दुनिया के इस नज़ारे को सही साबित करने के लिए आम तौर पर जो एकमात्र तर्क दिया जाता है, वह यह है कि पर्टरबेटिव स्ट्रिंग थ्योरी में एक मासलेस स्पिन-टू मोड होता है और इस प्रकार यह गुरुत्वाकर्षण की व्याख्या प्रदान कर सकता है, बशर्ते कोई एक ऐसा अंतर्निहित सिद्धांत खोजने में कामयाब हो जाए जिसके लिए पर्टरबेटिव स्ट्रिंग थ्योरी उसका पर्टरबेटिव विस्तार हो।
The sole argument generally given to justify this picture of the world is that perturbative string theories have a massless spin two mode and thus could provide an explanation of gravity, if one ever managed to find an underlying theory for which perturbative string theory is the perturbative expansion.
The sole argument generally given to justify this picture of the world is that perturbative string theories have a massless spin two mode and thus could provide an explanation of gravity, if one ever managed to find an underlying theory for which perturbative string theory is the perturbative expansion.
स्ट्रिंग थ्योरी की एक समस्या यह है कि यह एक ऐसा सिद्धांत है जो यह तो समझा सकता है कि समस्याएं क्या हैं, लेकिन समस्याएं ऐसी हैं कि आप उस पर उंगली भी नहीं रख सकते और यह नहीं कह सकते कि यह बिल्कुल यही भविष्यवाणी करती है, इसलिए चलिए बाहर जाकर इसकी जाँच करते हैं। इसलिए, यह इस काबिल भी नहीं है कि इसे गलत साबित किया जा सके, या इसे झूठा ठहराया जा सके, या इसके गलत होने को दिखाया जा सके।
One problem of the String Theory is that it's kind of a theory which can explain what the problems are, but the problems are such that you can't even pin it down and say this is exactly what it predicts, so lets go out and test it. So, it's not even capable of being wrong, or being falsified, or being showed to be wrong.
One problem of the String Theory is that it's kind of a theory which can explain what the problems are, but the problems are such that you can't even pin it down and say this is exactly what it predicts, so lets go out and test it. So, it's not even capable of being wrong, or being falsified, or being showed to be wrong.
खूबसूरती का मतलब अलग-अलग लोगों के लिए बहुत सी अलग-अलग चीजें होता है। चीजें खूबसूरत होने के कई अलग-अलग तरीके हो सकते हैं। लेकिन इसका वास्तव में एक बहुत ही खास मतलब है जो 'एलिगेंस' यानी लालित्य के ज्यादा करीब है। यानी हम गणित या भौतिकी में किसी विचार को सुंदर या एलिगेंट तब कहते हैं जब एक बहुत ही सरल सिद्धांत या एक बहुत ही सरल विचार, या सरल विचारों का समूह, बहुत प्रभावशाली साबित होता है और हर तरह की अप्रत्याशित संरचनाओं और अप्रत्याशित भविष्यवाणियों की ओर ले जाता है।
Beauty means a lot of different things to a lot of different people. A lot of different ways in which things can be beautiful. But this really has a very specific meaning and which is more along the lines of elegance which is that we say an idea is beautiful or elegant in mathematics or physics if a very simple principle or a very simple idea, or simple set of ideas, turns out to be very powerful and leads to all sort of unexpected structure and unexpected predictions.
Beauty means a lot of different things to a lot of different people. A lot of different ways in which things can be beautiful. But this really has a very specific meaning and which is more along the lines of elegance which is that we say an idea is beautiful or elegant in mathematics or physics if a very simple principle or a very simple idea, or simple set of ideas, turns out to be very powerful and leads to all sort of unexpected structure and unexpected predictions.
भौतिकी की वर्तमान स्थिति के बारे में समझने वाली मुख्य बात यह है कि हम - एक तरह से, अपनी ही सफलता के शिकार हैं। हमारे पास 'स्टैंडर्ड मॉडल' नाम का एक अविश्वसनीय रूप से सफल सिद्धांत है। और यह वास्तव में उन सभी चीज़ों की व्याख्या करता है जिन्हें हम बहुत कम प्राथमिक कणों और उनके बीच के कुछ बुनियादी बलों के संदर्भ में देख सकते हैं। और यह एक काफी खूबसूरत सिद्धांत है और यह वास्तव में हद दर्जे तक सफल है।
The main thing to understand about the current state of physics is that we have - are in some sense, a kind of victim of our own success. We have an incredibly successful theory called the Standard Model. And it really explains everything that we can observe about and in terms of a very small number of elementary particles and some basic forces between them. And it's a quite beautiful theory and it really is just absurdly successful.
The main thing to understand about the current state of physics is that we have - are in some sense, a kind of victim of our own success. We have an incredibly successful theory called the Standard Model. And it really explains everything that we can observe about and in terms of a very small number of elementary particles and some basic forces between them. And it's a quite beautiful theory and it really is just absurdly successful.
