« first day (2966 days earlier)      last day (985 days later) » 

07:10
@JohnRennie: Good Morning Sir :-)
@Vishnu Hi :-)
I'm answering another question at the moment but I shouldn't be long ...
How are you? We are meeting back after a long time.
@JohnRennie Sure sir. No problem.
07:23
@Vishnu I'm good thanks :-) How are you? Are you at college at the moment (I chat to so many students I forget who is at college and who isn't).
I am also fine sir. Thank you for asking. :-)
And yes, I'm in college.
We got our vacations. I just completed my fourth semester.
Isn't it exam time at the moment?
No sir. Exams are over.
@Vishnu Ah, exams just finished :-)
Yes :-)
And some extra time for experimenting.
07:25
How are you enjoying it? Not the exams!! I mean being back at college after all the covid stuff.
Yes sir. We came to campus for the first time back in October. It was really great to visit the campus and special sites like the display of the fighter jet MiG23. Also enjoyed the offline labs we had wherein we got to use Lathe machines and work with real engines, compressors and do experiments on it. It was a lot of fun. :-)
It was way better than the online labs we were used to during our first three semesters.
I really enjoyed being at university. Having access to all the cool equipment and meeting lots of new people.
Yes sir. :-)
If you are free, I just ran into a small issue regarding reinstalling Ubuntu. Will it be possible for you to help me out, sir?
Yes, I can try. What's the problem?
Earlier you had guided me on dual booting Ubuntu 18.04. I thought of upgrading to Ubuntu 20.04 and used the software update manager in Linux. It kind of messed up as after installation, it got stuck in booting often. And I managed to get to the desktop only once after repeated attempts. Still there were some little problems like duplicate apps and so on. So I decided to do a complete reinstallation. I took backup of important data in Ubuntu and prepared a flash drive for Ubuntu 20.04.
Restarted my system and F12, then into the installation wizard through the flash drive. Problem is, I have a doubt at the stage where it asks for installation type. I have attached two pictures of the wizard in the following folder:
HNQ
HNQ
07:39
2
Q: Alternate sky colors?

VoydAngelOk, so the sky is blue because of Raleigh Scattering - blue wavelengths of light scatter off of atmospheric particles in the air (more/easier than others) - I understand this pretty well. So, if our atmosphere had a different chemical composition, would the sky be a different color (barring thing...

The first option looked straightforward but the dialogue box that opens on proceeding looks risky as it warns of erasing all partitions which I don't want to. :/
Can you still boot into Windows?
If so I would boot into Windows then delete the Ubuntu partition from inside Windows.
@JohnRennie Yes sir. Windows works perfectly. Ubuntu problem comes up only when I select it from GRUB.
That way when you do the installation you can choose the option to install into the unoccupied space.
@JohnRennie Ah, in the disk manager by deleting the volume corresponding to the Ubuntu partition sir?
07:41
Isn't 22.04LTS out now?
I would install 22.04 rather than 20.04.
@Vishnu Yes
@JohnRennie Yes sir, a few days back.
@JohnRennie problem is, most of my batchmates are now using 20.04 and I think we still don't have software like ROS for 22.04.
@Vishnu That way it will be like when you first installed Ubuntu i.e. you have Windows filling only half the disk and the rest of the disk free for Ubuntu to install into.
@Vishnu Ah, good point, it will take the dev a while to port ROS to 22.04.
Yes, that has bitten me before when I've jumped to a new version and discovered some software I needed wasn't available.
@JohnRennie Ok sir. So the better way is to proceed back, boot into Windows and delete that partition and create a new one right? I still got the previous transcript of our discussion and I'll follow that along for the installation.
@JohnRennie :-)
I would boot into Windows and delete the Ubuntu partition, but not create a new one. Leave that part of the disk blank.
Then the Ubuntu installer can create whatever partition(s) it wants in the free space.
@JohnRennie Wouldn't delete volume automatically remove the partition as a whole? I haven't tried it. I thought proceeding via the installer and using the first option work work out. Sadly it gave a warning.
07:47
Yes. It's just that you said:
> boot into Windows and delete that partition and create a new one right?
"boot into Windows and delete that partition" is fine, but don't create a new partition in Windows.
Ah. Got it sir.
If you want to post a picture of what you see in Windows disk management I can have a look ...
Sure sir. I'm now having a situation with powering off through Ubuntu. :-)
It won't shut down?
I'll send in 5 minutes. Things just came back to control.
07:49
OK :-)
(Ubuntu obviously doesn't want to be deleted :-)
@JohnRennie the power off button was non responsive for some reason. It worked after I went to 'try Ubuntu' option sir.
@JohnRennie :-)
@JohnRennie I believe that the 127.5 GB partition here is the one we earlier allocated for Ubuntu, sir:
Yes, I agree. So you should be able to delete that partition then rerun the installer.
It's just possible deleting the partition might break Grub and give you a problem booting,
šŸ˜
I can't remember where the Grub binaries are installed. But if it does you can boot Windows and do a repair. That will delete Grub as well so you'll be back to how it was before the initial Ubuntu install.
@JohnRennie Now, it's successfully unallocated sir.
07:57
Perfect! Reboot and see what happens.
Ok sir. Fingers crossed. :-)
In the boot manager, it still shows Ubuntu along with Windows and the flash drive. Are we good to go, sir?
Yes, select Windows and double check Windows still starts.
Sure sir.
Actually you probably didn't need to bother and I'm being over cautious.
Whatever :-)
You should be fine to just boot off the flash drive and do the Ubuntu install.
@JohnRennie Yes sir, Windows seems to start normally. And I'm in desktop.
@JohnRennie :-)
08:01
Cool. Restart, boot from the flash drive and it should all be straightforward.
"It's better to be safe than sorry"
That's why I stopped the previous time.
I didn't want to clean everything off. :-)
I'll be around for a while if you run into any problems but it should be routine now.
Sure sir. Thank you very much.
 
