Ask a physicist anything.

[Chesterton]

1)A floating strawberry illusion is achieved with two parabolic mirrors, each having a focal length 7.5 cm, facing each other so that their centres are 7.5 cm apart. If a strawberry is placed on the lower mirror, an image of the strawberry is formed at the small opening at the center of the top mirror. Show that the final image is formed at that location and describe its characteristics.

2)Design a 10-hp 11:1 worm-gear speed-reducer mesh for a lumber mill planer feed drive for 3- to 10-h daily use. A 1720 rev/main squirrel-cage induction motor drives the planer feed (Ka = 1.25), and the ambient tempreture is 70F.

An African or European strawberry?

 

[Wiccan_Child]

Why is there a difference between the number of sausages in a sausage package and the number of sausage buns in a sausage bun package?

To make people buy extravagant numbers of each product. There's actually a conspiracy between the two companies.

 

[Nabobalis]

Where are you studying and I assume your doing a Phd?

 

[Wiccan_Child]

Where are you studying and I assume your doing a Phd?

I studied Physics, with a bent towards the particle and nuclear side of things. And no, I'm not doing a PhD .

 

[pgp_protector]

Okay. A little more difficult then:

Using lines, each circle is supposed to be connected to all three squares. There can be no gaps in the lines and no line can cross another line.

Can you solve it? It's easier if you draw it on a piece of paper.

Yes, with 1 line.

Start S1 -> C1 (Front side) -> S2(Back Side) -> C2(Front) -> S3 (Back) -> C3

All Circles Connected To All Squares No Crossing or Breaking of the line.

 

[TheReasoner]

Yes, with 1 line.

Start S1 -> C1 (Front side) -> S2(Back Side) -> C2(Front) -> S3 (Back) -> C3

All Circles Connected To All Squares No Crossing or Breaking of the line.

Sorry, I should say, you have to use nine lines. One line can only connect one circle to one square. No more.

 

[Nabobalis]

I studied Physics, with a bent towards the particle and nuclear side of things. And no, I'm not doing a PhD .

So what you doing now? I'm studying Physics also. Hopefully do a PhD after

 

[Chesterton]

Is the sum total of information in a thing the ideal essence of the thing itself?

Okay it may sound like a ponderous question but I have an entirely practical need: This Christmas, I'm thinking of giving my girlfriend information about the concept of a diamond instead of a diamond. She likes being fashionable, so I might work the angle that, since we're now living in the Information Age, her girlfriends who get "real" diamonds are just passé, and she's much better off getting information, and my love for her is greater because I gave her a couple sheets of paper describing the "ideal essence" of a certain rock, instead of the rock itself which (in my opinion this time of year) is a cheap imitation of its ideal essence.

Whadd'ya think?

 

[pgp_protector]

Sorry, I should say, you have to use nine lines. One line can only connect one circle to one square. No more.

Got It (Check PM to see if I'm Right )

 

[TheReasoner]

Got It (Check PM to see if I'm Right )

Yep. That'd be it

 

[pgp_protector]

Ok given that we're also asking Non Physics Questions


How do I Develop a C# Application for Windows to Run As a Service while allowing the Application to talk to other applications through a Custom DLL without using the TCP/IP Stack & Ports (too slow) so Need DMA comunications ?

<My Service> <--> <Custom DLL> <--> <User Application>

 

[TheReasoner]

How do I get an A in my physics class when I lack two mandatory math classes to even take the physics class I am in? (That is to say, the physics course requires the completion of two math courses. Us nanotech students have neither one yet. We'll take them next semester. For the record: The faculty had us enrolled in the course without consulting us at all)

The course is in classical mechanics and thermodynamics. With an emphasis on classical mechanics. The exam is in December, and we all have a less than stellar grasp on it...
Any tips?

 

[pgp_protector]

How do I get an A in my physics class when I lack two mandatory math classes to even take the physics class I am in? (That is to say, the physics course requires the completion of two math courses. Us nanotech students have neither one yet. We'll take them next semester. For the record: The faculty had us enrolled in the course without consulting us at all)

The course is in classical mechanics and thermodynamics. With an emphasis on classical mechanics. The exam is in December, and we all have a less than stellar grasp on it...
Any tips?

