Recent content by vhbelvadi

Update: Everything looks good. I'm not watching all threads, but I still get an overflowing updates stream.

Unlikely. I see updates, for example, from engineering, computer science homework and biology sections which I have never visited, let alone subscribed to. I'll visit my profile later on my Mac, check again and update here.

Can someone clarify the updates stream for me. What updates do I see there? It's not just from my subscriptions; I'm seeing updates from every single thread, so that's a lot and, if that is what it is, it makes the updates stream pretty useless.

The star. Edit: Is the unread stream broken? I don't understand what it shows: unread updates from my subscribed forums? Wouldn't that just be too much?

For long I've felt the PF app (iOS, no idea about Android) was lacking. Today's update is great. Makes it work great and look great. Nice work, developers.

Introduction: This isn't really a homework question in that I recently came across Feynman's original problem sets that had accompanied his famous lectures of 1960 and decided to solve them (and I've been doing rather badly). But at some point, I figured it would fall into this category best...

Well, inflection points can be arrived at by solving f "(x)=0 and finding values of x and substituting them again in the given equation. That should give you all inflection points of that function.

I doubt ISRO has a space programme involving astronauts yet. It's mostly unmanned missions, so unless that changes anytime in the coming years (as it should), you're better off looking into NASA and getting that US citizenship.

My first thoughts too: 'paper' is just too vague. Perhaps with more specifics, the maths would be as simple as @Nugatory shows. That said, in a watered-down point of view, I fail to see why the answer should be any more than an order or two of magnitude different from @Nugatory's estimate of...

@BruceW - An open air particle accelerator--my thoughts exactly! So, basically, it's 150g of particles colliding with air molecules, so wouldn't the collision (for now let's assume there's no batter for a good distance) cause the entire ball to disintegrate resulting in the generation of energy...

I came across this from xkcd today. The question seems interesting, but I was wondering if this expplanation quite covers this or are there other possibilities? (Also, is something wrong with this explanation?) Basically they're dealing with a baseball pitched at relativistic speeds...

It seems rather obvious when you put it that way! @cbetanco - So you account any of (all) the missing mass to neutrinos?

@ZapperZ, @mjacobsca - Thanks a lot. I think that quite clarifies everything!

So, -- pardon my ignorance :-) -- but what prevents them from colliding more often? Their size?

I'm aware a neutrino does not 'interact' with other particles nor have charge. But in the Super-K detector, neutrinos are said to be detected through the 'charged particles they generate when they occasionally interact with other particles.' How exactly does this occur? I mean, what does...