If neutrinos were the missing mass, wouldn't we be
detecting far more of them? Either the mass would
be big enough to have shown up earlier, or the
sheer number necessary to account for the missing
90% of matter would make them more likely to hit
our detectors.
I thought that the current theories of the big
bang set a limit on how many neutrinos would have
been produced. If there were lots more neutrinos
then the ratio of hydrogen to helium would be
different, something like that.
This is clearly not my area of expertise, but
perhaps there is someone out there who can make a
more coherent statement of the problem?
As it periodically swells and casts off a dust
nebula, it could move to our side of the past
nebulae (assuming that the less dense nebula moves
slower than the star).
Now the nebula acts as a reflector, and there is
less dust between the star and earth to hide it.
It could be that these effects magnify the apparent
brightness, compared to otherwise similar stars that stay within
their obscuring nebulae.
They probably have enough data to rule this out,
and the orbiting companion theory is more likely,
but it would be interesting to know if you could
explain some of the 600,000 fold brightness this
way.
My computer must need glasses.
It cannot tell which window I am looking at when
I type. I have to tell it which window to use
by clicking with the mouse.
With better computer vision, the computer would
know which window I was looking at when I started
typing. With highly acute vision, it could even
know which button I was looking at when I hit the
return key.
I will know that computer vision is a reality when
I no longer need to use a mouse. Likewise, I will
know that speech recognition is a reality when I
no longer need to use a keyboard (although I am
not certain I want to trade carpal tunnel for a
sore throat, or let the rest of the office hear
everything I would otherwise be typing).
A Nouse might be good enough to indicate which
window I wish to use (if the windows are large
enough). But I think I'll wait for the software
that can actually track my eyes.
I could see anti-alergy medications being
delivered this way, or other medications that
need to be delivered into the nasal cavity via
the channels that drain tears into the nose.
People currently smear petrolatum-based ointments
under the eyelid to cure conjuctivitis. For
people who are already comfortable with contacts,
this may be preferable.
It might also be a way to get to the brain, along
the optic nerve or other paths, bypassing the
blood-brain barrier.
For people who live in smoggy areas, how about
lenses that counteract ozone and nitrogen oxides
by dispensing a buffering solution? Or is that
as bad as politicians who suggest solving the
problem of ozone holes by issuing everybody hats?
"These studies raise the possibility that drugs to activate these natural factors could promote hair follicle growth in wanted places, and inhibitory drugs could prevent hair growth in unwanted places"
I love it that the name for a chemical signal
involved in baldness is called "noggin".
As a balding guy who isn't that worried about it,
I also like the idea that those people who are
worried enough to spend a lot of money on baldness
cures, will also be funding research into
squamous cell carcinomas. I am much more concerned
about losing someone to skin cancer than losing
my hair.
Re:I think you got the economics wrong. Physics, t
on
5595 Days and Counting
·
· Score: 1
Who needs batteries?
It is currently cost effective to put solar
panels on your roof, and generate enough power to
run your electric meter backwards feeding the
grid. The break-even period is less than 10 years
for a system that has a 30 year warrantee.
At the end of the month, you have generated more
power into the grid than you took out.
How the grid chooses to store that power is quite
flexible. It can simply offset the power that
would otherwise be used from hydroelectric dams,
allowing those to be run only at night, saving
up the water behind the dam during the day.
I never mentioned using solar power to supply
"the entire economy", and neither did the web site
for the elevator. The question is whether the
solar power satellites make sense economically,
or whether they have some of the same problems
that nuclear power plants have -- the tremendous
costs of the financing of huge projects makes
them less practical than simply making something
more efficient.
The cost of the real estate on my roof is cheap.
I have already paid for the roof. If putting
solar cloth on top of it generates more power
than my house uses, and is as cheap as it looks
like it will be, then it will simply become a
part of building a house, like the rest of the
roofing business.
The cost of real estate in geosynchronous orbit
is "astronomical", even with the elevator.
The tethered satellite used a different mechanism
than the one mentioned on the elevator web site.
The elevator connects the earth to the ionosphere,
where there are some pretty decent currents.
The voltage difference between the top of the
cable and the bottom (if the cable were doped to
be conductive or superconductive) would be useful.
The post made it sound like the glassy coating
was being removed.
The light then travels in the air filled core,
not in the glass.
The use in scanning near-field microscopes is
interesting, but don't we already have versions
of those that use nono-sized particles that emit
light (fluoresce), instead of the types that use
fiber optics as the light source?
