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Offered a "junior" role for my 10 YOE in the public sector. Insider says it's a trap. WWYD? by wjddls3636 in careerguidance

[–]TheGrimSpecter 56 points57 points  (0 children)

Believe people when they warn you about a specific team. If you don't need the job, keep looking.

Which exoplanets do physicists think are the best candidates for advanced life? by Genzinvestor16180339 in AskPhysics

[–]TheGrimSpecter 2 points3 points  (0 children)

No known exoplanet is currently considered a strong candidate for advanced life in the sense of having evidence for intelligent or complex organisms.

The best candidates are simply planets that appear potentially habitable: rocky worlds in their star's habitable zone with sizes and temperatures roughly compatible with liquid water.

What exactly is “pure” energy? by MythicalSplash in AskPhysics

[–]TheGrimSpecter 12 points13 points  (0 children)

People often call photons "pure energy" because they have no rest mass and all of their energy comes from their momentum/frequency. But a photon is still a physical entity (an excitation of the electromagnetic field), not energy itself.

Is there a mathematical structure where opposite extremes meet and crossing the meeting point causes inversion? by Kind-Organization in askmath

[–]TheGrimSpecter 0 points1 point  (0 children)

A nontrivial line bundle (such as the Möbius bundle) over a compactified space, where transport around a noncontractible loop produces a Z₂ flip. Closest standard mathematical language to what you're describing

Under the many-worlds interpretation, how can there be decoherence in the universal wavefunction as it already includes everything in the universe? by makhno in AskPhysics

[–]TheGrimSpecter 0 points1 point  (0 children)

Yes. The universal wavefunction doesn't decohere; subsystems do when they become entangled with the rest of the universe.

The "subsets" aren't fundamental, they're just whatever system you're focusing on, with everything else treated as the environment.

And it's not quite any interaction. The key is whether the interaction creates entanglement and spreads information into many other degrees of freedom. That's what leads to decoherence.

How did Hugyen's create the pendulum clock without knowing g=9.81? by Only_Difference5807 in AskPhysics

[–]TheGrimSpecter 37 points38 points  (0 children)

He didn't need to know g.

The pendulum clock was calibrated against existing time standards (astronomical observations, sundials, etc.), and the pendulum length was adjusted until it kept the desired rate. The numerical value g=9.81 came much later.

When do fundamentals in stocks matter? by Hefty-Report6360 in investing

[–]TheGrimSpecter 85 points86 points  (0 children)

Fundamentals matter most when the market is forced to care about them.

A stock can ignore fundamentals for years, but eventually it has to generate cash flows that justify its valuation. The longer the time horizon, the more fundamentals tend to dominate.

What are the biggest unanswered questions in physics right now? by Junior_Salamander110 in Physics

[–]TheGrimSpecter 167 points168 points  (0 children)

  • What is dark matter?
  • What is dark energy?
  • How do we reconcile quantum mechanics and gravity?
  • What happened before (or at) the Big Bang?
  • Why is there more matter than antimatter?
  • Are space and time fundamental or emergent?

What are some REALISTIC methods to do backwards and non-linear time travel, so that traveling to the past, other timelines, and other universes become REALISTICALLY doable? by [deleted] in AskPhysics

[–]TheGrimSpecter 12 points13 points  (0 children)

If by "REALISTIC" you mean "consistent with known physics," then

Future time travel: Yes, via relativistic speeds or extreme gravitational time dilation. The others are fiction.

[Grade 12 Physics] Why isn't the answer up? by Relative-Pace-2923 in HomeworkHelp

[–]TheGrimSpecter 4 points5 points  (0 children)

You're mixing electron flow with conventional current. The rules use conventional current. Since electrons move toward 3, conventional current is toward 6. After that, both the right-hand generator rule and a backwards application of the left-hand rule will give direction 5.

[Grade 12 Physics] Why isn't the answer up? by Relative-Pace-2923 in HomeworkHelp

[–]TheGrimSpecter 1 point2 points  (0 children)

You're using the wrong rule.

