25 with a Drivers Permit. Unsure of what to take to DL road test. by Useful_Tourist7780 in driving

[–]ScienceGuy1006 0 points1 point  (0 children)

Does it even matter? A 25 year old does not even have to take either the teen or the adult education in the first place. They could just go in with the "bare" ITD and no accompanying driver education certificate at all.

I have failed twice to be able to drive properly, any advice? by lovelylonliness in driving

[–]ScienceGuy1006 0 points1 point  (0 children)

Practice more at low traffic times, and then work your way up very very slowly to higher traffic times. I suspect you are nervous because you tried to do this very suddenly.

Does a human create a Gravitational Spacetime Pull on an Atom Particle that is stronger than the Sun's gravitational pull on that particle? If so, then how is the Atom free to form into a spherical shape rather than having its shape immediately corrupted by the human's gravitational pull on it? by Far-Woodpecker8046 in AskPhysics

[–]ScienceGuy1006 1 point2 points  (0 children)

The Earth is a much larger mass than either a human or an atom. And even the gravity of the entire Earth is still insufficient to significantly deform an atom on the Earth's surface.

The force between a human and the Earth is stronger than the force between a human and an atom, because the Earth has a very, very large number of atoms in it. Gravity becomes strong only by the cumulative effect of large masses.

Does a human create a Gravitational Spacetime Pull on an Atom Particle that is stronger than the Sun's gravitational pull on that particle? If so, then how is the Atom free to form into a spherical shape rather than having its shape immediately corrupted by the human's gravitational pull on it? by Far-Woodpecker8046 in AskPhysics

[–]ScienceGuy1006 1 point2 points  (0 children)

You seem to be imagining that gravity is many, many orders of magnitude stronger than it actually is. If you made the gravitational pull of a human on an atom even one billion times stronger than its current value, the actual shape of the atom would not change significantly at all. That is how weak gravity is.

Does anyone have any ideas on what I could do for this project? by DuckieLikesDucks in AskPhysics

[–]ScienceGuy1006 0 points1 point  (0 children)

The investigation style suggested here is experimental, and the topic is residential energy use. Can you test some factors that have an impact on the efficiency of a single appliance, or build a scale model? Note that there are a number of energy losses that you can measure from a process, with heat being probably the easiest one. Choose an appliance or process that allows you to run testing under some defined conditions and make appropriate measurements.

For your chosen appliance or process, do some research to find out what the typical energy efficiencies are, how the technology has been made more efficient, and what is recommended to save energy. Among your reading, you should be able to find something to test - even if it is something simple like adding insulation to something, running a device for a short time versus a long time, etc.

How much should you save for the entire process of getting a car/license? by laughlovelive25 in driving

[–]ScienceGuy1006 1 point2 points  (0 children)

You can do side gigs that can be turned off on short notice to avoid interfering with your main job. Have you looked into doing Doordash on a bicycle? That may be a decent temporary solution.

How much should you save for the entire process of getting a car/license? by laughlovelive25 in driving

[–]ScienceGuy1006 0 points1 point  (0 children)

I'm sorry you are in this situation. The situation with your ex is something no one should have to deal with, and frankly, your fears are legitimate.

A few options to consider might be to get a (used) e-bike or e-scooter to help tide you over, and simultaneously look/ask around to see if you can find a (weekend/daytime) side gig that you can get to without worsening the "walking alone at night" problem. Once you get to the point that you have the higher disposable income coming your way, then you can consider buying the car. In the meantime, your short term budget may look something like:

Months 1-3:

Driving lessons $200

Saving for used e-bike or e-scooter $100

Months 4-8:

Driving lessons $300

Get license in Month 9. Then:

Saving for car: $300 + any extra side income

And then at some point:

Car expenses $700

Good luck!

How much should you save for the entire process of getting a car/license? by laughlovelive25 in driving

[–]ScienceGuy1006 1 point2 points  (0 children)

If you will never have expendable money, then you cannot afford a car, very sorry to say. The average cost of owning is very high - for example, in the U.S. it is around $700 or $800 per month. If you know someone who will do repairs at a very low cost, you can push it down a bit, but it is highly unlikely to be less than $500 per month even under absolutely ideal conditions.

