly. If I have a stressful day and there’s a lot on my mind at night, I may find it more difficult to relax and go to sleep. But most of the time under normal, average conditions, I can get to sleep within 30 seconds or less.
I reached this point not by the exertion of conscious will but rather through a long-term process of sleep training. So don’t think that there’s some mental trick that you can use right away to make this happen instantly. However, once you’ve trained yourself to this point, the process is effortless. You’ll be able to do it automatically. It will be no more difficult than blinking.
Understanding the Training Process
The training process may take a long time — months or even years, depending on how far you want to go — but it’s not at all difficult, and it needn’t take a serious time commitment. In fact, the training will most likely save you a significant amount of time. The only challenging part is maintaining consistency long enough to get results.
First consider that it’s possible for you to fall asleep faster. Have you ever been really tired and sleepy at the end of a day, and you fell asleep very quickly after getting into bed? Have you ever drifted off while watching a movie or reading a book? Have you ever fallen asleep within less than 2 minutes after lying down? If you’ve done it before, then consider the possibility that your brain already knows how to fall asleep quickly, and if you create the right conditions, then you’re capable of doing this again. You just need to train your brain to do this more consistently.
The main reason that you aren’t falling asleep faster is that you haven’t trained your brain to do so. You may be able to reach that point eventually, but you’re not there yet. Similarly, you may be able to do the splits if you engage in flexibility training, but in the absence of such training, you probably won’t be able to do the splits at all.
If you want to fall asleep faster, you must incentivize your brain to drop all other activity and immediately transition into sleep when you desire to do so. That is the essence of this approach. If there are few consequences for a lazy approach to falling asleep, then your brain will continue to be lazy and inefficient in this area. You haven’t given it a good enough reason to select more efficient behaviors.
Your brain is always active, even during deep sleep, and it operates in different modes of consciousness, including beta (waking), alpha, theta, and delta phases. When you lie in bed waiting for sleep, you’re waiting for your brain to switch modes. An untrained brain will often take its own sweet time making the necessary state change. So you may dwell on other thoughts… or toss and turn… or just lie awake until your brain is finally ready to transition. This is a common experience. Without incentives to become more efficient, your brain will remain naturally lazy by default.
Your conscious mind might very much like to go to sleep, but it isn’t in charge. Your subconscious determines when you fall asleep. If your subconscious mind is in no hurry to fall asleep, then your conscious mind will have a hard time forcing it. In fact, your subconscious may continue to bubble up thoughts and ideas to occupy your conscious mind, distracting you with mental clutter instead of letting you relax and slide into sleep.
A trained subconscious mind is obedient and fast. When the conscious mind says to sleep, the subconscious activates sleep mode immediately. But this only works if you’re feeling at least partially sleepy. If the subconscious doesn’t agree with the need for sleep, it can still reject the request.
The process I’ll share next will teach your brain that putzing around isn’t an option anymore and that when you decide to go to sleep, it needs to transition immediately and without delay.
The Process
The process involves using short, timed naps to train your brain to fall asleep more quickly. Here’s how it works:
If and when you feel drowsy at some point during the day, give yourself permission to take a 20-minute nap. But only allow yourself exactly 20 minutes total. Use a timer to set an alarm. I often do this by using Siri on my iPhone by saying, “Set a timer for 20 minutes” or “Wake me up in 20 minutes.” The first one sets a countdown timer, while the later phrase sets an alarm to go off at a specific time. Sometimes I prefer to use a kitchen timer with a 20-minute countdown.
Begin the timer as soon as you lie down for your nap. Whether you sleep or not, and regardless of how long it takes you to fall asleep, you have 20 minutes total for this activity… not a minute more.
Simply relax and allow yourself to fall asleep as you normally would. You don’t have to do anything special here, so don’t try to force it. If you fall asleep, great. If you just lie there awake for 20 minutes, also great. And if you sleep for some fraction of the time, that’s perfectly okay too.
