# আপেক্ষিক পদার্থবিজ্ঞানে উপলব্ধি এবং বোধশক্তি এর বাধ্যবাধকতা

 The following sections (and figures) have been abridged out of this post. প্রবন্ধের পূর্ণ সংস্করণ একটি পিডিএফ ফাইল হিসাবে পাওয়া যায়. ()

#### 4. Explanations Based on LTT Effects চিত্র 2. Illustration of the traditional explanation for the observed superluminal motion. An object expanding at a speed ratio = 0.8, starting from a single point S. The solid circle represents the boundary one second later. The observer is far away on the right hand side, দ্য (at infinite distance). The dashed ellipse is the apparent boundary of the object, as seen by the observer. চিত্র 3. The radio jet and lobes in the hyperluminous radio galaxy Cygnus A. দুই লোব হটস্পট, কোর অঞ্চল এবং জেট বিমান পরিষ্কারভাবে সম্পূর্ণ প্রোফাইল দ্বারা. (Reproduced from an image courtesy of NRAO/AUI.) চিত্র 4. The top panel (একটি) shows an object flying along $A_-BA$ at a constant superluminal speed. The observer is at $O$. The object crosses $B$ (the point of closest approach to $O$) সময় $t=0$. The bottom panel (খ) shows how the object is perceived by the observer at $O$. It first appears at , then splits into two. The two apparent objects seem to go away from each other (along $J_1$ এবং $J_2$) as shown. চিত্র 5. The apparent angular positions of an object traveling at different speeds at a distance $y$ of one million light years from us. The angular positions ( $\phi$ in radians) are plotted against the observer’s time $t_O$ in years. চিত্র 6. Time evolution of the redshift from a superluminal object. It shows the redshifts expected from an object moving at $\beta = 300$ at a distance of ten million light years from us. The X axis is the observer’s time in years. (Since the X axis scales with time, it is also the redshift from an object at 116 light days –ten million light seconds–with the X axis representing $t_O$ in seconds.)