You are not running the same operating system you
were back in 1988. That is like saying you are
driving the same car, because it is a Chevy like
the one you have back in 1988.
Back in 1988, I was running 4.3 BSD, System 5
release 2, and Ultrix. I am really glad I am not
running those operating systems today. And back
then, I was really glad I was not running the UNIX
version 6 that I learned C on back in 1976.
It is unlikely that the space elevator will be
running Windows NT, and also unlikely it will be
running Red Hat 8.0. And that's a good thing.
In 2018, Bill will be 63 years old, by which time
he says he will have given away most of his money.
Windows NT will exist in the Smithsonian,
next to your own favorite operating system, but
it is unlikely that either one will be used for
projects of this type.
Also, I would hope that by that time, we will pay
by the kilogram instead of the pound (hey, I'm an
optimist...).
One of the cited uses for the elevator is to build
solar power satellites to beam power back down to
earth. I wonder if it will be necessary by then?
At current rates of improvement, solar panels will
be cheap enough to paint on roofs, and efficient
enough to produce a house's requirements on a
cloudy day. Too bad doping the carbon nanotubes to
conduct, and using the cable to generate power
like the shuttle's tether is not
compatible with using it as an elevator.
I think we web geeks have a different approach to
changing how science is taught in schools.
The subject of the article is about replacing
textbooks that are "collections of facts and
vocabulary words" with textbooks that are stories
about scientists. By providing material for free on the web,
we can supplement the facts and vocabulary words,
instead of replacing them.
My book is on the web for free, and I get lots of
email from teachers and home-schooling parents who
like the idea of teaching science by having kids
build radios, laser communicators, Gauss Rifles,
magnetic levitation devices, homemade solar cells,
and the like. The kids end up toys they can play
with. When they get interested in how the toy
works, they can read the explanation in my book,
but they just might also open the textbook they
were given, and learn some of those vocabulary
words.
It is related to Canine Distemper Virus, and the
Newcastle Virus famous for infecting chickens.
The "service pack" for Newcastle is usually total
destruction of all the birds in the area near the
infection. Probably because vaccinations cost
more than chickens do.
It would be interesting to see if innoculating
people with one of these (or Parainfluenza Virus)
would act as a vaccine, like using cowpox virus
to prevent smallpox.
The Phocine Distemper virus that is killing seals
is also related. Does Canine Distemper vaccine
work to protect seals from Phocine?
I'm not sure the solar panel is worth the weight,
or the danger of having something that expensive
and fragile on the bike.
Suppose you had a bike like
this one. The motor is rated at 1 horsepower
but only uses more than half of that on hills and
starting from a stop.
Half a horsepower is 373 watts. A half hour makes
187 watt-hours of power needed.
Let's say you were willing to wait an hour to
charge the bike enough to run for half an hour.
Angling the panel dead-on to the sun on a good
day will get you perhaps 60 watts of power into
the batteries per square meter of panel.
But you don't want to carry around a square meter
of panel -- the weight and wind resistance would
eliminate any benefits. Let's say you could put
up with lugging a third of that around, so we get
20 watts. It would take over 9 hours to charge
the batteries enough for a half hour ride.
I would suggest a pedal powered generator would be
a much faster way to charge the batteries. But if
you were willing to pedal, you wouldn't have
needed to attach all that weight to the bike in
the first place.
Do you think amneocentesis is creepy? Or does it
depend on the reason?
People test babies in the womb, and make a choice
to end the pregnancy if the baby has severe
problems. This may seem creepy to some, but it is
accepted medical practice.
People also use the testing to determine the sex
of the baby, and make a choice to end the
pregnancy. This is often much more objectionable
to more people than the first scenario.
We have already had people create children to be
organ donors for other children. There were
ethical concerns about that as well, but it was
determined to be acceptable.
As time goes by, we accept what becomes
commonplace. There have been cultures where
inter-racial marriage was against the law, on
grounds not unsimilar to your feeling "creepy"
about testing IVF results before implantation.
IVF itself caused quite a stir. Some wondered
whether the first "test-tube" baby would be
psychologically damaged by the publicity or the
knowledge. On the other hand, this is one kid who
can be certain there was no accident.
Consider this: IVF itself usually generates
several candidates for implantation, and often
not all of them are used. The unused candidates
are discarded. But they contain the same cells
that the umbilicus carries, and have the same
ability to save the first child. Why are the
ethicists insisting that a child be carried to
term? If two out of three candidates are
never implanted in a womb, why implant any? Or is
it that once the couple has gone to all of the
expense of IVF to save the first child, they might
as well implant the candidate, and get the second
child they wanted anyway, with a guarantee that it
does not suffer from the same problem as the first
one? Perhaps it is just two birds with one stone.