सिर्फ इसलिए कि आप किसी ऐसी चीज़ से शुरुआत कर रहे हैं जिसे आप जानते हैं - एक ऐसा सिद्धांत जिसके बारे में आप जानते हैं कि वह सही है और उस सिद्धांत की अपनी समझ को और विकसित करने की कोशिश करना - किसी ऐसी चीज़ को पूरी तरह फेंक देने और किसी अधिक काल्पनिक चीज़ के साथ नए सिरे से शुरुआत करने की कोशिश करने से शायद ज़्यादा फायदेमंद हो सकता है।
Just because you're starting from something which you know - a theory which you know is right and trying to further develop your understand of that theory is maybe a more fruitful thing to do than trying to just throw all that out and start afresh with something more speculative.
Just because you're starting from something which you know - a theory which you know is right and trying to further develop your understand of that theory is maybe a more fruitful thing to do than trying to just throw all that out and start afresh with something more speculative.
भौतिकी के नियमों के समय के साथ न बदलने के भौतिक निहितार्थ यह हैं कि ऊर्जा नाम की कोई चीज़ होती है और ऊर्जा संरक्षित रहती है, और यही बात - और यह तथ्य कि अंतरिक्ष में अलग-अलग दिशाओं में आगे-पीछे जाने पर भौतिकी के नियम नहीं बदलते, इसका मतलब यह है कि गति (momentum) नाम की कोई चीज़ होती है और गति संरक्षित रहती है और समय के साथ विकसित होने पर बदलती नहीं है।
The fact that the laws of physics don't change as if you move in time has physical implications that there's this thing called energy and energy is conserved, and the same thing - and the fact that the laws of physics don't change of you move back and forth in different directions in space implies that there is something called momentum and momentum is conserve and doesn't change as you evolve in time.
The fact that the laws of physics don't change as if you move in time has physical implications that there's this thing called energy and energy is conserved, and the same thing - and the fact that the laws of physics don't change of you move back and forth in different directions in space implies that there is something called momentum and momentum is conserve and doesn't change as you evolve in time.
गणित में अपनी मुश्किलें हो सकती हैं, लेकिन सच तो यह है कि इसे अन्य विज्ञानों की तरह उतनी समस्याओं का सामना नहीं करना पड़ा है, और इसमें लोग जो कुछ भी करते हैं, उसका अधिकांश हिस्सा पूरी तरह से व्यर्थ है। इस बात से शायद ही किसी को कोई खास फर्क पड़ता है। यहाँ वामपंथ, दक्षिणपंथ या विचारधारा जैसी कोई चीज़ें आड़े नहीं आतीं, क्योंकि इनका कोई वजूद ही नहीं है। असल में, गणित का उन चीज़ों से कोई लेना-देना ही नहीं है जिनकी लोग वैचारिक तौर पर चिंता करते हैं। इसलिए ज़्यादातर गणित ग्लोबल वार्मिंग, स्वास्थ्य सेवा या ऐसी ही किसी भी अन्य अहमियत वाली चीज़ के बारे में कुछ भी स्पष्ट रूप से नहीं बताता।
Mathematics can have its problems, but it's actually hasn't seen a lot of the problems as some of the other sciences and so much of it in what people are doing is completely useless. Nobody kind of in really cares very much. You don't really have kind of right and left and people in ideology coming in because there isn't any. It just doesn't actually connect up to the kinds of things that people ideologically worry about. So most of mathematics just doesn't tell you anything one way or another about global warming or about healthcare or about any number of things that you might care about.
Mathematics can have its problems, but it's actually hasn't seen a lot of the problems as some of the other sciences and so much of it in what people are doing is completely useless. Nobody kind of in really cares very much. You don't really have kind of right and left and people in ideology coming in because there isn't any. It just doesn't actually connect up to the kinds of things that people ideologically worry about. So most of mathematics just doesn't tell you anything one way or another about global warming or about healthcare or about any number of things that you might care about.
मेरे एक सहकर्मी अक्सर यह कहते हैं कि अकादमिक जगत या असल दुनिया में गणित शायद इकलौता ऐसा विषय है, जहाँ अगर दो लोगों के बीच किसी बात पर मतभेद हो जाए - यानी अगर वे किसी गणितीय विषय पर अध्ययन कर रहे हों और उनके पास कोई प्रमाण (प्रूफ) हो, लेकिन वे इस बात पर सहमत न हों कि वह प्रमाण सही है या नहीं - तो वे एक कमरे में बैठकर इस पर चर्चा करेंगे, और बहुत जल्द या दिन के अंत तक उनमें से कोई एक अपनी गलती मान लेगा।
One of my colleagues likes to say that, mathematics is the - he thinks about the only subject that he knows in academia or in the real world where if two people disagree about something - if people are studying some mathematical object and there's supposed to be a proof and they disagree about whether this proof or not, the will go into a room, sit down and talk about it and fairly quickly or at the end of the day one of them will admit they're wrong.
One of my colleagues likes to say that, mathematics is the - he thinks about the only subject that he knows in academia or in the real world where if two people disagree about something - if people are studying some mathematical object and there's supposed to be a proof and they disagree about whether this proof or not, the will go into a room, sit down and talk about it and fairly quickly or at the end of the day one of them will admit they're wrong.