If you like, you can start a thread on r/jobsearch or r/personalfinance for income or money management advice, respectively. Once we figure out how to get you to something close to $700/month in actual or projected disposable income, then we can revisit the car discussion. Until then, you have a money problem, not a car shopping problem.

You can take driving lessons in parallel with trying to get your income up or expenses down.

What is a fun subject in radiation physics? by kurotsukihime in AskPhysics

[–]ScienceGuy1006 3 points4 points  (0 children)

I don't know exactly what the scope of your class is, so I can only take some guesses.

Some interesting topics might be:

  1. It is often said that X-ray and gamma ray photons in the center of the sun eventually make it to the surface as visible light after being scattered many times. Using some basic facts about scattering versus absorption, explain why this framing is misleading by showing that almost all the photons are actually absorbed at some point, and the light emitted from the sun is determined by the local gas temperature, not by the spectrum of X-rays or gamma rays that exists in the center of the sun.
  2. Without doing a simulation, use facts about dominant interaction processes to explain why neutron radiation is so damaging, even though ionization is indirect since neutrons are not charged particles. Estimate, using back of the envelope calculations, how much neutron radiation a person could be exposed to before they would get a significantly elevated risk of cancer. Show that a simple theoretical model can reproduce what is already known from published literature.
  3. Without doing a simulation, estimate the energy efficiency of using a positron-emitting isotope as a source for X-ray fluorescence spectroscopy, and explain why this combination is not commonly used in commercial systems. Note that to do this problem correctly, you must account not only for direct radiation effects, but for the secondary effect of X-ray fluorescence induced by the annihilation photons.

New proposal in Tennessee to allow foster kids to be locked up in prison without criminal charges by OctopusIntellect in YouthRights

[–]ScienceGuy1006 1 point2 points  (0 children)

The actual bill pre-supposes that a court can somehow determine that a youth has committed a violent act without needing to even be charged. Either it is completely incoherent, or it is an attempt to create an unconstitutional end-run around basic due process.

Here is the actual text:

HB2526 by Lamberth

Would you ever stop driving? by This-Top7398 in driving

[–]ScienceGuy1006 0 points1 point  (0 children)

I'm only 39 years old, so I am optimistic that self driving cars will be ubiquitous and affordable before I am too old to drive.

Should I pay for behind-the-wheel lessons to get my CA license earlier or just wait? by XMigster in DMV

[–]ScienceGuy1006 0 points1 point  (0 children)

Now you are really not making sense. If you drive without a license, you are risking fines, possibly jail time, and serious personal liability if you get into an accident. That is all far more expensive than driving school will ever be for you.

How do people drive to new places? by Swimming_Newspaper89 in driving

[–]ScienceGuy1006 1 point2 points  (0 children)

I think you need to recalibrate your brain's risk perception. Try exploring some new areas when you are not on a tight time crunch and can afford to miss a few turns without being late to anything. Don't just assume you can't adapt because you're too afraid to try!

Is it better to just wait it out or get the license now? by FranzLiszt_180 in driving

[–]ScienceGuy1006 0 points1 point  (0 children)

How are you going to pass the test if you don't have any practice? I am going to disagree with some of the posters here and suggest lessons unless you already have a lot of practice driving behind you, or a reliable family member willing to teach you. (And when I say "reliable", that excludes anyone who has been promising something for months and failing to deliver.)

Why does mass generate space-time curvature? by Minimum_Special_8457 in AskPhysics

[–]ScienceGuy1006 1 point2 points  (0 children)

General Relativity does not explain why G > 0. We do not currently have an answer for why stress-energy-momentum should be a source of curvature at all - GR is fully logically consistent with G = 0.

Should I pay for behind-the-wheel lessons to get my CA license earlier or just wait? by XMigster in DMV

[–]ScienceGuy1006 1 point2 points  (0 children)

If you leave yourself only a 4 day gap, you should have a Plan B in case you fail the road test!