I am not forcing my ethics on this couple or any
other. Whether I would have made their choice or
not is unimportant. But I am glad that I do not
have that choice to make. Many of us would bend
our ethics to save our only child.
How many of you would donate some umbilical blood
to save a sibling, assuming your parents had the
foresight to preserve it? Many would donate a
kidney, or a lung. It seems unlikely that this
child will regret the decision later in life. He
was conceived on purpose. Great effort was made
to ensure that he did not have genetic problems.
The blastocyst that he came from could have been
used as it was, instead of being implanted to
create him. I don't think this kid will suffer
emotional upheaval when he is told about his
special circumstances. Is his case any more
disturbing than being told you were adopted? Many
people get over that.
If this is "playing god", then so is most of
medicine. Perhaps playing god is a noble
ambition, a better role model than playing first
person shooter.
The first stage uses the acidogen bacteria, that
break the fodder down into simple fatty acids.
In a cow, this also happens in the acidic stomach.
The second stage uses methanogens, which consume
those acids, and produce methane. The methane is
not produced by the cow (or the human) but by the
methanogenic bacteria.
In humans, the methanogens use sugars and acids
that humans do not have the enzymes to digest.
To counter methane production in humans,
adding the right enzymes to the food just before consumption
will make those sugars and acids available to the
human digestive system, and starve the methanogens
in the gut. This is how the product
Beano
works.
The part I like best is that the CO2 produced is
not only less of a greenhouse gas than the mathane,
but since it comes from the grass and grain that
the cows ate, it is completely renewable, and we
can take it back out of the air by growing more
grass and grain.
It would be interesting to see how much of my
natural gas bill I could save by digesting lawn
clippings, old newspapers, and other garbage I
would normally have dumped in a landfill. By
skipping the cow phase, I lose the milk, but I
should get more methane per pound of grass.
The data
here
seem to indicate that pig and chicken farmers
would get twice the methane that the dairy farmer
gets. And handling the waste from pig farms is
a big problem that this may help solve.
Think of the needle as a point source of something
that can excite molecules to emit light.
Now as you move the needle around, you know where
you put it. Now you can use a relatively huge
light sensor to look at the light that was
emitted by the molecule under the probe. The
sensor gives you the amount of light, and the
spectrum of the light. Knowing where you put the
probe gives you the X and Y location of the molecule.
Putting it all together gives you a 2 dimensional
map of which molecules are where.
If you go to
this page
you will get a new picture every time you hit the
refresh button.
The process is a scanning one, like an AFM, but
the probe exites the atoms underneath it to make
light. The light they make has spectral lines,
so you get more than just a picture. With a
picture, you get the amplitude and the color of
a spot. Here you also get that, but there is
more information in the "color", so you can tell
what type of molecule you are next to.
At 400 Mbps, even a QAM256 signal would be
blinking too fast for even the most Jolt-enhanced
epileptic.
If you would like to do this yourself for a few
dollars, there is a laser communication project
here
that uses a pocket laser pointer to send voice
signals over 8 miles.
I am currently modulating a laser pointer at
28.322 Mhz a few feet away from where I sit.
It can go faster, but my receiver circuit maxes
out at about 30 Mhz (it uses a $5 photodetector).
The goal is to make a WiFi speed link (13.2 Mbps
actually) that will go a few miles using cheap
parts (under $20 per node). I'll put the details
up on my web site when it's ready.
The article makes a distinction between the Xenon
ion thrusters and "chemical propellant".
The last orbital adjustments were made with
"small chemical propellant thrusters, activated for the first time since launch".
It looks like the 10 years number does not refer
to the Xenon ion thrusters.
My thought when I first read this was not
memories, but high efficiency (>85%) solar cells.
The folks working on
optical rectennas
are to the point where their remaining problems
are with making metal-insulator-metal tunneling
diodes that are small enough and fast enough.
They are close to demonstrating a working device,
and it looks to me like DNA scaffolding could not
only make it easier to build the MIM diodes, but
might make fabrication of the entire device
easier and faster. Instead of ion-beam
implantation, you grow the 2D crystals in a vat.
The idea is to make an array of tiny dipole
antennas, with a diode at the feedpoint. When
light hits the antennas, an AC current is
generated, then rectified by the diodes.
