MigL

Stuck in the house because of COVID-19; mostly watching movies. Just watched The Hunt. A low budget movie, which spoofs the Political divide in the US, and takes it to extremes to make its point. Some of these 'extremes' make the movie actually funny. And combined with the action ( girl fight at the end ) and gore, make it quite entertaining. If you happen to watch it, tell us whether you find it funny, sad, or embarrassing ( if you're American ).

What if COVID-19 gets all three, close to 80 year old, presidential hopefuls ? Should have kept a youngster like T Gabbard in the running, just in case...

X-rays act on electron's orbitals. Microwaves on intermolecular bonds. For a guy who's always on his phone, Mordred, you better hope one effect isn't worse than the other. ( don't know how you manage to contribute to the forum on your phone, I can barely read the texts ) edit; should be intramolecular

That's some of the non-standard terminology Studiot is referring to. That is not what QFT says. It says quantum particles are excitations of underlying quantum fields, and ,must meet or exceed a threshold of action to be real, but. can be physical ( ie have measurable effects ) even when they don't. Is that what you mean by physical and real ? And I doubt any 'real' physicist has mistaken quantum particle for classical particle since the 1930s.

I believe it was Caffa, on the Black Sea, where Mongol army besieged the inhabitants, and Venetian traders, on or about 1350, catapulting dead corpses and rats over the city walls. When the Venetians were finally able to make a break for it, they sailed west and docked in southern Italy. Within months Bubonic Plague had spread to most of Italy, and within years, to the rest of Europe. It is estimated that with the additional flare ups over the next century, the Black Death wiped out over a third of Europe''s population.

Ah, OK. I hadn't noticed the bolded part. My mistake; carry on.

I was gonna give you a +1 for being witty, JC. Then I realized that you had used the chemical name for hydrogen peroxide, instead of water. You blew it ! Oh well, you'll have to settle for a consolation prize ( +1 )

Not to be picky, Ghideon, and I realize the OP is poorly worded and incomplete, but... Why would both masses have the same velocity, v, at time t1, when they were accelerated by the same initial force ? If the retarding force slows the lesser mass more quickly, then the initiating force imparts greater acceleration to the lesser mass. So v is not the same for both masses.

Even if you gave me numbers I couldn't give you a numerical answer ( time ), but I would be able to tell you which would stop first. If the problem is not laid out specifically you can't expect a specific answer.

I thought the common cold was rhinovirus. But don't they all have the same symptoms ?

That doesn't specify anything... Especially since the 'retarding' force is also active during the initial force application that caused the velocities. But everything else being equal. They both feel equal retarding force ;(highly unlikely ) and if the retarding force is trivial compared to the initiating force, the lighter mass will experience greater negative acceleration, and, since it started with a proportionately greater velocity, they should come to a stop about the same time.

The relationship is F=ma where F is directional force a is directional acceleration m is mass Only forces will change velocity of a mass by accelerating it; if no force is acting, masses will continue at their current velocity. Obviously for the same force, the lesser mass will experience the greater acceleration. If that force ( and acceleration ) are limited to a certain time, then the less massive object will have a higher final velocity. From that point different forces come into play, that tend to slow the masses down, and accelerate it in the opposing direction ( reducing its velocity ). These can be due to surface friction, air resistance or even the 'level' of the surface. Unless all of these factors are specified, we can't even begin to answer how long it takes for the masses to come to rest.

Thanks Stringy.

I would assume flu is short for inFLUenza. And there have been many types of influenzas through the years. My mistake... There are three types of influenza virus ( virii ? ). You are right.

If the force causing the acceleration is not removed, neither will stop. If the force is removed, factors other than mass will cause them to stop. Things like frontal area or surface area if on the ground, streamlining or coefficient of friction, or even the fluid/atmosphere they are immersed in. IOW your question is not specific enough.

Isn't COVID-19 also a type of influenza ( caused by a different viral strain ) ? I can always tell when something is coming on. My tonsils ( never removed ) always swell slightly.

Yet in the same post you write... So is it a language issue ????????

Time is NOT space, or they would both be called space. You have existed your whole life; you CANNOT vacate a previous time, if you were then. ( I used 'then' not 'there' because you can go from here to there, but not from now to then ) It is even more complicated than that ( and one of the reasons there is no universal 'now' ). Different parts of the universe, those in deep gravity wells, or moving at relativistic speeds, compared to your frame will not experience time as you do, So while you go from T=1 to T=2, they may only go to T=1.5 ( or stay at T=1 on an event horizon ). They will experience time ( in their frame ) similarly, but NOT in comparison to your position on a space-time diagram. So why do you keep introducing different observer POVs in the same space-time diagram ? The space-time diagram, or map, of a past observer belongs to that observer, in the past. And the space-time diagram, or map, of a future observer, belongs to the future; it has nothing to do with YOUR present, or local time progression.

You realize that reaction can go forward or backward as long as conservation laws are obeyed. photons >> particle + antiparticle and particle + antiparticle >> photons In your example you will have an energy deficit when the particle/anti-particle pair come back together and annihilate. Or are you saying the energy of the incident photons must be larger by the amount [Gm+m-]/[rc^2] to create the particles ? You really don't explain yourself too well

If you get tired of marking student papers, you have a future as a screenwriter. Recently read statistics that 0.2% of infected people under 40 yrs age have died. But for those 80 yrs and up the fatality rate is over 20%. Meanwhile I have a sniffling, sore throat cold, due to the constant temperature changes this time of year ( and not dressing appropriately ), and I can't go out lest people think I have the COVID-19 scourge.

I have a problem with 'move1', Eise. A 'move' in spatial co-ordinate only, with no change in temporal co-ordinate, implies a horizontal line in the space-time diagram, and is 'spacelike'. IOW it is separated by more space than time, and implies superluminal motion; an impossibility. ANY spatial change of co-ordinate has to be accompanied by a temporal co-ordinate change such that it is 'timelike'. Would it help, Michel, if you viewed space and time as different 'properties' of space-time ? Just like the properties of mass and energy, they can be, and act, different, yet GR will also allow for the transformation of one to the other. Not sure about bananas and grandmother ( ? ) clocks.

Don't think an umbrella would help much... And the 'snow' would hurt like hell.

A Yang for J Biden's VP. With all these 80 yr-olds running for President, if they can't last the 1st term, the VP has got to be young enough to take over and carry on. ( is T Gabbard still soldiering on ? )

I refuse to go any further down the rabbit hole...

I can't do the math for wormholes either, but I'm sure Kip Thorne could have a good go at it. The following is his example... Bart and Lisa Simpson have two wormhole generators and they establish a 'portal' between the two, so that Bart can 'see' Lisa when he looks through his wormhole, and Lisa can 'see' Bart when she looks through hers. Bart takes his wormhole generator in a spaceship, and travels to a distant star at relativistic speeds, all the while looking at Lisa through his wormhole. Once he gets there, he turns around and comes back to Earth, all the while looking at Lisa through his wormhole. When he gets back to earth he finds that 100 years have elapsed, as opposed to 2 years for himself, and while Lisa is long dead, he can still 'see' her through the wormhole. So he steps through the wormhole and is transported back in time 98 years via a closed timelike loop. This would imply that K Thorne thinks there is a 'locality' between the two ends of a wormhole.