Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Yes—but only indirectly. No primordial curium-247 (247Cm) survives today. The evidence comes from uranium isotope patterns in meteorites: 247Cm decays to uranium-235 (235U), and minerals that separated curium from uranium before that decay could preserve different amounts of radiogenic 235U. Measurements have produced a historically important proposal, a later null result, and subsequent proxy-correlated and unusually large anomalies. Together they make an evolving, sample-dependent case rather than a universal proof that every uranium variation is caused by curium.
What scientists mean by “evidence for curium”
The claim concerns live 247Cm in material from the young Solar System, not a surviving piece of curium that can be detected directly. Curium-247 is radioactive and extinct in primordial Solar System matter. Its alpha decay produces 235U. Because 235U and uranium-238 (238U) are measured today, researchers can look for an excess or deficit of 235U that was generated after a mineral formed.
As an Amazon Associate I earn from qualifying purchases.
That signal is only useful if curium and uranium were separated chemically before the curium decayed. A calcium-aluminum-rich inclusion (CAI), refractory inclusion, or mineral that initially incorporated relatively more curium than uranium would receive more radiogenic 235U. Another component with the opposite chemical partitioning would receive less. The expected result is a relationship between uranium isotope composition and elements that acted as proxies for the original curium-to-uranium (Cm/U) separation.
This is why the strongest arguments do more than report a nonstandard uranium ratio. They ask whether the ratio varies with thorium, neodymium, or another chemically appropriate proxy, whether the pattern appears in a defined mineral suite, and whether ordinary isotope fractionation could produce the same result.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
The original Allende claim in 1980
Mitsunobu Tatsumoto and Tadashi Shimamura reported the first prominent case in their 1980 Nature paper, “Evidence for live 247Cm in the early solar system.” They measured uranium ratio variations in the Allende meteorite ranging from −35% to +19% and interpreted those differences as evidence that live 247Cm had been present when early Solar System solids formed.
The paper also inferred approximately 8 million years between the end of nucleosynthesis and formation of meteoritic grains from the radionuclide evidence considered in that study. Both the isotope range and the timing are historical interpretations by those authors, not modern values that all researchers accept. The result remains important because it established the daughter-product strategy: search for the uranium left behind by an extinct parent radionuclide.
“Variations of the 238U/235U ratio in the Allende meteorite, ranging from −35% to + 19%, are interpreted as evidence of live 247Cm in the early Solar System.”
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.Rank #2
Sale
Anker USB-C Hub, 5-in-1 USB Hub for Laptops, 4K HDMI Multiport Adapter | USB C Dongle with 90W Max Power Delivery, 3×5Gbps USB A Data Ports, for MacBook, Dell, and More (Charger Not Included)
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
—Tatsumoto and Shimamura, Nature, 1980
What later measurements found
Different studies have not examined identical materials or had identical analytical precision. The chronology below shows why their conclusions cannot be collapsed into a single number.
| Study | Material and measurement | Reported result | Interpretation or limit |
|---|---|---|---|
| 1980, Tatsumoto and Shimamura | Allende meteorite uranium ratios | −35% to +19% variation | Interpreted as live 247Cm; inferred about 8 Myr from the end of nucleosynthesis to meteoritic-grain formation |
| 2006, Earth and Planetary Science Letters | Almost 40 meteorite phases; 235U/238U tested at about 1–2 epsilon precision | No resolvable deviation from the chondritic value | Placed the initial Solar System 247Cm/235U below 8 × 10−5 for that sample set and approach |
| 2010, Science | Allende CAIs; 238U/235U values from 137.409 ± 0.039 to 137.885 ± 0.009 | Variation correlated with thorium/uranium and neodymium/uranium proxies | Interpreted as strong evidence for extant 247Cm decaying to 235U; initial 247Cm/235U estimated at about 1.1 × 10−4 to 2.4 × 10−4 |
| 2016, PNAS | Meteoritic refractory inclusions | 235U excesses up to about +6% relative to average Solar System composition | Authors argued the excesses could only be due to 247Cm decay, while also discussing kinetic uranium isotope fractionation during condensation as a possible source of variation |
| 2021, Science | Meteorite radionuclide record considered with 129I | Used the near-identical half-lives of 129I and 247Cm, approximately 15.6 Myr | Constrained the last astrophysical source of Solar System r-process elements; this is a broader implication, not a direct solution to every uranium anomaly |
How the isotope test works
1. A radioactive parent leaves a daughter isotope
At the time of condensation, a solid could contain both uranium and curium. As 247Cm decayed, each parent nucleus that transformed contributed an alpha-decay daughter, 235U. The original curium is gone, but its daughter atoms remain part of the uranium inventory.