Making the antennas has been possible for some
time now (500 nanometers). The work on making the
diodes is nearly ready. Now it looks like we have
a possible cheap and efficient means of
constructing them on a large scale.
Slashdot Mirror
I thought that the current theories of the big bang set a limit on how many neutrinos would have been produced. If there were lots more neutrinos then the ratio of hydrogen to helium would be different, something like that.
This is clearly not my area of expertise, but perhaps there is someone out there who can make a more coherent statement of the problem?
It might be fun to combine this with piezoelectric plastic film and put it in clothing, so it flashes colors as you move.
Suppose the star is moving towards the earth.
As it periodically swells and casts off a dust nebula, it could move to our side of the past nebulae (assuming that the less dense nebula moves slower than the star).
Now the nebula acts as a reflector, and there is less dust between the star and earth to hide it.
It could be that these effects magnify the apparent brightness, compared to otherwise similar stars that stay within their obscuring nebulae.
They probably have enough data to rule this out, and the orbiting companion theory is more likely, but it would be interesting to know if you could explain some of the 600,000 fold brightness this way.
No, that's not what the blood-brain barrier is.
There are chemicals you can put into the bloodstream that cannot reach the brain.
The brain is protected better than most organs.
My computer must need glasses.
It cannot tell which window I am looking at when I type. I have to tell it which window to use by clicking with the mouse.
With better computer vision, the computer would know which window I was looking at when I started typing. With highly acute vision, it could even know which button I was looking at when I hit the return key.
I will know that computer vision is a reality when I no longer need to use a mouse. Likewise, I will know that speech recognition is a reality when I no longer need to use a keyboard (although I am not certain I want to trade carpal tunnel for a sore throat, or let the rest of the office hear everything I would otherwise be typing).
A Nouse might be good enough to indicate which window I wish to use (if the windows are large enough). But I think I'll wait for the software that can actually track my eyes.
I could see anti-alergy medications being delivered this way, or other medications that need to be delivered into the nasal cavity via the channels that drain tears into the nose.
People currently smear petrolatum-based ointments under the eyelid to cure conjuctivitis. For people who are already comfortable with contacts, this may be preferable.
It might also be a way to get to the brain, along the optic nerve or other paths, bypassing the blood-brain barrier.
For people who live in smoggy areas, how about lenses that counteract ozone and nitrogen oxides by dispensing a buffering solution? Or is that as bad as politicians who suggest solving the problem of ozone holes by issuing everybody hats?
Indeed.
I love it that the name for a chemical signal involved in baldness is called "noggin".
As a balding guy who isn't that worried about it, I also like the idea that those people who are worried enough to spend a lot of money on baldness cures, will also be funding research into squamous cell carcinomas. I am much more concerned about losing someone to skin cancer than losing my hair.
Who needs batteries?
It is currently cost effective to put solar panels on your roof, and generate enough power to run your electric meter backwards feeding the grid. The break-even period is less than 10 years for a system that has a 30 year warrantee.
At the end of the month, you have generated more power into the grid than you took out.
How the grid chooses to store that power is quite flexible. It can simply offset the power that would otherwise be used from hydroelectric dams, allowing those to be run only at night, saving up the water behind the dam during the day.
I never mentioned using solar power to supply "the entire economy", and neither did the web site for the elevator. The question is whether the solar power satellites make sense economically, or whether they have some of the same problems that nuclear power plants have -- the tremendous costs of the financing of huge projects makes them less practical than simply making something more efficient.
The cost of the real estate on my roof is cheap. I have already paid for the roof. If putting solar cloth on top of it generates more power than my house uses, and is as cheap as it looks like it will be, then it will simply become a part of building a house, like the rest of the roofing business.
The cost of real estate in geosynchronous orbit is "astronomical", even with the elevator.
The tethered satellite used a different mechanism than the one mentioned on the elevator web site. The elevator connects the earth to the ionosphere, where there are some pretty decent currents. The voltage difference between the top of the cable and the bottom (if the cable were doped to be conductive or superconductive) would be useful.
The post made it sound like the glassy coating was being removed.
The light then travels in the air filled core, not in the glass.
The use in scanning near-field microscopes is interesting, but don't we already have versions of those that use nono-sized particles that emit light (fluoresce), instead of the types that use fiber optics as the light source?
Get real.
You are not running the same operating system you were back in 1988. That is like saying you are driving the same car, because it is a Chevy like the one you have back in 1988.