Try giving the instructor this.

Spoiler: ;)

 

[Wiccan_Child]

How do I get an A in my physics class when I lack two mandatory math classes to even take the physics class I am in? (That is to say, the physics course requires the completion of two math courses. Us nanotech students have neither one yet. We'll take them next semester. For the record: The faculty had us enrolled in the course without consulting us at all)

The course is in classical mechanics and thermodynamics. With an emphasis on classical mechanics. The exam is in December, and we all have a less than stellar grasp on it...
Any tips?

Either a good book or a good bribe. I learnt more about semiconductors in a hour reading a book than I did over three months of lectures. It's actually really interesting stuff, especially when you figure out how diodes work.

 

[Wiccan_Child]

Ok given that we're also asking Non Physics Questions


How do I Develop a C# Application for Windows to Run As a Service while allowing the Application to talk to other applications through a Custom DLL without using the TCP/IP Stack & Ports (too slow) so Need DMA comunications ?

<My Service> <--> <Custom DLL> <--> <User Application>

Not a clue! Though I was reading up on services and processes a few weeks ago, because I finally wanted to know why I was inundated with a legion of svhosts all the time. Turns out, they're sound fellas.

 

[Belk]

Ok given that we're also asking Non Physics Questions


How do I Develop a C# Application for Windows to Run As a Service while allowing the Application to talk to other applications through a Custom DLL without using the TCP/IP Stack & Ports (too slow) so Need DMA comunications ?

<My Service> <--> <Custom DLL> <--> <User Application>

Having it run as a service is not inherent in the application, you control that through the install routine. Basically it is just a normal application that you are running from the services section.

Setting the application up to use the custom .dll is harder. I've never tried that personally so afraid I can't be much help to you there, though why you would be communicating to other apps via tcp/ip i don't know. TCP/IP is transport layer and you only need to go down to application layer so a com+ should work fine and you would not need a custom .dll you could just use the standard communication add ins.

 

[Maxwell511]

I'm enjoying these physics-related threads so...

Ask a physicist anything .

Do you think that gravity's role will solve the problems of quantum superposition for marco entities?

As per Roger Penrose and such....

 

[TerranceL]

Ok, this has always confused me about quantum physics....

Schrodinger's cat.....

I don't understand how something could only be set, if it's observed.

What does observation have to do with if an something really happened?

Please don't throw math at me, just try to explain it in layman terms.

 

[Wiccan_Child]

Ok, this has always confused me about quantum physics....

Schrodinger's cat.....

I don't understand how something could only be set, if it's observed.

What does observation have to do with if an something really happened?

Please don't throw math at me, just try to explain it in layman terms.

|&#966;>! e[sup]-i&#952;[/sup]! &#916;[sup]2[/sup]!

OK, radioative decay is a random, spontaneous process. We cannot predict when a radioactive particle will decay. So, if we put such a particle in a box with a device that goes 'red' for 'not decayed', and 'green' for 'decayed' (or a cat...), we won't know what that device says.
More generally, a quantum particle exists as the sum total of all possible states it could be in. When we measure it (e.g., by sticking a probe next to it and measuring its energy), we interfere with the particle and limit what states it can be in. So if we measure it to have an energy of E&#177;&#916;E, then it is thereafter the sum of those states whose energies are between E-&#916;E and E+&#916;E.

So Schr&#246;dinger's cat is a simplified thought experiment to illustrate this. The cat exists as a superposition of the 'alive' state and the 'dead' state. We write this as |&#966;> = &#945;|alive> + &#946;|dead>.

It's mathematically heavy, and there's disagreement on just what a 'wavefunction' describes about a particle, but the basic idea is that an unmeasured particle has a wide range of possible states, and these states 'collapse' to just a few states when they are interfered with.

 

[Wiccan_Child]

Do you think that gravity's role will solve the problems of quantum superposition for marco entities?

As per Roger Penrose and such....

No, I disagree with the Penrose interpretation. I don't think mass precludes the major quantum effects, such as tunnelling, just because there's a lot of it. That's just my personal opinion.