1 hour later…
09:03
@JohnRennie: Everything seems to be working great. :-)
@Vishnu That was easy :-)
Yes sir. :-)
Just followed our previous conversation for Grub customizer too.
I kind of feel this 20.04 is booting bit faster and is smoother than 18.04. Not sure if it's my illusion.
I would guess it's real, but it's because you have a shiny clean new install.
Your 18.04 install was a year old and OSs tend to accumulate crud and get slower with time.
Ah yes :-)
Good bye, sir. It was nice to chat with you after a long time. :-)
Bye :-)
HNQ
HNQ
09:45
1
Q: Fourier Transform of a Wave Packet

SofvarIn the analysis of coherence and interference, I encountered the following expression: $$F(t)=\Re\int_0^\infty\mathrm d\omega e^{-i\omega t}H(\omega)$$, where $\Re$ denotes the real part of the integral, and $H(\omega)$ vanishes for $\omega<0$. I want to show the Fourier transform of $F(t)$ is $$...

 
2 hours later…
HNQ
HNQ
11:25
1
Q: Iā€™m trying to charge a capacitor. Would a bridge rectifier charge it like a battery would?

TechMeltsSince a bridge rectifier converts ac to dc. Will this charge my capacitor to max capacity how hooking it up to a battery would? The positive is charging the anode, while the cathode is grounded. Any reason why this circuit would not work? When just trying to convert ac to do soley for the purpose...

 
5 hours later…
HNQ
HNQ
16:52
2
Q: Energy-Momentum tensor in the non-relativistic limit of Klein-Gordon Field

Tan TixuanAssume we have a real Klein Gordon field $\phi(x,y,z,t)$, and we do the non-relativistic expansion of it in terms of a complex field $\psi(x,y,z,t)$ $$\phi=\frac{1}{\sqrt{2m}}(\psi e^{-imt}+\psi^* e^{imt}).\tag{1}$$ Notice that in the non-relativistic limit, $\psi$ obeys the Schrodinger equation ...

 
2 hours later…
HNQ
HNQ
18:35
2
Q: At which point is the magnetic field in a current carrying loop the strongest

Sujal MotagiAt which point inside a circular current carrying loop the strongest? Some sources say it is at the centre and some say it is at the circumference. And how can we mathematically prove this? And also, is the magnetic field line through the centre of the loop exactly a straight line? Because this d...

 
2 hours later…
HNQ
HNQ
20:43
3
Q: Am I in a superposition?

Juan PerezSomeone looks at me. Now, he knows my position and my momentum, with some uncertainty. Therefore, he hasn't measured neither my position not my momentum, since neither is known perfectly. He measured some other observable $O$, and found me in some eigenstate of $O$: $|\psi>$. $|\psi>$ is such tha...

 
3 hours later…
HNQ
HNQ
23:16
2
Q: What is this dynamics book that has questions and it's solutions?

FadedYoussefI found these questions online and was amazed by how organized this book was so it would be really helpful to know it's name


« first day (2966 days earlier)      last day (985 days later) »