Back in 1988, I was running 4.3 BSD, System 5 release 2, and Ultrix. I am really glad I am not running those operating systems today. And back then, I was really glad I was not running the UNIX version 6 that I learned C on back in 1976.
It is unlikely that the space elevator will be running Windows NT, and also unlikely it will be running Red Hat 8.0. And that's a good thing.
In 2018, Bill will be 63 years old, by which time he says he will have given away most of his money. Windows NT will exist in the Smithsonian, next to your own favorite operating system, but it is unlikely that either one will be used for projects of this type.
Also, I would hope that by that time, we will pay by the kilogram instead of the pound (hey, I'm an optimist...).
One of the cited uses for the elevator is to build solar power satellites to beam power back down to earth. I wonder if it will be necessary by then? At current rates of improvement, solar panels will be cheap enough to paint on roofs, and efficient enough to produce a house's requirements on a cloudy day. Too bad doping the carbon nanotubes to conduct, and using the cable to generate power like the shuttle's tether is not compatible with using it as an elevator.
Science teaches me here in the U.S. as well.
I think we web geeks have a different approach to changing how science is taught in schools.
The subject of the article is about replacing textbooks that are "collections of facts and vocabulary words" with textbooks that are stories about scientists. By providing material for free on the web, we can supplement the facts and vocabulary words, instead of replacing them.
My book is on the web for free, and I get lots of email from teachers and home-schooling parents who like the idea of teaching science by having kids build radios, laser communicators, Gauss Rifles, magnetic levitation devices, homemade solar cells, and the like. The kids end up toys they can play with. When they get interested in how the toy works, they can read the explanation in my book, but they just might also open the textbook they were given, and learn some of those vocabulary words.
It is related to Canine Distemper Virus, and the Newcastle Virus famous for infecting chickens.
The "service pack" for Newcastle is usually total destruction of all the birds in the area near the infection. Probably because vaccinations cost more than chickens do.
It would be interesting to see if innoculating people with one of these (or Parainfluenza Virus) would act as a vaccine, like using cowpox virus to prevent smallpox.
The Phocine Distemper virus that is killing seals is also related. Does Canine Distemper vaccine work to protect seals from Phocine?
I'm not sure the solar panel is worth the weight, or the danger of having something that expensive and fragile on the bike.
Suppose you had a bike like this one. The motor is rated at 1 horsepower but only uses more than half of that on hills and starting from a stop.
Half a horsepower is 373 watts. A half hour makes 187 watt-hours of power needed.
Let's say you were willing to wait an hour to charge the bike enough to run for half an hour.
Angling the panel dead-on to the sun on a good day will get you perhaps 60 watts of power into the batteries per square meter of panel.
But you don't want to carry around a square meter of panel -- the weight and wind resistance would eliminate any benefits. Let's say you could put up with lugging a third of that around, so we get 20 watts. It would take over 9 hours to charge the batteries enough for a half hour ride.
I would suggest a pedal powered generator would be a much faster way to charge the batteries. But if you were willing to pedal, you wouldn't have needed to attach all that weight to the bike in the first place.
Do you think amneocentesis is creepy? Or does it depend on the reason?
People test babies in the womb, and make a choice to end the pregnancy if the baby has severe problems. This may seem creepy to some, but it is accepted medical practice.
People also use the testing to determine the sex of the baby, and make a choice to end the pregnancy. This is often much more objectionable to more people than the first scenario.
We have already had people create children to be organ donors for other children. There were ethical concerns about that as well, but it was determined to be acceptable.
As time goes by, we accept what becomes commonplace. There have been cultures where inter-racial marriage was against the law, on grounds not unsimilar to your feeling "creepy" about testing IVF results before implantation.
IVF itself caused quite a stir. Some wondered whether the first "test-tube" baby would be psychologically damaged by the publicity or the knowledge. On the other hand, this is one kid who can be certain there was no accident.
Consider this: IVF itself usually generates several candidates for implantation, and often not all of them are used. The unused candidates are discarded. But they contain the same cells that the umbilicus carries, and have the same ability to save the first child. Why are the ethicists insisting that a child be carried to term? If two out of three candidates are never implanted in a womb, why implant any? Or is it that once the couple has gone to all of the expense of IVF to save the first child, they might as well implant the candidate, and get the second child they wanted anyway, with a guarantee that it does not suffer from the same problem as the first one? Perhaps it is just two birds with one stone.
I am not forcing my ethics on this couple or any other. Whether I would have made their choice or not is unimportant. But I am glad that I do not have that choice to make. Many of us would bend our ethics to save our only child.
