Light speed, or 300,000 kilometers a second, might seem like a speed
limit, but this is just an example of 3 + 1 thinking – where we still
haven’t got our heads around the concept of four dimensional space-time
and hence we think in terms of space having three dimensions and think
of time as something different.
For example, while it seems to us
that it takes a light beam 4.3 years to go from Earth to the Alpha
Centauri system, if you were to hop on a spacecraft going at 99.999 per
cent of the speed of light you would get there in a matter of days,
hours or even minutes – depending on just how many .99s you add on to
that proportion of light speed.
This is because, as you keep
pumping the accelerator of your imaginary star drive system, time
dilation will become increasingly more pronounced and you will keep
getting to your destination that much quicker. With enough .999s you
could cross the universe within your lifetime – even though someone you
left behind would still only see you moving away at a tiny bit less than
300,000 kilometres a second. So, what might seem like a speed limit at
first glance isn’t really a limit at all.
To try and comprehend
the four dimensional perspective on this, consider that it’s impossible
to move across any distance without also moving through time. For
example, walking a kilometer may be a duration of thirty minutes – but
if you run, it might only take fifteen minutes.
Read more at: <span>https://phys.org/news/2011-10-light-speed.html#jC</span>
Answer and explanation:
Gram positive bacteria :
1) They retain crystal violet stain thus staining purple
2)They only produce exotoxins.
3)Peptidoglycan is thicker and multilayered
4)Techoic acids are present in their cell walls.
5)Lipopolysaccharides are absent in their cell wall.
6)No periplasmic space present
Gram negative bacteria :
1) They retain red safaranin stain thus stain pink.
2)They produce both exotoxins as well as endotoxins.
3)Peptidoglycan is thinner and single layered.
4)Techoic acids are absent in their cell walls.
5)Lipopolysaccharides are present in their cell wall.
6)Periplasmic space in present.
A is the answer to this question
Explanation:
It’s an important question because the road to a successful career in science – as with technology, engineering and mathematics, the other STEM fields – can be challenging, often requiring a Ph.D. or other postgraduate training. And once in their fields, there can be political and economic pressures with which to contend. The Bureau of Labor Statistics projects workforce shortfalls for many science fields, though the projected needs differ across the life, physical and natural sciences.
When entering the stomach, the food is broken down and the nutrients are absorbed by the body to provide energy and nourishment. The rest of what's left gets discarded out of your body.