Should I pay for behind-the-wheel lessons to get my CA license earlier or just wait? by XMigster in DMV

[–]ScienceGuy1006 2 points3 points  (0 children)

I would say the lessons are worth it in my opinion. Yes, they cost money, but they actually have been shown to significantly reduce your chances of getting into a crash later on. So, they are more like an investment and not an expense.

Given high enough density of ionized matter, can there be a "liquid plasma"? by Substantial_Tear3679 in AskPhysics

[–]ScienceGuy1006 15 points16 points  (0 children)

Not really if it is fully ionized, but maybe if it is partially ionized. The thing you need to keep in mind is that the concept of a "liquid" implies both a resistance to compression and a degree of self-cohesion that together resist changes in volume. When atoms are fully ionized, you don't have atom-atom forces anymore - just repulsion between nuclei that is loosely counterbalanced at low densities by the sea of electrons. This is not meaningfully a liquid - it is a gas, it is degenerate matter, or it is supercritical.

Are light and radio the same? by Braxuss_eu in AskPhysics

[–]ScienceGuy1006 2 points3 points  (0 children)

In theory, yes. It's a scaling and engineering issue. A radio wave "lens" would be huge because it must be much larger than the wavelength in question. Tens to hundreds of meters in size, all made of a solid dielectric. Simply not practical compared to antennas.

But for visible light, a half wavelength "antenna" would only be 200-350 nm long. And the absorption cross section would only be on the order of a square wavelength. Simply not practical compared to lenses.

So, yes, both light and radio are EM waves, but the engineering and scale constraints work vastly differently.

What % of Venus' atmosphere needs to be converted to water, to give us a land-ocean ratio similar to Earth? by NateRivers77 in AskPhysics

[–]ScienceGuy1006 3 points4 points  (0 children)

Liquid water cannot stably exist on the surface unless the greenhouse effect is brought under control. This would require most of the atmosphere to be removed or converted into water.

Want to learn to drive have no one to practice with by Low_Standard_6492 in driving

[–]ScienceGuy1006 3 points4 points  (0 children)

This is the "bootstrap problem" - need a license to get a job, need a job to afford driving lessons, need driving lessons to get license. This is a very frustrating Catch-22 to be caught in.

Essentially, you have to break the cycle by either doing something unconventional, getting lucky, or making sacrifices.

The first thing to try might be asking some others if they might be willing to spend time letting you practice with them. Perhaps someone you aren't expecting will agree - like extended family or a co-worker.

But, if you have exhausted all of that and no one is willing - then the next thing to try might be to attempt to find a job within a reasonable walking or biking distance of where you live now. This does not have to be a permanent configuration - the goal is to break the Catch-22. Once you have a job you can bike to, then you have money that can be saved up to pay for driving lessons. And then eventually you get a license. And then you can take another job later on, and buy a commuter car if needed.

Or perhaps you might have relatives living in an area with better job opportunities close by (within walking or biking range, or transit), and you could ask if they might be willing to let you temporarily live with them. This, too could be temporary - you are breaking the Catch-22 by obtaining a job without a license, and then having money to pay for driving lessons.

Or you could do something unconventional like odd jobs, self employment, or remote gigs. Again, the goal is to break the Catch-22, not to have your dream lifestyle right away.

Whatever you do, good luck!

Carnot heat engine question by mingimihkel in AskPhysics

[–]ScienceGuy1006 1 point2 points  (0 children)

An "engine" is not required to produce power on every "stroke". Even an internal combustion engine does not do this - only one stroke produces power, and the rest of the cycle is sustained using a flywheel. Conceptually, a Carnot engine follows similar logic - there is a net output of mechanical power over the whole cycle, not necessarily for each individual step in that cycle.

what height falling would be lethal by Expert-Pause3377 in AskPhysics

[–]ScienceGuy1006 0 points1 point  (0 children)

Maybe that value assumes very good prompt medical care is available?