How many of you would donate some umbilical blood to save a sibling, assuming your parents had the foresight to preserve it? Many would donate a kidney, or a lung. It seems unlikely that this child will regret the decision later in life. He was conceived on purpose. Great effort was made to ensure that he did not have genetic problems. The blastocyst that he came from could have been used as it was, instead of being implanted to create him. I don't think this kid will suffer emotional upheaval when he is told about his special circumstances. Is his case any more disturbing than being told you were adopted? Many people get over that.
If this is "playing god", then so is most of medicine. Perhaps playing god is a noble ambition, a better role model than playing first person shooter.
There are two types of bacteria involved.
The first stage uses the acidogen bacteria, that break the fodder down into simple fatty acids. In a cow, this also happens in the acidic stomach.
The second stage uses methanogens, which consume those acids, and produce methane. The methane is not produced by the cow (or the human) but by the methanogenic bacteria.
In humans, the methanogens use sugars and acids that humans do not have the enzymes to digest. To counter methane production in humans, adding the right enzymes to the food just before consumption will make those sugars and acids available to the human digestive system, and starve the methanogens in the gut. This is how the product Beano works.
The part I like best is that the CO2 produced is not only less of a greenhouse gas than the mathane, but since it comes from the grass and grain that the cows ate, it is completely renewable, and we can take it back out of the air by growing more grass and grain.
It would be interesting to see how much of my natural gas bill I could save by digesting lawn clippings, old newspapers, and other garbage I would normally have dumped in a landfill. By skipping the cow phase, I lose the milk, but I should get more methane per pound of grass.
The data here seem to indicate that pig and chicken farmers would get twice the methane that the dairy farmer gets. And handling the waste from pig farms is a big problem that this may help solve.
More info here.
The article says December 2000, taking pictures for 6 months.
But if you haven't seen the pictures before, they're new to you...
The image doesn't go back to the needle.
Think of the needle as a point source of something that can excite molecules to emit light.
Now as you move the needle around, you know where you put it. Now you can use a relatively huge light sensor to look at the light that was emitted by the molecule under the probe. The sensor gives you the amount of light, and the spectrum of the light. Knowing where you put the probe gives you the X and Y location of the molecule. Putting it all together gives you a 2 dimensional map of which molecules are where.
If you go to this page you will get a new picture every time you hit the refresh button.
The process is a scanning one, like an AFM, but the probe exites the atoms underneath it to make light. The light they make has spectral lines, so you get more than just a picture. With a picture, you get the amplitude and the color of a spot. Here you also get that, but there is more information in the "color", so you can tell what type of molecule you are next to.
At 400 Mbps, even a QAM256 signal would be blinking too fast for even the most Jolt-enhanced epileptic.
If you would like to do this yourself for a few dollars, there is a laser communication project here that uses a pocket laser pointer to send voice signals over 8 miles.
I am currently modulating a laser pointer at 28.322 Mhz a few feet away from where I sit. It can go faster, but my receiver circuit maxes out at about 30 Mhz (it uses a $5 photodetector).
The goal is to make a WiFi speed link (13.2 Mbps actually) that will go a few miles using cheap parts (under $20 per node). I'll put the details up on my web site when it's ready.
Would wearing a Luminex garment make you appear brilliant?
Instant geek?
A Google search for "ion thrusters" returned a wealth of information, much of it suitable for an introduction. An excellent one is here.
These devices are not new -- they have been in use for years.
The article makes a distinction between the Xenon ion thrusters and "chemical propellant". The last orbital adjustments were made with "small chemical propellant thrusters, activated for the first time since launch".
It looks like the 10 years number does not refer to the Xenon ion thrusters.
My thought when I first read this was not memories, but high efficiency (>85%) solar cells.
The folks working on optical rectennas are to the point where their remaining problems are with making metal-insulator-metal tunneling diodes that are small enough and fast enough.
They are close to demonstrating a working device, and it looks to me like DNA scaffolding could not only make it easier to build the MIM diodes, but might make fabrication of the entire device easier and faster. Instead of ion-beam implantation, you grow the 2D crystals in a vat.
The idea is to make an array of tiny dipole antennas, with a diode at the feedpoint. When light hits the antennas, an AC current is generated, then rectified by the diodes.
Making the antennas has been possible for some time now (500 nanometers). The work on making the diodes is nearly ready. Now it looks like we have a possible cheap and efficient means of constructing them on a large scale.