2. Chemical partitioning creates a measurable contrast
Curium and uranium are chemically similar actinides, but minerals and condensates can still partition them differently. If one inclusion acquired a high Cm/U ratio and another acquired a low ratio, the same elapsed decay interval would add different amounts of 235U to their uranium. Their present-day 238U/235U ratios would therefore differ.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
3. Proxy elements test whether the pattern is radiogenic
Researchers cannot measure the extinct parent directly, so they use elements whose behavior should have tracked curium during formation. The 2010 CAI work looked for correlations with thorium/uranium and neodymium/uranium. A correlation of uranium isotope composition with these Cm/U proxies is more specific than an isolated ratio because it links the isotope signal to a plausible chemical separation process.
4. Alternative fractionation must be considered
Uranium isotopes can also be fractionated by physical and chemical processes that do not involve radioactive decay. The 2016 study discussed kinetic uranium isotope fractionation during nebular condensation as a competing explanation for some variations. Consequently, the mineral’s formation environment, volatility, temperature history, and condensation kinetics matter when deciding whether an anomaly is radiogenic.
Why the 2006 null result and later positive results can coexist
The 2006 study analyzed almost 40 phases and found no resolvable 235U/238U deviation from the chondritic value at approximately 1–2 epsilon precision. Its resulting upper limit—an initial 247Cm/235U ratio below 8 × 10−5—applies to the materials, precision, and model used in that work. “No resolvable deviation” means any effect was smaller than that study could distinguish; it does not demonstrate that every Solar System component had exactly the same isotope composition.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
The 2010 investigation focused on Allende CAIs, a narrower and chemically distinctive population. It resolved a range in 238U/235U and, crucially, reported correlations with thorium/uranium and neodymium/uranium. Its inferred initial ratio of about 1.1 × 10−4 to 2.4 × 10−4 is an estimate from that CAI study, not a value that should be merged with the lower 2006 upper limit.
The 2016 work examined refractory inclusions and reported much larger 235U excesses, reaching about +6% relative to average Solar System composition. The authors attributed those excesses to 247Cm decay, while acknowledging that condensation-related uranium fractionation is relevant to interpretation. Distinct sample types can therefore produce different apparent signals: a bulk or broad phase survey may average away a localized effect, whereas an individual inclusion can preserve a strong chemical contrast.
Recommended Free Tools
How to evaluate a reported curium signal
When reading a new measurement, check four points before treating it as proof.
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
- Sample scale and type: Is the result from a bulk meteorite, mineral separates, leachates, individual CAIs, or refractory inclusions? These materials can record different formation histories.
- Analytical resolution: What isotope precision was achieved, and is the reported difference larger than the stated uncertainty? The 2006 study’s approximately 1–2 epsilon precision sets a specific sensitivity for its null result.
- Proxy behavior: Do uranium ratios track thorium/uranium, neodymium/uranium, or another chemically justified Cm/U proxy? Correlation strengthens a radiogenic interpretation.
- Non-radiogenic processes: Could kinetic isotope fractionation during condensation, alteration, mixing, or laboratory processing generate the pattern without curium decay?
A convincing case must fit the isotope data, the element chemistry, and the inclusion’s formation history at the same time. A large ratio by itself is not enough.
What the inferred initial ratios tell us
The initial 247Cm/235U ratio is an estimate of how much curium existed relative to uranium when the relevant solids formed. Published values differ because studies use different samples, measurements, assumptions about chemical partitioning, and treatments of competing fractionation. The 2006 work reported an upper limit below 8 × 10−5, while the 2010 CAI study estimated approximately 1.1 × 10−4 to 2.4 × 10−4. These are not interchangeable measurements of one universally agreed reservoir.
Such ratios are valuable even when they disagree. They constrain the abundance of a short-lived actinide and test models of how freshly synthesized material was mixed into the solar nebula. They also show why a ratio must always be tied to the paper, sample suite, and analytical method that produced it.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11The wider astrophysical implication
The meteorite record can be combined with other extinct radionuclides to investigate where the Solar System’s heavy r-process elements came from. A 2021 Science study considered 247Cm together with iodine-129 (129I). Their half-lives are nearly identical—approximately 15.6 million years—so comparing their inferred early abundances can help constrain the timing and identity of the last astrophysical source that contributed r-process material before the Sun formed.
This application is broader than identifying the cause of one uranium anomaly. It uses radionuclide abundances as a clock for galactic nucleosynthesis. The result does not turn every 238U/235U difference into evidence for curium; it uses carefully modeled early Solar System inventories to address the history of heavy-element production.
Bottom line on whether curium was present
The best-supported answer is qualified: several meteorite studies report isotope patterns consistent with extinct 247Cm, including proxy correlations in Allende CAIs and 235U excesses in refractory inclusions. Other work found no resolvable deviation in its tested phases and set a lower abundance limit. Because the studies examine different materials and must account for non-radiogenic uranium fractionation, the evidence is a developing, sample-dependent scientific case. It strongly supports investigating live curium in the early Solar System, but it is not a blanket demonstration that all meteoritic uranium isotope variation came from curium decay.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