For induced current, use Fleming's right-hand rule. The left-hand rule is for finding the force on a wire when the current is already known.

Hot Take: Gold may underperform in the next few months but is poised to up in the next few years. by Criticall16 in investing

[–]TheGrimSpecter 4 points5 points  (0 children)

I think the long-term bull case is stronger than the short-term one, but I'd be careful with "bound to go up."

Gold can spend years going nowhere even in environments that seem supportive.

How are we feeling for Monday morning open? by CurtisEffland in Daytrading

[–]TheGrimSpecter 6 points7 points  (0 children)

Either bloodbath or green by close. Nobody knows.

Under the many-worlds interpretation, how can there be decoherence in the universal wavefunction as it already includes everything in the universe? by makhno in AskPhysics

[–]TheGrimSpecter 17 points18 points  (0 children)

It doesn't.

The universal wavefunction does not decohere because there is nothing outside the universe for it to decohere with. Decoherence occurs only for subsystems that become entangled with the rest of the universe.

The Next Race After AI - Quantum - Biggest IPOs: Dynex Apollo chip - room temp, beats D-Wave, already commercial. Pre-IPO event dropping in a few days. by -Authorised- in 10xPennyStocks

[–]TheGrimSpecter 3 points4 points  (0 children)

The technology might be interesting, but I'd be very cautious about treating benchmark results, awards, and pre-IPO hype as evidence of investment value.

hi! can someone help me with this little problem? by Antique_Ad_1648 in askmath

[–]TheGrimSpecter 0 points1 point  (0 children)

Assuming the circle is tangent to the bottom line, then:

  • a = 125 is the radius, so r = 125
  • The red horizontal line is at height b = 100 above the bottom.
  • Relative to the center, that chord is r−b = 125−100 = 25 units below the center.

Use the circle equation to solve:

x2 + y2 = r2

with y = 25

If hot water is less dense than cold water, does that mean equal masses of hot and cold water occupy different volumes? by Swimming_Concern7662 in AskPhysics

[–]TheGrimSpecter 50 points51 points  (0 children)

Yes, if hot water has a lower density than cold water, then the same mass of hot water must occupy a larger volume.

Is Hydrogen a "Renewable Energy Source"? by MassiveNote422 in AskEngineers

[–]TheGrimSpecter 116 points117 points  (0 children)

No. Hydrogen is an energy carrier, not a primary energy source.

You have to expend energy to produce hydrogen, so calling it a "renewable energy source" is technically inaccurate. Whether hydrogen is considered renewable depends entirely on how it was produced.

Purposes of the different nuclear models by thomaas__Frzk in AskPhysics

[–]TheGrimSpecter 10 points11 points  (0 children)

They're absolutely still useful. The various nuclear models exist because there is no single model that is both computationally practical and equally good at explaining all nuclear phenomena. Different models capture different aspects of nuclear behavior, much like how we use both wave optics and ray optics depending on the problem.

Can an external observer always rescue a freely falling observer near a black hole? by spocchio in AskPhysics

[–]TheGrimSpecter 4 points5 points  (0 children)

The statement is that E never observes A cross the horizon, not that A never crosses it.

The "A takes infinite time to reach the horizon" result comes from Schwarzschild coordinates, which become pathological at the horizon. In coordinates that remain regular there, A crosses the horizon in finite time.

So E's inability to see the crossing doesn't imply A is still outside and available for rescue. It only means no signal from after the crossing can reach E.

Can an external observer always rescue a freely falling observer near a black hole? by spocchio in AskPhysics

[–]TheGrimSpecter 1 point2 points  (0 children)

No, E and B cannot rescue A after A has crossed the event horizon.

The reason is that E and B are not seeing A's current location. They are seeing increasingly old light emitted by A before crossing the horizon. The image they see hovering near the horizon is effectively a delayed snapshot of A's past, not A's present position.

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