At the end of the 20 minutes, you must get up immediately. No lingering. This part is crucial. If you’re tempted to continue napping after the alarm goes off, then put the alarm across the room so you have to get up to turn it off. Or have someone else forcibly yank you off the couch or bed when they hear the alarm. But no matter what, get up immediately. The nap is over. If you’re still tired, you can take another nap later — wait at least an hour — but don’t let yourself go back to sleep right away.
I think it’s best to do your nap practice during the day if you can, but you can also do it in the evening, as long as it’s at least an hour before your normal bedtime. Perhaps the best time for an evening nap is right after dinner, when many people feel a little sleepy.
You don’t have to take the naps every day, but do them at least a few times a week if you can. I think the ideal practice would be one nap per day.
The next part of this process is to always wake up with an alarm in the morning. Set your alarm for a fixed time every day, seven days a week. When your alarm goes off each morning, get up immediately regardless of how much sleep you actually got. Again, no lingering.
Now when you go to bed at night, seek to go to bed at a time that will essentially require you to be sleeping the whole time you’re in bed in order to feel well rested in the morning. So if you feel you need a good 7 hours of sleep each night to feel rested, and you plan to get up at 5am every morning, then get yourself into bed and ready to sleep at about 10pm. If you take 30 minutes to fall asleep, then you’re getting less sleep than you need, and this is a disincentive to continuing that wasteful habit.
The message you’re sending to your brain is that the time you have to sleep is limited. You are going to get out of bed after a certain number of hours no matter what. You’re going to get up from your nap after a specific amount of time no matter what. So if your brain wants to sleep, it had better learn to go to sleep quickly and use the maximum time allotted for sleep. If it wastes time falling asleep, then it misses out on that extra sleep, and it will not have the opportunity to make it up by sleeping in later. Sleep time squandered is sleep time lost.
When you go to bed whenever and allow yourself to get up whenever, you reward your brain for continued laziness and inefficiency. It’s fine if you take a half hour to fall asleep since your brain knows it can just sleep in later. If you awaken with an alarm but go to bed earlier than necessary to compensate for the time it takes you to fall asleep, your still tell your brain that it’s fine to waste time transitioning to sleep because there’s still enough extra time to get the rest it needs.
Coffee and chocolate are also crutches because if you don’t get enough sleep, your brain can come to rely on a stimulant to keep it going when necessary. If you remove these outs, then your brain will soon connect the dots. It will learn that taking too long to fall asleep equals not getting enough sleep, which means going through the day tired and sleepy. By closing the door on potential outs like stimulants and extra snooze time, you leave only one remaining option for a solution. Sooner or later your brain will determine that going to sleep faster is indeed the solution, and it will adapt by transitioning into sleep much more quickly, so as to secure the full amount of rest it desires.
Instead of continuing to give your brain the message that oversleeping is okay or that stimulants are available, begin to condition it to understand that sleep time is a limited resource. Your brain is naturally good at optimizing scarce physiological resources; it evolved to do so over a long period of time. So if sleep time appears to be a limited resource, your brain can learn to optimize its use of this resource just as it has learned to optimize the use of oxygen and sugar.
If you get sleepy during the day as a result of limiting your sleep time at night, that’s perfectly okay. Take naps as needed. It’s okay to take multiple naps during the day if you need to, but keep them limited to 20 minutes max, and don’t have two naps within an hour of each other. Whenever you get up, stay up for at least an hour.
Once you get used to 20-minute naps — or if you don’t have that much time available for napping — try napping for shorter intervals. Give yourself 15, 10, or even 5 minutes for each nap. I sometimes take 3-4 minute naps (with a timer), which are surprisingly refreshing, but only if I fall asleep quickly.
Teach your brain that a 20-minute nap means 20 minutes of total time lying down. If your brain wants to ruminate during part of that time, it always means less sleep.
Also teach your brain that X number of hours in bed at night is all it gets, and so if it wants to get enough sleep, it had better spend virtually all of that time sleeping. If it spends time on non-sleep activity, it always robs itself of some sleep.
