Ask a physicist anything. (3)

[Wiccan_Child]

This thread was split automatically after 1000 replies and this thread has been automatically created.
The old thread automatically closed is here: "Ask a physicist anything. (2)"

 

[Wiccan_Child]

"Can you get electricity directly from a fusion reaction without having to heat to steam first?"

Fusion (and, for that matter, fission) reactors work by generating heat; the end products are hotter than the initial reactants. The trick is to a) remove that heat so the reactor doesn't melt, and b) turn that heat into electrical potential. Any system what cools the reactor will also remove the heat, so the cooling system has to be intimately linked to the 'make electricity' system.

Anyhoo, the short answer is: ...maybe. If you could get a fantastically conductive metal that became electrically charged when hot, that might do the trick.
But water cooling is such an efficient method there's not really much reason to change.

 

[pgp_protector]

Can you get electricity directly from a fusion reaction without having to heat to steam first?

Yes, use a thermocouple, thought that's not very efficient.

(A Thermocouple will convert Heat into Electricity, normally used for measuring temperature by measuring the Voltage, you can calculate the Temp)

 

[TerranceL]

The third thread... wow man.

Grats Wiccan on a truly epic thread.

 

[jayem]

If ALL sources of energy loss (i.e., friction, air resistance, etc.) could be eliminated, would it be possible to construct a perpetual motion machine?

 

[catzrfluffy]

What what you do if this was stuck on your computer permanently? Constantly giving you commentary on everything?

 

[BrianOnEarth]

If ALL sources of energy loss (i.e., friction, air resistance, etc.) could be eliminated, would it be possible to construct a perpetual motion machine?

Yes. But it wouldn't be very useful.

 

[pgp_protector]

What what you do if this was stuck on your computer permanently? Constantly giving you commentary on everything?

Reformat & Install a new OS.

 

[BrianOnEarth]

Maxwell511 wrote: Occam's Razor suggests an agenda. You hold one variable constant and test the outcome of changes in the other and vice verse. If both those tests fail to produce the outcome then you move onto the more complicated hypothesis.

You never say, with lack of experimental evidence, it is more likely that the single variable idea is more likely than the double variable hypothesis.

If you have two independent variables then the probability of both being true is lower than the probability of the most likely one being true, unless they have equal probabilities.

Suppose that medicine has a 90% chance of cure on its own and prayer has a 5% chance. The ways a cure can occur are:
medicine alone (90% x 95% = 85.5%)
prayer alone (5% x 10% = 0.5%)
both (90% x 5% = 4.5%)

 

[catzrfluffy]

[c]

[/c]
[c]

[/c]

How does that happen?

 

[Wiccan_Child]

If ALL sources of energy loss (i.e., friction, air resistance, etc.) could be eliminated, would it be possible to construct a perpetual motion machine?

Depends on what you mean by 'perpetual motion'. I've often imagined a spanner wheeling end-over-end through the vacuum of space, unimpeded by air resistance and the like. Would that constitute perpetual motion?

Perpetual motion machines would still be impossible because, to extract usable energy, you have to do just that: extract energy. Even if the system is 100% efficient and no energy is lost as useless heat, the system would still wind down as useful energy was extracted. For example, one billiard ball hitting another is (almost) 100% efficient in that little energy is lost to the baize; but almost all energy is lost upon collision (that, of course, being the 'useful' part).
So, no, perpetual motion machines would still be impossible. Unless twirling endlessly through the cosmic eternity is your goal...

 

[Wiccan_Child]

What what you do if this was stuck on your computer permanently? Constantly giving you commentary on everything?

Every fibre of my being and intellect would be devoted into giving it sentience, sapience, and the capacity to feel. I would thereafter devote the rest of my life to inflicting terrible agonies upon it.

 

[Wiccan_Child]

[c]

[/c]

The UPS truck has fallen down a slope, after which the driver (the man in brown in the background) had to try to convince the police (also in the background) that he wasn't a terrorist. The man in the foreground is simply a well-to-do gentlemen (hence his attire) showing off his new sewing machine.

[c]

[/c]

How does that happen?

The car acts like a Faraday cage, and the Thingy on top is a Tesla Coil. The latter shoots electricity through the air in long filaments, the paths of which ionise said air, causing it to glow purple. Thus, you see long, purple filaments.

 

[Wirraway]

can you use atomic decay as a true (and inexpensive) random number generator?

 

[Wiccan_Child]

can you use atomic decay as a true (and inexpensive) random number generator?

Yes. If our understanding of radioactive decay is right, then it's a truly random event.

 

[pgp_protector]

[c]

[/c]

How does that happen?

The car acts like a Faraday cage, and the Thingy on top is a Tesla Coil. The latter shoots electricity through the air in long filaments, the paths of which ionise said air, causing it to glow purple. Thus, you see long, purple filaments.

If I Recall correctly, this one is actually a Time Laps Photograph of a "Telsa Coil" Car Security System (Not really practical though )

Tesla coil protects your car with ring of lightning | DVICE
YouTube - Tesla Car Thief Protection

 

[ArnautDaniel]

Does one model a neutrino as a Dirac spinor or a Weyl spinor?

 

[alexacker]

We can harness strong nuclear force through the nuclear reactions.
We can harness electromagnetism, in a billion ways.
We can harness gravity indirectly ( Hydroelectric dams)

Can we somehow harness the weak nuclear force?

 

[BrianOnEarth]

We can harness strong nuclear force through the nuclear reactions.
We can harness electromagnetism, in a billion ways.
We can harness gravity indirectly ( Hydroelectric dams)

Can we somehow harness the weak nuclear force?

Just to clarify your question. Forces are not equivalent to energy. Forces can be employed in the process of storing or extracting energy.
So a compressed spring exerts a force. It contains stored energy (potential energy) which can be extracted by uncompressing the spring.
Energy contained in certain atoms can be released by adding particles (fusion) or removing particles (fission).
The potential energy of an object on a table can be extracted by removing the table and allowing the object to fall. But the object has to have acquired that energy by being placed on the table in the first place.
As you know hydroelectric energy is actually extracted from the sun. The sun's radiant energy vapourizes the oceans to create clouds and rainfall that give lakes potential energy. Gravity is not the energy source but gravity is used to store the energy of the sun/rain.

 

[catzrfluffy]

If I Recall correctly, this one is actually a Time Laps Photograph of a "Telsa Coil" Car Security System (Not really practical though )

Tesla coil protects your car with ring of lightning | DVICE
YouTube - Tesla Car Thief Protection

Sneeaky...

YouTube - car protection system

Hehe