Once you’ve adapted and you’re able to fall asleep quickly when you desire to do so, you can slack off on the training process, ditch the alarm, and wake up whenever you want. Most likely the training will stick. You can even add the caffeine back if you so desire. But for a period of at least a couple months to start, I recommend being strict about it. Take naps regularly, and use an alarm to get up at a consistent time every single day.
I still prefer to get up with an alarm most days. I don’t need it to fall asleep quickly, but I tend to linger in bed more than necessary without the alarm.
If this is too strict for you, I doubt you’ll succeed with this approach. If you give your brain an easy out, it will take that out, and it won’t learn the adaptation you’re trying to teach it here.
Everyone is different, so how long it takes you to adapt depends on your particular brain. I’m sure some people will adapt fairly quickly, within a few weeks, while others may take significantly longer. There are many factors that can influence the results, with perhaps the biggest one being your diet. In general, a lighter, healthier, and more natural diet will make it significantly easier to adapt to any sort of sleep changes. Regular exercise also makes it easier to adapt to sleep changes; cardio exercise in particular helps to rebalance hormones and neurotransmitters, many of which are involved in regulating sleep cycles. If you eat a heavily processed diet (i.e. shopping mostly outside the produce section) and you don’t exercise much, just be aware that I rarely see such people succeed with worthwhile sleep changes of any kind.
One last item I’ll share is that I’m able to fall asleep fastest when I’m cuddling someone, both for naps and when going to bed at night. On my own I can get to sleep in under 30 seconds normally, but when I’m cuddling a nice warm female body, that’s when I can often get to sleep in less than a second. So I invite you to experiment with this if you have a willing cuddle partner who enjoys serving as a human teddy bear.
Saturday, August 24, 2013
ہم اپنے بچوں کو نہیں پڑھاتے…محمد بن قاسم سندھ فتح کرکے کہاں گیا؟
محمد بن قاسم کے حوالے سے ہماری درسی کتابیں ہمیں بار بار یہ تو بتاتی ہیں کہ اُس نے سترہ سال کی چھوٹی سی عمر میں فوجی جرنیل کا عہدہ سنبھال کر سندھ پر حملہ کیا اور بڑی مہارت سے دیبل سے لے کر ملتان تک کا علاقہ تھوڑے سے عرصے میں فتح کر لیا۔ تاہم یہ کتابیں اس حوالے سے مکمل طور پر خاموش ہیں کہ محمد بن قاسم سندھ فتح کرنے کے بعد کہاں گیا۔
دلچسپ بات یہ ہے کہ ہمارے طلباء/نوجوانوں کو بھی میں نے کبھی یہ سوال اٹھاتے نہیں سنا۔ حالانکہ فطری سی بات ہے کہ بندے کو یہ تجسس پیدا ہوتا ہے کہ آخر جس نوجوان نے سترہ سال کی عمر میں سندھ فتح کر لیا اُس نے باقی کی زندگی کیسے گزاری۔ کسی مشہور شخص کی پیدائش کا احوال معلوم نہ ہونا تو اتنی حیرت کی بات نہیں۔ لیکن اگر کسی شخص نے چھوٹی سی عمر میں اتنا بڑا کارنامہ انجام دیا ہو تو اس کی موت کے حوالے سے کتابوں میں کوئی ذکر نہ ملنا یقیناً حیرت کی بات ہے۔
اسی تجسس نے لالاجی کو بے چین کر دیا اور لالا جی نے اس معاملے کو کریدنا شروع کر دیا۔ اس کے نتیجے میں جو چند باتیں مختلف ذرائع سے سامنے آئیں وہ پیش خدمت ہیں:
پہلی بات تو یہ ہے کہ محمد بن قاسم سندھ کی فتح کے بعد کچھ زیادہ عرصہ زندہ نہیں رہا۔ سترہ سال کی عمر میں سندھ پر حملہ کرنے نکلا۔ اُس زمانے میں سفر کی مشکلات اور طوالت کو سامنے رکھئے، پھر دیبل (موجودہ کراچی کے آس پاس کوئی جگہ) سے لیکر ملتان تک کی فتوحات میں لگ بھگ تین سال لگ گئے۔ تقریباً سارے ہی مورخین اس بات پر متفق ہیں کہ محمد بن قاسم کی وفات بیس (۲۰) سال کی عمر میں ہوئی۔
دوسری بات یہ ہے کہ محمد بن قاسم کی موت میدانِ جنگ میں لڑتے ہوئے نہیں ہوئی۔ نہ ہی کسی بیماری کی وجہ سے ہوئی۔ اگرچہ مورخٰین موت کے حوالے سے کوئی متفقہ فیصلہ نہیں دیتے تاہم اس بات پر سب متفق ہیں کہ محمد بن قاسم کی موت اپنے ہی حاکم کی طرف سے دی گئی سزا کے نتیجے میں واقع ہوئی۔
موت کیسے ہوئی ، حاکم کیوں ناراض ہوا، کیا سزا سنائی گئی…ان باتوں پر مورخین میں اختلاف پایا جاتا ہے۔ محمد بن قاسم کی موت کے حوالے سے دو بیانات ملتے ہیں:
1) چھچھ نامہ سندھ کی تاریخ پر پہلی باقاعدہ کتاب سمجھی جاتی ہے۔ چھچھ نامہ میں محمد بن قاسم کے سندھ پر حملے اور سندھ کے مختلف شہروں کے محاصرے، جنگوں اور فتوحات کی تفصیلات درج ہیں۔ اس کتاب کا انگریزی ترجمہ انٹرنیٹ پر دستیاب ہے۔ اس کتاب کے مطابق محمد بن قاسم نے راجہ داہر کی موت اور اس کی فوج کو شکست دینے کے بعد مسلمانوں کے دستور کے مطابق مالِ غینمت اور راجہ کی بیوی اور بیٹیوں کو اپنے حاکم حجاج بن یوسف کو بھجوا دیا۔ راجہ داہر کی بیٹیوں نے حجاج بن یوسف سے جھوٹ بولا کہ وہ خلیفہ کے لائق نہیں کیوں کہ محمد بن قاسم نے انہیں پہلے ہی استعمال کر لیا تھا۔ اس بات پر حجاج بہت ناراض ہوا اور حکم دیا کہ محمد بن قاسم کو بیل کی کھال میں بند کر کے واپس لے آؤ۔ اس کے حکم پر عمل کیا گیا تاہم بیل کی کھال میں دم گھُٹنے سے محمد بن قاسم کی راستے ہی میں موت واقع ہو گئی۔ بعد میں حجاج کو راجہ داہر کی بیٹیوں کا جھوٹ معلوم ہو گیا۔ انہوں نے محمد بن قاسم سے اپنے باپ کی موت کا بدلہ لینے کے لئے یہ جھوٹ بولا تھا۔ حجاج نے ان لڑکیوں کو زندہ دیوار میں چنوا دیا۔
2) أحمد بن يحيى بن جابر البلاذري ایک مسلمان مورخ ہے جو خلیفہ المتوکل کے دربار تک رسائی رکھتا تھا۔ اس نے مسلمانوں کے ابتدائی دور کی تاریخ کو قلم بند کیا ہے۔ البلاذري نے ایک کتاب لکھی تھی فتوح البلدان کے نام سے جس کا انگریزی ترجمہ فلپ کے ہِٹی(Philip K Hitti) نے ‘The Origins of the Islamic State’کے نام سے کیا ہے۔ البلاذري کے مطابق714ء میں حجاج کی موت کے بعد اُس کے بھائی سلیمان بن عبدالمالک نے حکومت سنبھالی۔ وہ حجاج بن یوسف کو سخت ناپسند کرتا تھا۔ اُس نے عنان حکومت سنبھالتے ہی حجاج کے منظورِنظر افراد کو قید کروا دیا۔ محمد بن قاسم بھی حجاج بن یوسف کے پسندیدہ افراد میں گنا جاتا تھا(یاد رہے کہ محمد بن قاسم حجاج بن یوسف کا داماد بھی تھا اور بعض مورخین کا خیال ہے کہ بھانجا بھی تھا)۔ چنانچہ محمد بن قاسم کو بھی قید کر دیا گیا۔ قید کے دوران میں ہونے والے تشدد کے نتیجے میں محمد بن قاسم کی موت واقع ہو گئی۔
محمد بن قاسم کی موت کے حوالے سے یہ باتیں قوم کے نونہالوں سے چھپا کر ہمارا محکمہ تعلیم کیا حاصل کرنا چاہتا ہے اس کا تو پتہ نہیں۔ تاہم اپنے ماضی کے ناپسندیدہ واقعات کو چھُپایا تو جا سکتا ہے، مٹایا نہیں جا سکتا۔ جو قوم اپنی تاریخ سے پوری طرح آگاہ نہیں ہوتی، وہ کبھی بھی پورے اعتماد سے دوسری قوموں کے ساتھ برابری کی بنیاد پر تعلقات استوار نہیں کر سکتی۔
Friday, August 23, 2013
Scientists confirm: Ancient Egyptians wore jewelry made of materials from outer space
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The University College London (UCL) Petrie Museum in London is home to ancient Egyptian iron beads that were once thought to be hammered out of traditional iron ore. Researchers from UCL have dispelled this notion, revealing that the earliest jewelry artifacts were actually made from materials from outer space.
UCL Archaeologist and Professor Thilo Rehren is uncovering fascinating new evidence on the ancient Egyptian beads. He says, “The shape of the beads was obtained by smithing and rolling, most likely involving multiple cycles of hammering, and not by the traditional stone-working techniques such as carving or drilling which were used for the other beads found in the same tomb.”
“Even 100 years ago, [the beads] attracted attention as being something strange,” Rehren said.
Rehren and a team of researchers are proving that the beads are actually cosmic jewelry, hammered from pieces of meteorites. Their evidence suggests that the ore used to make the beads originates from an era existing two millenniums before communities learned how to smelt and tamper traditional iron ore into iron.
Rehren and a team of researchers are proving that the beads are actually cosmic jewelry, hammered from pieces of meteorites. Their evidence suggests that the ore used to make the beads originates from an era existing two millenniums before communities learned how to smelt and tamper traditional iron ore into iron.
The beads from the UCL Petrie Museum were discovered in 1911 near the village of el-Gerzeh in Lower Egypt. Dug up in a cemetery that dates back to approximately 3200 B.C., the beads were found to be corroded to their core. Using x-rays, the researchers have determined the continuity of the beads. They’ve concluded that the beads do not come from magnetite, which typically resembles meteoric iron, but actually come from meteoric iron from outer space origins. Scanning the beads further with neutron beams and gamma-rays, the researchers determined that the unique textures of nickel, phosphorous, cobalt, and germanium were indeed reminiscent of meteoric iron. The neutron beams and gamma-rays also helped them bypass more invasive testing that could have damaged the rare objects.
“The really exciting outcome of this research is that we were for the first time able to demonstrate conclusively that there are typical trace elements such as cobalt and germanium present in these beads, at levels that only occur in meteoritic iron,” Professor Rehren said.
How the beads were made
Rehren continues, “We are also excited to be able to see the internal structure of the beads, revealing how they were rolled and hammered into form. This is very different technology from the usual stone bead drilling, and shows quite an advanced understanding of how the metal smiths worked this rather difficult material.”
Their study, published in the Journal of Archaeological Science, further explains how the rock from outer space was meticulously hammered into thin sheets and then rolled into tubes that were woven around wooden sticks to create 0.8-inch-long, tube-shaped beads.
The nine beads from the museum are thought to be at least 5000 years old. They make up a necklace that was very valuable for its time and included gold and other precious gems.
Their results suggest that during the fourth millennium BC, meteoritic iron work had already been mastered.
Their results suggest that during the fourth millennium BC, meteoritic iron work had already been mastered.
This meteoritic iron-nickel alloy is a much harder and more brittle rock that predated copper and traditional iron ore work. This meteoritic iron work was the first basic training ground for blacksmiths, helping to pave the way for future learning of copper work and traditional iron work.
source:
Saturday, August 17, 2013
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